Serologic Monitoring of Public Health Interventions Against Strongyloides stercoralis

CAJAL, PAMELA; ECHAZÚ, ADRIANA; JUAREZ, MARISA; LAMMIE, PATRICK; KROLEWIECKI, ALEJANDRO J.; CARO, NICOLÁS; CIMINO, RUBÉN O.; GIL, JOSE F.; VARGAS, PAOLA; NASSER, JULIO

AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE

AMER SOC TROP MED & HYGIENE

Año: 2017

0002-9637

NorthwesternArgentina is endemic for soil-transmitted helminths, and annual deworming programsare carried out in prioritized areas. High prevalence of Strongyloidesstercoralis was reported in this area; therefore, conAU2 trol programsincluding ivermectin are being evaluated. The NIE-enzyme linked immunosorbentassay (ELISA) was used for this purpose. In this community trial, two groups ofpatients, classified according to housing and living conditions were evaluated.Simultaneous with baseline survey, Group 1 was moved to new households withaccess to improved water and sanitation facilities (W and S), where deworming(MDA, massive drug administration) took place within 1 month; whereas Group 2received MDA but remained living with unimproved W and S. The mean timeinterval between baseline and the follow-up was 331 days for Group 1 and 508for Group 2. Anti-NIE levels were measured for each individual before and afterinterventions and follow-up optical density (OD) ratios were calculated to quantifythe variation. A significant decrease of the anti-NIE levels between baselineand follow-up was observed in both groups. Nonetheless, the number of patientsthat achieved the cure criteria (OD ratio < 0.6) was higher in Group 1 thanGroup 2 with values of 72.7% (24/33) and 45.0% (18/40), respectively (P =0.0197). Our results support the conclusion that a combined interventionincluding deworming and improvements in life conditions is more effective, interms of the proportion of subjects cured than deworming alone. Furthermore, wefound that NIE-ELISA is a useful test for assessing the response to treatmentand to evaluate the outcome of control intervention programs.