Publications by authors named "Gobena Ameni"

113 Publications

Population structure and transmission of in Ethiopia.

Microb Genom 2021 May;7(5)

Department of Veterinary Medicine, University of Cambridge, Cambridge, UK.

Bovine tuberculosis (bTB) is endemic in cattle in Ethiopia, a country that hosts the largest national cattle herd in Africa. The intensive dairy sector, most of which is peri-urban, has the highest prevalence of disease. Previous studies in Ethiopia have demonstrated that the main cause is , which has been investigated using conventional molecular tools including deletion typing, spoligotyping and Mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR). Here we use whole-genome sequencing to examine the population structure of in Ethiopia. A total of 134 . isolates were sequenced including 128 genomes from 85 mainly dairy cattle and six genomes isolated from humans, originating from 12 study sites across Ethiopia. These genomes provided a good representation of the previously described population structure of , based on spoligotyping and demonstrated that the population is dominated by the clonal complexes African 2 (Af2) and European 3 (Eu3). A range of within-host diversity was observed amongst the isolates and evidence was found for both short- and long-distance transmission. Detailed analysis of available genomes from the Eu3 clonal complex combined with previously published genomes revealed two distinct introductions of this clonal complex into Ethiopia between 1950 and 1987, likely from Europe. This work is important to help better understand bTB transmission in cattle in Ethiopia and can potentially inform national strategies for bTB control in Ethiopia and beyond.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1099/mgen.0.000539DOI Listing
May 2021

Poultry health services in Ethiopia: availability of diagnostic, clinical, and vaccination services.

Poult Sci 2021 Jan 28;100(6):101023. Epub 2021 Jan 28.

Animal and Human Health, International Livestock Research Institute (ILRI) 5689, Addis Ababa, Ethiopia.

Currently, there is a need for more and better poultry health services in Ethiopia. However, nationwide data showing the weaknesses of poultry health services are scanty. Hence, availability of diagnostic, vaccination, and clinical services for poultry was assessed. Focus group discussions and household questionnaire survey were conducted with poultry keepers in 10 districts. Lack of poultry health experts, clinical services, drugs, vaccination, and knowledge and skills were identified as top five key findings. In total, 31.6% of respondents reported availability of poultry diagnosis service. Having flock size of 11-20 chickens had higher probabilities of accessing better diagnosis service (AOR = 2.77; 95% CI: 1.12-3.64). Access to diagnosis was directly linked with the availability of veterinary clinics in their localities (AOR = 2.65; 95% CI: 1.16-6.63). Moreover, low access to treatment services (22.98%) was reported and traditional remedies with priority index of 0.68 were reported to be the most commonly used. Chicken flocks with a history of disease occurrence were more likely to have a decision to go for modern treatment services (AOR = 4.26; 95% CI: 2.28-7.95). Only 35.7% of chicken keepers had their flocks vaccinated, and this was irregularly and randomly given, mainly against Newcastle disease. Only 52.9% of them were vaccinated by trained animal health experts. Chicken flocks with availability of veterinary clinics within 5 km were more likely (AOR = 1.62; 95% CI: 1.03-2.54) to have access to vaccination services. Only 53.0% of the chicken flocks had availability of clinics and chicken flocks in Tigray (AOR = 2.15; 95% CI: 1.03- 4.52) and Oromia (AOR = 5.74; 95%CI: 2.51-13.10) had better availability of clinics. Chicken flocks found in Bako district were less likely (AOR = 0.41; 95% CI: 0.18-0.92). The low availability of diagnostic, vaccination, and clinical services shows that poultry health services in Ethiopia have not received attention despite its top national agenda. Hence, the existing low poultry health services need to be solved through public-private partnership, producing adequate poultry health experts, availing vaccines, diagnostics, and therapeutics in the local markets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.psj.2021.101023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8080080PMC
January 2021

Phenotypic and genotypic drug sensitivity profiles of Mycobacterium tuberculosis infection and associated factors in northeastern Ethiopia.

BMC Infect Dis 2021 Mar 12;21(1):261. Epub 2021 Mar 12.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.

Background: Tuberculosis is a devastating and a deadly disease despite the novel advances in its diagnostic tools and drug therapy. Drug resistant Mycobacterium contributes a great share to tuberculosis mortality. Status of drug resistance and patients' awareness toward the disease is unknown in northeastern Ethiopia. Thus, the aim of this study was to determine the phenotypic and genotypic drug sensitivity patterns and associated factors in Oromia Special Zone and Dessie Town, northeastern Ethiopia.

Methods: In a cross-sectional study, 384 smear positive tuberculosis cases were recruited and Löwenstein-Jensen culture was done. The performance of GenoTypic MTBDRplus assay using the conventional BACTEC MGIT 960 as a "gold standard" was determined. Drug resistant strains were identified using spoligotyping. Pearson Chi-square test was used to determine the association of drug sensitivity test and tuberculosis type, lineages, dominant strains and clustering of the isolates.

Results: The 384 smear positive Mycobacterium samples were cultured on LJ media of which 29.2% (112/384) as culture positive. A fair agreement was found between MTBDRplus assay and the conventional MGIT test in detecting the Mycobacterium tuberculosis with sensitivity, specificity, positive and negative predictive value of 94.2, 30.2, 68.4 and 76.5%, respectively. Among LJ culture positive samples 95 of them gave valid result for MTBDRplus assay and 16.8% (16/95) as drug resistant. Similarly, MGIT subculture was made for the 112 isolates and 69 of them gave positive result with 15.9% (11/69) as drug resistant. Cohen's kappa value showed almost a perfect agreement between the two testing methods in detecting rifampicin (sensitivity 100% and specificity 98.3%) and multi-drug resistance (sensitivity 83.3% and specificity 100%). Spoligotyping identified 76.5% (13/17) of the drug resistant isolates as Euro-American and family 33 as the predominant family. Significant association was observed between drug resistant isolates and the dominant strains (χ2: 34.861; p = 0.040) of the Mycobacterium.

Conclusion: Higher magnitude of drug resistance was found in the study area. The GenoTypic MDRTBplus assay had an acceptable drug sensitivity testing performance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12879-021-05961-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7953820PMC
March 2021

A Meta-Analysis of the Effect of Bacillus Calmette-Guérin Vaccination Against Bovine Tuberculosis: Is Perfect the Enemy of Good?

Front Vet Sci 2021 18;8:637580. Epub 2021 Feb 18.

Department of Animal Science, The Pennsylvania State University, University Park, PA, United States.

