Publications by authors named "Elizabeth A Cromwell"

30 Publications

  • Page 1 of 1

Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning.

PLoS Negl Trop Dis 2021 Jul 28;15(7):e0008824. Epub 2021 Jul 28.

Department of Health Policy Planning and Management, University of Health and Allied Sciences, Ho, Ghana.

Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 0·71 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 50·2% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0008824DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8318275PMC
July 2021

The effect of HIV infection and exposure on cognitive development in the first two years of life in Malawi.

Eur J Paediatr Neurol 2020 Mar 21;25:157-164. Epub 2019 Nov 21.

Department of Epidemiology and Social Sciences, University of Antwerp, Antwerp, Belgium; Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.

Objectives: To assess longitudinal patterns and determinants of cognitive development in infants living with HIV, infants exposed to maternal HIV infection, and HIV-unexposed infants.

Methods: Prospective, community-based cohort study of 555 Malawian infants aged 8 weeks to 24 months, using multivariable linear mixed-effects regression models with random intercepts to analyze repeated measures of cognitive function.

Results: At 3 months of age, cognitive scores on the Bayley Scales of Infant Development (BSID 3rd edition) were lower in the 96 HIV-infected infants (mean = 14.1 (SD:4.8)) compared to the 289 HIV-exposed (mean = 16.5 (SD:3.7)) and the 170 unexposed infants (mean = 17.5 (SD:3.3)). Over the first two years of life, the small deficit in cognitive development of infants living with HIV who survived and remained in care did not increase (mean score 52.9 among HIV-infected vs 55.6 among HIV unexposed). In multivariable analysis, malnutrition and a more advanced clinical infant HIV stage had a negative impact on cognition at age 3, while financial security, care by the biological mother, and ART for mother and child were associated with better cognitive status at this young age. The positive influence of maternal ART reversed with age.

Conclusions: Malawian infants exposed to HIV had a cognitive development that was similar to their unexposed peers in the first two years of life, while that of HIV infected infants lagged behind from the start. Early initiation of effective ART in all HIV infected mothers and infants, and prevention of infant malnutrition are important to safeguard cognitive development of children affected by HIV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejpn.2019.11.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7136137PMC
March 2020

Mapping the global distribution of podoconiosis: Applying an evidence consensus approach.

PLoS Negl Trop Dis 2019 12 2;13(12):e0007925. Epub 2019 Dec 2.

Department of Global Heath and Infection, Brighton and Sussex Medical School, Falmer, Brighton, United Kingdom.

Background: Podoconiosis is a type of elephantiasis characterised by swelling of the lower legs. It is often confused with other causes of tropical lymphedema and its global distribution is uncertain. Here we synthesise the available information on the presence of podoconiosis to produce evidence consensus maps of its global geographical distribution.

Methods And Findings: We systematically searched available data on podoconiosis in SCOPUS and MEDLINE from inception, updated to 10 May, 2019, and identified observational and population-based studies reporting podoconiosis. To establish existence of podoconiosis, we used the number of cases reported in studies and prevalence data with geographical locations. We then developed an index to assess evidence quality and reliability, assigning each country an evidence consensus score. Using these summary scores, we then developed a contemporary global map of national-level podoconiosis status. There is evidence of podoconiosis in 17 countries (12 in Africa, three in Latin America, and two in Asia) and consensus on presence in six countries (all in Africa). We have identified countries where surveillance is required to further define the presence or absence of podoconiosis. We have highlighted areas where evidence is currently insufficient or conflicting, and from which more evidence is needed.

Conclusion: The global distribution of podoconiosis is not clearly known; the disease extent and limits provided here inform the best contemporary map of the distribution of podoconiosis globally from available data. These results help identify surveillance needs, direct future mapping activities, and inform prevention plans and burden estimation of podoconiosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0007925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6907864PMC
December 2019

Epilepsy in Africa: Can we end suffering and financial hardship due to lack of access to effective and affordable care?

EClinicalMedicine 2019 Mar 3;9:9-10. Epub 2019 Apr 3.

Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.eclinm.2019.03.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6510717PMC
March 2019

A database of geopositioned onchocerciasis prevalence data.

Sci Data 2019 May 22;6(1):67. Epub 2019 May 22.

Institute for Health Metrics and Evaluation, University of Washington, 2301 5th Ave., Seattle, WA, United States.

Onchocerciasis is a neglected tropical disease with numerous symptoms and side effects, and when left untreated can lead to permanent blindness or skin disease. This database is an attempt to combine onchocerciasis prevalence data from peer-reviewed publications into a single open-source dataset. The process followed to extract and format the information has been detailed in this paper. A total of 14,043 unique location, diagnostic, age and sex-specific records from 1975-2017 have been collected, organized and marked for collapse where a single geo-position is shared between multiple records. The locations vary from single villages up to smaller administrative units and onchocerciasis control program-defined foci. This resulting database can be used to by the global health community to advance understanding of the distribution of onchocerciasis infection and disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41597-019-0079-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531454PMC
May 2019

Ecological and Socioeconomic Predictors of Transmission Assessment Survey Failure for Lymphatic Filariasis.

Am J Trop Med Hyg 2019 07;101(1):271-278

Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington.

