Epidémiologie des protozoaires, helminthes et mycètes intestinaux chez les personnes vivant avec le VIH dans trois départements de la Région du Centre

Abstract

The decline of the immune system caused by the Human Immunodeficiency Virus (HIV) increases the opportunistic infections. Intestinal parasites are among the most important agents responsible for chronic and severe digestive disorders. Sub-Saharan Africa faces economic hardships and the problem of environmental sanitation; however, the care given to subject infected with HIV in the different support units would contribute to a reduction in the frequency of these intestinal infections. In this study, we are comparing the prevalences of these parasitic infections among individuals infected with HIV (HIV+) and non-infected (HIV-) individuals in four HIV health care units in the Center Region of Cameroon. Stool samples were collected from 528 subjects, including 283 HIV-positive individuals and 245 HIV-negative subjects. This sampling was carried out from July 2013 to September 2015 in the Yaoundé University Teaching Hospital, the Yaoundé Central Hospital, the Ntui District Hospital and the Akonolinga District Hospital. All relevant information regarding HIV status, socio-demographic factors and clinical signs were collected through interview and consultation of medical notebooks of participants. Stool samples were examined using complementary directs examinations. A total of 128 (24.2%) participants were tested positive for protozoan infection, 9 (1.7%) subjects with intestinal worms and 187 (35.4%) others with yeast. The prevalence of parasites (protozoa and helminths) was 27.9% in HIV-positive subjects and 22.4% in HIV-negative subjects, although we did not observe any difference (P = 0.1502). Also, the rates of yeast infections were 29.0% and 42.9% respectively among HIV+ and HIV- subjects, the difference in frequency being significant (P = 0.0009). 11 taxa of parasites were identified, 06 of them were found in both HIV+ and HIV- subjects; while some species of amoeba, flagellates and coccidia have only been found in a serological modality. Cryptosporidium sp. and Entamoeba histolytica / dispar were significantly more frequent in HIV-positive subjects (P < 0.0455); on the other hand Trichomonas intestinalis, Entamoeba coli and yeasts were more observed in HIV-negative subjects (P < 0.0210). Microsporidia spores and Strongyloides larvae have not been identified. Concerning socio-demographic parameters according to HIV status, the prevalence of parasites (protozoa and helminths) were significantly higher in HIV positive subjects than in their seronegative counterparts living in semi-urban and rural areas, in those aged over 45 and among unemployed individuals (P < 0.0241). On the other hand, HIV-negative people were more parasitized in urban areas and in the age group 29 to 45 years than HIV-positive people (P < 0.0418). The frequencies of yeasts did not vary significantly according to HIV status in one type of area. However, they were found more in HIV-negative women compared to HIV-positive, in HIV-negative individuals in the age group 29 to 45, those who spent less than 25 years in the place of residence, and also in non-agricultural workers in the informal sector compared to their HIV-positive counterparts (P < 0.0184). In addition, the densities of infesting stages of Cryptosporidium sp., Blastocystis sp., Entamoeba histolytica / dispar and Endolimax nana did not vary significantly according to the HIV status of the subjects; however, the egg density of Ascaris lumbricoides was higher in HIV negative subjects (P = 0.0205). Amongst HIV infected subjects, Cryptosporidium sp. was significantly associated with the decrease in CD4 cell count (P = 0.0035), individuals infected with this parasite exhibiting a CD4 count < 500 cells / mm3. Similarly, a difference in frequencies was noted in HIV+ people infected with Blastocystis sp., but unlike the previous one, Blastocystis sp. was more observed in HIV+ subjects who had a CD4 count ≥ 500 cells / mm3 (P = 0.0453). In addition, the highest frequencies of yeast infection were noted among subjects in clinical stages A and C of HIV infection (P = 0.0004). The species Cryptosporidium sp., Isospora belli, Iodamoeba buetschlii were also significantly found in HIV+ subjects who were not taking antiretroviral therapy (P < 0.0226). Moreover, the oocysts density of Cryptosporidium sp. was higher in individuals with CD4 < 500 cells / mm3 and in those with clinical stage B (P < 0.0001). The eggs density of Ascaris lumbricoides was higher in subjects at clinical stage A (P = 0.0035). The percentages of multiple infections were similar in HIV positive (9.9%) and HIV negative (9.8%) subjects. Blastocystis sp., Entamoeba histolytica / dispar and yeasts were most observed in intestinal co-infections. Also, the frequencies of co-infections were significantly associated with semi-urban and rural settings among HIV-positive subjects (P < 0.0001), but among seronegative subjects, the difference in co-infection rates was not significant depending on the type of area (P = 0.2369). In summary, this study presents that intestinal parasites were more prevalent among HIV-positive individuals in rural and semi-urban areas, individuals aged > 45 years old and unemployed than among their counterpart HIV-negative. The frequency of yeast infection was higher in HIV negative subjects; but significantly higher in HIV-positive subjects in clinical stages A and C. Cryptosporidium sp., Entamoeba histolytica / dispar and Blastocystis sp. were the parasites most frequently found amongst HIV infected individuals, but with lower frequencies compared to previous studies.