Global Trachoma Mapping Project Research Articles

Progress towards the elimination of trachoma in Nigeria.

Trachoma is targeted for elimination as a public health problem worldwide by 2030. In Nigeria, elimination activities are implemented at the local government area (LGA) level. They started in 2002 by conducting baseline population-based prevalence surveys (PBPSs), which continued in a systematic manner with engagement from the Global Trachoma Mapping Project in 2013, and subsequently Tropical Data. The results led to the development of Nigeria's first trachoma action plan and its subsequent revision with additional information. Following 449 baseline PBPSs, 122 LGAs had an active trachoma prevalence above the elimination threshold, requiring interventions, while 231 LGAs required community-based interventions for trichiasis management. By 2021, >34 million antibiotic treatments had been provided in 104 LGAs, with 89 LGAs eliminating active trachoma. Nationally, water and sanitation coverages increased by 3% and 18%, respectively, in 7y. Systematic trichiasis case finding and management were carried out in 231 LGAs, resulting in the management of 102527 people. Fifty-four LGAs decreased trichiasis prevalence unknown to the health system to <0.2% in persons ≥15y of age. Where this elimination prevalence threshold was reached, trichiasis services were transitioned to routine eye/healthcare systems. Such progress relied on strong leadership and coordination from the national trachoma program and tremendous support provided by partners. Attaining elimination of trachoma as a public health problem in Nigeria by 2030 is feasible if funding support is sustained.

Exploring water, sanitation, and hygiene coverage targets for reaching and sustaining trachoma elimination: G-computation analysis.

Trachoma is the leading infectious cause of blindness. To reduce transmission, water, sanitation, and hygiene (WaSH) improvements are promoted through a comprehensive public health strategy. Evidence supporting the role of WaSH in trachoma elimination is mixed and it remains unknown what WaSH coverages are needed to effectively reduce transmission. We used g-computation to estimate the impact on the prevalence of trachomatous inflammation-follicular among children aged 1-9 years (TF1-9) when hypothetical WaSH interventions raised the minimum coverages from 5% to 100% for "nearby" face-washing water (<30 minutes roundtrip collection time) and adult latrine use in an evaluation unit (EU). For each scenario, we estimated the generalized prevalence difference as the TF1-9 prevalence under the intervention scenarios minus the observed prevalence. Data from 574 cross-sectional surveys conducted in 16 African and Eastern Mediterranean countries were included. Surveys were conducted from 2015-2019 with support from the Global Trachoma Mapping Project and Tropical Data. When modeling interventions among EUs that had not yet met the TF1-9 elimination target, increasing nearby face-washing water and latrine use coverages above 30% was generally associated with consistent decreases in TF1-9. For nearby face-washing water, we estimated a ≥25% decrease in TF1-9 at 65% coverage, with a plateau upon reaching 85% coverage. For latrine use, the estimated decrease in TF1-9 accelerated from 80% coverage upward, with a ≥25% decrease in TF1-9 by 85% coverage. Among EUs that had previously met the elimination target, results were inconclusive. Our results support Sustainable Development Goal 6 and provide insight into potential WaSH-related coverage targets for trachoma elimination. Targets can be tested in future trials to improve evidence-based WaSH guidance for trachoma.

Launch of the global leprosy mapping initiative- mapping priorities to achieve leprosy targets

To support the achievement of global leprosy targets, there is a need for improved leprosy data management and mapping. At the 2022 International Leprosy Congress, the Global Leprosy Mapping Initiative was announced with a goal to develop tools, processes, and best practices to support ministries of health to map leprosy, with a focus on capacity building, sustainability, and knowledge exchange to facilitate the achievement of global leprosy targets. This initiative will build on lessons learned from the Global Trachoma Mapping Project, bringing together a diverse group of leprosy stakeholders to support the development of global leprosy data and mapping standards, tools, and resources. This approach will allow for greater efficiencies in targeting interventions, facilitate advocacy and fundraising, and will support countries on the path to achieve zero leprosy. As the project is implemented over the next 3 years and beyond, partners are invited to engage and collaborate.