More than 50 million cattle are likely exposed to bovine tuberculosis (bTB) worldwide, highlighting an urgent need for bTB control strategies in low- and middle-income countries (LMICs) and other regions where the disease remains endemic and test-and-slaughter approaches are unfeasible. While Bacillus Calmette-Guérin (BCG) was first developed as a vaccine for use in cattle even before its widespread use in humans, its efficacy against bTB remains poorly understood. To address this important knowledge gap, we conducted a systematic review and meta-analysis to determine the direct efficacy of BCG against bTB challenge in cattle, and performed scenario analyses with transmission dynamic models incorporating direct and indirect vaccinal effects ("herd-immunity") to assess potential impact on herd level disease control. The analysis shows a relative risk of infection of 0.75 (95% CI: 0.68, 0.82) in 1,902 vaccinates as compared with 1,667 controls, corresponding to a direct vaccine efficacy of 25% (95% CI: 18, 32). Importantly, scenario analyses considering both direct and indirect effects suggest that disease prevalence could be driven down close to Officially TB-Free (OTF) status (<0.1%), if BCG were introduced in the next 10-year time period in low to moderate (<15%) prevalence settings, and that 50-95% of cumulative cases may be averted over the next 50 years even in high (20-40%) disease burden settings with immediate implementation of BCG vaccination. Taken together, the analyses suggest that BCG vaccination may help accelerate control of bTB in endemic settings, particularly with early implementation in the face of dairy intensification in regions that currently lack effective bTB control programs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2021.637580DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7930010PMC
February 2021

Epidemiology of Bovine Tuberculosis and Its Zoonotic Implication in Addis Ababa Milkshed, Central Ethiopia.

Front Vet Sci 2021 17;8:595511. Epub 2021 Feb 17.

Aklilu Lemma Institute of Pathobiology, Sefere Selam Campus, Addis Ababa University, Addis Ababa, Ethiopia.

Bovine tuberculosis (bTB) continues to be one of the most widely distributed chronic infectious diseases of zoonotic importance, which causes a significant economic loss in animal production. A cross-sectional study was conducted to estimate the prevalence of bTB and its associated risk factors and type the isolated in central Ethiopia. A total of 65 dairy farms and 654 cattle were tested for bTB using a single intradermal comparative cervical tuberculin (SICCT) test. Data on farm management, animal-related characteristics, and the owner's knowledge of the zoonotic importance of bTB were collected using a structured questionnaire. In addition, a total of 16 animals from different farms were identified for postmortem examination. Lowenstein Jensen (LJ) culture was also conducted, and spoligotyping was used to type the strains isolated. Chi-square test and logistic regression models were used to analyze the herd- and animal-level risk factors. Herd- and animal-level prevalence rates of bTB were 58.5% (95% CI: 46.2%-69.2%) and 39.3% (95% CI: 35.5%-43.5%), respectively. At the herd level, poor farm management was the predictor for bTB positivity ( < 0.05). Animal breed, poor BCS, farm type, and poor farm management conditions were significant predictors of bTB positivity ( < 0.05) at an individual animal level. All animals identified for postmortem examination were found to have gross TB-like lesions. A total of 14 strains were identified from 12 animals that were positive for LJ culture. The strain with the largest number of clusters (five isolates) was SB1176, followed by SB0134 (three isolates), SB0192 (two isolates), and SB2233 (two isolates), and two new strains, each consisting of only one isolate. The majority (58.5%) of the respondents did not know the zoonotic importance of bTB. The result of this study showed a high prevalence of bTB in the Addis Ababa milkshed and a low level of consciousness of the owners on its transmission to humans. Therefore, the launching of acceptable control measures of bTB and the creation of public awareness about its zoonotic transmission and prevention measures are required.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2021.595511DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7925636PMC
February 2021

A case of early neonate bovine tuberculosis in Ethiopia.

Clin Case Rep 2021 Jan 29;9(1):487-490. Epub 2020 Nov 29.

Disease Dynamics Unit Department of Veterinary Medicine University of Cambridge Cambridge UK.

This report illustrates that calves may be infected with bovine tuberculosis at early age under natural conditions and progression can be rapid. Thus, testing of calves needs to be considered in any control program to reduce the risk of transmission.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ccr3.3563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7812992PMC
January 2021

Evaluation of the Control Options of Bovine Tuberculosis in Ethiopia Using a Multi-Criteria Decision Analysis.

Front Vet Sci 2020 16;7:586056. Epub 2020 Dec 16.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Bovine tuberculosis (BTB) is a zoonotic bacterial infection caused by and is characterized by the development of granulomatous lesions in the lymph nodes, lungs and other tissues. It poses serious public health impacts and food security challenges to the agricultural sector in terms of dairy and meat productions. In Ethiopia, BTB has been considered as a priority disease because of its high prevalence in urban and peri-urban dairy farms. However, there has not been any national control program in the country. Thus, in order to initiate BTB control program in the country, information on control options is needed to tailor the best option for the Ethiopian situation. The objective of this study was to identify, evaluate and rank various BTB control options in Ethiopia using a multi-criteria decision analysis based on preference ranking organization method for enrichment evaluations (PROMETHEE) approach while accounting for the stakeholders' preferences. Control options were evaluated under two scenarios: with (scenario 1) and without (scenario 2) bacillus Calmette-Guérin (BCG) vaccination. Nine potential control options were identified that include combinations of three control options (1) test and slaughter with or without government support, (2) test and segregation, and (3) BCG vaccination. Under scenario 1, BCG vaccination, BCG vaccination and test and slaughter with partial compensation by government, and BCG vaccination and test and slaughter with full compensation by government were the top three ranked control options. Under scenario 2, test and slaughter with full compensation by government was the preferred control option, followed by test and segregation supported by test and slaughter with full government compensation, and test and slaughter with half compensation by government. Irrespective of the variability in the weighting by the stakeholders, the sensitivity analysis showed the robustness of the ranking method. In conclusion, the study demonstrated that BCG vaccination, and test and slaughter with full compensation by government were the two most preferred control options under scenarios 1 and 2, respectively. National level discussions were strongly recommended for further concretization and implementation of these control measures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2020.586056DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7772415PMC
December 2020

Poultry disease occurrences and their impacts in Ethiopia.

Trop Anim Health Prod 2021 Jan 3;53(1):54. Epub 2021 Jan 3.

International Livestock Research Institute (ILRI), P.O. Box: 5689, Addis Ababa, Ethiopia.

Poultry production contributes significantly to the livelihoods of Ethiopian farmers and to the national economy although it is hampered by different factors, including poultry diseases. There is scarcity of published evidences on the occurrence and impacts of poultry diseases although such evidences are important for policy makers in designing appropriate interventions. A total of 595 households were interviewed and 11 FGDs were conducted to collect data on the occurrence of diseases and the number of dead chickens in the last 12 months. Hence, respiratory diseases, sudden death, and eye-face-head diseases were mentioned in all of the FGDs as the most frequently occurring disease in the districts. Of households interviewed, 86.1% reported poultry disease occurrence in the last 12 months, and gastrointestinal, eye-face-head, and neurological diseases were identified to be the top three ranked diseases of chickens in the districts. Flocks with access to diagnostic services (Adj. OR = 4.16; P = 0.004) and/or access to animal health providers (Adj. OR = 10.50; P = 0.001) were more likely to report disease occurrence. In the studied population, the diseases resulted in deaths of 2219 chickens valued at 352,219.5 Birr (11,740.65 USD) and a mean crude mortality of 31.87%. Female-lead households (mean difference = 5.95%; P = 0.018) and multiple age units present on the farm (mean difference = 20.92%; P = < 0.000) had higher chicken mortality. Similarly, higher mortality was reported in flocks without access to diagnosis (mean difference = 9.97%; P = < 0.000) and vaccination (mean difference = 12.34%; P = < 0.000) services. The high occurrence of disease and mortalities might be explained by a lack of an organized poultry health service delivery system in the country. Therefore, a carefully designed health service delivery system addressing needs of poultry producers, supported by relevant policy and corresponding strategies, is recommended to address the indicated challenges. Moreover, private health providers with well-defined roles need to be engaged to successfully and sustainably solve the poultry disease problems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11250-020-02465-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7779415PMC
January 2021

Differences in plasma proteomes for active tuberculosis, latent tuberculosis and non-tuberculosis mycobacterial lung disease patients with and without ESAT-6/CFP10 stimulation.

