African Journal of Parasitology, Mycology and Entomology

Introduction: Malaria is one of the strongest known forces of evolutionary selection in the recent history of the human genome, having had important implications in human adaptation and in the response to its infections. The objective of this systematic review was to provide an update on human genetics that have been described as affecting the human susceptibility to malaria around the world and particularly in Africa. Methods: Through world wide web research vectors and using PubMed and Google Scholar, we reviewed relevant original articles, review papers, short reports, and peer-reviewed papers on human genetics factors described as related to human susceptibility to malaria. Here, we reviewed the literature on human genetic polymorphisms associated with protection from Plasmodium infections and/or disease. Results: After reviewing and summarizing 140 manuscripts, we found that several factors appeared to hamper an effective control of malaria, including the complex biology of Plasmodium parasites, parasite genetic diversity, environmental factors, resistance to antimalarial drugs, and the lack of a highly effective vaccine for public health use. Although the cellular and molecular regulatory mechanisms underlying the pathogenesis of disease are still not fully understood, it is well-established that genetic determinants of the host play an important role in the outcome of infection and the severity of the disease. Conclusions: The interaction between malaria parasites and humans has led to the selection of several inherited traits conferring protection against malaria, such as hemoglobinopathies, enzymopathies, and immunogenetic variation, whilst others’ polymorphism describes susceptibility to the infection. Full article

Introduction: Microbial bioaerosols in indoor hospital air are one of the main potential sources of nosocomial infections. This study aimed to assess the composition of fungal bioaerosols in the indoor air of the Sourô Sanou University Hospital Center (SSUHC) in Burkina Faso. Methods: This study was carried out in two departments of the SSUHC. The indoor air sampling was carried out from August to December 2019. Sample collection was performed using the passive sedimentation method and incubated at 30 °C for 48 to 96 h. A total of 267 samples were analysed. Fungal identification was conducted based on the macroscopic and microscopic features of fungi. Results: Of the 267 samples analysed, 369 isolates belonging to 12 genera were identified. Aspergillus spp. was the most frequently isolated fungal agent with 64%, followed by Rhizopus spp. and Mucor spp. with 19.5% and 5.7%, respectively. Cladosporium spp., Penicillium spp., and Rhizomucor spp. accounted for 2.7%, 2.7%, and 1.9%, respectively. Among the genus Aspergillus spp., the most frequently isolated was A. niger (34.3%), followed by A. flavus (30.9%) and A. fumigatus (19.9%). Conclusions: This study showed that Aspergillus spp. is the most common fungal bioaerosol isolated in the indoor air of the SSUHC in Burkina Faso. Full article

Introduction. Due to the lack of systemic antifungals (SAs), many invasive fungal infections (IFIs) do not yet benefit from effective treatment in Africa. Yet, fungi are a major threat to human health. This study aimed to assess the availability of SAs and compare this availability between West Africa (WA) and North Africa (NA). Materials and methods. The information processed was obtained during the same period between February and June 2021 in Senegal, Mauritania, and Côte d’Ivoire as well as in Morocco and Tunisia. In WA, data were received from wholesale drug suppliers and private pharmacies while in NA, the data were those available on the websites of the pharmacy and drug directorates. Results. All classes of SAs were available. However, this availability was not uniform depending on location, whether in WA or NA. Fluconazole and itraconazole were the only SA available in WA. In NA, all classes of SAs have been found, particularly in Morocco, while flucytosine was the only molecule absent in Tunisia. Conclusion. NA is ahead of WA as regards the burden of IFIs both diagnostically and in the availability of SAs. Studies on the epidemiology of IFIs in Africa, particularly in WA, are limited. The partial data available highlight that IFIs are not negligible, though these may be underestimated. Thus, a network based on the directory of African pharmacy and drug directorates must be set up and run in collaboration with the national laboratory directorates for the harmonization of procedures in order to reduce morbidity and mortality related to IFIs. Full article

Introduction: The incidence of Candida infections is increasing worldwide. In clinical laboratories of resource-constrained countries, Candida speciation is commonly limited to germ tube tests and culture onto a chromogenic medium. In this study, we evaluated the diagnostic performance of Chromogenic Candida Lab-Agar^® (CCL) in identifying Candida species from clinical samples. Methods: We evaluated the diagnostic performance of CCL with 83 yeast isolates collected from 73 clinical samples at the laboratory department of Sourô Sanou University Hospital of Bobo-Dioulasso, Burkina Faso. Clinical specimens included vaginal swabs, urine, and blood cultures. After preliminary isolation on Sabouraud chloramphenicol agar, yeast isolates were inoculated onto the CCL medium and incubated at 35 °C for 48 h. Matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF MS) and ribosomal DNA internal transcribed spacer (ITS) sequencing were used as reference methods. Results: Among yeast species, Candida albicans was the most prevalent (43.4%), followed by C. krusei (13.3%), C. glabrata (12.0%), C. kefyr (8.4%), and C. tropicalis (7.2%). The overall agreement rate of CCL was 56.6% and varied across Candida species; it was 94.4% for C. albicans, 50% for C. glabrata, 18.2% for C. krusei, and 33.3% for C. tropicalis. Conclusions: This study showed that CCL had moderate accuracy in identifying Candida at the species level from clinical specimens in a routine laboratory in Burkina Faso. The misidentification of non-albicans species may expose patients to inadequate antifungal treatment. Therefore, identifying yeast in a routine based on CCL is not enough and should be associated with more accurate methods. Full article

