AIDS, the most advanced stage of HIV infection, occurs when the immune system is severely weakened, marked by CD4 counts below 200 cells/mm³ and the onset of potentially life-threatening opportunistic infections (OIs).[1,2] Patients with severe forms of HIV infection have their immune systems impaired, making them more vulnerable to opportunistic infections and co-infections linked to HIV infection.[3-5] Intestinal parasite infestations are more prevalent in HIV-positive individuals than any other opportunistic infection. The most prevalent gastrointestinal tract (GIT) symptom among HIV-positive people is diarrhea, which increases as immunodeficiency advances.[6]

Both opportunistic and non-opportunistic intestinal protozoans can produce intestinal parasite infestations in HIV-reactive persons, which raises the illness burden among AIDS patients worldwide.[7] The most common opportunistic enteric protozoa in HIV/AIDS patients include intestinal coccidian parasites like Cryptosporidium spp., Cyclospora spp., and Isospora belli, along with non-coccidian parasites such as Microsporidia spp., Entamoeba histolytica (less strongly opportunistic), Giardia lamblia, and Strongyloides stercoralis.[8-11] The non-opportunistic parasites category also includes additional parasites including Ascaris lumbricoides, hookworms, Trichuris trichiura, and other gastrointestinal parasites.[12,13]

The three different forms of diarrheal symptoms acute, moderate or curable, and chronic are caused by opportunistic intestinal parasites. In patients with AIDS, severe intestinal parasite-caused infections such cryptosporidiosis, isosporiasis, cyclosporiasis, and microsporidiosis are thought to be emerging infectious disorders that can cause life-threatening diarrhea in individuals with AIDS.[14,15]

The study's goal is to identify intestinal parasite infestations in HIV-reactive individuals early on and assist clinicians in selecting the most effective treatment regimens to reduce potential complications. Understanding intestinal parasite-induced opportunistic parasitic infections (OPIs) in HIV/AIDS patients is essential.

This study was conducted in the Parasitology section of the Department of Microbiology at Teerthanker Mahaveer Hospital, Moradabad, Uttar Pradesh, India. It was an observational study involving HIV-seropositive patients from various wards of TMU Hospital, the Integrated Counselling and Testing Centre (ICTC), and the Antiretroviral Therapy (ART) Centre in Moradabad. Following approval from the Institutional Ethics Committee, a total of 70 HIV-positive individuals were enrolled in the study.

Regardless of whether they had symptoms or not, patients with HIV seropositive status were chosen at random for this study. Throughout the study period, detailed patient information was gathered from both the medical record department (MRD) and the patients themselves. Stool samples were taken from all HIV patients, symptomatic and asymptomatic, after their agreement. The stools of every patient were gathered in a plastic container with a tight lid that was dry, clean, and impervious to leaks. The individual's name, age, sex, work, history of clinical signs, including diarrhea, and history of antibiotic and antiparasitic medication treatment were all recorded in addition to collecting the sample. The stool sample was processed using the standard procedure for parasite detection.

After, stool samples were collected from participants based on predefined inclusion and exclusion criteria. The collected samples were undergoing a series of examinations, beginning with routine microscopy. This includes both macroscopic and microscopic evaluations.

The macroscopic examination assesses the stool samples for color, consistency, the presence of mucus, visible blood, and any noticeable parasites. Following this, microscopic examination was performed using a wet mount technique prepared with normal saline and iodine. This was helped to detect the presence of pus cells, red blood cells (RBCs), trophozoites, ova, and cysts.

In addition to routine microscopy, stool samples also be subjected to a stool concentration method to enhance the detection of parasitic elements. Furthermore, all samples were examined using the Modified Ziehl-Neelsen staining technique (increased phenolic concentration and 0.5 to 1% H₂SO₄). Samples that test negative under this method were recorded as having no parasites seen. However, samples that test positive were further analyzed to identify specific parasites, including Cryptosporidium, Cyclospora, Isospora belli, and Microsporidium.

Ethics statement

The institutional ethical committee gave its approval to this investigation with reference number TMU/ IEC/ 2024-25/ PG/ 135. Prior to the collection and processing of samples, each subject provided their informed consent. Enrolled participants were given a general explanation of the study's purpose and nature, freedom to decline participation or to withdraw at any moment without compromising their ability to obtain other health services. The data gathered was kept private.