The transmission assessment survey (TAS) is recommended to determine whether cessation of mass drug administration (MDA) for lymphatic filariasis (LF) is warranted. Ministries of health typically implement TASs in evaluation units (EUs) that have had more than five rounds of annual MDA. Under TAS guidelines, sample size calculations determine a decision value: if the number of individuals testing positive exceeds this threshold, then MDA continues in the EU. The objective of this study was to determine whether fine scale geospatial covariates could be used to identify predictors of TAS failure. We geo-referenced 746 TAS EUs, of which 65 failed and extracted geospatial covariates using R to estimate odds of failure. We implemented stepwise backward elimination to select covariates for inclusion in a logistic regression to estimate the odds of TAS failure. Covariates included environmental predictors (aridity, distance to fresh water, elevation, and enhanced vegetation index), cumulative rounds of MDA, measures of urbanicity and access, LF species, and baseline prevalence. Presence of was significantly associated with TAS failure (odds ratio [OR]: 4.79, 95% CI: 2.52-9.07), as was population density (OR: 2.91, 95% CI: 1.06-7.98). The presence of nighttime lights was highly protective against failure (OR: 0.22, 95% CI: 0.10-0.50), as was an increase in elevation (OR: 0.36, 95% CI: 0.18-0.732). This work identifies predictors associated with TAS failure at the EU areal level, given the data presently available, and also identifies the need for more granular data to conduct a more robust assessment of these predictors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4269/ajtmh.18-0721DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6609191PMC
July 2019

Mapping diphtheria-pertussis-tetanus vaccine coverage in Africa, 2000-2016: a spatial and temporal modelling study.

Lancet 2019 May 5;393(10183):1843-1855. Epub 2019 Apr 5.

Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Department of Health Metrics Sciences, University of Washington, Seattle, WA, USA. Electronic address:

Background: Routine childhood vaccination is among the most cost-effective, successful public health interventions available. Amid substantial investments to expand vaccine delivery throughout Africa and strengthen administrative reporting systems, most countries still require robust measures of local routine vaccine coverage and changes in geographical inequalities over time.

Methods: This analysis drew from 183 surveys done between 2000 and 2016, including data from 881 268 children in 49 African countries. We used a Bayesian geostatistical model calibrated to results from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017, to produce annual estimates with high-spatial resolution (5 ×    5 km) of diphtheria-pertussis-tetanus (DPT) vaccine coverage and dropout for children aged 12-23 months in 52 African countries from 2000 to 2016.

Findings: Estimated third-dose (DPT3) coverage increased in 72·3% (95% uncertainty interval [UI] 64·6-80·3) of second-level administrative units in Africa from 2000 to 2016, but substantial geographical inequalities in DPT coverage remained across and within African countries. In 2016, DPT3 coverage at the second administrative (ie, district) level varied by more than 25% in 29 of 52 countries, with only two (Morocco and Rwanda) of 52 countries meeting the Global Vaccine Action Plan target of 80% DPT3 coverage or higher in all second-level administrative units with high confidence (posterior probability ≥95%). Large areas of low DPT3 coverage (≤50%) were identified in the Sahel, Somalia, eastern Ethiopia, and in Angola. Low first-dose (DPT1) coverage (≤50%) and high relative dropout (≥30%) together drove low DPT3 coverage across the Sahel, Somalia, eastern Ethiopia, Guinea, and Angola.

Interpretation: Despite substantial progress in Africa, marked national and subnational inequalities in DPT coverage persist throughout the continent. These results can help identify areas of low coverage and vaccine delivery system vulnerabilities and can ultimately support more precise targeting of resources to improve vaccine coverage and health outcomes for African children.

Funding: Bill & Melinda Gates Foundation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S0140-6736(19)30226-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6497987PMC
May 2019

Slaying little dragons: the impact of the Guinea Worm Eradication Program on dracunculiasis disability averted from 1990 to 2016.

Gates Open Res 2018 Jun 18;2:30. Epub 2018 Jun 18.

Institute for Health Metrics and Evaluation, University of Washington, Seattle, Seattle, WA, USA.

The objective of this study was to document the worldwide decline of dracunculiasis (Guinea worm disease, GWD) burden, expressed as disability-adjusted life years (DALYs), from 1990 to 2016, as estimated in the Global Burden of Disease study 2016 (GBD 2016). While the annual number of cases of GWD have been consistently reported by WHO since the 1990s, the burden of disability due to GWD has not previously been quantified in GBD. The incidence of GWD was modeled for each endemic country using annual national case reports. A literature search was conducted to characterize the presentation of GWD, translate the clinical symptoms into health sequelae, and then assign an average duration to the infection. Prevalence measures by sequelae were multiplied by disability weights to estimate DALYs. The total DALYs attributed to GWD across all endemic countries (n=21) in 1990 was 50,725 (95% UI: 35,265-69,197) and decreased to 0.9 (95% UI: 0.5-1.4) in 2016. A cumulative total of 12,900 DALYs were attributable to GWD from 1990 to 2016. Using 1990 estimates of burden propagated forward, this analysis suggests that between 990,000 to 1.9 million DALYs have been averted as a result of the eradication program over the past 27 years.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12688/gatesopenres.12827.1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6139381PMC
June 2018

Preventive chemotherapy coverage for neglected tropical diseases: does one metric fit all?

Lancet Glob Health 2018 09 24;6(9):e936-e937. Epub 2018 Jul 24.

Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA 98121, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S2214-109X(18)30345-0DOI Listing
September 2018

Estimating the number of cases of podoconiosis in Ethiopia using geostatistical methods.

Wellcome Open Res 2017 4;2:78. Epub 2017 Sep 4.

Wellcome Trust Brighton and Sussex Centre for Global Health Research, Brighton and Sussex Medical School, Brighton, UK.

Background: In 2011, the World Health Organization recognized podoconiosis as one of the neglected tropical diseases. Nonetheless, the number of people with podoconiosis and the geographical distribution of the disease is poorly understood. Based on a nationwide mapping survey and geostatistical modelling, we predict the prevalence of podoconiosis and estimate the number of cases across Ethiopia.