Proteome Sci 2020 Oct 31;18(1):10. Epub 2020 Oct 31.

J. Craig Venter Institute, Rockville, MD, USA.

Background: Tuberculosis (TB) is one of the world's most problematic infectious diseases. The pathogen Mycobacterium tuberculosis (Mtb) is contained by the immune system in people with latent TB infection (LTBI). No overt disease symptoms occur. The environmental and internal triggers leading to reactivation of TB are not well understood. Non-tuberculosis Mycobacteria (NTM) can also cause TB-like lung disease. Comparative analysis of blood plasma proteomes from subjects afflicted by these pathologies in an endemic setting may yield new differentiating biomarkers and insights into inflammatory and immunological responses to Mtb and NTM.

Methods: Blood samples from 40 human subjects in a pastoral region of Ethiopia were treated with the ESAT-6/CFP-10 antigen cocktail to stimulate anti-Mtb and anti-NTM immune responses. In addition to those of active TB, LTBI, and NTM cohorts, samples from matched healthy control (HC) subjects were available. Following the generation of sample pools, proteomes were analyzed via LC-MS/MS. These experiments were also performed without antigen stimulation steps. Statistically significant differences using the Z-score method were determined and interpreted in the context of the proteins' functions and their contributions to biological pathways.

Results: More than 200 proteins were identified from unstimulated and stimulated plasma samples (UPSs and SPSs, respectively). Thirty-four and 64 proteins were differentially abundant with statistical significance (P < 0.05; Benjamini-Hochberg correction with an FDR < 0.05) comparing UPS and SPS proteomic data of four groups, respectively. Bioinformatics analysis of such proteins via the Gene Ontology Resource was indicative of changes in cellular and metabolic processes, responses to stimuli, and biological regulations. The m7GpppN-mRNA hydrolase was increased in abundance in the LTBI group compared to HC subjects. Charged multivesicular body protein 4a and platelet factor-4 were increased in abundance in NTM as compared to HC and decreased in abundance in NTM as compared to active TB. C-reactive protein, α-1-acid glycoprotein 1, sialic acid-binding Ig-like lectin 16, and vitamin K-dependent protein S were also increased (P < 0.05; fold changes≥2) in SPSs and UPSs comparing active TB with LTBI and NTM cases. These three proteins, connected in a STRING functional network, contribute to the acute phase response and influence blood coagulation.

Conclusion: Plasma proteomes are different comparing LTBI, TB, NTM and HC cohorts. The changes are augmented following prior blood immune cell stimulation with the ESAT-6/CFP-10 antigen cocktail. The results encourage larger-cohort studies to identify specific biomarkers to diagnose NTM infection, LTBI, and to predict the risk of TB reactivation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12953-020-00165-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7603755PMC
October 2020

Genotype Diversity of and Pathology of Bovine Tuberculosis in Selected Emerging Dairy Regions of Ethiopia.

Front Vet Sci 2020 30;7:553940. Epub 2020 Sep 30.

Animal and Plant Health Agency, Weybridge, United Kingdom.

Bovine tuberculosis (bTB) is endemic in Ethiopia with higher prevalence in cattle, particularly in the central parts. Spread of to wider regions is inevitable in uncontrolled conditions. This study was conducted to explore the pathology, characterize strains, and describe genotypic diversity to demonstrate possible epidemiological links in emerging dairy areas of Ethiopia, namely, Mekelle and Gondar. Twenty-seven bTB positive cattle identified by the Single Intradermal Comparative Cervical Tuberculin (SICCT) test were subjected to post-mortem inspection to determine lesion distribution and pathological score. Samples from tissues with visible tuberculous or suspected non-visible lesions were processed and cultured following a standard protocol. Isolates identified as by Region of Difference (RD)-based Polymerase Chain Reaction (PCR) were also spoligotyped to determine their spoligotype patterns. Post-mortem inspection of visceral organs indicated bTB suggestive lesions in 41% of the animals, with 25% being in the lungs. Lymph nodes from 77% of the animals had lesions. Fifty-five isolates identified from 24 of the slaughtered animals were confirmed as . No other mycobacterial species were isolated. Spoligotyping classified strains from 21 of these animals into seven spoligotype patterns: SB0133, SB0134, SB1176, SB2233, SB2290, SB2467, and SB2520. More than one spoligotype were identified from five of these animals, and none of the last four spoligotypes had been reported in Ethiopia before. SB0134 was the most predominant type (47%) followed by SB0133 (25.5%). SB0133, SB2290, SB2467, and SB1176 are spoligotypes lacking spacers 3-7, characteristics of strains of the African 2 (Af2) clonal complex, while SB0134, SB2233, and SB2520 do not belong to any of the established clonal complexes and likely to have a different evolutionary history. Despite a small sample size, the present study showed strain diversity with multiple genotypes identified in a single herd and even within a single animal, and the genotypes showed no sign of geographical localization, which could be a consequence of significant movement of bTB diseased cattle around the country, spreading the disease. Therefore, any future control programme of bTB in Ethiopia needs to address the risks of cattle movement.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fvets.2020.553940DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7554335PMC
September 2020

Tuberculosis in small ruminants and dromedary camels in Ethiopia: A systematic review and meta-analysis.

Prev Vet Med 2020 Dec 17;185:105181. Epub 2020 Oct 17.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia; Department of Veterinary Medicine, College of Food and Agriculture, United Arab Emirates University, P.O. Box 15551, Al Ain, United Arab Emirates.

Tuberculosis (TB) is a chronic infectious disease of livestock with serious economic and public health impact in Ethiopia. The disease is reported from cattle, small ruminants and dromedary camels in the country. However, there is no organized summary report on the magnitude and distribution pattern of TB in small ruminants and dromedary camels, unlike that of bovine TB. Consequent to this gap, this review was organized to provide pooled prevalence estimates, and examine level of heterogeneity among studies at national level. In addition, it attempts to illustrate the spatial distribution patterns along the three livestock species based on available reports. Tuberculosis articles on the aforesaid livestock species were searched online using PubMed, CAB direct, Web of Science and AJOL databases. Eighteen articles published from January 2000 to May 15, 2020, written in the English language that fulfill the selection quality criteria were considered for the review. Altogether, 50 district based observational studies conducted on 10,371 goats, 6262 dromedary camels, and 1457 sheep were used for analysis. Accordingly, the pooled prevalence estimates of TB, in a random effect model were 2.3 % (95 % CI: 1.7, 3.1) for goats, 0.8 % (95 % CI: 0.5, 1.4) for sheep and 8.2 % (95 % CI: 6.6, 10.2) for dromedary camels. The subgroup analysis revealed presence of statistically significant differences (p < 0.001) in pooled prevalence estimates among the three species. In multivariable meta-regression model, diagnostic methods used for screening (single intra-dermal comparative cervical tuberculin test (SICCTT)> 2mm, SICCTT > 4mm and detailed postmortem inspection) were the only predictors identified to show statistically significant difference (p<0.001) and explained 68.6 % of the explainable heterogeneity (R =0.686) in goat TB studies. In general, study reports on small ruminant and dromedary camel TB are limited throughout the country. The most significant data gaps were in Gambella, and Benshangul-Gumuz regional states, where no single report could be retrieved on small ruminant TB. Limitation of study reports and lack of comparable categories constrained further investigation on other predictors in sheep and camel studies. Thus, the authors would like to emphasize the need for more representative studies in the species of concern in all regions of the country. Meanwhile, the relatively higher proportion of TB in dromedary camels demands special attention in arid and semiarid parts of the country, as it is the leading livestock species on which agropastoralist and pastoralists livelihoods depend.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prevetmed.2020.105181DOI Listing
December 2020

Molecular epidemiology of clinical Mycobacterium tuberculosis complex isolates in South Omo, Southern Ethiopia.

