A study of opportunistic parasitic infections and CD4 counts in HIV-seropositive individuals in Narketpally, South India

Context: Human immunodeficiency virus (HIV), causative agent in AIDS, is fast becoming a major threat in the Indian subcontinent with an estimated 3.7 million persons being infected with HIV. The progressive decline in immunological and mucosal defensive mechanisms predisposes HIV-positive individuals to gastrointestinal infections, thus increasing susceptibility to a number of opportunistic intestinal pathogens, among which protozoan and coccidian parasites like Cryptosporidium Sp., Isospora Sp., Cyclospora Sp. are being frequently detected. Objectives: To determine the opportunistic parasitic infections of the gastrointestinal tract in HIV-seropositive individuals and simultaneously their TCD4+ counts in South India. Settings and Design: Individuals seropositive for HIV infection were selected, and a Performa including age, sex, marital status, history of exposure, present clinical condition along with socioeconomic status, hygiene, etc was collected. Statistical Analysis Used: Percentages, Mean, Standard deviation. Results: Cryptosporidium Sp and Isospora Sp were found in 17.8% and 17.1% of all samples, respectively. Entamoeba histolytica, Giardia lamblia, Entamoeba coli and Blastocystis hominis were seen in 15.6%, 12.6%, 10.4% and 4% of all examined feces, respectively. Among helminths, Hymenolepis nana, Ascaris lumbricoides, Ancylostoma duodenale, and Strongyloides stercoralis were found in 0.5%, 0.4%, 0.1%, and 0.03% of all patients, respectively. The TCD4+ counts in case of coccidian infections were 365 cells/mm 3 ± 86.43 whereas in case of other protozoan, helminthic and mixed parasitic infections they were: 468±40.50 cells/mm ³ , 429±190 cells/mm ³ and 312±65.74 cells/mm ³ respectively. Our data showed that among HIV-seropositive stool samples screened routinely, 44.6% were found positive for at least one parasitic agent. Concentration technique improved the findings to 59.5%. Among the intestinal parasites 88.4% infections were by protozoan parasites compared to 11% by helminthes. Of the protozoan parasitic infections Cryptosporidium Sp., Isospora Sp., Entamoeba histolytica, Giardia lamblia were most frequently detected. Conclusions: Among intestinal parasites 88.4% infections were by protozoan parasites compared to 11% by helminthes. Of the protozoan parasitic infections Cryptosporidium Sp., Isospora Sp., Entamoeba histolytica, Giardia lamblia were detected in the majority of cases. Our findings also suggest that the intestinal parasitic infections vary with the geographical areas and studies must be carried out in respective regions to evaluate the frequent causes of intestinal parasitic infections in HIV-seropositive individuals. Early diagnosis of opportunistic infections and prompt treatment definitely contribute to increased life expectancy of infected individuals by delaying the progression to AIDS.

Keywords: Human immunodeficiency virus, opportunistic parasitic infections, TCD4+

Human immunodeficiency virus (HIV), causative agent in AIDS, is fast becoming a major threat in the Indian subcontinent with an estimated 3.7 million persons being infected with HIV. ^[1] Infections of the gastrointestinal tract play a critical role in HIV pathogenesis, reaching a rate of up to 50% in developed countries and 95% in the developing countries. ^[2] The progressive decline in immunological and mucosal defensive mechanisms predisposes HIV-positive individuals to gastrointestinal infections thus increasing susceptibility to a number of opportunistic intestinal pathogens, among which protozoan and coccidian parasites like Cryptosporidium Sp., Isospora Sp., Cyclospora Sp. are being frequently detected. ^[3],[4] After the emergence of HIV, those parasites, until then known solely in veterinary medicine as commensals are now recognized as opportunistic pathogens. Infection by these agents constitutes a major secondary aggravating factor of the disease, often responsible for worsening the general health condition due to manifestations of diarrhea which are often difficult to control, sometimes resulting in death.

The present study aims at finding out intestinal parasitic infections with special emphasis on protozoans including coccidian parasites which are responsible for the majority of infections in immunocompromised and HIV-positive individuals. ^[5]

The study included 452 HIV-infected individuals visiting Kamineni Institute of Medical Sciences (KIMS), Narketpally, Nalgonda from July 2004 to June 2007. Their HIV status was confirmed by three different types of commercially available Enzyme Linked Immunosorbant Assay (ELISA) kits, as recommended by the National AIDS Control Organization (NACO).

Stool samples were collected in a suitable container under universal precautions. The patients’ consent was obtained for the collection of blood samples and a questionnaire was designed in such a way as to know about the history of the patients (age, sex, present or previous history of diarrhea, sexual behavior, socioeconomic status and personal hygiene). Blood samples (3 ml) were collected for absolute TCD4+ count.

Routine stool examination was done on all fecal samples by simple wet/saline and iodine mounts. Concentration technique by Formol-ether sedimentation method was simultaneously done on all stool samples and screened for the presence of parasites. Smears from all the stool samples were stained with Modified acid fast stain or Kinyoun’s stain for coccidian parasites. ^[6] The absolute TCD4+ counts were done by flow cytometry method in possible cases and the mean absolute TCD4+ count was calculated in various parasitic infections. ^[7]

Statistical Analysis Used

Percentages, Mean, Standard deviation

Of the 452 individuals enrolled in our study, 110 (24.4%) had symptoms of present diarrhea and general stool examination showed the presence of intestinal parasites in 202 (44.6%) of them. The concentration technique by Formol-ether sedimentation method increased the positivity rate to 269 (59.5%). Mixed infections with more than one parasite and not more than three were observed in 41 (9%) stool samples. Of the 452 subjects 223 (49.3%) and 229 (50.6%) were males and females respectively with the majority in the age group of 21-40. Eleven percent of all patients were below the age of 20 years. The age and sex distribution of all subjects is showed in [Table 1].

