While we found no evidence for an association between parasite carriage by microscopy or PCR and concurrent antibody prevalence or titre in study participants

aged 6 years and older (data not shown), parasite carriage was associated with elevated antibody prevalence and titre in younger children. When parasite carriage among 1- to 5-year-old children was categorized as parasite-free, submicroscopic infection or patent (microscopically detectable) infection, antibody prevalence Tanespimycin increased across these categories for AMA-1 (P < 0·001), MSP-119 (P = 0·006) and MSP-2 (P < 0·001), but not CSP (P = 0·77). Antibody titre increased across these categories of parasite carriage for AMA-1, MSP-119, MSP-2 and CSP (Figure 3; P = 0·001). Anti-gSG6 antibody prevalence and titre also increased across these categories (P < 0·001). Pairwise comparisons are presented in Table 2. We further explored the dynamics of antibody titres

in relation to malaria infections in children 1–5 years of age (i) who were consistently parasite-positive throughout the study; (ii) who were parasite-free throughout the study; (iii) who were parasite-positive at enrolment but did not become re-infected after treatment; and (iv) who were parasite-free at enrolment but acquired an infection during follow-up. Children below 5 years of age who were consistently parasite-positive during the study did not have consistently higher titres of learn more antibodies against AMA-1 (P = 0·21), MSP-119 (P = 0·26), MSP-2 (P = 0·91), CSP (P = 0·29) or gSG6 (P = 0·23) compared with children who were consistently parasite-negative (Figure 4; Table 3). However, the dynamics of antibody titres were influenced by parasite exposure during the study. In children of this age group who were consistently parasite-positive, antibody titre against AMA-1 (P = 0·39), MSP-119 (P = 0·47), MSP-2 (P = 0·48) and gSG6 (P = 0·25) did Resveratrol not change significantly with time, while antibody titres for CSP showed a statistically significant decrease (P = 0·011). In contrast, we found evidence for

a decline in antibody titres for AMA-1 (P < 0·0001), MSP-119 (P = 0·015), CSP (P = 0·016) and gSG6 (P = 0·0005) with a borderline significant trend for MSP-2 (P = 0·08) for children of this age group who were never parasite-positive by microscopy or PCR during the study. Similarly, antibody titres decreased in children who were parasite-positive at enrolment but did not become re-infected after treatment for AMA-1 (P < 0·0001), MSP-119 (P = 0·003), MSP-2 (P = 0·0001), CSP (P < 0·0001) and gSG6 (P < 0·0001). Children who acquired an infection during the study showed no consistent patterns in antibody titres: antibody titres for all antigens were stable or elevated 6 weeks after enrolment in children aged 1–5 years, with a decline between weeks 6 and 16 to (below) enrolment levels.