BMC Infect Dis 2020 Oct 13;20(1):750. Epub 2020 Oct 13.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO. Box 1176, Addis Ababa, Ethiopia.

Background: Tuberculosis (TB) is caused by Mycobacterium tuberculosis complex (MTBC). Mapping the genetic diversity of MTBC in high TB burden country like Ethiopia is important to understand principles of the disease transmission and to strengthen the regional TB control program. The aim of this study was to investigate the genetic diversity of Mycobacterium tuberculosis complex (MTBC) isolates circulating in the South Omo, southern Ethiopia.

Methods: MTBC isolates (N = 156) were genetically analyzed using spacer oligotyping (spoligotyping) and mycobacterial interspersed repetitive unit-variable number of tandem repeat (MIRU-VNTR) typing. Major lineages and lineages were identified using MTBC databases. Logistic regression was used to correlate patient characteristics with strain clustering.

Results: The study identified Euro-American (EA), East-African-Indian (EAI), Indo-Oceanic (IO), Lineage_7/Aethiops vertus, Mycobacterium bovis and Mycobacterium africanum major lineages in proportions of 67.3% (105/156), 22.4% (35/156), 6.4% (10/156), 1.9% (3/156), 1.3% (2/156) and 0.6% (1/156), respectively. Lineages identified were Delhi/CAS 23.9% (37/155), Ethiopia_2 20.6% (32/155), Haarlem 14.2% (22/155), URAL 14.2%(22/155), Ethiopia_3 8.4% (13/155), TUR 6.5% (10/155), Lineage_7/Aethiops vertus 1.9% (3/155), Bovis 1.3% (2/155), LAM 1.3% (2/155), EAI 0.6% (1/155), X 0.6% (1/155) and Ethiopia HRv-like strain 0.6% (1/155). Of the genotyped isolates 5.8% (9/155) remained unassigned. The recent transmission index (RTI) was 3.9%. Orphan strains compared to shared types (AOR: 0.09, 95% CI: 0.04-0.25) were associated with reduced odds of clustering. The dominant TB lineage in pastoral areas was EAI and in non-pastoral areas was EA.

Conclusion: The epidemiological data, highly diverse MTBC strains and a low RTI in South Omo, provide information contributing to the TB Control Program of the country.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12879-020-05394-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7557052PMC
October 2020

Epidemiology of epizootic lymphangitis of carthorses in northern Ethiopia using conventional diagnostic methods and nested polymerase chain reaction.

BMC Vet Res 2020 Oct 7;16(1):375. Epub 2020 Oct 7.

Aklilu Lema Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.

Background: Epizootic lymphangitis (EL), caused by Histoplasma capsulatum variety farciminosum (HCF) is a contagious, chronic disease of equines, characterized by development of nodular lesions in the lymph nodes, lymphatic vessels and skin. It is one of the most important diseases of equines in Ethiopia, causing significant economic loss, particularly in the livelihood of carthorse owners. To date there is neither effective diagnostic nor control measure implemented in the country. Furthermore, there is a shortage of data on the epidemiology of the disease in different regions of this country. The aim of this study was to investigate epidemiology of EL in northern Ethiopia, using the conventional methods as well as nested polymerase chain reaction (PCR).

Results: The presence of HCF genetic material was confirmed in 44% (84/191) of the carthorses. Subclinical infection was observed in 18.2% (22/121) of the apparently healthy carthorses. Considering the nested PCR as a gold standard, sensitivity and specificity of clinical examination were 74% and 92.5%, respectively, while the area under the ROC curve (AUR) was 0.83 (95% confidence interval, 0.77, 0.896). Moreover, a moderate (k = 0.675) agreement observed between the nested PCR and clinical examination.

Conclusions: This study demonstrated widespread occurrence of EL in northern Ethiopia, and the advantage of the nested PCR in detecting infection of HCF, even before the clinical symptoms became apparent.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-020-02582-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7541241PMC
October 2020

Cellular and Cytokine Responses in the Granulomas of Asymptomatic Cattle Naturally Infected with Mycobacterium bovis in Ethiopia.

Infect Immun 2020 11 16;88(12). Epub 2020 Nov 16.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Cell (CD3 T cell and CD68 macrophages), cytokine (interferon gamma-positive [IFN-γ] and tumor necrosis factor alpha-positive [TNF-α]), and effector molecule (inducible nitric oxide synthase-positive [iNOS]) responses were evaluated in the lymph nodes and tissues of cattle naturally infected with Detailed postmortem and immunohistochemical examinations of lesions were performed on 16 cows that were positive by the single intradermal cervical comparative tuberculin (SICCT) test and that were identified from dairy farms located around the city of Addis Ababa, Ethiopia. The severity of the gross lesion was significantly higher ( = 0.003) in culture-positive cows ( = 12) than in culture-negative cows ( = 4). Immunohistochemical techniques showed that in culture-positive cows, the mean immunolabeling fraction of CD3 T cells decreased as the stage of granuloma increased from stage I to stage IV ( < 0.001). In contrast, the CD68 macrophage, IFN-γ, TNF-α, and iNOS immunolabeling fractions increased from stage I to stage IV ( < 0.001). In the early stages, culture-negative cows showed a significantly higher fraction of CD68 macrophage ( = 0.03) and iNOS ( = 0.007) immunolabeling fractions than culture-positive cows. Similarly, at advanced granuloma stages, culture-negative cows demonstrated significantly higher mean proportions of CD3 T cells ( < 0.001) than culture-positive cows. Thus, this study demonstrates that, following natural infection of cows with , as the stage of granuloma increases from stage I to stage IV, the immunolabeling fraction of CD3 cells decreases, while the CD68 macrophage, IFN-γ, TNF-α, and iNOS immunolabeling fractions increases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/IAI.00507-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671892PMC
November 2020

Brucellosis in ruminants and pastoralists in Borena, Southern Ethiopia.

PLoS Negl Trop Dis 2020 07 24;14(7):e0008461. Epub 2020 Jul 24.

Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge Madingley Road, United Kingdom.

