Danny Haddad

The Global Trachoma Mapping Project: Methodology of a 34-Country Population-Based Study

ABSTRACT Purpose: To complete the baseline trachoma map worldwide by conducting population-based surveys in an estimated 1238 suspected endemic districts of 34 countries. Methods: A series of national and sub-national projects owned, managed and staffed by ministries of health, conduct house-to-house cluster random sample surveys in evaluation units, which generally correspond to “health district” size: populations of 100,000–250,000 people. In each evaluation unit, we invite all residents aged 1 year and older from h households in each of c clusters to be examined for clinical signs of trachoma, where h is the number of households that can be seen by 1 team in 1 day, and the product h × c is calculated to facilitate recruitment of 1019 children aged 1–9 years. In addition to individual-level demographic and clinical data, household-level water, sanitation and hygiene data are entered into the purpose-built LINKS application on Android smartphones, transmitted to the Cloud, and cleaned, analyzed and ministry-of-health-approved via a secure web-based portal. The main outcome measures are the evaluation unit-level prevalence of follicular trachoma in children aged 1–9 years, prevalence of trachomatous trichiasis in adults aged 15 + years, percentage of households using safe methods for disposal of human feces, and percentage of households with proximate access to water for personal hygiene purposes. Results: In the first year of fieldwork, 347 field teams commenced work in 21 projects in 7 countries. Conclusion: With an approach that is innovative in design and scale, we aim to complete baseline mapping of trachoma throughout the world in 2015.

Mapping the Global Distribution of Trachoma: Why an Updated Atlas Is Needed

Trachoma is the leading infectious cause of blindness worldwide, and responsible for the loss of an estimated 1.3 million disability-adjusted life years, mainly in sub-Saharan Africa [1]. Geographically, trachoma is a greater public health risk in dry, dusty, and hot settings, where poor, rural communities suffer a disproportionate burden of disease. Trachoma is caused by infection with the bacterium Chlamydia trachomatis, but the condition has a number of clinical manifestations that are the consequences of current or past infection [2]. Prevalence of infection and clinical signs of follicular conjunctivitis are highest in children under 10 y of age. Recurrent episodes of infection and associated inflammation can cause scarring, visual impairment, and potential blindness later in life. In 1998, the World Health Organization (WHO) established an international alliance eliminate trachoma as a public health problem by 2020, called the Alliance for Global Elimination of Trachoma by the year 2020 (GET2020). The goal of GET2020 is to reduce the burden of trachoma in any community to less than one case of trachomatous trichiasis (TT) per 1,000 total population, and to less than 5% prevalence of “trachomatous inflammation–follicular” (TF) in children aged 1–9 y [3]. The strategy employed to reach these targets is based on a combination of interventions known as SAFE: Surgery to correct trichiasis, Antibiotics for C. trachomatis infection, Facial cleanliness, and Environmental improvement to reduce transmission. In order to allow time for programme implementation and impact by 2020, it will be necessary to scale up to full SAFE implementation in all endemic districts by 2015. An essential component of this effort is producing up-to-date and accessible maps of the distribution of trachoma for advocacy, planning, and operational research purposes.

The Geographical Distribution and Burden of Trachoma in Africa

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.

Prevalence of Trachoma in Unity State, South Sudan: Results from a Large-Scale Population-Based Survey and Potential Implications for Further Surveys

Background Large parts of South Sudan are thought to be trachoma-endemic but baseline data are limited. This study aimed to estimate prevalence for planning trachoma interventions in Unity State, to identify risk factors and to investigate the effect of different sampling approaches on study conclusions. Methods and Findings The survey area was defined as one domain of eight counties in Unity State. Across the area, 40 clusters (villages) were randomly selected proportional to the county population size in a population-based prevalence survey. The simplified grading scheme was used to classify clinical signs of trachoma. The unadjusted prevalence of trachoma inflammation-follicular (TF) in children aged 1–9 years was 70.5% (95% CI: 68.6–72.3). After adjusting for age, sex, county and clustering of cases at household and village level the prevalence was 71.0% (95% CI: 69.9–72.1). The prevalence of trachomatous trichiasis (TT) in adults was 15.1% (95% CI: 13.4–17.0) and 13.5% (95% CI: 12.0–15.1) before and after adjustment, respectively. We estimate that 700,000 people (the entire population of Unity State) require antibiotic treatment and approximately 54,178 people require TT surgery. Risk factor analyses confirmed child-level associations with TF and highlighted that older adults living in poverty are at higher risk of TT. Conditional simulations, testing the alternatives of sampling 20 or 60 villages over the same area, indicated that sampling of only 20 villages would have provided an acceptable level of precision for state-level prevalence estimation to inform intervention decisions in this hyperendemic setting. Conclusion Trachoma poses an enormous burden on the population of Unity State. Comprehensive control is urgently required to avoid preventable blindness and should be initiated across the state now. In other parts of South Sudan suspected to be highly trachoma endemic, counties should be combined into larger survey areas to generate the baseline data required to initiate interventions.