Methods: We used nationwide data collected in Ethiopia between 2008 and 2013. Data were available for 141,238 individuals from 1,442 villages in 775 districts from all nine regional states and two city administrations. We developed a geostatistical model of podoconiosis prevalence among adults (individuals aged 15 years or above), by combining environmental factors. The number of people with podoconiosis was then estimated using a gridded map of adult population density for 2015.

Results: Podoconiosis is endemic in 345 districts in Ethiopia: 144 in Oromia, 128 in Southern Nations, Nationalities and People's [SNNP], 64 in Amhara, 4 in Benishangul Gumuz, 4 in Tigray and 1 in Somali Regional State. Nationally, our estimates suggest that 1,537,963 adults (95% confidence intervals, 290,923-4,577,031 adults) were living with podoconiosis in 2015. Three regions (SNNP, Oromia and Amhara) contributed 99% of the cases. The highest proportion of individuals with podoconiosis resided in the SNNP (39%), while 32% and 29% of people with podoconiosis resided in Oromia and Amhara Regional States, respectively. Tigray and Benishangul Gumuz Regional States bore lower burdens, and in the remaining regions, podoconiosis was almost non-existent.  Discussion: The estimates of podoconiosis cases presented here based upon the combination of currently available epidemiological data and a robust modelling approach clearly show that podoconiosis is highly endemic in Ethiopia. Given the presence of low cost prevention, and morbidity management and disability prevention services, it is our collective responsibility to scale-up interventions rapidly.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12688/wellcomeopenres.12483.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5668927PMC
September 2017

The relationship between entomological indicators of Aedes aegypti abundance and dengue virus infection.

PLoS Negl Trop Dis 2017 03 23;11(3):e0005429. Epub 2017 Mar 23.

Department of Entomology and Nematology, University of California, Davis, Davis, California, United States of America.

Routine entomological monitoring data are used to quantify the abundance of Ae. aegypti. The public health utility of these indicators is based on the assumption that greater mosquito abundance increases the risk of human DENV transmission, and therefore reducing exposure to the vector decreases incidence of infection. Entomological survey data from two longitudinal cohort studies in Iquitos, Peru, linked with 8,153 paired serological samples taken approximately six months apart were analyzed. Indicators of Ae. aegypti density were calculated from cross-sectional and longitudinal entomological data collected over a 12-month period for larval, pupal and adult Ae. aegypti. Log binomial models were used to estimate risk ratios (RR) to measure the association between Ae. aegypti abundance and the six-month risk of DENV seroconversion. RRs estimated using cross-sectional entomological data were compared to RRs estimated using longitudinal data. Higher cross-sectional Ae. aegypti densities were not associated with an increased risk of DENV seroconversion. Use of longitudinal entomological data resulted in RRs ranging from 1.01 (95% CI: 1.01, 1.02) to 1.30 (95% CI: 1.17, 1.46) for adult stage density estimates and RRs ranging from 1.21 (95% CI: 1.07, 1.37) to 1.75 (95% CI: 1.23, 2.5) for categorical immature indices. Ae. aegypti densities calculated from longitudinal entomological data were associated with DENV seroconversion, whereas those measured cross-sectionally were not. Ae. aegypti indicators calculated from cross-sectional surveillance, as is common practice, have limited public health utility in detecting areas or populations at high risk of DENV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0005429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5363802PMC
March 2017

Barriers to successful early infant diagnosis of HIV infection at primary care level in Malawi.

Pediatr Infect Dis J 2015 Mar;34(3):273-5

From the *Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina; †Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi; ‡Department of Pediatrics & Child Health, Queen Elizabeth Central Hospital, Blantyre, Malawi; and §School of Medicine, University of Washington, Seattle, Washington.

HIV-infected women seeking early infant HIV diagnosis (EID) services in Malawi were asked about factors potentially associated with returning for EID results. Many (33.3%) infants failed to complete the EID process because of time and costs required for multiple visits. Infants of mothers receiving antiretroviral treatment were less likely to drop out (adjusted risk ratio 0.51), suggesting that EID completion may improve in programs providing antiretroviral treatment to all pregnant women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/INF.0000000000000625DOI Listing
March 2015

Prevalence of trachoma at sub-district level in ethiopia: determining when to stop mass azithromycin distribution.

PLoS Negl Trop Dis 2014 Mar 13;8(3):e2732. Epub 2014 Mar 13.

The Carter Center, Atlanta, Georgia, United States of America.

Background: To eliminate blinding trachoma, the World Health Organization emphasizes implementing the SAFE strategy, which includes annual mass drug administration (MDA) with azithromycin to the whole population of endemic districts. Prevalence surveys to assess impact at the district level are recommended after at least 3 years of intervention. The decision to stop MDA is based on a prevalence of trachomatous inflammation follicular (TF) among children aged 1-9 years below 5% at the sub-district level, as determined by an additional round of surveys limited within districts where TF prevalence is below 10%. We conducted impact surveys powered to estimate prevalence simultaneously at the sub-district and district in two zones of Amhara, Ethiopia to determine whether MDA could be stopped.

Methodology: Seventy-two separate population-based, sub-district surveys were conducted in 25 districts. In each survey all residents from 10 randomly selected clusters were screened for clinical signs of trachoma. Data were weighted according to selection probabilities and adjusted for correlation due to clustering.

Principal Findings: Overall, 89,735 residents were registered from 21,327 households of whom 72,452 people (80.7%) were examined. The prevalence of TF in children aged 1-9 years was below 5% in six sub-districts and two districts. Sub-district level prevalence of TF in children aged 1-9 years ranged from 0.9-76.9% and district-level from 0.9-67.0%. In only one district was the prevalence of trichiasis below 0.1%.