Current status of trachoma elimination in Africa

Background: Trachoma is a disease of the eye caused by infection with the bacterium Chlamydia trachomatis. It is among the oldest diseases known to mankind, being mentioned in the Ebbers Papyrus and found in the eyelids of Egyptian mummies. It is a public health problem in 44 countries globally and is responsible for the blindness or visual impairment of about 1.9 million people. As of June 2019, an estimated 138 million people live in trachoma endemic communities globally of which over 50% are in Ethiopia alone, and about 40% are in other African countries. Trachoma can be eliminated as a public health problem using a package of interventions known as the “SAFE strategy”, comprising Surgery for TT, Antibiotics to clear ocular C. trachomatis infection and Facial cleanliness and Environmental improvement (particularly improved access to water and sanitation) to reduce transmission. Methods and materials: Through the Global Trachoma Mapping Project (GTMP) and later on using the Tropical Data platform, 2076 district-level population-based baseline surveys, 927 impact assessments and 402 surveillance surveys were conducted. Three Crossborder Partnerships have been established to strengthen collaboration among neighboring countries and synergize elimination efforts. Results: Several encouraging achievements have been recorded thus far in Africa. Morocco and Ghana have been validated by WHO as having eliminated trachoma as a public health problem while Togo has presented its elimination dossier to WHO and is pending validation of its claim. In addition, nine countries are on the final stages of implementation and are preparing the evidence to present their dossiers for validation. These achievements would not have been possible without the generous support of several bilateral, multilateral and private donors including governments and people of the affected countries. The trachoma elimination program is a good model of public private partnerships. Conclusion: The elimination program is making steady progress in all known endemic countries. Country ownership and leadership is key in the process. Among the challenges confronting the country programs are difficulty of attaining the elimination threshold in some hyper-endemic settings, risk of recrudescence of active disease, difficulty of finding trachomatous trichiasis cases in remote villages, insecurity and funding shortfalls in the face of declining morbidity.

Milestones in the fight to eliminate trachoma

Trachoma, a chronic conjunctivitis that can result in vision loss from trichiasis, is targeted for global elimination by 2020. Several milestones in the long process towards elimination are noteworthy for the impact they have had on changing or accelerating progress. The purpose of this review is to describe the milestones and the impact they have had both for trachoma elimination and beyond. Eight milestones are presented. They are discovery of the causative agent; development of a clinical grading scheme; establishment of the World Health Organization Alliance for the Global Elimination of Trachoma by 2020; setting targets that define elimination; building an evidence base for trichiasis surgery; azithromycin donation programme; use of the SAFE strategy (Surgery, Antibiotics, Facial cleanliness, and Environmental improvement); and The Global Trachoma Mapping Project. These milestones have significantly pushed the progress towards elimination. Despite challenges to achieving the goal of elimination by 2020, there is continued commitment into the future to ensure that this preventable cause of blindness is no longer a threat.

Trachoma, Anti-Pgp3 Serology, and Ocular Chlamydia trachomatis Infection in Papua New Guinea.

BackgroundIn Melanesia, the prevalence of trachomatous inflammation–follicular (TF) suggests that public health–level interventions against active trachoma are needed. However, the prevalence of trachomatous trichiasis is below the threshold for elimination as a public health problem and evidence of conjunctival infection with trachoma’s causative organism (Chlamydia trachomatis [CT]) is rare. Here, we examine the prevalence of ocular infection with CT and previous exposure to CT in three evaluation units (EUs) of Papua New Guinea.MethodsAll individuals aged 1–9 years who were examined for clinical signs of trachoma in 3 Global Trachoma Mapping Project EUs were eligible to take part in this study (N = 3181). Conjunctival swabs were collected from 349 children with TF and tested by polymerase chain reaction to assess for ocular CT infection. Dried blood spots were collected from 2572 children and tested for anti-Pgp3 antibodies using a multiplex assay.ResultsThe proportion of children with TF who had CT infection was low across all 3 EUs (overall 2%). Anti-Pgp3 seroprevalence was 5.2% overall and there was no association between anti-Pgp3 antibody level and presence of TF. In 2 EUs, age-specific seroprevalence did not increase significantly with increasing age in the 1- to 9-year-old population. In the third EU, there was a statistically significant change with age but the overall seroprevalence and peak age-specific seroprevalence was very low.ConclusionsBased on these results, together with similar findings from the Solomon Islands and Vanuatu, the use of TF to guide antibiotic mass drug administration decisions in Melanesia should be reviewed.