Brucellosis is a bacterial zoonotic disease that has important veterinary and public health consequences as well as economic impact in sub Saharan Africa including Ethiopia. A cross-sectional study was conducted in four selected districts of Borena Pastoral setting in Southern Ethiopia from October 2017 to February 2018 to estimate the prevalence of brucellosis and assess associated risk factors in cattle, sheep, goats and occupationally associated humans. A total of 750 cattle, 882 sheep and goats and 341 human subjects were screened for evidence of brucellosis using the Rose Bengal Test (RBT) with positive results confirmed by Competitive-ELISA(c-ELISA). Structured questionnaires were used for collection of metadata from individual animals, herders and animal attendants to test the association between explanatory and outcome variables. The overall animal level prevalence was 2.4% (95% confidence interval, CI: 1.4-3.7) in cattle, 3.2% (95% CI: 2.1-4.6) in sheep and goats, and 2.6% (95% CI: 1.2-5) in humans occupationally linked to livestock production systems. Herd size, parity, and history of abortion were risk factors associated with Brucella seropositivity (P<0.05) in cattle whereas in sheep and goats the results showed that district, age group, flock size, and history of abortion were significantly associated risk factors with Brucella seropositivity (P<0.05). Assisting calving and presence of seropositive animals in a household (P<0.05) were significantly associated with Brucella seropositivity in humans. Evidence of brucellosis in various animal species and the associated human population illustrates the need for a coordinated One Health approach to controlling brucellosis so as to improve public health and livestock productivity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0008461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7406081PMC
July 2020

In Vitro Evaluation of the Effects of Selected Plants on the Growth of the Mycelial Form of Histoplasma capsulatum Variety farciminosum in Ethiopia.

J Equine Vet Sci 2020 08 30;91:103139. Epub 2020 May 30.

Department of Clinical Studies, College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia. Electronic address:

Epizootic lymphangitis is prevalent in equines in Ethiopia, causing remarkable economic and welfare impacts but often neglected. Lack of effective treatment contributed to its continued occurrence, and hence, search for an effective treatment should be considered a priority area to minimize its impacts. Previous ethnobotanical studies have reported that Curcuma longa, Phytolacca dodecandra, and Datura stramonium were used to treat cutaneous fungal infections and reduce their incidence. The treatment effects of these plants against epizootic lymphangitis should be studied. The in vitro growth inhibitory effects of methanol extracts of the root of C. longa, berry of P. dodecandra, and leaf of D. stramonium were evaluated. Histoplasma capsulatum var farciminosum was isolated from clinical cases of epizootic lymphangitis in carthorses in central Ethiopia. The nested polymerase chain reaction was used to confirm the identity of the isolates. Serial twofold dilutions of the extract of berries of P. dodecandra and leaves of D. stramonium were done in sterile water, whereas dilution of the extract of roots of C. longa was done in dimethylsulphoxide. The effects of the plants on the growth of Histoplasma capsulatum var farciminosum were assessed by agar dilution assay. Culture media with no antifungal agent and media containing ketoconazole served as negative and positive control, respectively. The methanol extract of C. longa showed inhibitory effects at concentrations ranging from 0.07 to 5 mg/mL. Similarly, the methanol extract of P. dodecandra showed growth inhibitory effects at concentrations ranging from 0.156 to 5 mg/mL. That is, the growth inhibitory concentration of C. longa was 0.07 mg/mL, whereas that of P. dodecandra was 0.156 mg/mL. In contrast, D. stramonium showed no inhibitory effect. This preliminary observation showed that methanol extracts of C. longa and P. dodecandra showed inhibitory effects on the growth of Histoplasma capsulatum var farciminosum requiring further repeated in vitro evaluation so as to generate adequate evidence, which would justify in vivo trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jevs.2020.103139DOI Listing
August 2020

Prevalence of latent tuberculosis infection and associated risk factors in prison in East Wollega Zone of western Ethiopia.

PLoS One 2020 19;15(5):e0233314. Epub 2020 May 19.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Background: Latent tuberculosis infection (LTBI) is the major source of active TB and is an obstacle to the strategy of World Health Organization to end TB by 2035. In Ethiopia, there are hundreds of prisons and they are conducive settings for the transmission of TB and could serve as the sources of infection to the general public. However, there is little data on the epidemiology of TB in prisons in Ethiopia. The objective of the present study was to estimate the prevalence of LTBI and evaluate associated risk factors in prisons in East Wollega Zone in western Ethiopia.

Methods: A cross-sectional design and systematic sampling technique were used to select 352 prisoners from a total of 2620 prisoners during the two months (May and June, 2019). The selected inmates were consented for their willingness to participate in the study. Thereafter, they were interviewed and 2ml of blood sample was collected from each prisoner and screened for LTBI using interferon-gamma release assay (IGRA). The data were analyzed using SPSS version 25 and logistic regression was used to model the likelihood of LTBI occurrence and to identify risk factors associated with LTBI.

Results: The prevalence of LTBI was 51.2% (95% CI: 46.45-57%) and higher prevalence was recorded in males (53%) than in females (43.5%) although the difference was not significant. Prisoners whose age ≥45 years (AOR = 2.48, 95%CI, 1.04-5.9), who chewed khat (AOR = 2.27; 95% CI, 1.27-4.19), who were prisoned over a year (AOR = 1.81, 95%CI, 1.04-3.18) and who were in overcrowded pens (AOR = 1.91, 95% CI, 1.002-3.65) were at higher risk of LTBI.

Conclusions: The prevalence of LTBI in prisoners in West Wollega Zone of western Ethiopia was high and could serve as sources of infection to the public. Hence optimum handling of prisoners, and regular follow up and treatment of TB cases in prisons were recommended to minimize the burden of TB in the Zone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0233314PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7237014PMC
August 2020

Targeted-Sequencing Workflows for Comprehensive Drug Resistance Profiling of Mycobacterium tuberculosis Cultures Using Two Commercial Sequencing Platforms: Comparison of Analytical and Diagnostic Performance, Turnaround Time, and Cost.

Clin Chem 2020 06;66(6):809-820

Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region, China.

Background: The emergence of Mycobacterium tuberculosis with complex drug resistance profiles necessitates a rapid and comprehensive drug susceptibility test for guidance of patient treatment. We developed two targeted-sequencing workflows based on Illumina MiSeq and Nanopore MinION for the prediction of drug resistance in M. tuberculosis toward 12 antibiotics.

Methods: A total of 163 M. tuberculosis isolates collected from Hong Kong and Ethiopia were subjected to a multiplex PCR for simultaneous amplification of 19 drug resistance-associated genetic regions. The amplicons were then barcoded and sequenced in parallel on MiSeq and MinION in respective batch sizes of 24 and 12 samples. A web-based bioinformatics pipeline, BacterioChek-TB, was developed to translate the raw datasets into clinician-friendly reports.

Results: Both platforms successfully sequenced all samples with mean read depths of 1,127× and 1,649×, respectively. The variant calling by MiSeq and MinION could achieve 100% agreement if variants with an allele frequency of <40% reported by MinION were excluded. Both workflows achieved a mean clinical sensitivity of 94.8% and clinical specificity of 98.0% when compared with phenotypic drug susceptibility test (pDST). Turnaround times for the MiSeq and MinION workflows were 38 and 15 h, facilitating the delivery of treatment guidance at least 17-18 days earlier than pDST, respectively. The higher cost per sample on the MinION platform ($71.56) versus the MiSeq platform ($67.83) was attributed to differences in batching capabilities.

