Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2014 Feb 13;8(2):e2708.
doi: 10.1371/journal.pntd.0002708. eCollection 2014 Feb.

Pilot assessment of soil-transmitted helminthiasis in the context of transmission assessment surveys for lymphatic filariasis in Benin and Tonga

Brian K Chu  1 , Katherine Gass  1 , Wilfrid Batcho  2 , Malakai 'Ake  3 , Améyo M Dorkenoo  4 , Elvire Adjinacou  2 , 'Eva Mafi  3 , David G Addiss  5
Affiliations

Pilot assessment of soil-transmitted helminthiasis in the context of transmission assessment surveys for lymphatic filariasis in Benin and Tonga

Brian K Chu et al. PLoS Negl Trop Dis. .

Abstract

Background: Mass drug administration (MDA) for lymphatic filariasis (LF) programs has delivered more than 2 billion treatments of albendazole, in combination with either ivermectin or diethylcarbamazine, to communities co-endemic for soil-transmitted helminthiasis (STH), reducing the prevalence of both diseases. A transmission assessment survey (TAS) is recommended to determine if MDA for LF can be stopped within an evaluation unit (EU) after at least five rounds of annual treatment. The TAS also provides an opportunity to simultaneously assess the impact of these MDAs on STH and to determine the frequency of school-based MDA for STH after community-wide MDA is no longer needed for LF.

Methodology/principal findings: Pilot studies conducted in Benin and Tonga assessed the feasibility of a coordinated approach. Of the schools (clusters) selected for a TAS in each EU, a subset of 5 schools per STH ecological zone was randomly selected, according to World Health Organization (WHO) guidelines, for the coordinated survey. In Benin, 519 children were sampled in 5 schools and 22 (4.2%) had STH infection (A. lumbricoides, T. trichiura, or hookworm) detected using the Kato-Katz method. All infections were classified as light intensity under WHO criteria. In Tonga, 10 schools were chosen for the coordinated TAS and STH survey covering two ecological zones; 32 of 232 (13.8%) children were infected in Tongatapu and 82 of 320 (25.6%) in Vava'u and Ha'apai. All infections were light-intensity with the exception of one with moderate-intensity T. trichiura.

Conclusions: Synchronous assessment of STH with TAS is feasible and provides a well-timed evaluation of infection prevalence to guide ongoing treatment decisions at a time when MDA for LF may be stopped. The coordinated field experiences in both countries also suggest potential time and cost savings. Refinement of a coordinated TAS and STH sampling methodology should be pursued, along with further validation of alternative quantitative diagnostic tests for STH that can be used with preserved stool specimens.

PubMed Disclaimer

Conflict of interest statement

GlaxoSmithKline's contribution to this study was only financial and none of the authors have any affiliation with GlaxoSmithKline. Additionally the funds were awarded to the Task Force for Global Health for general operational research and not solely or specifically for this pilot assessment of LF and STH in Benin and Tonga. As there is no author affiliation with GlaxoSmithKline, this does not alter our adherence to all PLOS NTDs policies on sharing data and materials.

References

    1. World Health Organization (2012) Weekly Epidemiological Record 23: 225 Geneva –232.
    1. Preventive chemotherapy and transmission control databank: lymphatic filariasis World Health Organization, Geneva.
    1. Horton J (2000) Albendazole: a review of anthelmintic efficacy and safety in humans. Parasitology 121 Suppl: S113–132. - PubMed
    1. Beach MJ, Streit TG, Addiss DG, Prospere R, Roberts JM, et al. (1999) Assessment of combined ivermectin and albendazole for treatment of intestinal helminth and Wuchereria bancrofti infections in Haitian schoolchildren. Am J Trop Med Hyg 60: 479–486. - PubMed
    1. De Rochars MB, Direny AN, Roberts JM, Addiss DG, Radday J, et al. (2004) Community-wide reduction in prevalence and intensity of intestinal helminths as a collateral benefit of lymphatic filariasis elimination programs. Am J Trop Med Hyg 71: 466–470. - PubMed

Publication types