A history of low socioeconomic status and poor personal hygiene was mentioned by 69% and 76.3% patients respectively. Of the 229 females 17 (7.4%) referred previous history of sex outside marriage (multiple partners) whereas 135 (60.5%) of the 223 infected males described the same behavior. Of the 269 samples positive for intestinal parasites Coccidian and other protozoan parasitic infections were observed in 121 (49.9%) and 117 (43.4%) respectively, with 31 of them (11.5%) displaying helminths. Cryptosporidium Sp, Isopsora Sp and Entamoeba histolytica were found in 17.8%, 17.1% and 15.6% respectively, constituting the majority of infections followed by Giardia lamblia, Entamoeba coli and Cyclospora Sp in 12.6%, 10.4% and 10% respectively.

The absolute TCD4+ count in case of coccidian infections was 365 cells/mm ³ ± 86.43 cells/mm ³ whereas in case of other protozoan, helminthic and mixed parasitic infections they were: 468±40.50 cells/mm ³ , 429 ± 190 cells/mm ³ and 312±65.74 cells/mm ³ respectively, as shown in [Table 2].

Although HIV is the causative agent in AIDS, most of the morbidity and mortality seen in AIDS patients results from opportunistic infections, which take advantage of deficient cell-mediated (CMI) and humoral defense mechanisms. ^[5]

A wide variety of infections are encountered in HIV-positive individuals at different stages, including bacterial, fungal, viral protozoal and helminthic infections. ^[8] The present study is focused on finding various intestinal parasitic infections in HIV-seropositive individuals with special emphasis on coccidian parasites, who presented any one cardinal symptom such as present or previous history of diarrhea, loss of weight, fatigue, malaise, etc and also giving history of low socioeconomic status and poor hygiene. The absolute TCD4+ counts are evaluated in the cases because there are reports emphasizing the importance of TCD4+ counts in intestinal parasitic infections where patients with higher TCD4+ counts take less time or respond well to treatment compared to those who have comparatively low TCD4+ counts who respond poorly. ^[9],[10] The results showed an alarming increase in the occurrence of intestinal parasitic infections (59.6%) which included Coccidian (49.9%), other protozoan (43.4%), and helminthic (11.5%) parasites. The TCD4+ counts in coccidian parasites (365 ± 86.43 cells/mm ³ ) and mixed parasitic infections (312 ± 65.74 cells/mm ³ ) were lower than those observed in case of other protozoan (468±40.50 cells/mm ³ ) and helminthic (429±190 cells/mm ³ ) infections. This indicates that as the disease progresses and the TCD4+ counts decline the HIV-seropositive individuals are prone to intestinal parasitic infections of which protozoan and in particular coccidian parasites play a major role. Low socioeconomic status, poor hygiene, unavailability of safe drinking water and frequent contact with livestock may be responsible for high percentage of infections by protozoan parasites compared to others.

The study revealed infection rate with Cryptosporidium Sp and Isospora Sp in 17.8% and 17.1% respectively contradicting the study done by Mukhopadhya et al., and Kumar et al., in South India which showed a higher rate of Isospora Sp infections. ^[11],[12] Entamoeba histolytica, Giardia lamblia and Isospora Sp infection rate was considerably higher in our study compared with the study done by Nancy Malla et al., in North India. ^[4] Incidence of helminthic infections by Ancylostoma and Strongyloides was lower in our study compared to the investigation revealed in South India by Kumar et al. ^[12] Entamoeba coli was surprisingly third in the list of other protozoan infections behind Entamoeba histolytica and Giardia. Blastocystis hominis was observed in 0.4% cases. ^[13] Helminthic infections were seen in 11% of cases in our study compared to 4.4% in a Korean study. ^[14] Emphasis on specific measures to prevent opportunistic infections is important because of the limitations of highly active antiretroviral therapy (HAART).

With better knowledge and diagnosis of opportunistic parasitic infections in HIV-seropositive individuals, and specific antimicrobial prophylaxis by itself or in conjunction with antiretroviral therapy can reduce substantial morbidity and mortality caused by opportunistic infections in HIV-infected individuals. The TCD4+ counts must also be evaluated in HIV-confirmed cases to follow up the cases.

Our findings highlight the importance of screening HIV-seropositive individuals and evaluating the absolute TCD4+ counts regularly, cultivating hygienic habits in patients so that they do not contract such infections which in the course of time could be responsible for their death.

Our findings also suggest that the intestinal parasitic infections vary with the geographical areas and studies must be carried out in respective regions to evaluate the frequent causes of intestinal parasitic infections in HIV-seropositive individuals. Early diagnosis of opportunistic infections and prompt treatment definitely contribute to increased life expectancy of infected individuals by delaying the progression to AIDS.

To all our colleagues both teaching and non-teaching.

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/1755-6783.77180

[Table 1], [Table 2]