Prevalence of Trachoma in Pakistan: Results of 42 Population-Based Prevalence Surveys from the Global Trachoma Mapping Project

ABSTRACTPurpose: Previous phases of trachoma mapping in Pakistan completed baseline surveys in 38 districts. To help guide national trachoma elimination planning, we set out to estimate trachoma prevalence in 43 suspected-endemic evaluation units (EUs) of 15 further districts.Methods: We planned a population-based trachoma prevalence survey in each EU. Two-stage cluster sampling was employed, using the systems and approaches of the Global Trachoma Mapping Project. In each EU, residents aged ≥1 year living in 30 households in each of 26 villages were invited to be examined by trained, certified trachoma graders. Questionnaires and direct observation were used to evaluate household-level access to water and sanitation.Results: One EU was not completed due to insecurity. Of the remaining 42, three EUs had trichiasis prevalence estimates in ≥15-year-olds ≥0.2%, and six (different) EUs had prevalence estimates of trachomatous inflammation—follicular (TF) in 1–9-year-olds ≥5%; each EU requires trichiasis and TF prevalence estimates below these thresholds to achieve elimination of trachoma as a public health problem. All six EUs with TF prevalences ≥5% were in Khyber Pakhtunkhwa Province. Household-level access to improved sanitation ranged by EU from 6% to 100%. Household-level access to an improved source of water for face and hand washing ranged by EU from 37% to 100%.Conclusion: Trachoma was a public health problem in 21% (9/42) of the EUs. Because the current outbreak of extremely drug-resistant typhoid in Pakistan limits domestic use of azithromycin mass drug administration, other interventions against active trachoma should be considered here.

Unimproved water sources and open defecation are associated with active trachoma in children in internally displaced persons camps in the Darfur States of Sudan.

PurposeTo estimate the proportion of children with trachomatous inflammation—follicular (TF) and adults with trachomatous trichiasis (TT) in internally displaced persons (IDP) camps in the Darfur States of Sudan and to evaluate associated risk factors.MethodsIDP camps were identified from government census data. We conducted a subanalysis of data collected in these camps during 2014–2015 as part of surveys covering 37 districts of the Darfur States within the Global Trachoma Mapping Project. A random-effects hierarchical model was used to evaluate factors associated with TF in children or TT in adults.ResultsThirty-six IDP camps were represented in the survey data, in which 1926 children aged 1–9 y were examined, of whom 38 (8%) had TF. Poor sanitation, younger age and living in a household that purchased water from a vendor were associated with TF in children aged 1–9 y. Of 2139 individuals examined aged ≥15 y, 16 (0.7%) had TT. TT was strongly independently associated with being older and living alone.ConclusionTrachoma is found at low levels in these camps, but still at levels where intervention is needed. Disease elimination in conflict-related settings presents a unique challenge for the trachoma community, and may require an innovative approach. Understanding how best to undertake trachoma elimination interventions in these areas should be prioritized.