Conclusion: Our study demonstrates the interchangeability of MiSeq and MinION platforms for generation of accurate and actionable results for the treatment of tuberculosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/clinchem/hvaa092DOI Listing
June 2020

Tuberculosis knowledge and attitude among non-health science university students needs attention: a cross-sectional study in three Ethiopian universities.

BMC Public Health 2020 May 6;20(1):631. Epub 2020 May 6.

Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, Addis Ababa, Ethiopia.

Background: Ethiopia is among the 14 high TB, TB/HIV and MDR-TB burden countries globally. Prior studies indicate students attending universities in Ethiopia may be at increased risk for active tuberculosis (TB) relative to the general population, mainly due to the dramatic increase in expansion of the enrollment scale of universities.This study sought to gain insight about non-health science university students' TB knowledge and attitudes to help develop a strategy for TB education in this population.

Methods: A cross-sectional study was conducted from October to December 2018 among non-health science university students at three eastern Ethiopia public universities. Participants were considered having 'good' knowledge on TB when they correctly mentioned the communicability, means of transmission and prevention methods of TB and recognized modern medicine as the best treatment for TB. Participants were considered as having 'acceptable' attitude towards TB when they indicated they would seek immediate care for TB diagnosis, not hide a TB diagnosis and feel compassion to help people with TB.

Results: A total of 1720 non-health science university students participated. Only 614 (35.7%) of the students had 'good' knowledge on TB. This differed significantly between universities, with students from Haramaya and Dire Dawa universities more likely to have 'good' TB knowledge than their counterparts from Jigjiga University [COR (Crude Odds Ratio):1.62 and 1.94, respectively; and 95% Confidence Interval (CI): (1.236, 2.079) and (1.511, 2.483), respectively]. Only a third of students, 555 (32.3%) mentioned 'bacteria' as causing TB, and 836 students (48.6%) had ever heard of Multi Drug Resistant-TB (MDR-TB). An 'acceptable' attitude towards people with TB was observed in 666 students (38.7%). Even though 739 students (43%) felt compassion and desire to help TB patients, 213 (12%) and 382 (22%) mentioned they fear and tend to stay away from TB patients, respectively.

Conclusions: The present study revealed that non-health science university students lack important TB knowledge and have misconceptions about TB in eastern Ethiopia. University administrators and other stakeholders striving against TB should provide due attention to university settings and consider development of student education programs to improve awareness and knowledge of TB disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12889-020-08788-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7203974PMC
May 2020

An African origin for .

Evol Med Public Health 2020 31;2020(1):49-59. Epub 2020 Jan 31.

Molecular Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.

Background And Objectives: and are two of the most important agents of tuberculosis in livestock and the most important causes of zoonotic tuberculosis in humans. However, little is known about the global population structure, phylogeography and evolutionary history of these pathogens.

Methodology: We compiled a global collection of 3364 whole-genome sequences from and originating from 35 countries and inferred their phylogenetic relationships, geographic origins and age.

Results: Our results resolved the phylogenetic relationship among the four previously defined clonal complexes of , and another eight newly described here. Our phylogeographic analysis showed that likely originated in East Africa. While some groups remained restricted to East and West Africa, others have subsequently dispersed to different parts of the world.

Conclusions And Implications: Our results allow a better understanding of the global population structure of and its evolutionary history. This knowledge can be used to define better molecular markers for epidemiological investigations of in settings where whole-genome sequencing cannot easily be implemented.

Lay Summary: During the last few years, analyses of large globally representative collections of whole-genome sequences (WGS) from the human-adapted Mycobacterium tuberculosis complex (MTBC) lineages have enhanced our understanding of the global population structure, phylogeography and evolutionary history of these pathogens. In contrast, little corresponding data exists for M. bovis, the most important agent of tuberculosis in livestock. Using whole-genome sequences of globally distributed M. bovis isolates, we inferred the genetic relationships among different M. bovis genotypes distributed around the world. The most likely origin of M. bovis is East Africa according to our inferences. While some M. bovis groups remained restricted to East and West Africa, others have subsequently dispersed to different parts of the world driven by cattle movements.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/emph/eoaa005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081938PMC
January 2020

Low Prevalence of Mycobacterium bovis in Tuberculosis Patients, Ethiopia.

Emerg Infect Dis 2020 03;26(3):613-615

An estimated 17% of all tuberculosis cases in Ethiopia are caused by Mycobacterium bovis. We used M. tuberculosis complex isolates to identify the prevalence of M. bovis as the cause of pulmonary tuberculosis. Our findings indicate that the proportion of pulmonary tuberculosis due to M. bovis is small (0.12%).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3201/eid2603.190473DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7045829PMC
March 2020

Infectious and parasitic diseases of poultry in Ethiopia: a systematic review and meta-analysis.

Poult Sci 2019 Dec;98(12):6452-6462

International Livestock Research Institute (ILRI), P.O. Box 5689, Addis Ababa, Ethiopia.

In Ethiopia, poultry production is an important source of domestic food and nutrition security while providing income for nearly 80% of Ethiopians. However, several infectious and parasitic diseases hamper poultry production. To date, evidence on the nationwide burden of specific diseases has not been collated to inform targeting of poultry health interventions. The objective of this systematic review is to summarize and analyze the literature on poultry diseases since 2000. A detailed systematic review protocol was designed according to Cochrane collaboration, Strengthening the Reporting of Observational Studies in Epidemiology (STROBE), and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statements. The review revealed that 14 infectious and parasitic diseases of poultry were reported in 110 published studies from 2000 to 2017, and 81.82% (90/110) of the studies covered 6 diseases: Newcastle disease (ND), infectious bursal disease (IBD), avian coccidiosis, helminth infestation, ecto-parasite infestation, and Salmonella infection. The pooled prevalence estimates of ND and IBD were 44% (95% confidence interval [CI]: 27 to 63) and 41% (95% CI: 23 to 60), respectively. Among the parasitic diseases, avian coccidiosis, helminth infestation, and ecto-parasite infestation had estimated pooled prevalences of 37% (95% CI: 30 to 44), 62% (95% CI: 45 to 78), and 50% (95% CI: 33 to 68), respectively. The pooled prevalence estimate of Salmonella infection was found to be 51% (95% CI: 32 to 70). Most of the studies were conducted in central Ethiopia, in the State of Oromia, and focused on extensive farming systems. While the number of studies was low, the overall trend of disease reporting in the literature is increasing (Y = 0.99X-3.34). In conclusion, the high-pooled prevalence estimates of diseases and the scarcity of reported data for all of Ethiopia indicate an important data gap on infectious-disease distribution in the country. While the high-pooled prevalence points towards the need for intervention to control poultry diseases, there is also a need to ensure all diseases that result in production losses and public health risks are studied appropriately in all Ethiopian production systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3382/ps/pez521DOI Listing
December 2019

Utility of urine as a clinical specimen for the diagnosis of pulmonary tuberculosis in people living with HIV in Addis Ababa, Ethiopia.

J Clin Tuberc Other Mycobact Dis 2019 Dec 19;17:100125. Epub 2019 Sep 19.

Addis Ababa University, School of Medicine, College of Health Science, Department of Medical Microbiology, Immunology and Parasitology, Addis Ababa, Ethiopia.

