Co-infecton Of HIV And Intestinal Parasites In Highly Endemic Areas Of HIV/AIDS In China

Co-infecton of HIV and intestinal parasites in highly endemic areas of HIV/AIDS in ChinaParasitic disease is still a public health problem in China, notably in certain underdeveloped rural areas in central China where the incidence of parasitic disease remains high. Illegal blood collection and supply and other factors have triggered a HIV epidemic in some of these areas, and thus considerable HIV and parasite co-infections may exist. Parasitic infections often elicit an immune response shift from a T helper 1 (Th1) type to a Th2 type. This change is conducive to HIV viral DNA replication and promotes the progression of HIV towards AIDS. HIV infections also exacerbate the clinical symptoms of parasite infections and complicate treatment. Therefore, the prevention and control of HIV and parasite co-infections have become a focus of international parasitological research. However, there is a lack of relevant research information in China, so that our cross-sectional surveys and studies have mainly focused on the following questions:(â…°) to investigate the prevalence of intestinal parasite infections in highly endemic areas of HIV/AIDS; (â…±) to understand the local rate of parasite and HIV co-infection; (â…²) to study the effects of parasite and HIV co-infection on immune functions and possible risk factors contributed to the co-infection. The objectives of the present study were two folds, first, to provide data on the control and prevention of parasite and HIV co-infections, and second, to decrease the adverse effects of parasitic infections on people living with HIV.First, a cross-sectional survey was carried out among the common population in rural areas of Fuyang in Anhui province, focusing on the incidence of intestinal parasite infections. A total of 1,291 individuals were recruited, and eight species of intestinal parasites were detected. Their respective prevalences were 0.56% for Ascaris lumbricoides,4.03% for hookworm,0.28% for Trichuris trichiura,0.42% for Clonorchis sinensis,21.39% for Blastocystis hominis,3.89% for Giardia intestinalis, 1.67% for Entamoeba spp. and 4.44% for Cryptosporidium spp. Strongyloides stercoralis was not found. The intestinal helminth infection rate was 4.72%(34/720) in total population, the intestinal protozoa infection rate was 24.31%(175/720), and the prevalence of anemia was 34.7%. The co-infection rate of HIV and intestinal protozoa was 28.3%(13/46), with B. hominis and Cryptosporidium spp. co-infection rates of 19.6%(9/46) and 13.0%(6/46), respectively. The prevalence of Cryptosporidium spp. among HIV positives was significantly higher than among HIV negatives (P<0.001). Results showed that local intestinal helminth infection rates were low but elevated prevalences of intestinal protozoa can be found. HIV co-infections with intestinal helminths are rare but co-infections with protozoan were common. HIV positives had a disproportionately high prevalence of Cryptosporidium spp. Further studies on HIV co-infections with intestinal parasites, especially with intestinal protozoa, should be the focus for future studies.Second, an investigation of co-infections of HIV and parasites among HIV positive people and a HIV negative control group was conducted. A total of 624 people were recruited, including 309 people with HIV and 315 HIV negative controls. There were 302 people with HIV and 302 HIV negative controls that were eligible. Results showed that intestinal helminth co-infection rate was 4.3% (13/302) among people with HIV positive, with hookworm being the most common species (3.64%; 11/302). The prevalence among HIV negative individuals was not significantly different from that among HIV positives. The co-infection rate with intestinal protozoa was 23.2%(70/302) among those with HIV; B. hominis was the most common species (16.23%; 49/302), followed by Cryptosporidium spp. (8.28%; 25/302). No significant difference was found between the prevalences of B. hominis among the HIV negative and the HIV positive group. However, significant difference was found in Cryptosporidium spp. co-infected with HIV (8.28%) than the negative control group (2.97%). A multivariate logistic regression analysis showed that the factors significantly associated with parasite co-infections included sex (men: OR=6.700,95% CI:2.030,22.114), age (less than 42 years old:OR=4.148,95% CI: 1.348,12.761), and poor personal hygiene habits (OR=0.324,95% CI:0.105,0.994). These results confirmed that HIV positive people were more susceptibility to Cryptosporidium spp. than HIV negative ones, and that surveillance and research on Cryptosporidium spp. co-infections among HIV positive individuals should be strengthened.Results from cytokine test showed that intestinal helminth co-infections among HIV positives decreased the level of interferon gamma (IFN-y) and interleukin 10 (IL-10), and increased the level of interleukin 4 (IL-4). Th2-type immune response was increased and T values (T=Th1/(Th1+Th2) decreased among intestinal helminth co-infection people. The CD4 count was not significantly different between those with and without intestinal helminth co-infections. The interleukin 2 (IL-2) level increased notably in people co-infected with B. hominis but the levels of other cytokines did not change significantly. CD4 counts and the CD4/CD8 ratio were significantly lower in the group with Cryptosporidium spp. co-infection in comparison with the non-infected. Results suggested that a co-infection with Cryptosporidium spp. may aggravate the stress on the immune system of HIV positive people, and accelerate the progression of the infection to AIDS.Results of the cross-sectional survey show that Cryptosporidium spp. is an important parasite among people with HIV. However, employing the common diagnostic methods resulted in a considerable number of mis-or undiagnosed infections. In the present study, the use of a nested PCR essay was explored for the detection of Cryptosporidium spp. oocysts in feces. Gene sequencing was employed to determine the genotype. The results suggest that Whatman's FTA Card is a better method to extract Cryptosporidium spp. DNA from stool samples compared to the QIAamp DNA Stool Mini Kit. It is simple to operate and highly sensitive compared to the QIAamp DNA Stool Mini Kit. The Cryptosporidium spp. detected among HIV positive individuals were C. meleagridis and C. baileyi.A survey of the water-borne transmission cycle of Cryptosporidium spp. was also carried out, using the Filta-Max xpress rapid method to detect the parasite in surface and drinking water. Cryptosporidium spp. oocysts were found in 30.43% of all drinking water samples and in 55.56% of the surface water samples. Cryptosporidium spp. oocysts were found more often in ponds than in rivers, and more frequently in bottled water as compared to well water.We conclude that the local prevalence of intestinal helminths is low, with hookworm being the main species. Infections with protozoa were more common, and B. hominis and Cryptosporidium spp. are the most common parasites. The prevalence of Cryptosporidium spp was significantly higher among HIV positive individuals in comparison with their HIV negative peers. Helminth infections can lead to an immune response shift from the Thl type to the Th2-type and further the progression of HIV towards AIDS. B. hominis infections have no significant effect on immune function but the impact of Cryptosporidium spp. infections on the immune system remains to be further studied. Contaminated bottled water and shallow well water are the main source of infection for Cryptosporidium spp.