Asymptomatic P. falciparum Infection is Not Associated with Serological Positivity to Soil Transmitted Helminths in Children 9118

Abstract Description Asymptomatic Plasmodium carriage poses a major public health threat, hindering malaria eradication, yet the mechanisms governing this phenomenon remain unclear. Many LMICs are endemic for both malaria and soil-transmitted helminths (STH). Helminths are known to secrete various proteins during infection to regulate host immune responses as a survival strategy meanwhile reducing host immune responses to other inflammatory processes. We conducted a two-part study in Cameroon to evaluate the possible role of STH in asymptomatic Plasmodium infection. STH IgG serological positivity (i.e. exposure) was assessed via indirect ELISA methods using recombinant Trichuris, Ascaris, and Strongyloides antigens. Overall, 85.8% of children had asymptomatic P. falciparum infection by microscopy, 88.8% had serologic positivity for at least one STH antigen, and 76.1% had asymptomatic P. falciparum plus STH exposure. We found no significant difference in the proportion of children with STH exposure and asymptomatic vs. symptomatic P. falciparum carriage, or in the proportion of asymptomatic P. falciparum carriers who were STH-exposed vs. STH-unexposed. STH reactive antibody OD values were no different in asymptomatic vs. symptomatic P. falciparum carriers and, in asymptomatic children, there was no correlation between anti-STH antibody OD values and P. falciparum load. While limitations exist, we observed no association between STH serological positivity and asymptomatic P. falciparum infection. Funding Sources NIAID Grant R21AI152578 University of Utah 3I Seed Grant University of Utah Development Funds Capacity Building Grant from the Institute Pasteur International Division Topic Categories Microbial, Parasitic, and Fungal Immunology (MPF)