Statistical analysis

Tables and figures were created by using Microsoft Word and Excel.

Our study included 70 HIV-positive individuals in total; 49 (70%) of the patients were male, and 21 (30%) were female. Of the 70 patients with HIV who tested positive, only 19 had intestinal parasite infestations; the remaining patients had no intestinal parasite infection. At 19/70, the prevalence rate was 27.14%. (table:1)

Patients under the age of 18 were not included in this study based on the inclusion and exclusion criteria. Our study found that patients with HIV are more common in the age ranges of 19–30 years old (31.42%) and 31–40 years old (24.28%).

Out of the 19 patients (27.14%) infected, the majority were infected with opportunistic intestinal parasites, such as I. belli (3 patients, 15.78%), E. histolytica (3 patients, 15.78%), and S. stercoralis (3 patients, 15.78%), followed by Cryptosporidium and Cyclospora species (2 patients, 10.52% and 1 patient, 5.26%) respectively. And 2 (10.52%) are caused by non-opportunistic parasites like Hymenolepsis nana, two (10.52%) by Hookworm, one (5.26%) by Trichuris trichiura, and two (10.52%) by Ascaris lumbricoides. (table:2)

Twelve of the 19 patients who had opportunistic intestinal parasite infections had three cases of Isospora belli, three cases of Entamoeba histolytica, and three cases of Strongyloides stercoralis. Cryptosporidium species and Cyclospora species accounted for two and one cases, respectively. (fig: 1)

Table: 1 Overall prevalence of parasitic infection among study population

Table: 2 Prevalence of intestinal parasite species among the study population

Intestinal parasites were present in 27.14% of the study population (19/70). The reason was that the majority of HIV patients were asymptomatic, meaning they had no symptoms associated with intestinal infections, and most of the patients was newly infected with HIV. As a result, the study population's infection rate was low.

The prevalence of intestinal parasites in the study by Namaji MAAS et al.[5] was 40.99%, which is greater than the results of our investigation. Intestinal parasite prevalence among HIV-reactive patients was 38.7% in another study by Ramakrishnan K et al.6 from India, which is also higher than our data. The Chandi DH et al.[16] study found that 23.75% of patients with HIV were infected, which is quite comparable to our findings. However, Seema K et al.[17] earlier reported a lower prevalence of intestinal parasites in HIV/AIDS patients (12.59%), which is lower than our findings.

Isospora belli, a coccidian parasite, accounts for 3 (15.78%) of the total number of parasite-infected patients (19/70). S. stercoralis, E. histolytica also reported as 3 (15.78%) and 3 (15.78%) respectively and Hookworm, A. lumbricoides, and H. nana are the next most common parasites that cause intestinal parasitic infestations in the study population. Similar finding to our study reported by the researcher Wiwanitkit V[18] from Thailand found that the most common opportunistic parasites causing diarrhea in HIV/AIDS patients were I. belli (5%) and S. stercoralis (3%) respectively. Another study by Rao RP[19] from India found that the most common parasite overall was C. parvum (21/100), which is higher than our study. Similar studies were also conducted by other researchers from other countries, and they also found that non-opportunistic intestinal parasites such as H. nana, T. trichiura, and A. lumbricoides were present.[20,21]

Of the twelve and nineteen opportunistic intestinal parasites that were reported in our study, three (25%) were coccidian parasite, Isospora belli, three (25%) Strongyloides stercoralis, and three (25%) Entamoeba histolytica. These parasites were reported to be highly prevalent in intestinal parasitic infestations. Similar to our study, Wiwanitkit V[18] from Thailand identified I.  belli (5%) and S. stercoralis (3%) as the two most prevalent opportunistic parasites causing diarrhea in HIV/AIDS patients. In comparison to our study, other related research conducted by Ramakrishnan K et al.[6] also produced findings that were comparable.

The high rate of intestinal parasitic infestation in the study population highlights the urgent need for intervention to prevent its harmful effects.

In our investigation, S. stercoralis and I. belli infection rates were significantly higher in HIV-seropositive patients. Thus, it is essential to screen patients for HIV infection and parasite infestations early in the course of the illness. Even with free anti-retroviral drugs available, opportunistic gut infections are still a risk. HIV patients should receive routine intestinal parasite screening and basic medical care; it potentially aids in reducing the spread of parasite infestations linked to HIV that cause diarrhea.

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