Conclusions/significance: The experience from these zones in Ethiopia demonstrates that impact assessments designed to give a prevalence estimate of TF at sub-district level are possible, although the scale of the work was challenging. Given the assessed district-level prevalence of TF, sub-district-level surveys would have been warranted in only five districts. Interpretation was not as simple as stopping MDA in sub-districts below 5% given programmatic challenges of exempting sub-districts from a highly regarded program and the proximity of hyper-endemic sub-districts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0002732DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3953063PMC
March 2014

Validity of US norms for the Bayley Scales of Infant Development-III in Malawian children.

Eur J Paediatr Neurol 2014 Mar 31;18(2):223-30. Epub 2013 Dec 31.

Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA. Electronic address:

Objective: Most psychometric tests originate from Europe and North America and have not been validated in other populations. We assessed the validity of United States (US)-based norms for the Bayley Scales of Infant and Toddler Development-III (BSID-III), a neurodevelopmental tool developed for and commonly used in the US, in Malawian children.

Methods: We constructed BSID-III norms for cognitive, fine motor (FM), gross motor (GM), expressive communication (EC) and receptive communication (RC) subtests using 5173 tests scores in 167 healthy Malawian children. Norms were generated using Generalized Additive Models for location, scale and shape, with age modeled continuously. Standard z-scores were used to classify neurodevelopmental delay. Weighted kappa statistics were used to compare the classification of neurological development using US-based and Malawian norms.

Results: For all subtests, the mean raw scores in Malawian children were higher than the US normative scores at younger ages (approximately <6 months) after which the mean curves crossed and the US normative mean exceeded that of the Malawian sample and the age at which the curves crossed differed by subtest. Weighted kappa statistics for agreement between US and Malawian norms were 0.45 for cognitive, 0.48 for FM, 0.57 for GM, 0.50 for EC, and 0.44 for RC.

Conclusion: We demonstrate that population reference curves for the BSID-III differ depending on the origin of the population. Reliance on US norm-based standardized scores resulted in misclassification of the neurological development of Malawian children, with the greatest potential for bias in the measurement of cognitive and language skills.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejpn.2013.11.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4019333PMC
March 2014

Trachoma prevalence in Niger: results of 31 district-level surveys.

Trans R Soc Trop Med Hyg 2014 Jan 25;108(1):42-8. Epub 2013 Nov 25.

The Carter Center, Trachoma Control Program, 1149 Ponce de Leon, Atlanta GA 30306, USA.

Background: The leading cause of preventable blindness worldwide is trachoma, a condition caused by an infection of the inner eyelid. In Niger, a landlocked republic in Western Africa, surveys in 1988-89 identified trachoma as endemic in all but one region and, as a result, there is a National Prevention of Blindness Program plan to eliminate trachoma by 2015.

Methods: Thirty-one districts in eastern and western Niger were surveyed for trachoma prevalence from May 2009 to March 2012 as part of routine program impact evaluations. Prevalence surveys were implemented independently in each district using a two-stage cluster random design. Probability proportional to size was used to randomly select villages and 25 households were selected in each cluster. The prevalence of trachoma of clinical grade trachomatous follicular (TF) was estimated in children aged 1-9 years, and the prevalence of blinding trachoma, trachomatous trichiasis (TT), was measured in adults aged ≥15 years.

Results: A total of 14 211 households was surveyed; 58 617 individuals were evaluated for clinical signs of trachoma, of whom 27 087 were children aged 1-9 years. District-wide implementation of the full SAFE strategy is warranted in 16 districts where TF prevalence exceeds 10% and targeted implementation of the SAFE strategy (surgery for trichiasis; antibiotic therapy to control transmission; facial cleanliness for hygiene promotion; environmental change for improvements in access to water and sanitation) is recommended in the remaining 15 districts. The prevalence of TT among adults exceeded 1% in nine districts, suggesting that surgical services to treat TT should be implemented district-wide.

Conclusions: These results establish the need for continued SAFE strategy implementation throughout Niger.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/trstmh/trt101DOI Listing
January 2014

Trachoma among children in community surveys from four African countries and implications of using school surveys for evaluating prevalence.

Int Health 2013 Dec 30;5(4):280-7. Epub 2013 Oct 30.

The Carter Center, 1149 Ponce de Leon Ave, Atlanta, GA 30306, USA.

Background: School surveys provide a convenient platform to obtain large child cohorts from multiple communities and are widely used as a proxy to determine community prevalence of neglected tropical diseases. The purpose of this study was to compare trachoma prevalence between preschool- and school-aged children and children who attend and do not attend school.

Methods: We analysed data from community-based trachoma surveys conducted from 2008-2011 in Ethiopia, Mali, Niger and Nigeria. The surveys utilised a cross-sectional, randomised cluster design. Individual-level data on school attendance was collected.

Results: Overall, 75 864 children aged 1-15 years from 2100 communities were included in the analysis. The prevalence of trachomatous inflammation follicular (TF) among these children in surveyed districts was 19.1% (95% CI 17.9-20.2%) in Ethiopia, 6.2% (95% CI 5.4-6.9%) in Niger, 4.6% (95% CI 4.2-4.9%) in Mali and 4.2% (95% CI 3.5-4.9%) in Nigeria. Controlling for age, sex and clustering, the OR of TF for school-attendees compared to non-attendees was 0.64 (95% CI 0.56-0.73) in Ethiopia, 0.67 (95% CI 0.56-0.80) in Mali, 1.03 (95% CI 0.81-1.16) in Niger and 1.06, (95% CI 0.65-1.73) in Nigeria.

