HIV and intestinal parasite co-infections among a Chinese population: an immunological profile

Background:Parasite infections often result in a switch of the human body’s predominant immune reaction from T-helper 1(Th1)-type to Th2-type.Hence,parasite infections are widely expected to accelerate the progression of human immunodeficiency virus(HIV)infections to acquired immunodeficiency syndrome(AIDS).In the People’s Republic of China,both parasitic diseases and AIDS are epidemic in certain rural areas,and co-infections are relatively common.However,no population-based studies have yet investigated the frequency of HIV and parasite co-infections,and its effects on immune responses.We studied(1)the immune status of an HIV-infected population,and(2)the effect of co-infection of HIV and intestinal parasites on selected parameters of the human immune system.Methods:A total of 309 HIV-infected individuals were recruited and compared to an age-matched and sex-matched control group of 315 local HIV-negative individuals.Questionnaires were administered to all participants to obtain information on sociodemographic characteristics,sanitation habits,family income,and recent clinical manifestations.Two consecutive stool samples and 10 ml samples of venous blood were also collected from each individual for the diagnosis of parasite infections and quantitative measurements of selected cytokines and CD4+T-lymphocytes,respectively.Results:During the study period,79 HIV-infected individuals were not under highly active antiretroviral therapy(HAART)and were thus included in our analysis;the prevalence of intestinal helminth infections was 6.3%and that of protozoa was 22.8%.The most common protozoan infections were Blastocystis hominis(B.hominis)(13.9%)and Cryptosporidium spp.(10.1%).The prevalence of Cryptosporidium spp.in HIV-infected individuals was significantly higher than that in HIV negative individuals(P<0.05).Compared to the non-co-infected population,no significant difference was found for any of the measured immunological indicators(P>0.05).However,the following trends were observed:IFN-γlevels were lower,but the IL-4 level was higher,in the population co-infected with HIV and helminths.In the population co-infected with HIV and B.hominis,the IL-2 level was higher.The population co-infected with HIV and Cryptosporidium spp.had markedly lower CD4+T-lymphocyte counts.Conclusion:According to the immunologic profile, co-infection with helminths is disadvantageous to HIV-infected individuals. It was associated with a shift in the Th1/Th2 balance in the same direction as that caused by the virus itself, which might indicate an acceleration of the progress from an HIV infection to AIDS. Co-infection with Cryptosporidium spp. was not associated with a significant change in immune factors but co-infection with Cryptosporidium spp. was associated with a reduced level of CD4 + T-lymphocytes, confirming the opportunistic nature of such infections. Co-infection with B. hominis, on the other hand, was associated with an antagonistic shift in the immunological profile compared to an HIV infection.

Co-infection of HIV and parasites in China: Results from an epidemiological survey in rural areas of Fuyang city, Anhui province, China

The aim of this study was to investigate epidemiological characteristics of co-infection of HIV and intestinal parasites in a HIV/AIDS highly endemic area in China.A cross-sectional survey was carried out in two villages where HIV/AIDS prevalence in residents was over 1%.Stool samples of all residents in the two targeted villages were examined for the presence of intestinal parasites.Blood examination was performed for the HIV infection detection and anemia test.A questionnaire survey was carried out in all residents participating in the study.A total of 769 individuals were enrolled in the investigation,720 of whom were involved in stool examination of intestinal parasites.The infection rates of parasites in the residents of the targeted villages were as follows: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 lamblia,1.67%for Entamoeba spp.,4.44%for Cryptosporidium spp.,and no infection for Strongyloides stercoralis.The overall infection rate of intestinal worms was 4.72%,intestinal parasite infection rate was 24.31%,the anemia prevalence rate was 34.68%,the co-infection rate of HIV and intestinal helminthes 2.17%,the co-infection rate of HIV and intestinal protozoa 28.26%,of which the co-infection rates of HIV and Blastocystis hominis,and HIV and Cryptosporidium spp.were 19.57%and 13.04%,respectively.A significant difference of Cryptosporidium spp.infection rate was found between HIV-positive group(13.04%)and HIV-negative group(4.70%)(P<0.05).Higher prevalence of anemia(34.68%)occurred in the study villages,particularly in children(>50%)and women(>39%).It was concluded that the infection rate of intestinal protozoa in the residents was higher than that of intestinal helminthes in the local setting,and a same pattern appeared in the co-infection rate of HIV and parasites.An interestingfinding is that the infection rate of Cryptosporidium spp.among the HIV-positives was significantly higher than that in the HIV-negatives,and children and women had higher anemia prevalence.

Urgent needs in fostering neglected tropical diseases(NTDs)laboratory capacity in WHO Western Pacific Region:results from the external quality assessment on NTDs diagnosis in 2012-2015

Background:Neglected tropical diseases(NTDs)are a heterogeneous group of mainly chronic,debilitating and often stigmatizing diseases that largely affects low-income and politically marginalized populations,causing a large burden of public health,social and economies in the NTDs endemic countries.NTDs are caused by infections with a range of pathogen,including bacteria,parasites,protozoa and viruses.The accurate diagnosis of NTDs is important for reducing morbidity,preventing mortality and for monitoring of control programs.External Quality Assessment(EQA),a component of laboratory quality assurance,aims to assess the performance of participating laboratories in detecting parasitic infections.The aim of this paper is to report the findings and put forward the recommendations on capacity build from the EQA results of participating NTDs laboratories in selected countries in the WHO Western Pacific Region from 2012 to 2015.Methods:Reference or public health laboratories at national level working on NTDs in 6 countries participated in EQAs organized by the National Institute of Parasitic Diseases(NIPD)of Chinese Center for Disease Control and Prevention(CDC)based in Shanghai,China.Two representatives of each participating laboratory were invited to NIPD to detect NTDs’parasitic infections using the same prepared samples for serological tests(IHA and ELISA)and helminth eggs’morphological tests(Direct smear and Kato-Katz).All of the results were scored and analyzed by using SPSS statistics 19.0 software.Results:The percentage of participants who had EQA score≥60 during 2012-2015 for direct smear test were 80.00%(2012),71.43%(2013),100%(2014)and 75.00%(2015),whereas for Kato-Katz test were 80.00%(2012),57.14%(2013),100%(2014)and 37.50%(2015),respectively.The detection rate of helminth eggs varied in different species,with Ascaris lumbricoides being the highest at 94.07%in average.All laboratories did very well with ELISA tests as shown by the high scores in all four years except Lab A in the first and last EQA.For the positive or negative judgments of serum samples,the total coincidence rates of ELISA between 2012 and 2015 were 90.00%,99.29%,94.29%and 98.75%,respectively.While the total coincidence rates of IHA were respectively 100%,95.00%,90.00%and 97.50%.However,detecting low levels of serum antibody remained problematic for IHA when the titres of samples were taken into consideration.Conclusion:This study demonstrate that EQA scheme have been beneficial to the participating laboratories.The EQA programme identifies certain deficiencies which were needed to overcome and improved the laboratories’performance in helminthiasis diagnosis.However,further optimization of accuracy and uniformity in NTDs diagnosis remains a big challenge.