Prevalence of and risk factors for trachoma in Kwara state, Nigeria: Results of eight population-based surveys from the Global Trachoma Mapping Project

ABSTRACTPurpose: To determine the prevalence of and risk factors for trachoma in selected local government areas (LGAs) of Kwara State, Nigeria.Methodology: Population-based cross-sectional surveys were conducted in eight LGAs of Kwara State using Global Trachoma Mapping Project (GTMP) protocols. In each LGA, 25 villages were selected using probability-proportional-to-size sampling; 25 households were selected from each village using compact segment sampling. All residents of selected households aged ≥1 year were examined by GTMP-certified graders for trachomatous inflammation—follicular (TF) and trichiasis using the simplified trachoma grading scheme. Water, sanitation, and hygiene (WASH) data were also collected.Results: A total of 28,506 residents were enumerated in 4769 households across the eight LGAs. TF prevalence in children aged 1–9 years ranged from 0.2% (95% CI 0.0–0.3%) to 1.3% (95% CI 0.7–2.1%), while trichiasis prevalence in persons ≥15 years was <0.2% in each LGA. Access to improved water source was the lowest in Edu (62%), while access to improved sanitation facilities was the lowest in Asa (6%) and the highest in Ilorin East (64%). Children aged 1–4 years had 0.63 (95% CI 0.40–0.99) times lower odds of having TF compared to children aged 5–9 years. Children in households with ≥5 resident 1–9-year-old children had 1.63 (95% CI 1.02–2.60) times greater odds of having TF compared to those in households with <5 resident children.Conclusion: Trachoma is not a public health problem in Kwara State. Provision of adequate water and sanitation services should be a priority here, as a foundation for the health of the population.

Completing Baseline Mapping of Trachoma in Nepal: Results of 27 Population-Based Prevalence Surveys Conducted in 2013 and 2014

ABSTRACTPurpose: Trachoma is endemic in parts of Nepal; implementation of the surgery, antibiotics, facial cleanliness, environmental improvement (SAFE) strategy started in 2002. Some suspected-endemic districts had not previously been mapped. We aimed to estimate the prevalences of trachomatous inflammation—follicular (TF) and trichiasis in those districts.Methods: Population-based prevalence surveys were undertaken in 27 districts. In each of those districts, two-stage cluster sampling was used to select a sample of 2000 children aged 1–9 years and 4000 adults aged ≥15 years from a total of 40 wards (clusters), drawn evenly from two subdistricts. Consenting eligible participants were examined for trachoma by Global Trachoma Mapping Project (GTMP)-certified graders, using the World Health Organization simplified grading system. Data were analyzed at district level using GTMP methods.Results: A total of 43,200 households were surveyed, and 162,094 people were examined for trachoma. District-level TF prevalence in 1–9-year-olds ranged from 0% to 4.3% (95% confidence interval [CI] 2.4–6.2). Among adults aged ≥15 years, trichiasis prevalence ranged from 0% to 0.33% (95% CI 0.08–0.65).Conclusion: TF was not a public health problem in any of the 27 districts surveyed; thus, antibiotic mass drug administration is not needed. In two districts (Dhanusa and Gorkha), trichiasis prevalence in adults aged ≥15 years was ≥0.2%; thus, further trichiasis surgery interventions at public health level are warranted to achieve elimination. These findings will facilitate planning for elimination of trachoma as a public health problem in Nepal.

Prevalence of Trachoma in Four Local Government Areas of Jigawa State, Nigeria

ABSTRACTPurpose: To determine the prevalence of trachoma and water and sanitation coverage in four local government areas (LGAs) of Jigawa State, Nigeria: Birnin Kudu, Buji, Dutse and Kiyawa.Methodology: A population-based cross-sectional survey was conducted in each LGA using Global Trachoma Mapping Project (GTMP) protocols. From each LGA, 25 villages were selected using probability-proportional-to-population size sampling; in each village, 25 households were selected using the random walk technique. All residents aged ≥1 year in selected households were examined by GTMP-certified graders for trachomatous inflammation – follicular (TF) and trichiasis, defined according to the WHO simplified trachoma grading scheme definitions. Water, sanitation and hygiene data were also collected through questioning and direct observation.Results: In 2458 households of four LGAs, 10,669 residents were enumerated. A total of 9779 people (92% of residents) were examined, with slightly more females examined (5012; 51%) than men. In children aged 1–9 years, the age-adjusted prevalence of TF ranged from 5.1% (95% CI 2.5–9.0%) in Birnin Kudu to 12.8% (95% CI 7.6–19.4%) in Kiyawa, while the age- and gender-adjusted trichiasis prevalence in persons aged ≥15 years ranged from 1.9% (95% CI 1.4–2.5%) in Birnin Kudu to 3.1% (95% CI 2.2–4.0) in Dutse. Access to improved water sources was above 80% in all LGAs surveyed but access to improved sanitation facilities was low, ranging from 23% in Buji to 50% in Kiyawa.Conclusion: Trachoma is a public health problem in all four LGAs surveyed. The full SAFE strategy needs to be implemented to achieve trachoma elimination.

