BACKGROUND: Measurement of @entity311 endemicity is typically based on vector or parasite measures. A complementary approach is the detection of parasite specific IgG antibodies. We determined the antibody levels and seroconversion rates to both @entity3965 and P. falciparum merozoite antigens in individuals living in areas of varying @entity3965 endemicity in Par   state, Brazilian Amazon region. METHODOLOGY/PRINCIPAL FINDINGS: The prevalence of antibodies to recombinant antigens from @entity3965 and @entity3964 was determined in 1,330 individuals. Cross sectional surveys were conducted in the north of Brazil in Anaj  s, Bel  m, Goian  sia do Par  , Jacareacanga, Itaituba, Trair  o, all in the Par   state, and Sucuriju, a free- @entity311 site in the neighboring state Amap  . Seroprevalence to any P. vivax antigens (MSP1 or AMA-1) was 52.5%, whereas 24.7% of the individuals were seropositive to any P. falciparum antigens (MSP1 or AMA-1). For P. vivax antigens, the seroconversion rates (SCR) ranged from 0.005 (Sucuriju) to 0.201 (Goian  sia do Par  ), and are strongly correlated to the corresponding Annual Parasite Index (API). We detected two sites with distinct characteristics: Goian  sia do Par   where seroprevalence curve does not change with age, and Sucuriju where seroprevalence curve is better described by a model with two SCRs compatible with a decrease in force of @entity281 occurred 14 years ago (from 0.069 to 0.005). For P. falciparum antigens, current SCR estimates varied from 0.002 (Bel  m) to 0.018 (Goian  sia do Par  ). We also detected a putative decrease in disease transmission occurred    29 years ago in Anaj  s, Goian  sia do Par  , Itaituba, Jacareacanga, and Trair  o. CONCLUSIONS: We observed heterogeneity of serological indices across study sites with different endemicity levels and temporal changes in the force of @entity281 in some of the sites. Our study provides further evidence that serology can be used to measure and monitor transmission of both major species of @entity311 parasite.

Serologically defined variations in XXXX endemicity in par   state, Brazil.

@entity311 :: ('MESH:D008288', 'Disease') :: ['malaria'] @entity3965 :: ('5855', 'Species') :: ['P. vivax'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity3964 :: ('5833', 'Species') :: ['P. falciparum']
@entity311 :: (MESH:D008288,Disease) :: ['malaria']
