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Objectives: The Human Immunodeficiency Virus (HIV) causes a progressive alteration of the immune system leading to increased susceptibility to infectious agents. A few studies have been done on gastrointestinal parasites in HIV-infected persons in Cameroon. However, these studies need to be updated. The objective of this study was to identify and determine the prevalence of gastrointestinal parasites in relation to associated factors in HIV+ patients at the Bafoussam Regional Hospital. Methods: The study was conducted from May to December 2021 on 240 patients aged from 3 to 73 years. Stool samples were tested for parasites and HIV viral loads were assessed in blood samples. Results: The analyses revealed that 58 (24.2%) patients were carriers of at least one parasite species. A total of 7 parasite species were identified, the most predominant being Entameba histolytica (12.62%) followed by Cryptosporidium spp (4.54%). A high majority, 91.3% had undetectable viral loads with the presence of intestinal parasitosis. However, the most infested patients were those with viral loads above 50 copies/ml. Concerning the duration of antiretroviral treatment, the rate of infestation was higher in patients with less than 12 months on treatment (OR=2.8; p=0.04). The prevalence of infestation was significantly higher in those under 20 years of age (OR = 5.13; p = 0.03). The distribution of gastrointestinal parasite species according to viral loads varied significantly for Blastocystis hominis and Dicrocoelum dendriticum with p

Malaria remains a major public health problem worldwide, with eradication efforts thwarted by drug and insecticide resistance and the lack of a broadly effective malaria vaccine. In continuously exposed communities, polyclonal infections are thought to reduce the risk of severe disease and promote the establishment of asymptomatic infections. We sought to investigate the relationship between the complexity of P. falciparum infection and underlying host adaptive immune responses in an area with high prevalence of asymptomatic parasitaemia in Cameroon. A cross-sectional study of 353 individuals aged 2 to 86 years (median age = 16 years) was conducted in five villages in the Centre Region of Cameroon. Plasmodium falciparum infection was detected by multiplex nested PCR in 316 samples, of which 278 were successfully genotyped. Of these, 60.1% (167/278) were polyclonal infections, the majority (80.2%) of which were from asymptomatic carriers. Host-parasite factors associated with polyclonal infection in the study population included peripheral blood parasite density, participant age and village of residence. The number of parasite clones per infected sample increased significantly with parasite density (r = 0.3912, p

Asymptomatic malarial parasitemia is highly prevalent in Plasmodium falciparum endemic areas and often associated with increased prevalence of mild to moderate anemia. The aim of this study was to assess the prevalence of anemia during asymptomatic malaria parasitemia and its interplay with persistent infection in highly exposed individuals. A household-based longitudinal survey was undertaken in a malaria hyperendemic area in Cameroon using multiplex nested polymerase chain reaction to detect plasmodial infections. Residents with P. falciparum asymptomatic parasitemia were monitored over a 3-week period with the aid of structured questionnaires and weekly measurements of axillary temperatures. Of the 353 individuals included (median age: 26 years, range 2–86 years, male/female sex ratio 0.9), 328 (92.9%) were positive for malaria parasitemia of whom 266 (81.1%) were asymptomatic carriers. The prevalence of anemia in the study population was 38.6%, of which 69.2% were asymptomatic. Multivariate analyses identified high parasitemia (> 327 parasites/µL) and female gender as associated risk factors of asymptomatic malarial anemia in the population. Furthermore, risk analyses revealed female gender and anemia at the time of enrolment as key predictors of early development of febrile illness (< 3 weeks post enrolment) among the asymptomatic individuals. Together, the data reveal an extremely high prevalence of asymptomatic malaria parasitemia and anemia in the study area, unveiling for the first time the association of asymptomatic malarial anemia with early clinical conversion from asymptomatic to symptomatic infection. Furthermore, these findings underscore the negative impact of asymptomatic malaria parasitemia on individual health, necessitating the development of appropriate control and preventive measures.