Conclusion: Estimating the prevalence of trachoma through examination of only school-going children risks underestimating the true prevalence.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/inthealth/iht027DOI Listing
December 2013

A novel electronic data collection system for large-scale surveys of neglected tropical diseases.

PLoS One 2013 16;8(9):e74570. Epub 2013 Sep 16.

The Carter Center, Atlanta, Georgia, United States of America ; Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland ; University of Basel, Basel, Switzerland.

Background: Large cross-sectional household surveys are common for measuring indicators of neglected tropical disease control programs. As an alternative to standard paper-based data collection, we utilized novel paperless technology to collect data electronically from over 12,000 households in Ethiopia.

Methodology: We conducted a needs assessment to design an Android-based electronic data collection and management system. We then evaluated the system by reporting results of a pilot trial and from comparisons of two, large-scale surveys; one with traditional paper questionnaires and the other with tablet computers, including accuracy, person-time days, and costs incurred.

Principle Findings: The electronic data collection system met core functions in household surveys and overcame constraints identified in the needs assessment. Pilot data recorders took 264 (standard deviation (SD) 152 sec) and 260 sec (SD 122 sec) per person registered to complete household surveys using paper and tablets, respectively (P = 0.77). Data recorders felt a lack of connection with the interviewee during the first days using electronic devices, but preferred to collect data electronically in future surveys. Electronic data collection saved time by giving results immediately, obviating the need for double data entry and cross-correcting. The proportion of identified data entry errors in disease classification did not differ between the two data collection methods. Geographic coordinates collected using the tablets were more accurate than coordinates transcribed on a paper form. Costs of the equipment required for electronic data collection was approximately the same cost incurred for data entry of questionnaires, whereas repeated use of the electronic equipment may increase cost savings.

Conclusions/significance: Conducting a needs assessment and pilot testing allowed the design to specifically match the functionality required for surveys. Electronic data collection using an Android-based technology was suitable for a large-scale health survey, saved time, provided more accurate geo-coordinates, and was preferred by recorders over standard paper-based questionnaires.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0074570PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3774718PMC
May 2014

The geographical distribution and burden of trachoma in Africa.

PLoS Negl Trop Dis 2013 8;7(8):e2359. Epub 2013 Aug 8.

London School of Hygiene and Tropical Medicine, London, United Kingdom.

Background: There remains a lack of epidemiological data on the geographical distribution of trachoma to support global mapping and scale up of interventions for the elimination of trachoma. The Global Atlas of Trachoma (GAT) was launched in 2011 to address these needs and provide standardised, updated and accessible maps. This paper uses data included in the GAT to describe the geographical distribution and burden of trachoma in Africa.

Methods: Data assembly used structured searches of published and unpublished literature to identify cross-sectional epidemiological data on the burden of trachoma since 1980. Survey data were abstracted into a standardised database and mapped using geographical information systems (GIS) software. The characteristics of all surveys were summarized by country according to data source, time period, and survey methodology. Estimates of the current population at risk were calculated for each country and stratified by endemicity class.

Results: At the time of writing, 1342 records are included in the database representing surveys conducted between 1985 and 2012. These data were provided by direct contact with national control programmes and academic researchers (67%), peer-reviewed publications (17%) and unpublished reports or theses (16%). Prevalence data on active trachoma are available in 29 of the 33 countries in Africa classified as endemic for trachoma, and 1095 (20.6%) districts have representative data collected through population-based prevalence surveys. The highest prevalence of active trachoma and trichiasis remains in the Sahel area of West Africa and Savannah areas of East and Central Africa and an estimated 129.4 million people live in areas of Africa confirmed to be trachoma endemic.

Conclusion: The Global Atlas of Trachoma provides the most contemporary and comprehensive summary of the burden of trachoma within Africa. The GAT highlights where future mapping is required and provides an important planning tool for scale-up and surveillance of trachoma control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0002359DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3738464PMC
February 2014

Correlation between dengue-specific neutralizing antibodies and serum avidity in primary and secondary dengue virus 3 natural infections in humans.

PLoS Negl Trop Dis 2013 13;7(6):e2274. Epub 2013 Jun 13.

Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, California, United States of America.

Although heterotypic secondary infection with dengue virus (DENV) is associated with severe disease, the majority of secondary infections are mild or asymptomatic. The mechanisms of antibody-mediated protection are poorly understood. In 2010, 108 DENV3-positive cases were enrolled in a pediatric hospital-based study in Managua, Nicaragua, with 61 primary and 47 secondary infections. We analyzed DENV-specific neutralization titers (NT50), IgM and IgG avidity, and antibody titer in serum samples collected during acute and convalescent phases and 3, 6, and 18 months post-infection. NT50 titers peaked at convalescence and decreased thereafter. IgG avidity to DENV3 significantly increased between convalescent and 3-month time-points in primary DENV infections and between the acute and convalescent phase in secondary DENV infections. While avidity to DENV2, a likely previous infecting serotype, was initially higher than avidity to DENV3 in secondary DENV infections, the opposite relation was observed 3-18 months post-infection. We found significant correlations between IgM avidity and NT50 in acute primary cases and between IgG avidity and NT50 in secondary DENV infections. In summary, our findings indicate that IgM antibodies likely play a role in early control of DENV infections. IgG serum avidity to DENV, analyzed for the first time in longitudinal samples, switches from targeting mainly cross-reactive serotype(s) to the current infecting serotype over time. Finally, serum avidity correlates with neutralization capacity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0002274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3681624PMC
December 2013

Monitoring of mass distribution interventions for trachoma in Plateau State, Nigeria.

PLoS Negl Trop Dis 2013 10;7(1):e1995. Epub 2013 Jan 10.

The Carter Center, Atlanta, Georgia, United States of America.