Background: Tuberculosis is a common cause of mortality and morbidity among people living with HIV/AIDS. Despite the increased prognosis of tuberculosis among HIV infected patients, diagnosis of pulmonary tuberculosis (PTB) smear microscopy has a low sensitivity due to low bacterial load in a sputum specimen of HIV patients. Having alternative specimens for increasing detection of is very important.

Objective: The aim of this study was to evaluate the efficacy of urine as clinical specimen for the diagnosis of pulmonary tuberculosis in people living with HIV.

Method: A total of 117 HIV-seropositive individuals from three public health facilities in Addis Ababa, Ethiopia were enrolled consecutively from December 2013 to July 2014. A total of 117 paired morning sputum and urine samples were simultaneously collected from anti-retroviral therapy (ART) naïve PTB suspected individuals living with HIV. Both sputum and urine samples were processed for culture using Lowenstein-Jensen medium, and the left was subjected to PCR using RD9 primers. Chi-square test and kappa value were used to compare different methods used.

Result: Out of 117 suspected PTB HIV-infected people, sputum culture alone detected more mycobacterial isolates 33 (28.2%) than the urine specimen alone 17 (14.5%). Of the 33 patients positive for sputum culture, 13 patients were observed as a urine culture positive. Of the 84 individuals negative for mycobacterial by sputum culture, four (4.8%) were urine culture positive and thus, the sensitivity, and the agreement between urine culture as compare to sputum culture were 39.4% and 0.49, respectively. On the other hand, the sensitivity of RD9-based PCR directly on urine was 72.7% by considering sputum culture as a reference standard. Moreover, RD9-based PCR directly on sputum detected 9 (7.7%) individuals who were sputum culture negative for . The detection rate of from urine in patients those who couldn't produce sputum were 9(34.6%).

Conclusion: PCR and culture examination of urine samples also can improve the detection rate of in PTB suspected HIV positive individuals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jctube.2019.100125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6880017PMC
December 2019

Tuberculosis at Farmer-Cattle Interface in the Rural Villages of South Gondar Zone of Northwest Ethiopia.

Tuberc Res Treat 2019 16;2019:2106981. Epub 2019 Oct 16.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.

Background: Tuberculosis (TB) has been an important public health concern in Ethiopia, particularly at areas of human-animal intersection. However, limited epidemiological information is available in this respect in the country. Therefore, the present study was conducted to investigate the transmission of TB at human-cattle interface, associated risk factors and public awareness about the disease at South Gondar Zone, northwest Ethiopia.

Methods: A cross sectional study was conducted between March 2015 and April 2018 on 186 farmers and 476 cattle in South Gondar Zone, northwest Ethiopia. Bacteriological examination, region of difference (RD) 9-based polymerase chain reaction (PCR), single intradermal comparative tuberculin test (SICTT), and questionnaire were used for undertaking this study.

Results: Culture positivity in farmers was 59.7% (111/186) and all the culture positive isolates were . About 68% (74/111) of culture positive respondents did not know about the transmission of TB from cattle to human or vice versa. The animal and herd prevalence of bovine TB were 1.5% (7/476) and 7.4% (7/95), respectively. Although the result was not statistically significant, the odds of bovine TB in cattle owned by TB positive households was slightly higher than those owned by TB free households (adjusted odds ratio, AOR = 1.39; 95% CI: 0.31-7.10; = 0.76).

Conclusion: Although SIDCTT reactivity was slightly higher in cattle owned by TB positive households, all the human isolates were and no was isolated from farmers, which could be due to the low prevalence of bovine TB in the area.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2019/2106981DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6816001PMC
October 2019

Monitoring quality indicators for the Xpert MTB/RIF molecular assay in Ethiopia.

PLoS One 2019 12;14(11):e0225205. Epub 2019 Nov 12.

Aklilu Lemma Institute of Pathology, Addis Ababa University, Addis Ababa, Ethiopia.

Introduction: In Ethiopia, >300 GeneXpert instruments have been deployed for tuberculosis (TB) testing using the Xpert MTB/RIF cartridge. Implementing quality indicators is necessary for monitoring and evaluating the quality of Xpert MTB/RIF diagnostic services.

Objective: To assess the use of quality indicators for the Xpert MTB/RIF molecular assay in Ethiopia and to compare the findings with the predefined targets described in the literature.

Methods: Clinical specimens collected from patients with suspected TB were subjected to Xpert MTB/RIF testing at the National TB Reference Laboratory (NTRL) between January and December 2018. Data were collected from GeneXpert software and Laboratory Information System (LIS) databases. Quality indicators were calculated and analyzed. Bivariate and multivariate analyses were performed using SPSS software version 20 (SPSS Inc., Chicago, Illinois, USA).

Results: Of the 2515 specimens tested, 2274 (90.4%) had successful test results; 18.2% were positive for Mycobacterium tuberculosis (MTB). Among MTB positives (n = 413), 4.8% and 1.0% were rifampicin (RIF)-resistant and RIF-indeterminate cases, respectively. Unsuccessful results were 241 (9.6%); 8.9% of the total number of tests were errors, 0.04% had invalid results and 0.6% 'no result'. The most frequent error was probe check failure (error 5007). Instrument module A4, B2, B3, C3, and D3 (p<0.05) and tester experience (p<0.05) had a statistically significant association with errors in multivariate analysis. Additional 42 MTB cases (9.2% of the total cases) were detected among unsuccessful results by follow-up tests. Sixty-four percent of the initial test results were released within the turnaround time (TAT) ≤24 hours.

Conclusion: Most of the quality indicators for the Xpert MTB/RIF molecular assay were maintained within the targets. However, the error rate and TAT were out of the targets. Defective modules and lacking experience were the factors affecting successful test outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0225205PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6850546PMC
March 2020

Evaluation of Mycobacterium tuberculosis lipoarabinomannan antigen assay and rapid serology blood test for the diagnosis of bovine tuberculosis in Ethiopia.

BMC Vet Res 2019 Oct 22;15(1):359. Epub 2019 Oct 22.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Background: Bovine tuberculosis (bTB) is prevalent in dairy cattle in Ethiopia. Currently used diagnostic tools such as the single intradermal comparative tuberculin test (SICTT) are time consuming and labor intensive. A rapid, easy-to-use and cost-effective diagnostic test would greatly contribute to the control of bTB in developing countries like Ethiopia. In the present study, two point-of-care diagnostic tests were evaluated for the detection of bTB: LIONEX® Animal TB Rapid test, a membrane-based test for the detection of antibodies to Mycobacterium bovis in blood and ALERE® Determine TB Lipoarabinomannan (LAM) Ag, an immunoassay for the detection of lipoarabinomannan (LAM) antigen (Ag) of mycobacteria in urine. A combination of the SICTT and gamma interferon (IFN-γ) test was used as the gold standard for the validation of these point-of-care tests, as it was not feasible to slaughter the study animals to carry out the historical gold standard of mycobacterial culture. A total of 175 heads of cattle having three different bTB infection categories (positive SICTT, negative SICTT, and unknown SICTT status) were used for this study.

