Introduction: Malaria remains a public health challenge, especially in sub-Saharan Africa where asymptomatic malaria is not uncommon. In the present study, the prevalence of asymptomatic falciparum malaria was investigated in almajirai, and the genetic polymorphisms of chloroquine (CQ) resistance biomarkers were assessed. Methodology: A total of 440 apparently healthy almajirai between 3 and 12 years of age were randomly enrolled in Maiduguri, northeast Nigeria, between July and December 2010. Parasitemia and gametocytemia were assessed by light microscopy, and polymorphisms of Pfcrt K76T and Pfmdr1 N86Y were detected by nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Results: The mean age of the subjects was 8.3 ± 4.5 years, with subjects ≤ 5 years accounting for 10.7% (47/440) of the population. Prevalence of asymptomatic falciparum parasitemia and gametocytemia were 12.7% (56/440) and 8.6% (38/440), respectively. Geometric mean parasite density (GMPD) was 240 (160-630) parasites/µL, while geometric mean gametocyte density (GMGD) was 53 (24-96) gametocytes/µL. The GMPD was higher among subjects ≤ 5 years of age (p = 0.027). Pfcrt 76T was detected in 5.4% (3/56) of the isolates, and no isolates harbored Pfmdr1 86Y mutant. Conclusions: The study reveals asymptomatic falciparum malaria in almajirai and low levels of Pfcrt 76T and Pfmdr1 86Y alleles. These findings could hinder malaria control measures, and hence almajirai should be incorporated into malaria control programs.

Background: Entamoeba histolytica is a protozoan parasite and the causative agent of amoebic liver abscess and amoebic dysentery in humans. It is most common in developing countries such as Mexico, India, East and South Africa and regions of Central and South America. The estimations of the worldwide burden of amoebiasis indicated that approximately 500 million people were infected by the parasite and 10% of these individuals had invasive amoebiasis. Genetic variation among E. histolytica isolates collected from a wide geographical range has already been demonstrated in numerous studies. However, the level of intra-species genetic variation in E. histolytica populations in South Africa remains unknown.Methods & Materials: Stool samples were collected from patients attending different health centres in the Limpopo Province and Pretoria. Genomic DNA was isolated from these samples and a nested PCR was used to amplify the 16S-like ribosomal RNA genes. The PCR amplicons were sequenced and the genetic variation as well as the phylogenetic relationships among the detected E. histolytica isolates was investigated.Results: Sequence analysis revealed 13 unique genotypes grouped into 5 different clades from among 61 E. histolytica stool isolates. Interestingly, two strains were exactly identical, in that A was substituted by G in the same position, indicating that they are possibly from the same source. The other genotypes showed varying degree of polymorphism in the 439 bp PCR product of the 16S-like rRNA gene revealing the existence of genetic variations within the species of E. histolytica infecting humans. Conclusion:In this study the presence of new E. histolytica genotypes in two area of South Africa exploring a small region of the 16S-like rRNA gene may be a unique finding yet genotyping the whole gene would probably reveal more genetic diversity and clustering which could point towards the existence of intraspecies variation in E. histolytica infecting humans and shed light on clinical outcome factors. Moreover, molecular phylogenetic results have demonstrated that the 16S-like rRNA gene of all E. histolytica isolates tested are closely clustered together and are possibly restricted to the study region and have shown how valuable the 16S-like rRNA gene is in epidemiological studies.