Prevalence of Trachoma in Kogi State, Nigeria: Results of four Local Government Area-Level Surveys from the Global Trachoma Mapping Project

ABSTRACTPurpose: To determine the prevalence of trachoma in four Local Government Areas (LGAs) of Kogi State, Nigeria.Methods: In June 2014, we conducted population-based, cross-sectional surveys according to Global Trachoma Mapping Project (GTMP) protocols in selected LGAs of Kogi State. In each LGA, 25 clusters were selected with probability proportional to size. In each of these clusters, 25 households were enrolled for the survey. All residents of selected households aged ≥1 year were examined by GTMP-certified graders for trachomatous inflammation–follicular (TF) and trichiasis using the simplified trachoma grading scheme. Data on sources of household water and types of sanitation facilities were collected through questioning and direct observation.Results: The age-adjusted TF prevalence in 1–9-year-olds ranged from 0.4% (95% CI 0.1–0.8%) in Bassa to 1.0% (95% CI 0.3–1.9%) in Omala. Across all four LGAs, only one case of trichiasis was found; this individual was in Omala, giving that LGA a trichiasis prevalence in individuals aged ≥15 years of 0.02% (95% CI 0.00–0.07%). Between 77 and 88% of households had access to water for hygiene purposes, while only 10–30% had access to improved sanitation facilities.Conclusion: Trachoma is not a public health problem in any of the 4 LGAs surveyed. There is, however, the need to increase access to adequate water and sanitation services to contribute to the health and social and economic well-being of these communities.

Progress Towards Elimination of Trachoma as a Public Health Problem in Eritrea: Results of a Systematic Review and Nine Population-based Prevalence Surveys Conducted in 2014

ABSTRACTPurpose: To assess Eritrea’s progress towards elimination of trachoma as a public health problem, we reviewed and compiled current knowledge on the distribution and burden of trachoma in Eritrea, then undertook further population-based surveys where indicated, with support from the Global Trachoma Mapping Project (GTMP).Methods: For the systematic review, undertaken in March 2014, we searched (1) PubMed, using the terms ((blind* or trachoma or trichiasis) AND Eritrea); (2) the online database of rapid assessments of avoidable blindness; (3) our own grey literature collections; and (4) the Global Atlas of Trachoma database. In June and July 2014, we conducted nine population-based prevalence surveys, for each of which 30 villages were systematically selected with probability proportional to population size; in each village, 30 households were systematically selected. All consenting residents of selected households aged ≥1 year were examined by GTMP-certified graders for signs of trachoma. Data on household-level access to water and sanitation were also collected.Results: One previous rapid assessment of avoidable blindness, three peer-reviewed publications, and two grey literature reports detailing sets of trachoma prevalence surveys conducted in 2006 and 2011, respectively, were located. Post-intervention impact surveys were needed in seven evaluation units (EUs, framed at sub-Zoba-level: population range 40,000–120,000) of Debub and Northern Red Sea, while baseline surveys were needed in two EUs of Anseba. Four of the seven impact survey EUs and both baseline survey EUs returned trachomatous inflammation—follicular prevalences in 1–9-year-olds of ≥5%; six of the seven impact survey EUs and one of the two baseline survey EUs returned trichiasis prevalences in ≥15-year-olds of ≥0.2%. The prevalence of access to water and sanitation varied widely between EUs.Conclusion: Interventions are still required in Eritrea to eliminate trachoma as a public health problem. Data from these surveys will guide the Ministry of Health to undertake programme planning using a sound evidence base.

