Adriana Echazú 1 , 2 , * , Marisa Juarez 1 , Paola A. Vargas 1 , 2 , Silvana P. Cajal 1 , Ruben O. Cimino 1 , 3 , Viviana Heredia 4 , Silvia Caropresi 4 , Gladys Paredes 4 , Luis M. Arias 5 , Marcelo Abril 6 , Silvia Gold 6 , Patrick Lammie 7 , Alejandro J. Krolewiecki 1 , 2
9 October 2017
Recommendations for soil-transmitted helminth (STH) control give a key role to deworming of school and pre-school age children with albendazole or mebendazole; which might be insufficient to achieve adequate control, particularly against Strongyloides stercoralis. The impact of preventive chemotherapy (PC) against STH morbidity is still incompletely understood. The aim of this study was to assess the effectiveness of a community-based program with albendazole and ivermectin in a high transmission setting for S. stercoralis and hookworm.
Community-based pragmatic trial conducted in Tartagal, Argentina; from 2012 to 2015. Six communities (5070 people) were enrolled for community-based PC with albendazole and ivermectin. Two communities (2721 people) were re-treated for second and third rounds. STH prevalence, anemia and malnutrition were explored through consecutive surveys. Anthropometric assessment of children, stool analysis, complete blood count and NIE-ELISA serology for S. stercoralis were performed.
STH infection was associated with anemia and stunting in the baseline survey that included all communities and showed a STH prevalence of 47.6% (almost exclusively hookworm and S. stercoralis). Among communities with multiple interventions, STH prevalence decreased from 62% to 23% (p<0.001) after the first PC; anemia also diminished from 52% to 12% (p<0.001). After two interventions S. stercoralis seroprevalence declined, from 51% to 14% (p<0.001) and stunting prevalence decreased, from 19% to 12% (p = 0.009).
Hookworm’ infections are associated with anemia in the general population and nutritional impairment in children. S. stercoralis is also associated with anemia. Community-based deworming with albendazole and ivermectin is effective for the reduction of STH prevalence and morbidity in communities with high prevalence of hookworm and S. stercoralis.
Soil-transmitted helminth (STH) infections are a relevant public health problem in resource restricted settings due to their potential to perpetuate poverty, since chronic infections are associated with learning and grow impairment in children and reduced productivity in adults. The current strategy for STH control gives a key role to preventive chemotherapy of risk groups (preschool and school age children and women of childbearing age) with anthelmintic drugs. The drugs recommended for regular deworming are albendazole or mebendazole. This strategy does not target Strongyloides stercoralis, an STH resistant to the recommended drugs in single doses. The efficacy of ivermectin, alone or in combination, for the treatment of Strongyloides stercoralis infection has been reported in controlled trials. We conducted a pragmatic study aiming to assess the effectiveness of community based preventive chemotherapy with albendazole plus ivermectin for the control of STH prevalence and morbidity, in endemic communities of Northwestern Argentina. We found high baseline prevalence of hookworm and Strongyloides stercoralis and significant nutritional and hematological morbidity associated with these infections. After three rounds of preventive chemotherapy with albendazole and ivermectin we observed a significant decline in the prevalence of infection and in the prevalence and severity of morbidity.