BackgroundTranscriptomic research of blood cell lineages supports the understanding of distinct features of the immunopathology in human malaria.MethodsWe used microarray hybridization, validated by real-time RT-PCR to analyze whole blood gene expression in healthy Gabonese children and children with various conditions of Plasmodium falciparum infection, including i) asymptomatic infection, ii) uncomplicated malaria, iii) malaria associated with severe anemia and iv) cerebral malaria.FindingsOur data indicate that the expression profile of 22 genes significantly differed among the investigated groups. Immunoglobulin production, complement regulation and IFN beta signaling, in particular IRF7 and ISRE binding signatures in the corresponding genes, were most conspicuous. Down-regulation in cerebral malaria seems to rely on AhRF, GABP and HIF1 hypoxia transcription factors. ARG1, BPI, CD163, IFI27, HP and TNFAIP6 transcript levels correlated positively with lactatemia, and negatively with hemoglobin concentrations.InterpretationDifferences in gene expression profile reflect distinct immunopathological mechanisms of P. falciparum infection. They emerge as potential prognostic markers for early therapeutic measures and need to be validated further.FundThis work was supported by a grant of the NGFN (Nationales Genomforschungsnetz 01GS0114) and by a CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil) PhD scholarship for A. B. W. Boldt. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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Relapses of enteric fever induced by Schistosoma intercalatum have been observed to occur in central Africa. In Libreville, Gabon, 70 children (ages, 2.1-15.9 years) who were seronegative for human immunodeficiency virus and were hospitalized for septicemic salmonellosis underwent rectal biopsy for diagnosis of S. intercalatum infection. A nontyphoidal Salmonella species was isolated from 53 of the 70 patients: Salmonella typhimurium in 14 cases; Salmonella enteritidis in 7 cases; Salmonella galiema in 4 cases; Salmonella arizonae in 3 cases; and other species in 25 cases. Schistosomal eggs were present in the rectal mucosa of 48 (90.6%) of these 53 patients, in 11 (64.7%) of 17 patients with septicemia due to Salmonella typhi or Salmonella paratyphi, and in 21 (38.2%; P < .001) of 55 controls. Clinical symptoms were not different among patients coinfected with S. intercalatum and nontyphoidal Salmonella vs. those with enteric fever. Treatment with antibiotics induced apyrexia only after administration of antiparasitic therapy in 30 patients. These data strongly suggest interactions between S. intercalatum and Salmonella in infected children with clinically severe nontyphoidal salmonellal septicemia.

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Hydrogen breath tests were performed in Gabon (Central Africa) after a loading dose of lactose in 67 well-nourished African children (50 with intestinal parasites and 17 unparasitized) and in 18 unparasitized young adults. All had normal nutritional status, and none had diarrhea or digestive symptoms. Parasites that were found included Ascaris lumbricoides in 76% of the parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16%, and Necator Americanus in 14%. A similar proportion of parasitized (64%) or unparasitized (62.8%) subjects were lactose malabsorbers. Giardia infection was associated with a higher, but not significantly different, proportion of lactose intolerance (10 of 12, 83.3%). The presence of infection with A. lumbricoides or T. trichiura did not increase the percentage of lactose malabsorption. These data indicate that a decrease of lactase activity in well-nourished African children is not related to the presence or the importance of Ascaris or other intestinal parasites if the nutritional status is normal.