Mass Drug Administration for Trachoma: How Long Is Not Long Enough?

Background Blinding trachoma is targeted for elimination by 2020 using the SAFE strategy (Surgery, Antibiotics, Facial cleanliness, and Environmental improvements). Annual mass drug administration (MDA) with azithromycin is a cornerstone of this strategy. If baseline prevalence of clinical signs of trachomatous inflammation – follicular among 1-9 year-olds (TF1-9) is ≥10% but <30%, the World Health Organization guidelines are for at least 3 annual MDAs; if ≥30%, 5. We assessed the likelihood of achieving the global elimination target of TF1-9 <5% at 3 and 5 year evaluations using program reports. Methodology/Principal Findings We used the International Trachoma Initiative’s prevalence and treatment database. Of 283 cross-sectional survey pairs with baseline and follow-up data, MDA was conducted in 170 districts. Linear and logistic regression modeling was applied to these to investigate the effect of MDA on baseline prevalence. Reduction to <5% was less likely, though not impossible, at higher baseline TF1-9 prevalences. Increased number of annual MDAs, as well as no skipped MDAs, were significant predictors of reduced TF1-9 at follow-up. The probability of achieving the <5% target was <50% for areas with ≥30% TF1-9 prevalence at baseline, even with 7 or more continuous annual MDAs. Conclusions Number of annual MDAs alone appears insufficient to predict program progress; more information on the effects of baseline prevalence, coverage, and underlying environmental and hygienic conditions is needed. Programs should not skip MDAs, and at prevalences >30%, 7 or more annual MDAs may be required to achieve the target. There are five years left before the 2020 deadline to eliminate blinding trachoma. Low endemic settings are poised to succeed in their elimination goals. However, newly-identified high prevalence districts warrant immediate inclusion in the global program. Intensified application of the SAFE strategy is needed in order to guarantee blinding trachoma elimination by 2020.

Global challenges in the management of congenital cataract: proceedings of the 4th International Congenital Cataract Symposium held on March 7, 2014, New York, New York.

Childhood cataracts have become a leading cause of preventable childhood blindness in many areas of the world. Here we summarize regional focus group discussions from the 4th Annual International Congenital Cataract Symposium on the current situation, challenges, and recommendations for the management of congenital cataracts in sub-Saharan Africa, the Middle East and North Africa, South Asia, Central America, South America, and developed nations. Strategies for managing congenital cataracts must be adapted and developed according to regional conditions. A basic framework for acceptable outcomes must focus on developing systems to address the critical components of education, access, quality care, and good follow-up.

Integrating Data and Resources on Neglected Tropical Diseases for Better Planning: The NTD Mapping Tool (NTDmap.org)

Neglected tropical diseases (NTDs) affect more than 1,000,000,000 poor and marginalized people worldwide [1]. NTDs are caused by diverse pathogens with differing modes of transmission and a range of vectors and intermediate hosts, which have their own ecological peculiarities. While there is considerable overlap in the geographical distribution of different NTDs at a national level [1], epidemiological differences of individual NTDs give rise to marked geographical variation at local levels. Since cost-effectiveness of intervention is greatest when targeted to areas having a high burden of multiple diseases, maps of the distribution of the different NTDs are essential for planning and implementing NTD interventions, as well as for providing visualization of program progress, so important for advocacy. In recent years there have been concerted, and very successful, efforts to develop detailed information resources on the geographical distribution of different NTDs (Table 1). Table 1 Currently available resources on the geographical distribution of NTDs. An important element of targeted NTD intervention is the delivery of mass drug administration (MDA) for treating the five major “preventive chemotherapy” NTDs, including lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminths (STH), and trachoma [2]. MDAs targeting these NTDs are implemented alongside improvements in water and sanitation and hygienic behavior, as well as vector control. To help galvanize such global health efforts, the World Health Organization (WHO) and the NTD community defined targets to be achieved by 2020 and strategies to reach these targets (Table 2). As countries make progress towards the 2020 goals with an ever-increasing amount of data being collected, it is important to develop readily accessible tools that policymakers and program staff and partners can use to access, visualize, and compare data. Table 2 The five main NTDs and the drugs and strategies used to target them programmatically. In this Innovation to Application article, we describe the creation of an innovative NTD mapping tool (www.ntdmap.org) developed by a consortium of research and program partners for use particularly by program implementers. Its functionality and accessibility have been designed specifically to meet the needs of national programs and international partners. This tool provides an online resource allowing users to visualize and manipulate geographical data on a range of variables for the planning and managing of integrated NTD programs.

