Fast Technology Analysis Enables Identification of Species and Genotypes of Latent Microsporidia Infections in Healthy Native Cameroonians.

Several enteric microsporidia species have been detected in humans and other vertebrates and their identifications at the genotype level are currently being elucidated. As advanced methods, reagents, and disposal kits for detecting and identifying pathogens become commercially available, it is important to test them in settings other than in laboratories with "state-of-the-art" equipment and well-trained staff members. In the present study, we sought to detect microsporidia DNA preserved and extracted from FTA (fast technology analysis) cards spotted with human fecal suspensions obtained from Cameroonian volunteers living in the capital city of Yaoundé to preclude the need for employing spore-concentrating protocols. Further, we tested whether amplicon nucleotide sequencing approaches could be used on small aliquots taken from the cards to elucidate the diversity of microsporidia species and strains infecting native residents. Of 196 samples analyzed, 12 (6.1%) were positive for microsporidia DNA; Enterocytozoon bieneusi (Type IV and KIN-1), Encephalitozoon cuniculi, and Encephalitozoon intestinalis were identified. These data demonstrate the utility of the FTA cards in identifying genotypes of microsporidia DNA in human fecal samples that may be applied to field testing for prevalence studies.

Co-infections of malaria and geohelminthiasis in two rural communities of Nkassomo and Vian in the Mfou health district, Cameroon.

BACKGROUND: Human co-infection with malaria and helmimths is ubiquitous throughout Africa. Nevertheless, its public health significance on malaria severity remains poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: To contribute to a better understanding of epidemiology and control of this co-infection in Cameroon, a cross-sectional study was carried out to assess the prevalence of concomitant intestinal geohelminthiasis and malaria, and to evaluate its association with malaria and anaemia in Nkassomo and Vian. Finger prick blood specimens from a total of 263 participants aged 1-95 years were collected for malaria microscopy, assessment of haemoglobin levels, and molecular identification of Plasmodium species by PCR. Fresh stool specimens were also collected for the identification and quantification of geohelminths by the Kato-Katz method. The prevalence of malaria, geohelminths, and co-infections were 77.2%, 28.6%, and 22.1%, respectively. Plasmodium falciparum was the only malaria parasite species identified with mean parasite density of 111 (40; 18,800) parasites/µl of blood. The geohelminths found were Ascaris lumbricoides (21.6%) and Trichuris trichiura (10.8%), with mean parasite densities of 243 (24; 3,552) and 36 (24; 96) eggs/gram of faeces, respectively. Co-infections of A. lumbricoides and P. falciparum were the most frequent and correlated positively. While no significant difference was observed on the prevalences of single and co-infections between the two localities, there was a significant difference in the density of A. lumbricoides infection between the two localities. The overall prevalence of anaemia was 42%, with individuals co-infected with T. trichiura and P. falciparum (60%) being the most at risk. While the prevalence of malaria and anaemia were inversely related to age, children aged 5-14 years were more susceptible to geohelminthiasis and their co-infections with malaria. CONCLUSION/SIGNIFICANCE: Co-existence of geohelminths and malaria parasites in Nkassomo and Vian enhances the occurrence of co-infections, and consequently, increases the risk for anaemia.

Evidence for high prevalence of Pneumocystis jirovecii exposure among Cameroonians.

Cameroon lacks the capacity for routine Pneumocystis pneumonia (PcP) diagnosis, thus, the prevalence of Cameroonian exposure to this microbe is unknown. It is known that Pneumocystis infecting different mammalian host species represent diverse phylogenetic backgrounds and are now designated as separate species. The highly sensitive nature of ELISA and the specificity afforded by using human-derived P. jirovecii Msg peptides has been shown to be useful for serological analysis of human sera. Thus, sera from patients in Yaoundé, the capital city of Cameroon, were analyzed for anti-P. jirovecii antibodies by enzyme-linked immunosorbent assay (ELISA) using three recombinant major surface glycoprotein (Msg) peptide fragments, MsgA1, MsgB, and MsgC1. Based on serum recognition of one or more of the three fragments, 82% of the total samples analyzed was positive for antibodies to P. jirovecii Msg, indicating high prevalence of P. jirovecii infection or colonization among Cameroonians. Different Msg fragments appear to be recognized more frequently by sera from different geographic regions of the globe. Antibodies in the Cameroonian serum samples recognized MsgA1>MsgC1>MsgB, suggesting that different P. jirovecii strains exist in different parts of the world and/or human populations differ in their response to P. jirovecii. Also, HIV(+) patients diagnosed with respiratory infections (such as TB and pneumonia) and maintained on trimethoprim/sulfamethoxazol prophylaxis had relatively lower anti-Msg titers. Whether PcP prophylaxis has significant effects on the quality of life among HIV(+) patients in Cameroon warrants further investigation.

Measure of viral load by using the Abbott Real-Time HIV-1 assay on dried blood and plasma spot specimens collected in 2 rural dispensaries in Cameroon.

BACKGROUND: This study aimed to evaluate the use of dried blood spots (DBSs) and dried plasma spots (DPSs) locally collected in 2 rural dispensaries in Cameroon for the quantification of HIV-1 RNA. METHODS: Forty-one subjects were sampled and spots of whole blood and plasma were deposited onto Whatman 903 cards and dried at ambient temperature under local conditions. Two sets of DBS and DPS cards were done per patient. The rest of the liquid plasma (LP) was frozen until use. LPs were tested at the "Chantal Biya" International Reference Centre (Yaoundé, Cameroon) by the Abbott Real-Time HIV-1 assay (Abbott Molecular Diagnostics, Wiesbaden, Germany). One series of DBS and DPS was transported and tested between 2 and 6 weeks later at the Virology Laboratory of Saint-Etienne (France). The second series was routed by mail and tested after up to 3 months of storage at ambient temperature. RESULTS: From the first series, the correlation rate between viral loads obtained from LP and DBS, and from LP and DPS, was 0.98 and 0.99, respectively; specificity of DBS and DPS results was 100%. The results obtained from the second series indicate a great stability of DBS after long-term storage. CONCLUSION: This study demonstrates that DBSs collected under local conditions in resource-limited settings are suitable for the differed quantification of HIV-1 RNA.