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.
PLoS Negl Trop Dis 2018;
12:e0006543. [PMID:
29897902 PMCID:
PMC6016948 DOI:
10.1371/journal.pntd.0006543]
[Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 06/25/2018] [Accepted: 05/18/2018] [Indexed: 11/19/2022] Open
Abstract
Background
As highly trachoma-endemic countries approach elimination, some districts will have prevalences of trachomatous inflammation–follicular in 1–9-year-olds (TF1-9) of 5.0–9.9%. The World Health Organization (WHO) previously recommended that in such districts, TF prevalence be assessed in each sub-district (groupings of at least three villages), with three rounds of azithromycin treatment offered to any sub-district in which TF≥10%. Given the large number of endemic districts worldwide and the human and financial resources required to conduct surveys, this recommendation may not be practical. In a group of 8 Malawi districts with baseline TF prevalences of 5.0–9.9%, the Malawi Ministry of Health administered one round of azithromycin mass treatment, to the whole of each district, achieving mean coverage of ~80%. Here, we report impact surveys conducted after that treatment.
Methods
We undertook population-based trachoma surveys in 18 evaluation units of the 8 treated districts, at least 6 months after the MDA. The standardized training package and survey methodologies of Tropical Data, which conform to WHO recommendations, were used.
Results
Each of the 18 evaluation units had a TF1-9 prevalence <5.0%.
Conclusion
The study demonstrates that in Malawi districts with TF of 5.0–9.9%, one round of azithromycin MDA with ~80% coverage associates with a reduction in TF prevalence to <5%. Further evidence for this approach should be collected elsewhere.
Until now, in trachoma elimination programmes, the WHO recommendation for district-wide annual rounds of antibiotic mass drug administration was only applicable to districts with a trachomatous inflammation—follicular (TF1-9) prevalence of 10% or more. Districts with a TF1-9 prevalence of <5% were considered not to require intervention with antibiotics for trachoma. For districts with a prevalence of 5.0–9.9%, programmes were encouraged to determine the TF1-9 prevalence at sub-district or “community” level. With the recent rapid scale-up in trachoma mapping, there are now a large number of districts known to have TF1-9 prevalence of 5.0–9.9%, so this recommendation is likely to pose an implementation challenge to health ministries and their partners. In this study, we have demonstrated that in districts with TF1-9 5.0–9.9%, a single round of mass drug administration with high coverage to the whole district can be followed by an impact survey TF1-9 prevalences of <5%. This approach is likely to reduce the commodity need (one round of MDA to 100% of the population compared to 3 or more rounds to an average 50% of the population), reduce the number of surveys required, and ultimately accelerate the speed of progress to elimination. We recommend that this finding be further explored elsewhere to determine its generalizability, in order to justify consideration of global policy change.
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