Result: The sensitivity and specificity of TB LAM Ag were 72.2% (95% CI = 62.2, 80.4) and 98.8% (95% CI = 93.6, 99.7), respectively, while the sensitivity and specificity of the LIONEX Animal TB rapid test assay were 54% (95% CI = 44.1 64.3) and 98.8% (95% CI = 93.6, 99.7) respectively. The agreement between TB LAM Ag and SICTT was higher (κ = 0.85; 95% CI = 0.65-0.94) than between TB LAM Ag and IFN-γ (κ = 0.67; 95% CI = 0.52-0.81). The agreement between LIONEX Animals TB Rapid blood test and SICTT was substantial, (κ = 0.63; 95% CI = 0.49-0.77) while the agreement between LIONEX Animal TB rapid blood test and IFN-γ test was moderate (κ = 0.53; 95% CI = 0.40-0.67). Analysis of receiver operating curve (ROC) indicated that the area under the ROC curve (AUC) for TB LAM Ag was 0.85 (95% CI = 0.79-0.91) while it was 0.76 (95% CI; =0.69-0.83) for LIONEX Animal TB rapid test assay.

Conclusion: This study showed that TB LAM Ag had a better diagnostic performance and could potentially be used as ancillary either to SICTT or IFN-γ test for diagnosis of bTB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-019-2114-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6805383PMC
October 2019

High helminthic co-infection in tuberculosis patients with undernutritional status in northeastern Ethiopia.

Infect Dis Poverty 2019 Oct 18;8(1):88. Epub 2019 Oct 18.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Background: Tuberculosis and parasitosis are the widely distributed diseases in Ethiopia with the leading cause of mortality and morbidity, respectively. There has been no information on the status of co-infections of tuberculosis and parasitosis in Oromia Zone of Amhara Region and South Wollo, Ethiopia. Hence, this study primarily focuses on determining the status of tuberculosis and parasitosis co-infections and associated factors.

Methods: The study was conducted in Oromia Special Zone of the Amhara Regional State and South Wollo Zone, northeastern Ethiopia from April 2015 to January 2017. Tuberculosis cases confirmed by health personnel at the health institutions were the source of the study sample. In a cross-sectional study 384 smear positive pulmonary and extra-pulmonary tuberculosis cases were recruited. Faecal specimens provided by the study participants were examined for parasitic co-infections using direct saline microscopic test, Kato-Katz and concentration techniques. Nutritional status was determined using body mass index and mid-upper arm circumferences. Data were analyzed using descriptive statistical methods and Pearson chi-square.

Results: Tuberculosis and parasitosis co-infection prevalence was 10.8%, and the proportion of intestinal helminths accounted for 9.7% while intestinal protozoa accounted for 1.9%. Cases with single parasitic infection was 89.3% among co-infected individuals. Co-infection of both disease was not significantly associated with gender and age (P > 0.05). The prevalence of undernutrition was 58.6% as determined using body mass index and 73.0% as determined using mid-upper arm circumference with no significant association with gender. Among all forms of tuberculosis cases (384) screened for the study, the bacterial positivity was relatively more common in males (55.5%) than females (44.5%). Tuberculosis lymphadenitis was found to be the most prevalent (85.9%) form of extra-pulmonary tuberculosis with cervical adenopathy (75.3%) being the commonly existing disease.

Conclusions: The rate of helminthic co-infection is predominantly high than that of intestinal protozoa. Single parasitic co-infection was more common than double or multiple co-infections. Both body mass index and mid-upper arm circumference anthropometric parameters revealed greater risk of undernutrition in tuberculosis patients. Thus, screening and prompt treatment of parasites in tuberculosis patients and a support of nutritional supplementation for malnourished tuberculosis patients should be further studied which might enhance the disease treatment and minimize the risk of its complexity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40249-019-0600-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6798427PMC
October 2019

Smear positive tuberculosis and genetic diversity of M. tuberculosis isolates in individuals visiting health facilities in South Gondar Zone, northwest Ethiopia.

PLoS One 2019 8;14(8):e0216437. Epub 2019 Aug 8.

Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.

Background: Tuberculosis (TB), a bacterial infectious disease, continues to be a public health concern in many developing countries. However, lack of data concerning the public health burden and potential risk factors for the disease hampers control programs in target areas. Therefore, the aims of present study were to determine the prevalence of TB and genetic diversity of M. tuberculosis isolates from individuals visiting health facilities in South Gondar Zone, northwest Ethiopia.

Methods: A cross-sectonal study was conducted between March 2015 and April 2017. Bacteriological examination, region of difference (RD) 9 based polymerase chain reaction (PCR) and spoligotyping were used.

Results: The overall prevalence of all smear positive TB was 6.3% (186/2953). Extra pulmonary TB (EPTB) was clinically characterized in about 62.4% (116/186) TB-positive cases. Some demographic characteristics, such as patients' origin (districts where patients were recruited) [patients' origin (chi-square (χ2) value; 62.8,p<0.001) were found to be significantly associated risk factors for the occurrence of TB in the study area. All the mycobacterial isolates were found to be M. tuberculosis. Among the 35 different spoligotype patterns identified, 22 patterns were shared types.The three dominantly identified families were T, CAS and Manu, each consisting of 46.9%, 24.0% and 10.4% of the isolates, respectively.

Conclusion: The present study revealed that TB continues to be a public health problem in South Gondar Zone which suggests a need of implementing effective disease control strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0216437PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687116PMC
April 2020

Network analysis of dairy cattle movement and associations with bovine tuberculosis spread and control in emerging dairy belts of Ethiopia.

BMC Vet Res 2019 Jul 26;15(1):262. Epub 2019 Jul 26.

Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.

Background: Dairy cattle movement could be a major risk factor for the spread of bovine tuberculosis (BTB) in emerging dairy belts of Ethiopia. Dairy cattle may be moved between farms over long distances, and hence understanding the route and frequency of the movements is essential to establish the pattern of spread of BTB between farms, which could ultimately help to inform policy makers to design cost effective control strategies. The objective of this study was, therefore, to investigate the network structure of dairy cattle movement and its influence on the transmission and prevalence of BTB in three emerging areas among the Ethiopian dairy belts, namely the cities of Hawassa, Gondar and Mekelle.

Methods: A questionnaire survey was conducted in 278 farms to collect data on the pattern of dairy cattle movement for the last 5 years (September 2013 to August 2018). Visualization of the network structure and analysis of the relationship between the network patterns and the prevalence of BTB in these regions were made using social network analysis.

Results: The cattle movement network structure display both scale free and small world properties implying local clustering with fewer farms being highly connected, at higher risk of infection, with the potential to act as super spreaders of BTB if infected. Farms having a history of cattle movements onto the herds were more likely to be affected by BTB (OR: 2.2) compared to farms not having a link history. Euclidean distance between farms and the batch size of animals moved on were positively correlated with prevalence of BTB. On the other hand, farms having one or more outgoing cattle showed a decrease on the likelihood of BTB infection (OR = 0.57) compared to farms which maintained their cattle.

Conclusion: This study showed that the patterns of cattle movement and size of animal moved between farms contributed to the potential for BTB transmission. The few farms with the bulk of transmission potential could be efficiently targeted by control measures aimed at reducing the spread of BTB. The network structure described can also provide the starting point to build and estimate dynamic transmission models for BTB, and other infectious diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12917-019-1962-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660945PMC
July 2019