RESUMO
Background: Plasmodium falciparum and Hookworm infections are prevalent in West Africa and they cause iron deficiency anemia and protein malnutrition in Children. Immune response of these parasites interact and their interactions could have repercussions on vaccine development and efficacy. The current goal of hookworm eradication lies on vaccination. We evaluated the effect of P. falciparum coinfection and albendazole treatment on naturally acquired antibody profile against hookworm L3 stage larvae antigen. Methods: In a longitudinal study, 40 individuals infected with Necator americanus only, 63 participants infected with N. americanus and P. falciparum, and 36 nonendemic controls (NECs) were recruited. The study was done in the Kintampo North Metropolis of Ghana. Stool and blood samples were taken for laboratory analyses. Serum samples were obtained before hookworm treatment and 3 weeks after treatment. Results: The malaria-hookworm (N. americanus and P. falciparum) coinfected subjects had significantly higher levels of IgE (ß = 0.30, 95% CI = [0.12, 0.48], p = 0.023) and IgG3 (ß = 0.15, 95% CI = [0.02, 0.52], p = 0.004) compared to those infected with hookworm only (N. americanus). The N. americanus groups had significantly higher levels of IgG3 (ß = 0.39, 95% CI = [0.14-0.62], p = 0.002) compared to the control group. Similarly, N. americanus and P. falciparum coinfected participants had significantly higher levels of IgE (ß = 0.35, 95% CI = [0.70-0.39], p = 0.002) and IgG3 (ß = 0.54, 95% CI = [0.22-0.76], p = 0.002). Moreover, albendazole treatment led to a significant reduction in IgE, IgA, IgM, and IgG3 antibodies against hookworm L3 stage larvae (p < 0.05). Conclusion: P. falciparum is associated with improved IgE and IgG response against hookworm L3 stage larvae. Treatment with single dose of albendazole led to reduction in naturally acquired immune response against hookworm infection. Thus, P. falciparum infection may have a boosting effect on hookworm vaccine effectiveness.
RESUMO
BACKGROUND: Vitamin A deficiency is an important public health problem in many developing countries. Women of childbearing age and children are documented as the most affected groups. OBJECTIVE: The objective was to determine the length of time mothers are protected postpartum against vitamin A depletion after receiving either 400,000 IU vitamin A in 2 divided doses or 200,000 IU as a single dose plus a placebo 24 h apart. DESIGN: Mothers (n = 168) were recruited by trained fieldworkers 7-10 d after delivery. Modified-relative-dose-response (MRDR) tests were performed at baseline in 167 women, and vitamin A was administered within 6 wk after delivery. The women were randomly assigned to 2 main treatment groups, and each treatment group was divided into 3 follow-up subgroups. Each subgroup was invited back once at month 1, 3, or 5 for a second MRDR test. RESULTS: The serum retinol concentration and the MRDR value were 1.4 +/- 0.5 micromol/L and 0.048 +/- 0.037, respectively, at baseline. A significant improvement in vitamin A status occurred after vitamin A treatment as assessed by the MRDR test (P < 0.0001). Serum retinol concentrations were not different after vitamin A treatment (P = 0.87). CONCLUSIONS: The mothers had marginally depleted liver reserves of vitamin A at baseline on the basis of MRDR test results. Liver reserves of vitamin A significantly improved in both treatment groups, and the improvement was maintained for >or= 5 mo.