Prevalence of trachoma in the Afar Region of Ethiopia: results of seven population-based surveys from the Global Trachoma Mapping Project

ABSTRACTPurpose: Trachoma is to be eliminated as a public health problem by 2020. To help the process of planning interventions where needed, and to provide a baseline for later comparison, we set out to complete the map of trachoma in Afar, Ethiopia, by estimating trachoma prevalence in evaluation units (EUs) of grouped districts (“woredas”).Methods: We conducted seven community-based surveys from August to October 2013, using standardised Global Trachoma Mapping Project (GTMP) survey methodologies.Results: We enumerated 5065 households and 18,177 individuals in seven EUs covering 19 of Afar’s 29 woredas; the other ten were not accessible. 16,905 individuals (93.0%) were examined, of whom 9410 (55.7%) were female. One EU incorporating four woredas (Telalak, Dalefage, Dewe, Hadele Ele) was shown to require full implementation of the SAFE strategy for three years before impact survey, with a trachomatous inflammation-follicular (TF) prevalence in 1–9-year-olds of 17.1% (95%CI 9.4–25.5), and a trichiasis prevalence in adults aged ≥15 years of 1.2% (95%CI 0.6–2.0). Five EUs, covering 13 woredas (Berahle, Aba’ala, Dupti, Kurri, Elidihare, Ayesayeta, Afamboo, Bure Mudaitu, Gewane, Amibara, Dulecho, Dalolo, and Konebo), had TF prevalences in children of 5–9.9% and need one round of azithromycin mass treatment and implementation of the F and E components of SAFE before re-survey; three of these EUs had trichiasis prevalences in adults ≥0.2%. The final EU (Mile, Ada’ar) had a sub-threshold TF prevalence and a trichiasis prevalence in adults just >0.2%.Conclusion: Trachoma is a public health problem in Afar, and implementation of the SAFE strategy is required.

Prevalence of trachoma in the area councils of the Federal Capital Territory, Nigeria: results of six population-based surveys

ABSTRACTPurpose: The World Health Organization’s (WHO’s) global trachoma elimination programme recommends mapping of trachoma at district level for planning of elimination activities in affected populations. This study aimed to provide data on trachoma prevalence for the Area Councils of Nigeria’s Federal Capital Territory (FCT).Methods: Using the Global Trachoma Mapping Project (GTMP) protocols, in March and April 2014, we conducted a population-based cross-sectional survey in each of the six Area Councils of FCT. Signs were defined based on the WHO simplified grading scheme.Results: 98% to 100% of the targeted households were enrolled in each Area Council. The number of children aged 1–9 years examined per Area Council ranged from 867 to 1248. The number of persons aged ≥15 years examined ranged from 1302 to 1836. The age-adjusted prevalence of trachomatous inflammation—follicular in 1–9-year-olds was <5% in each Area Council. The age- and gender-adjusted prevalence of trichiasis in those aged ≥15 years ranged from 0.0% to 0.3%; two Area Councils (Gwagwalada and Kwali) had prevalences above the 0.2% elimination threshold. The proportion of households with access to improved latrines and water sources ranged from 17 to 90% and 39 to 85% respectively.Conclusions: Gwagwalada and Kwali Area Councils need to perform more trichiasis surgeries to attain the trichiasis elimination prevalence target of 0.2% in persons aged ≥15 years. No Area Council requires mass antibiotic administration for the purposes of trachoma’s elimination as a public health problem. All Area Councils need to accelerate provision of access to improved water sources and latrine facilities, to achieve universal coverage.