Mass drug administration (MDA) with antibiotics is a key component of the SAFE strategy for trachoma control. Guidelines recommend that where MDA is warranted the whole population be targeted with 80% considered the minimum acceptable coverage. In other countries, MDA is usually conducted by salaried Ministry of Health personnel (MOH). In Plateau State, Nigeria, the existing network of volunteer Community Directed Distributors (CDD) was used for the first trachoma MDA. We conducted a population-based cluster random survey (CRS) of MDA participation to determine the true coverage and compared this to coverage reported from CDD registers. We surveyed 1,791 people from 352 randomly selected households in 24 clusters in three districts in Plateau State in January 2011, following the implementation of MDA. Households were enumerated and all individuals present were asked about MDA participation. Household heads were questioned about household-level characteristics and predictors of participation. Individual responses were compared with the CDD registers. MDA coverage was estimated as 60.3% (95% CI 47.9-73.8%) by the survey compared with 75.8% from administrative program reports. CDD registration books for comparison with responses were available in 19 of the 24 clusters; there was a match for 658/682 (96%) of verifiable responses. CDD registers did not list 481 (41.3%) of the individuals surveyed. Gender and age were not associated with individual participation. Overall MDA coverage was lower than the minimum 80% target. The observed discrepancy between the administrative coverage estimate from program reports and the CRS was largely due to identification of communities missed by the MDA and not reported in the registers. CRS for evaluation of MDA provides a useful additional monitoring tool to CDD registers. These data support modification of distributor training and MDA delivery to increase coverage in subsequent rounds of MDA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0001995DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3542118PMC
June 2013

Methods for estimating population coverage of mass distribution programmes: a review of practices in relation to trachoma control.

Trans R Soc Trop Med Hyg 2012 Oct 9;106(10):588-95. Epub 2012 Aug 9.

The Carter Center, Atlanta, GA, USA.

In the context of trachoma control, population coverage with mass drug administration (MDA) using antibiotics is measured using routine data. Due to the limitations of administrative records as well as the potential for bias from incomplete or incorrect records, a literature review of coverage survey methods applied in neglected tropical disease control programmes and immunisation outreach was conducted to inform the design of coverage surveys for trachoma control. Several methods were identified, including the '30 × 7' survey method for the Expanded Programme on Immunization (EPI 30×7), other cluster random sampling (CRS) methods, lot quality assurance sampling (LQAS), purposive sampling and routine data. When compared against one another, the EPI and other CRS methods produced similar population coverage estimates, whilst LQAS, purposive sampling and use of administrative data did not generate estimates consistent with CRS. In conclusion, CRS methods present a consistent approach for MDA coverage surveys despite different methods of household selection. They merit use until standard guidelines are available. CRS methods should be used to verify population coverage derived from LQAS, purposive sampling methods and administrative reports.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trstmh.2012.07.011DOI Listing
October 2012

Evaluation of household latrine coverage in Kewot woreda, Ethiopia, 3 years after implementing interventions to control blinding trachoma.

Int Health 2011 Dec;3(4):251-8

Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, GA 30322, USA.

The SAFE strategy for trachoma control includes Surgery, Antibiotic distribution, Facial cleanliness and Environmental improvements, including promotion of latrine construction. In this study, household latrine coverage was estimated in order to evaluate SAFE implementation in a district of Ethiopia where reported coverage in rural areas was 97%. Characteristics of latrine adopters and non-adopters were explored. Interviews were conducted in 442 households selected at random in a multistage cluster sample. Overall, estimated household latrine coverage was 56.2% (95% CI 37.5-74.8%) and in rural areas coverage was 67.7% (95% CI 59.6-75.7%). Previously owning a latrine was reported by 12.7% (95% CI 8.9-16.5%) of respondents, of which 32.0% (95% CI 15.9-48.2%) had built a replacement. Latrine adopters were more likely to be male (P < 0.0001), to report their primary occupation as agriculture (P < 0.0001), have more than five residents in their household (P = 0.004) and live in a rural area (P < 0.0001). Respondents who were advised by a health extension worker (P < 0.0001) or development agent (P < 0.0001) were more likely to have built a latrine. Household latrine coverage has increased from the 2007 zonal estimate (8.9%), but was lower than that reported. Latrine promotion should include emphasis on rebuilding latrines. More support may be needed by small households as well as those with a female head if universal latrine access is to be achieved in Kewot.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.inhe.2011.06.007DOI Listing
December 2011

The prevalence of blinding trachoma in northern states of Sudan.

PLoS Negl Trop Dis 2011 31;5(5):e1027. Epub 2011 May 31.

Federal Ministry of Health, Khartoum, Sudan.

Background: Despite historical evidence of blinding trachoma, there have been no widespread contemporary surveys of trachoma prevalence in the northern states of Sudan. We aimed to conduct district-level surveys in this vast region in order to map the extent of the problem and estimate the need for trachoma control interventions to eliminate blinding trachoma.

Methods And Findings: Separate, population based cross-sectional surveys were conducted in 88 localities (districts) in 12 northern states of Sudan between 2006 and 2010. Two-stage cluster random sampling with probability proportional to size was used to select the sample. Trachoma grading was done using the WHO simplified grading system. Key prevalence indicators were trachomatous inflammation-follicular (TF) in children aged 1-9 years and trachomatous trichiasis (TT) in adults aged 15 years and above. The sample comprised 1,260 clusters from which 25,624 households were surveyed. A total of 106,697 participants (81.6% response rate) were examined for trachoma signs. TF prevalence was above 10% in three districts and between 5% and 9% in 11 districts. TT prevalence among adults was above 1% in 20 districts (which included the three districts with TF prevalence >10%). The overall number of people with TT in the population was estimated to be 31,072 (lower and upper bounds = 26,125-36,955).

