Assessing Onchocerciasis Subcriticality from Pre-Intervention Cross-Sectional Surveys.

Assessing Onchocerciasis Subcriticality from Pre-Intervention Cross-Sectional Surveys. Am J Trop Med Hyg. 2020 May 26;: Authors: Kelly JD, Rebollo Polo M, Marie Zoure HG, Oldenburg CE, Keenan JD, Porco TC, Lietman TM Abstract Elimination of an infectious disease requires subcritical transmission, or a reproductive number less than one, and can be assessed with cross-sectional surveys conducted by neglected tropical disease programs. Here, we assess the distribution of onchocerciasis prevalence taken from surveys across sub-Saharan Africa before the initiation of ivermectin in mass drug administrations. Pre-intervention nodular palpation cross-sectional surveys were available from 15 countries in the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) database. We determined whether the distribution of the prevalence over communities in an area was consistent with a geometric distribution, which previous studies have suggested indicates a subcritical disease. If not, we fitted a negative binominal distribution (hypothetically supercritical) or a mixture of two distributions: geometric (hypothetically subcritical) and Poisson (hypothetically supercritical). The overall distribution of community-level onchocerciasis prevalence estimates from the ESPEN dataset from 2005 to 2014 was not consistent with a geometric distribution. By contrast, data from several countries and parts of countries were consistent with...
Source: The American Journal of Tropical Medicine and Hygiene - Category: Tropical Medicine Authors: Tags: Am J Trop Med Hyg Source Type: research