Alternative approaches for monitoring and evaluation of lymphatic filariasis following mass drug treatment with ivermectin, diethylcarbamazine and albendazole in East New Britain Province, Papua New Guinea.
<h4>Background</h4>WHO recommends two annual rounds of mass drug administration (MDA) with ivermectin, diethylcarbamazine, and albendazole (IDA) for lymphatic filariasis (LF) elimination in treatment naïve areas that are not co-endemic for onchocerciasis such as Papua New Guinea (PNG). W...
Saved in:
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2025-01-01
|
| Series: | PLoS Neglected Tropical Diseases |
| Online Access: | https://doi.org/10.1371/journal.pntd.0012128 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <h4>Background</h4>WHO recommends two annual rounds of mass drug administration (MDA) with ivermectin, diethylcarbamazine, and albendazole (IDA) for lymphatic filariasis (LF) elimination in treatment naïve areas that are not co-endemic for onchocerciasis such as Papua New Guinea (PNG). Whether two rounds of MDA are necessary or sufficient and the optimal sampling strategies and endpoints for stopping MDA remain undefined.<h4>Methods and findings</h4>Two cross-sectional studies were conducted at baseline (N = 49 clusters or villages) and 12 months after mass drug administration (MDA) with IDA (N = 47 villages) to assess lymphatic filariasis (LF) by circulating filarial antigenemia (CFA) and microfilariae (Mf). Before MDA, children aged 6-9 years (N~50) and those ≥ 10 years (N~50) in each village were randomly sampled. Before MDA, the population mean prevalence of LF in East New Britain Province (ENBP), Papua New Guinea, was estimated using population proportionate sampling (PPS, N = 30) to be 59/2,561 (2.3%) CFA positive and 14/2,561 (0.6%) Mf positive. No children were Mf positive. However, LF infection was highly heterogeneous; 8 villages (26.7%) had a CFA prevalence >2%, and 7 villages (23.3%) had an Mf prevalence >1%. To identify sentinel villages with LF in areas under-sampled by PPS, 19 additional villages suspected to have LF were sampled, with 15 (79%) having >2% CFA prevalence and 7 (38%) >1% Mf (range 1-22%). Twenty-four villages were evaluated before and after MDA in age-matched adults ( ≥ 18 years). Treatment reduced CFA prevalence by 34% and Mf prevalence by 90%. Post-MDA model-based geostatistics efficiently selected an additional 23 villages, of which 20 (87%) had a CFA prevalence > 2%. None of these villages had >1% Mf. Post-MDA, two of four districts had no villages with >1% Mf.<h4>Conclusions</h4>Model-based geostatistics was more effective than PPS in sampling high-risk LF sites in a heterogeneous area. Low LF prevalence and partial reduction of CFA limit children's effectiveness as sentinels. A single round of high-coverage MDA with IDA achieved elimination targets in low-prevalence villages in PNG. Higher-prevalence areas will need additional MDA rounds, which could be targeted to smaller evaluation units to cut costs.<h4>Trial registration</h4>Clinicaltrials.gov NCT04124250. |
|---|---|
| ISSN: | 1935-2727 1935-2735 |