BackgroundMalaria immuno-epidemiological data suggest that two key immunological processes, including anti-parasite and anti-disease immunity, may be implicated in the maintenance of asymptomatic infections. However, in highly exposed persons where the duration of chronic malaria infection could range from a few weeks to several years, the host immunological factors that determine the persistence of asymptomatic parasitemia remain poorly understood. This study therefore aimed to define the association between antibody or cytokine responses with asymptomatic malarial parasitemia amongst highly exposed individuals in Cameroon.MethodsAn initial cross-sectional study was carried out (week 1) and individuals were classified as having asymptomatic Plasmodium parasitemia with no fever (AS), symptomatic Plasmodium parasitemia with an axillary temperature ≥37.5°C (SY) and non-infected (NI) (no Plasmodium parasitemhia and a normal body temperature). Asymptomatic individuals were followed for 10 weeks before being treated with artemisinin-based combination treatment (ACT) and a final sample taken at week 16, 5 weeks after treatment. Those who continued to carry Plasmodium parasites with no measureable fever were defined as having chronic asymptomatic malaria. Antibody levels to P. falciparum schizont extract (SE), merozoite extract (ME), erythrocyte binding antigen-175 (EBA-175) and merozoite surface protein-1 (MSP-1) were quantified by ELISA. The growth inhibitory activities of circulating anti-parasite antibodies were quantified using the 3D7 laboratory strain of P. falciparum and a Sybr Green-I based parasite growth inhibition assay. Plasma levels of 38 cytokines were measured by Luminex technology.ResultsAmongst infected individuals, parasitemia significantly decreased with increased age although this decrease in parasitemia with age was only observed until age 20. Individuals older than 20 years of age had low parasitemia and this remained constant between the ages of 20 and 80. Although there was no difference in the magnitude of the antibody response between AS, SY and NI groups to any of the antigens tested, median levels of antibody against P. falciparum crude extracts and recombinant proteins EBA-175 and MSP-1 were significantly higher in those older than 20 years of age compared with the younger age group as might be expected from lower parasite levels. Parasite densities and P. falciparum clones fluctuated widely over the 10-week follow-up period in individuals with persistent asymptomatic parasitemia but collectively there was no change in the antibody levels over time within this group. Similar to antibody levels, many levels of the cytokines measured were stable over time. However, IL-10 levels decreased after treatment indicating that this cytokine was associated with parasite carriage in asymptomatic individuals. The ratio of IL-10 to pro-inflammatory cytokines, tumor necrosis factor-α (TNF-α) and lymphotoxin-α (LT-α) ratios were higher in the symptomatic group compared to the asymptomatic individuals but only in the younger (ConclusionTaken together, the above findings indicate that asymptomatic carriage of Plasmodium falciparum in children living in a hyperendemic area occurs independently of antibody responses, but is associated with induction of IL-10.

Background The need to start treatment early for pregnant women who present with clinical features of malaria usually conflicts with the need to confirm diagnosis by microscopy (MP) before treatment, due to delays in obtaining results. Parasite sequestration in the placenta is also a problem. Rapid diagnostic tests (RDT), which detect soluble antigens, are a valuable alternative. The objective of this study was to evaluate pretreatment parasite prevalence by microscopy and by RDT and to assess the accuracy of RDT with MP as reference. Methods A prospective cross-sectional study was carried out at the obstetrical unit of the Central Hospital in Yaoundé, during the period January-August 2015. Consenting patients with symptoms of suspected malaria in pregnancy were recruited and a blood sample taken for MP and RDT before treatment was started. The estimates of diagnostic performance (with 95% confidence interval) were calculated in OpenEpi online software using the Wilson’s score. The agreement, as reflected by the Cohen’s kappa, was calculated and interpreted using known intervals. Results The results showed that, out of the 104 patients recruited, 69.2% (95%CI: 59.1–77.5) were MP positive while 77.94% (95%CI: 63.1–80.9) were RDT positive. The sensitivity of the malaria RDT was 91.67% (95%CI: 83.69–96.77) while the specificity was 53.13% (95%CI: 31.39–65.57). The diagnostic accuracy of the RDT with MP as reference was 79.81% (95%CI: 70.0–86.1). All cases were due to Plasmodium falciparum. A Cohen’s kappa of 0.45 (95%CI: 0.26–0.64) was obtained, consistent with a moderate agreement between the tests. Conclusions The diagnostic accuracy of the CareStart™ malaria Pf/PAN compared to microscopy was high, but not as desirable, with a false negative RDT at very high parasitaemia. In tertiary facilities, RDTs appear to provide a better diagnostic solution compared to microscopy. However, future studies with larger sample sizes should make this observation more generalizable; as missing a case could have serious consequences on pregnancy outcome.