Completion of Baseline Trachoma Mapping in Malawi: Results of Eight Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project

Abstract

Purpose: Following a first phase of trachoma mapping in Malawi with the Global Trachoma Mapping Project, we identified and mapped trachoma districts previously suspected to be non-endemic, although adjacent to districts with estimated trachoma prevalences indicating a public health problem. Methods: We conducted population-based surveys in eight evaluation units (EUs) comprising eight districts in Malawi (total population 3,230,272). A 2-stage cluster random sampling design allowed us to select 30 households from each of 30 clusters per EU; all residents aged 1 year and older in selected households were examined for evidence of trachomatous inflammation–follicular (TF) and trachomatous trichiasis (TT). Results: None of the eight EUs had a TF prevalence in 1–9-year-olds ≥10%, one district (Dedza) had a TF prevalence between 5.0% and 9.9%, and only one district (Karonga) had a trichiasis prevalence in adults ≥0.2%. Conclusion: The prevalence of TF and TT in six of eight EUs surveyed was consistent with an original categorization of trachoma being unlikely to be a public health problem. In the absence of formal surveys, health management information system data and other locally available information about trachoma is likely to be useful in predicting areas where public health interventions against trachoma are required.

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

“…We also sought to trim fieldwork time by not collecting household-level data on access to water and sanitation, which was routinely integrated within trachoma surveys in other GTMP sub-projects. [20][21][22][23][24][25][26] Due to a paucity of cases of active trachoma, our graders did not undertake live subject inter-grader agreement exercises to qualify for survey deployment, but were instead assessed using a standard set of 50 conjunctival photographs. During the GTMP, Lao PDR 27 and Cambodia 28 circumvented a similar lack of local cases by sending trainee graders to Ethiopia for field training and certification, but this was not possible for Viet Nam.…”

Prevalence of Trachoma and Access to Water and Sanitation in Benue State, Nigeria: Results of 23 Population-Based Prevalence Surveys

“…We have surveyed each of Benue State's 23 LGAs, and found prevalence estimates of TF and trichiasis that are very modest in comparison to more northern states of Nigeria, 13,14,17,[22][23][24][25]39,40 or other settings in sub-Saharan Africa. [41][42][43][44][45] Only two LGAs (Gwer East and Okpokwu) require public health-level implementation of the S component of the SAFE strategy. Only two LGAs (Gwer East and Ukum) had TF prevalences suggesting a need for the A, F, and E components of SAFE.…”

One round of azithromycin MDA adequate to interrupt transmission in districts with prevalence of trachomatous inflammation—follicular of 5.0-9.9%: Evidence from Malawi

“…Training of graders, recorders and supervisors was conducted in Mangochi District, Malawi, by a Tropical Data-certified Master Grader Trainer (KK) and a Tropical Data-certified Recorder Trainer (AC). All grader trainees had previously been GTMP-certified [ 17 , 20 ]. Grader trainees participated in two days of refresher training, which covered methods for examining subjects for TF, trachomatous inflammation—intense (TI) and trachomatous trichiasis (TT), and the recognition of and referral pathways for other diseases.…”