From River Blindness to Neglected Tropical Diseases—Lessons Learned in Africa for Programme Implementation and Expansion by the Non-governmental Partners

After more than 20 years of action against some of the most debilitating neglected tropical diseases (NTDs), lessons have been learned by the non-governmental development organisations (NGDOs) in the light of changes in programme strategies and partnerships. This article aims to summarise the development of the non-governmental networks supporting the NTD programmes, starting with the original 1992 model to combat onchocerciasis (river blindness), and will review the lessons learned that have equipped the NGDOs to step up their support to NTD control and elimination. At the beginning of the 1990s, a small group of seven NGDOs began to work together to support onchocerciasis control [1]. Today, more than 50 international and national NGDOs (of which 30 collaborate at the international level) work together to control or eliminate five priority NTDs affecting more than one billion of the poorest people [2]. This is a significant contribution to the objectives of World Health Assembly resolutions and the London Declaration on NTDs [3], as well as addressing Millennium Development Goal (MDG) 1, “Eradicate extreme poverty and hunger;” MDG 6 “Combat HIV/AIDS, malaria, and other diseases;” and MDG 8, “Develop a global partnership for development.” In 2013, the first annual report of the London Declaration on Neglected Tropical Diseases recorded increased treatments and funding and significant progress towards the World Health Organization (WHO)’s roadmap for implementation for control, elimination, or eradication by 2020. This achievement has been made possible by developing networks of NGDOs and partnerships with governments of the endemic countries, with international and bilateral agencies, with drug donation programmes for specific diseases, and with the communities affected by those diseases [4]. By 2011, NGDOs reported support in 125 countries to more than 330 million treatments for five priority diseases: onchocerciasis, trachoma, lymphatic filariasis (LF), schistosomiasis, and soil-transmitted helminthiasis (STH) [5]. These diseases have effective mass drug administration (MDA) strategies supported by donated or very-low-cost drugs available to control or eliminate them [6,7].

Quality assurance and quality control in the Global Trachoma Mapping Project

Abstract. In collaboration with the health ministries that we serve and other partners, we set out to complete the multiple-country Global Trachoma Mapping Project. To maximize the accuracy and reliability of its outputs, we needed in-built, practical mechanisms for quality assurance and quality control. This article describes how those mechanisms were created and deployed. Using expert opinion, computer simulation, working groups, field trials, progressively accumulated in-project experience, and external evaluations, we developed 1) criteria for where and where not to undertake population-based prevalence surveys for trachoma; 2) three iterations of a standardized training and certification system for field teams; 3) a customized Android phone–based data collection app; 4) comprehensive support systems; and 5) a secure end-to-end pipeline for data upload, storage, cleaning by objective data managers, analysis, health ministry review and approval, and online display. We are now supporting peer-reviewed publication. Our experience shows that it is possible to quality control and quality assure prevalence surveys in such a way as to maximize comparability of prevalence estimates between countries and permit high-speed, high-fidelity data processing and storage, while protecting the interests of health ministries.

Elimination of blinding trachoma by 2020: a call for rapid scale-up and strengthening programmes

Elimination of blinding trachoma is targeted for the year 2020, making scale-up extremely urgent. Preferred practices have been developed for mass drug administration and trichiasis surgery to assist new countries and districts. However, these need to be utilised on a broader scale to ensure quality output of programmes and the highest coverage possible of their implementation. Although in recent years there has been a significant increase in programmatic funding, there are still gaps. In addition, continued insecurity in several regions and outbreaks that require refocusing of staff threaten the goal. Close partnerships and collaboration enable the trachoma community to be well on track to reaching the goal, but it cannot be business as usual to achieve this.