Conclusion: Trachoma mapping is complete in the northern states of Sudan except for the Darfur States. The survey findings will facilitate programme planning and inform deployment of resources for elimination of trachoma from the northern states of Sudan by 2015, in accordance with the Sudan Federal Ministry of Health (FMOH) objectives.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0001027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3104955PMC
September 2011

Incremental cost of conducting population-based prevalence surveys for a neglected tropical disease: the example of trachoma in 8 national programs.

PLoS Negl Trop Dis 2011 Mar 8;5(3):e979. Epub 2011 Mar 8.

Georgia Institute of Technology, Atlanta, Georgia, USA.

Background: Trachoma prevalence surveys provide the evidence base for district and community-wide implementation of the SAFE strategy, and are used to evaluate the impact of trachoma control interventions. An economic analysis was performed to estimate the cost of trachoma prevalence surveys conducted between 2006 and 2010 from 8 national trachoma control programs in Africa.

Methodology And Findings: Data were collected retrospectively from reports for 165 districts surveyed for trachoma prevalence using a cluster random sampling methodology in Ethiopia, Ghana, Mali, Niger, Nigeria, Sudan, Southern Sudan and The Gambia. The median cost per district survey was $4,784 (inter-quartile range [IQR] = $3,508-$6,650) while the median cost per cluster was $311 (IQR = $119-$393). Analysis by cost categories (personnel, transportation, supplies and other) and cost activity (training, field work, supervision and data entry) revealed that the main cost drivers were personnel and transportation during field work.

Conclusion: Population-based cluster random surveys are used to provide the evidence base to set objectives and determine when elimination targets have been reached for several neglected tropical diseases, including trachoma. The cost of conducting epidemiologically rigorous prevalence surveys should not be a barrier to program implementation or evaluation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pntd.0000979DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3050919PMC
March 2011

Randomised trial of face-washing to develop a standard definition of a clean face for monitoring trachoma control programmes.

Trans R Soc Trop Med Hyg 2011 Jan 30;105(1):7-16. Epub 2010 Oct 30.

The Carter Center, One Copenhill, Atlanta, GA 30307, USA.

Surgery, antibiotics, facial cleanliness and environmental improvements (SAFE) are recommended for trachoma control. Programmes assess clean faces in children, but no standard definition of a clean face exists. We conducted a randomised controlled trial of face-washing to develop a valid and repeatable definition of a clean face. A total of 424 children were randomised to washed and unwashed groups after a first observation. Three additional observations were made throughout the day. Photographs were taken at each observation. No difference was observed in wet nasal discharge, dust, food or flies on the face between the face washed and unwashed groups at baseline or after washing. A difference was observed in the presence of ocular discharge (P < 0.001) and dry nasal discharge (P < 0.001) after washing. Agreement among observers was highest for flies (Kappa = 0.89, 95% CI = 0.87-0.91), followed by nasal (Kappa = 0.64, 0.62-0.66) and ocular (Kappa = 0.48, 0.46-0.50) discharge. The ability of any definition to identify whether a face had been washed decreased at each observation. This study suggests that the absence of ocular and dry nasal discharge can be used as an indicator of 'clean face', although it is not a good predictor of whether a face has been washed and is difficult to recommend.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trstmh.2010.09.008DOI Listing
January 2011

Effect of a community intervention with pit latrines in five districts of Amhara, Ethiopia.

Trop Med Int Health 2010 May 16;15(5):592-9. Epub 2010 Mar 16.

Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Cambridge, UK.

Objective: To evaluate the change in household latrine coverage and investigated predictors of latrine uptake after 3 years of implementation of trachoma control interventions in Dera, Ebinat, Estie, Enebsie Sarmedir and Huleteju Enese districts of Amhara, Ethiopia.

Methods: Before and after study, baseline surveys were conducted prior to programme implementation and an evaluation after 3 years of interventions. Multi-stage cluster random sampling was used in both surveys.

Results: A total of 1096 and 1117 households were sampled and assessed for the presence of household latrines at baseline and evaluation, respectively. The proportion of households with a pit latrine increased by 32.3% overall (95% confidence interval [CI]: 27.9-38.0), ranging from 8.0% (95% CI: 5.1-10.8) in Ebinat to 58.9% (95% CI: 51.9-66.8) in Enebsie Sarmedir. Logistic regression analysis of associations between household latrine ownership and potential factors showed that increasing household size (OR(per additional person) = 1.2[95% CI: 1.1-1.3]), higher socio-economic status (tin roof) (OR = 1.8[95% CI: 1.2-2.9]) and participation in health education (OR = 1.6[95% CI: 1.1-2.5]) were independent predictors of latrine ownership.

Conclusion: Our study documented heterogeneous increase in household latrine coverage after 3 years of latrine promotion; two of five districts had achieved Millennium Development Goal 7.9 and halved the proportion of households without latrine access. We attribute the striking increase in household latrines to increased political commitment of the local government and intensive community mobilisation under the trachoma control programme in Amhara region.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1365-3156.2010.02500.xDOI Listing
May 2010

Estimation of population coverage for antibiotic distribution for trachoma control: a comparison of methods.

Int Health 2009 Dec;1(2):182-9

The Carter Center, 1 Copenhill Avenue, Atlanta, Georgia, USA.