Impact Survey Results after SAFE Strategy Implementation in 15 Local Government Areas of Kebbi, Sokoto and Zamfara States, Nigeria

ABSTRACTPurpose: To determine prevalence of trachoma after interventions in 15 local government areas (LGAs) of Kebbi, Sokoto and Zamfara States, Nigeria.Methods: A population-based impact survey was conducted in each LGA using Global Trachoma Mapping Project (GTMP) protocols. In each LGA, 25 villages were selected, except in Arewa LGA, where we selected 25 villages from each of four subunits to obtain finer-resolution prevalence information. Villages were selected with probability proportional to size. In each village, 25 households were enrolled and all consenting residents aged ≥1 year were examined by GTMP-certified graders for trachomatous inflammation—follicular (TF) and trachomatous trichiasis (TT). Information on sources of household water and types of sanitation facilities used was collected through questioning and direct observation.Results: The number of households enrolled per LGA ranged from 623 (Kware and Tangaza) to 2488 (Arewa). There have been marked reductions in the prevalence of TF and TT since baseline surveys were conducted in all 15 LGAs. Eight of the 15 LGAs have attained TF prevalences <5% in children, while 10 LGAs have attained TT prevalences <0.2% in persons aged ≥15 years. Between 49% and 96% of households had access to water for hygiene purposes within 1 km of the household, while only 10–59% had access to improved sanitation facilities.Conclusion: Progress towards elimination of trachoma has been made in these 15 LGAs. Collaboration with water and sanitation agencies and community-based trichiasis surgery are still needed in order to eliminate trachoma by the year 2020.

Prevalence of trachoma in 13 Local Government Areas of Taraba State, Nigeria

ABSTRACTPurpose: The purpose of these surveys was to determine the prevalence of trachomatous inflammation—follicular (TF) in children aged 1–9 years and trichiasis prevalence in persons aged ≥15 years, in 13 Local Government Areas (LGAs) of Taraba State, Nigeria.Methods: The surveys followed Global Trachoma Mapping Project (GTMP) protocols. Twenty-five households were selected from each of 25 clusters in each LGA, using two-stage cluster sampling providing probability of selection proportional to cluster size. Survey teams examined all the residents of selected households aged ≥1 year for the clinical signs TF, trachomatous inflammation—intense (TI) and trichiasis.Results: The prevalence of TF in children aged 1–9 years in the 13 LGAs ranged from 0.0–5.0%; Ussa LGA had the highest prevalence of 5% (95%CI: 3.4–7.2). Trichiasis prevalence ranged from 0.0–0.8%; seven LGAs had trichiasis prevalences above the threshold for elimination. The backlog of trichiasis in the 13 LGAs (estimated combined population 1,959,375) was 3,185 people. There is need to perform surgery for at least 1,835 people to attain a trichiasis prevalence in each LGA of <0.2% in persons aged ≥15 years. In six of the 13 LGAs, 80% of households could access washing water within 1 km of the household, but only one LGA had >80% of households with access to improved latrines.Conclusion: One of 13 LGAs requires antibiotic mass drug administration for active trachoma. Community-based trichiasis surgery needs to be provided in seven LGAs. There is a need to increase household-level access to improved washing water and latrines across the State.

Trachoma in Viet Nam: results of 11 surveillance surveys conducted with the Global Trachoma Mapping Project

ABSTRACTPurpose: Following interventions against trachoma in Viet Nam, impact surveys conducted in 2003–2011 suggested that trachoma was no longer a public health problem. In 2014, we undertook surveillance surveys to estimate prevalence of trachomatous inflammation—follicular (TF) and trichiasis.Methods: A population-based prevalence survey was undertaken in 11 evaluation units (EUs) encompassing 24 districts, using Global Trachoma Mapping Project methods. A two-stage cluster sampling design was used in each EU, whereby 20 clusters and 60 children per cluster were sampled. Consenting eligible participants (children aged 1–9 years and adults aged ≥50 years) were examined for trachoma.Results: A total of 9391 households were surveyed, and 20,185 participants (98.8% of those enumerated) were examined for trachoma. EU-level TF prevalence in 1–9-year-olds ranged from 0% to 1.6%. In one cluster (in Hà Giang Province), the percentage of children with TF was 10.3%. The overall pattern of cluster-level percentages of children with TF, however, was consistent with an exponential distribution, which would be consistent with trachoma disappearing. Among people aged ≥50 years, prevalence of trichiasis by EU ranged from 0% to 0.75%; these estimates are equivalent to 0–0.13% in all ages. The prevalence of trichiasis unknown to the health system among people aged ≥50 years, by EU, ranged from 0% to 0.17%, which is equivalent to 0–0.03% in all ages.Conclusion: Findings suggest that trachoma is no longer a public health problem in any of the 11 EUs surveyed. However, given the high proportion of children with TF in one cluster in Hà Giang Province, further investigations will be undertaken.