Introduction: Human filariasis causes high morbidity and severe illness. There is a link between helminth infection and anemia. The objective of this study was to estimate the prevalence of blood-dwelling microfilariae among pregnant women in Burkina Faso using a molecular technique and attempt to find an association between anemia and filarial infection. Methods: A total of 1018 dried blood spot samples (DBS) were collected from pregnant women at the Health District of Nanoro. The DNA was isolated from DBS samples using a rapid and simple method. Afterward, the isolated DNA was assayed using the Filaria real-time PCR (F-RT-PCR) method. Results: Ten F-RT-PCR-positive samples were obtained as follows: two W. bancrofti (0.2%), four L. loa (0.39%), and four M. perstans (0.39%). No concomitant filarial infections were detected, as well as no coinfections between filarial disease and malaria. There was no link between the presence of W. bancrofti, L. loa, or M. perstans and anemia in pregnant women. Conclusions: The prevalence and intensity of human filariasis in this study were low for all of the samples in which microfilariae were detected. The F-RT-PCR can be a confirmatory test for diagnosis in remote areas due to its effectiveness in detecting and differentiating, both sensitively and specifically, a wide range of filarial parasites. Full article

Introduction: Schistosomiasis is classically described as a rural parasitic infection affecting deprived communities. In Mali, where Schistosoma haematobium and S. mansoni are endemic, the disease is also spreading to urban areas. Our study aimed to describe the prevalence and schistosomiasis maintenance factors in the district of Bamako. Materials and methods: An observational cross-sectional study was carried out in April 2023 involving schoolchildren randomly selected aged 6 to 14 years from Taliko (a peri-urban area crossed by the Woyowayanko river known as an important breeding and infestation habitat of snails) and Missabougou (an area subjected to social and environmental changes, including the development of the canal serving the district). Data on sociodemographics, symptoms, and human–water contact activities were recorded through a structured questionnaire. Filtration and Kato–Katz techniques were used for S. haematobium and S. mansoni diagnosis. Overall, 736 urine samples and 668 stool samples were examined. Multivariate logistic analysis was employed to test for associations between variables. Results: The prevalence of S. haematobium was 18.2% [95% CI: 14.5–21.8%] and that of S. mansoni was 8.1% [95% CI: 4.2–11.9%]. This prevalence was significantly higher in Taliko than in Missabougou: 34.4% [95% CI: 29.1–39.6%] versus 2.4% [95% CI: 0–8.0%] (p = 0.001) for S. haematobium and 12.1% versus 4.3% for S. mansoni (p = 0.001). In Taliko, children frequenting the river were significantly more affected with S. haematobium and hematuria and had higher parasite intensity (p < 0.05). Children with macroscopic hematuria who attended a school close to the river (p = 0.018) in Taliko, as well as children who used to urinate in water, were more infected (p < 0.05). In Missabougou, no significant variation in human–water contact activities was recorded. Conclusion: Our results show that S. haematobium and S. mansoni were still rampant in the district of Bamako; they also highlight that the use of water from the Woyowayanko river appears to be the major risk factor for the maintenance of schistosomiasis in the district of Bamako. Full article

Background: In Mali, Chloroquine has been abandoned in 2005 because of the high in vivo and in vitro resistance rate of Plasmodium falciparum to this molecule. Artemisinin-based combination therapies (ACT) are currently recommended to treat uncomplicated malaria. Few antimalarials are in development. Assessing the prevalence of known antimalarial drug resistance markers might help in designing new combination regimens. This study aims to measure the dynamics of molecular markers of chloroquine in Kolle before, during and after chloroquine withdrawal. Method: Dried blood spot samples collected from previous drug efficacy studies conducted in Kolle between 2001 and 2015 were selected and Pfcrt and Pfmdr genes were genotyped for SNPs conferring resistance to chloroquine. Results: A total of 652 samples were analyzed. The overall prevalences of the mutant alleles Pfcrt 76T and Pfmdr1 86Y were 72.9% and 20%, respectively. The yearly prevalence rate for both mutant alleles remained constant from 2001 to 2015 (p > 0.05). Conclusion: The prevalence of the Pfcrt mutant allele remained high from 2001 to 2015 in Mali, although the prevalence of the Pfmdr1 mutant allele was low. Full article

