Bacteremia and malaria coinfection is a common and life-threatening condition in children residing in sub-Saharan Africa. We previously showed that coinfection with Gram negative (G[−]) enteric Bacilli andPlasmodium falciparum(Pf[+]) was associated with reduced high-density parasitemia (HDP, >10,000 parasites/μL), enhanced respiratory distress, and severe anemia. Since inflammatory mediators are largely unexplored in such coinfections, circulating cytokines were determined in four groups of children (n=206, aged <3 yrs): healthy;Pf[+] alone; G[−] coinfected; and G[+] coinfected.Staphylococcus aureusand non-TyphiSalmonellawere the most frequently isolated G[+] and G[−] organisms, respectively. Coinfected children, particularly those with G[−] pathogens, had lower parasite burden (peripheral and geometric mean parasitemia and HDP). In addition, both coinfected groups had increased IL-4, IL-5, IL-7, IL-12, IL-15, IL-17, IFN-γ, and IFN-αand decreased TNF-αrelative to malaria alone. Children with G[−] coinfection had higher IL-1βand IL-1Ra and lower IL-10 than thePf[+] group and higher IFN-γthan the G[+] group. To determine how the immune response to malaria regulates parasitemia, cytokine production was investigated with a multiple mediation model. Cytokines with the greatest mediational impact on parasitemia were IL-4, IL-10, IL-12, and IFN-γ. Results here suggest that enhanced immune activation, especially in G[−] coinfected children, acts to reduce malaria parasite burden.
Validez de constructo interna y externa del AGQ y PTEGQ en español
