A Multicenter Evaluation of Diagnostic Tools to Define Endpoints for Programs to Eliminate Bancroftian Filariasis

Autor: Kapa D. Ramaiah, Mark Bradley, Anne-Marie Legrand, Khalfan A. Mohammed, Makoto Itoh, Eric A. Ottesen, Madsen Beau De Rochars, Sandra J. Laney, Jeffrey T. Talbot, Nese Ituaso-Conway, Katherine Gass, Kimberly Y. Won, Nils Pilotte, Dominique Kyelem, Tilaka S. Liyanage, Gary J. Weil, Ramakrishna U. Rao, Hayley Joseph, Catherine Plichart, Patrick J. Lammie, Peter Fischer, Steven A. Williams, Wayne Melrose, Daniel A. Boakye, John O. Gyapong
Rok vydání: 2012
Předmět:
Zdroj: PLoS Neglected Tropical Diseases
PLoS Neglected Tropical Diseases, Vol 6, Iss 1, p e1479 (2012)
ISSN: 1935-2735
DOI: 10.1371/journal.pntd.0001479
Popis: Successful mass drug administration (MDA) campaigns have brought several countries near the point of Lymphatic Filariasis (LF) elimination. A diagnostic tool is needed to determine when the prevalence levels have decreased to a point that MDA campaigns can be discontinued without the threat of recrudescence. A six-country study was conducted assessing the performance of seven diagnostic tests, including tests for microfilariae (blood smear, PCR), parasite antigen (ICT, Og4C3) and antifilarial antibody (Bm14, PanLF, Urine SXP). One community survey and one school survey were performed in each country. A total of 8,513 people from the six countries participated in the study, 6,443 through community surveys and 2,070 through school surveys. Specimens from these participants were used to conduct 49,585 diagnostic tests. Each test was seen to have both positive and negative attributes, but overall, the ICT test was found to be 76% sensitive at detecting microfilaremia and 93% specific at identifying individuals negative for both microfilariae and antifilarial antibody; the Og4C3 test was 87% sensitive and 95% specific. We conclude, however, that the ICT should be the primary tool recommended for decision-making about stopping MDAs. As a point-of-care diagnostic, the ICT is relatively inexpensive, requires no laboratory equipment, has satisfactory sensitivity and specificity and can be processed in 10 minutes—qualities consistent with programmatic use. Og4C3 provides a satisfactory laboratory-based diagnostic alternative.
Author Summary Lymphatic filariasis (LF), a mosquito-borne parasitic disease, is a candidate for elimination largely because of the success of mass drug administration (MDA) campaigns, in which entire at-risk populations are given a once-yearly regimen of single-dose treatment with two medications. As a result, a diagnostic tool is needed to determine when the prevalence of LF has fallen below the threshold for sustained transmission so that MDA programs can be stopped. To determine the best diagnostic tool available, a multi-country study was conducted to assess the performance of seven diagnostic tests on a panel of patient specimens. The selection of the most effective diagnostic test was based on an evaluation of each test's accuracy, technical requirements, programmatic feasibility and reliability, as well as confidence in test performance. This study found advantages and disadvantages to each test. Based on the data and experiences it was determined that the ICT test, a point-of-care rapid card test, is the preferred diagnostic tool for use in defining the end-point of MDA, although the Og4C3 test provides a suitable laboratory-based alternative.
Databáze: OpenAIRE
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