Background: Vulvovaginal infections are common in women. In Togo’s medical biology laboratories, routine diagnosis is often limited to filamentation testing, and the identification of fungal species is rarely performed. The aim of this study was to update the spectrum of Candida species isolated in vulvovaginitis and to determine their antifungal susceptibility profiles. Methods: Cross-sectional analytical study was carried out in women presenting leukorrhea received in two public laboratories in Lomé from June 2015 to October 2015. Socio-demographic and clinical data were collected through a structured questionnaire during an individual interview. Vulvovaginal samples were cultured in Sabouraud dextrose agar with chloramphenicol. Identification of fungi was determined by filamentation test and API 20C AUX^® gallery. The antifungal susceptibility profile was performed on five antifungal agents by a semi-solid medium microdilution technique of the ATB Fungus 3^® gallery. Results: Candida albicans/dubliniensis/africana complex was isolated in 51.6% of cases by API 20C AUX^® gallery. The same species were isolated by filamentation test in 12.3% of cases. All Candida species identified were sensitive to Voriconazole, whereas four species including Candida albicans/dubliniensis/africana complex had variable sensitivities compared to the five antifungal agents tested. Conclusions: This study demonstrated a high distribution of non-albicans species of Candida in Togo. Empirical treatment of candidiasis could contribute to increasing antifungal resistance. Routine fungi identification, at least by using an auxanogram test, could be instituted in medical laboratories to improve the therapeutic management of these diseases. Full article

Introduction: Blastocystis sp. is an intestinal protozoan that is commonly reported, but whose clinical significance remains controversial. Clinical forms of this infection range from asymptomatic carriage to clinical signs, specifically gastrointestinal ones. There is a lack of data on the epidemiology of this protist in Gabon. This study was carried out to provide data on the frequency of Blastocystis sp. infection and its association with clinical signs and the haemoglobin rate. Methods: A cross-sectional study was conducted between September 2018 and November 2019. Stool samples were collected in five of the nine provinces of Gabon from children and adults. Sociodemographic and clinical data were recorded using a standardised pre-tested questionnaire. Haematological parameters and temperature were reported in a laboratory register. Parasitological diagnosis was performed using stool direct examination and a Merthiolate-Iodine-Formaldehyde (M.I.F) concentration to detect Blastocystis sp. Results: In total, 843 participants were interviewed and examined; 414 brought back stool samples. The frequency of Blastocystis sp. infection was 45.2% (n = 187/414), and it increased with age: from 20.0% in young children to 49.5% in adults (P = 0.0057). Being a male (P = 0.08) tended to be associated with Blastocystis sp. carriage. In the multivariate logistic regression, only males were associated with Blastocystis sp. infection and had a 4.3-fold higher risk of being infected than females did (adjusted odds ratio = 4.3; 95% CI = 1.2–15.6; P = 0.03). Diarrhoea, abdominal pain and colitis were observed in some patients with Blastocystis sp. monoinfection. No relation between Blastocystis sp. carriage and anaemia was found. Conclusion: The frequency of Blastocystis sp. infection was high. Males were more at risk of being infected. Blastocystis sp. could be used as indicator in the improvement of environmental sanitation and hygiene, coupled with improved housing. Additional investigations in a population with clinical symptoms should be performed. Full article

Introduction: The onset of Plasmodium falciparum (P. falciparum) resistance to antimalarial drugs requires the careful surveillance of African parasite populations. Genomic tools are implemented to detect evolutionary changes that could impact malaria control and elimination strategies. Here, we evaluate the genome-wide pattern of selection and sequence variation in P. falciparum populations in Abidjan, Côte d’Ivoire. Methods: The study was conducted in three localities of Abidjan from 2013 to 2014. We collected 70 blood samples after receiving written informed consent from patients above two years of age. After extracting P. falciparum and human DNA from isolates, we performed whole-genome sequencing and used population genomics approaches to investigate the genetic diversity and complexity of infections and identify loci under positive directional selection. Results: We observed an excess of rare variants in the population, showing a clear mutation process in the isolates. Moderate Fst estimates (0.3) was detected for surfin, an immune invasion gene family. Seven iHS regions that had at least two SNPs with a score > 3.2 were identified. These regions code for genes that have been under strong directional selection. Two of these genes were the chloroquine resistance transporter (crt) on chromosome 7 and the dihydropteroate reductase (dhps) on chromosome 8. Our analyses showed that a recent selective sweep occurred for the erythrocyte membrane protein (Pfemp1). Conclusion: Our analyses identified genes under selective drug pressure and balancing selection on protective immune-specific genes. These findings demonstrate the effectiveness of genomics analyses to follow the evolution of malaria parasites and adopt appropriate strategies to eliminate malaria in Côte d’Ivoire. Full article

Introduction: Severe anemia caused by severe malaria remains concentrated in children under 5 years old in Africa. In addition to blood-transfusion-related infections that pose a health concern, transfusion of severely anemic blood to a patient with severe anemia is another important concern. Method: Following the observation of a case of severe anemia in a blood donor, we conducted a secondary data analysis from a previous study to assess the frequency of anemia in blood donors in San, Mali. Results: In total, out of 140 volunteers, 13 (9%, 95% CI: 5.43–15.41) blood donors had moderate to severe anemia, based on Mali hemoglobin (Hb) normal values (10.5–16.5 g/dL, MRTC-GLP laboratory). In particular, we observed one case of severe anemia with an Hb level of 6.5 g/dL. Conclusions: To the best of our knowledge, this is the first report of severe anemia in blood donors in a malaria endemic area in Mali. Full article