Prevalence of Trachoma in Senegal: Results of Baseline Surveys in 17 Districts

ABSTRACTPurpose: Senegal is endemic for trachoma, an infectious and potentially blinding eye disease. To complete the country’s district-level baseline map of trachoma, we conducted population-based surveys in 17 health districts that were suspected-endemic but had yet to be surveyed.Methods: We randomly selected 30 clusters (villages) per district and 30 households per village, and estimated the district-level prevalences of trachomatous inflammation—follicular (TF) in children aged 1–9 years, and trichiasis in persons aged ≥15 years. Data on household-level water, sanitation, and hygiene variables were also collected. Global Trachoma Mapping Project methods were followed in training, fieldwork, and data handling.Results: 25,704 children aged 1–9 years and 30,345 adults aged 15 years and above were examined. In children aged 1–9 years, the prevalence of TF was <5% in all 17 districts, with the exception of Saint-Louis (5.1%, 95% CI 3.2–7.5). Trichiasis prevalence in participants aged 15 years and above ranged by district from 0%–1.1% (95% CI 0.7–1.5), with 9 districts having trichiasis prevalences above the elimination threshold of 0.2%. Trichiasis was seen to be significantly less frequent in males than in females (0.17% [95% CI 0.12–0.24] versus 0.49% [95% CI 0.38–0.61], p < 0.001). The prevalence of trichiasis rose steeply with age; 62% of cases were observed in people aged 55 years or above.Conclusions: Active trachoma is not a public health problem in 16 of the 17 surveyed districts, and implementation of the full Surgery (S) – Antibiotics (A) – Facial cleanliness (F) – Environmental improvement (E) strategy is not a programmatic priority. Increased provision of trichiasis surgery is warranted in nine districts.

Prevalence of trachoma in Yemen: results of population-based prevalence surveys of 42 evaluation units in nine governorates

ABSTRACTPurpose: In suspected trachoma-endemic areas of Yemen, we sought to determine the prevalence of the sign trachomatous inflammation—follicular (TF) in children aged 1–9 years, and the potential individual and household risk factors for TF in that age group. We also sought to determine the prevalence of trichiasis in adults aged ≥15 years.Methods: We conducted a cluster-sampled survey in each of 42 evaluation units (EUs) comprising 166 rural districts of nine Governorates (Adh Dhale’a, Al Hodeihah, Al Jawf, Hadramoot, Hajjah, Ibb, Lahj, Ma’rib, Taiz) using the Global Trachoma Mapping Project systems and methodologies. Fieldwork was undertaken from September 2013 to March 2015. Risk factors for TF in children aged 1–9 years were evaluated using multilevel random effects logistic regression.Results: The TF prevalence in children aged 1–9 years was ≥10% in two EUs (7 districts) and 5–9.9% in six EUs (24 districts). In adults aged ≥15 years, trichiasis prevalence was ≥0.2% in five EUs (19 districts). Being older (within the 1–9-year age bracket), being male, living in a household with higher numbers of children, and living in a household that reported the use of open defecation, were each independently associated with higher odds of TF.Conclusions: These surveys provided baseline data to enable planning for trachoma elimination. The World Health Organization Alliance for the Global Elimination of Trachoma by 2020 stands ready to assist Yemen once security considerations permit further surveys and implementation of control activities.