Trachoma control includes mass drug administration (MDA) with antibiotics targeting coverage of at least 80%. Coverage is traditionally calculated by dividing doses distributed by population estimate, which is unreliable. We compared a verifiable coverage assessment method against self-reported participation and the traditional calculation, and examined factors associated with MDA participation in Akobo County, Southern Sudan. During MDA, recipients were marked with indelible ink and followed-up using a two-stage household survey: 25 clusters from three districts, and 10 households per cluster. All household members were enumerated; asked about self-reported participation and observed for indelible marks. Household heads were interviewed to assess factors associated with MDA. Overall 11 419 treatments were given and 1358 residents from 247 households surveyed. By traditional methods MDA coverage was 20.9% (95% CI: 20.6-21.3); 61.5% (95 % CI: 49.4-73.6) by self-reporting; and 37.5% (95% CI: 25.1%-49.9%) from observed ink marks. Controlling for other factors, presence of a health worker (OR 2.3, 95% CI: 1.5-3.6); head of household knowledge of azithromycin (OR 1.6, 95% CI: 1.5-3.1); and head of household advance notice of MDA (OR 34.9, 18.1-66.3) were independent predictors of participation. Cluster randomised surveys can estimate MDA coverage better than the traditional method and implementation of indelible marking merits investigation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.inhe.2009.09.002DOI Listing
December 2009

Evaluation of community intervention with pit latrines for trachoma control in Ghana, Mali, Niger and Nigeria.

Int Health 2009 Dec;1(2):154-62

The Carter Center, 1 Copenhill Avenue, Atlanta, GA 30307, USA.

Trachoma is the leading cause of preventable blindness worldwide and is controlled with an integrated strategy of treatment and prevention which includes latrine provision and promotion. We aimed to evaluate the latrine uptake, construction, and usage in villages participating in latrine promotion programmes supported by The Carter Center in Ghana, Mali, Niger and Nigeria where 113 457 new latrines have been reported from 2002 to 2008. In each country a two stage cluster random sampling design was used to select villages and households for evaluation. Household heads were interviewed using a standardised structured questionnaire and latrines were inspected. The sample included 1154 households (Ghana: 326; Mali: 293; Niger: 300; and Nigeria: 235). Overall, 813 (70.5%, 95% confidence interval [CI] 65.7-74.8) had pit latrines, ranging from 30.3% of households in Niger to over 92.0% of households in Ghana and Mali. Of those with latrines 762 (93.7%) were found to be usable and 659 (86.5%) were in use. Overall 659/1154 (57.1%) of households in the targeted communities were using latrines at least 12 months after latrine promotion was initiated. Latrine promotion had been successful increasing access to sanitation in different country contexts and demonstrates the target population are willing to construct, use and maintain household latrines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.inhe.2009.08.001DOI Listing
December 2009

Estimation of effects of community intervention with antibiotics, facial cleanliness, and environmental improvement (A,F,E) in five districts of Ethiopia hyperendemic for trachoma.

Br J Ophthalmol 2010 Mar 5;94(3):278-81. Epub 2009 Nov 5.

Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge, Cambridge, UK.

Aims: The WHO recommends the SAFE (surgery, antibiotics, facial cleanliness and environmental improvement) strategy for trachoma control. We aimed to investigate the association between active trachoma and community intervention with antibiotics, facial cleanliness, environmental improvement (A,F,E) components of SAFE in five trachoma hyperendemic districts of Amhara region, Ethiopia.

Methods: Cluster random surveys were undertaken to evaluate SAFE following 3 years of interventions. Children aged 1-9 years were examined for trachoma signs using the WHO simplified grading system and structured questionnaires used to assess uptake of A, F and E. Active trachoma signs (trachomatous inflammation-follicular (TF) and trachomatous inflammation-intense (TI)) were used to derive an ordinal severity score where TI was considered more severe than TF. Associations between active trachoma and potential factors were investigated using ordinal logistic multilevel regression models.

Results: A total of 1813 children aged 1-9 years were included in the analysis. Factors independently associated with reduced odds of active trachoma signs were: number of times treated with azithromycin (p-trend=0.026); months since last mass azithromycin distribution (p-trend<0.001); clean face (OR=0.6; 95% CI 0.5 to 0.8); and household pit latrine (OR=0.8; 95% CI 0.7 to 0.9).

Conclusion: These findings are important, since they make the case for continued implementing the A,F,E interventions simultaneously, and suggest appropriate timing of SAFE evaluations within 6-12 months after the last mass azithromycin distribution.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bjo.2009.168260DOI Listing
March 2010

The excess burden of trachomatous trichiasis in women: a systematic review and meta-analysis.

Trans R Soc Trop Med Hyg 2009 Oct 10;103(10):985-92. Epub 2009 Apr 10.

The Carter Center, 1 Copenhill, 453 Freedom Parkway, Atlanta, GA 30307, USA.

It is widely accepted that women carry an increased burden of trachomatous trichiasis compared with men, but there is no systematic review of the available prevalence surveys in the peer-reviewed literature. A literature search was conducted to identify population-based trachoma prevalence surveys utilising the WHO simplified grading system that included data for trichiasis. Of 53 identified studies, 24 studies from 12 different countries met the inclusion criteria. Prevalence data were pooled in a meta-analysis to estimate an overall odds ratio (OR). The overall odds of trichiasis in women compared with men was 1.82 (95% CI 1.61-2.07). Individual survey ORs ranged from 0.83 (95% CI 0.40-1.73) in Myanmar to 3.82 (95% CI 2.36-6.19) in Ethiopia. There were statistically significant differences in odds of trichiasis by gender in 17 of 24 studies, all of which showed increased odds of trichiasis in women compared with men. These data confirm the perception that women have a greater burden of trichiasis, and this burden persists across all populations studied. Women must be specifically and deliberately targeted for trichiasis surgery if the aim of eliminating blindness from trachoma is to be achieved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.trstmh.2009.03.012DOI Listing
October 2009
-->