Report of high prevalence of schistosome infection in Biomphalaria snails from a geographic area with no previous prevalence of human schistosomiasis in Nigeria.

Previous study using the traditional method of screening snails for infection reported shedding of Schistosoma cercaria by Biomphalaria snails from a river in Nkalagu, southeastern Nigeria. This is contrary to published reports that Biomphalaria from this part of the country does not shed schistosome cercaria. Here, we employed the use of polymerase chain reaction (PCR) methods to screen and characterize the Biomphalaria snails from Nkalagu. Snails were collected from the River Uzuru in dry season, identified and subjected to molecular assays. Genomic DNA (gDNA) was extracted from whole tissues of the 212 Biomphalaria snails and amplified using conventional PCR to check for the schistosome infection level. Assay for the detection of S. mansoni infection was further done using a nested PCR (nPCR). We amplified the entire internal transcribed spacer 2 (ITS2) regions from gDNA of the 212 snails. The representative samples were sequenced and subjected to BLAST searches to confirm snail species. Of the 212 snails screened, 164 (77.4%) of the snails were infected with schistosomes, but only 16 (9.76%) of the snails were positive for S. mansoni infection. Amplification of the snails' ITS2 region yielded a product of 460 bp, and BLAST searches confirmed the snails to be B. pfeifferi, and BLAST searches confirmed the snails to be B. pfeifferi. This paper reports for the first time the presence of S. mansoni positive B. pfeifferi in Nkalagu, which suggest there may be cases of intestinal schistosomiasis in this part of Nigeria.

Effect of placental malaria on birth weight of babies in Nnewi, Anambra state, Nigeria.

BACKGROUND & OBJECTIVES: In malaria-endemic countries, one adverse consequence of placental malaria on infants is low birth weight (LBW) caused by intra-uterine growth retardation and pre-term delivery. The effect of placental malaria on birth weight of babies was investigated in Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, Anambra state, Nigeria. METHODS: Placental blood was collected from 364 women who gave birth in NAUTH. Thin and thick placental blood smears were made and checked for the presence of malaria parasites. Plasmodium falciparum antigen rapid kit was used to confirm the presence of P. falciparum. New-borns were weighed and classified as normal birth weight (≥2500 g) or LBW (<2500 g). Analysis of variance (ANOVA), Student's t and Pearson chi-square tests were used to compare means and percentages. Risk factors for LBW were also determined. RESULTS: Placental malaria was found in 55.2% (n = 201) of the women. Placental malaria was associated with gravidity while age was not. In all the age groups, primigravidae and secundigravidae were mostly infected. Women with placental malaria delivered more LBW babies (32.1%) than their uninfected counterparts (5.5%), with primigravidae having more LBW babies. Similarly, weight of babies born by infected women was significantly different from that of uninfected women (p <0.0001). In multivariate analysis, placental malaria was associated with LBW (OR 0.1, 95% CI 0.06-0.17, p <0.0001). CONCLUSION: The result suggests a high prevalence of placental malaria and its close association with LBW in pregnant women attending antenatal clinic in NAUTH. It was also found that the percentage of LBW was highest in primigravidae.