Multiple protozoal infections in a single immunocompromised patient: A case report

Abstract

Immunocompromised patients with human immunodeficiency virus (HIV) infection are prone to multiple infections, of which parasitic infections are an important cause. Parasitic protozoal infections - both by common and rare protozoa are documented in such patients. Here, we report a rare and interesting case of five protozoal infections affecting a single HIV-infected person at the same time of initial presentation. A 64-years-male came to us with complaints of chronic diarrhea for 6 months. He was investigated and found to be positive for HIV I. His stool examination revealed cysts of Entameba histolytica and Giardia lamblia and oocysts of Cryptosporidium species and Cystoisospora species. His toxoplasma IgG was also positive in high titer. The patient was medically diagnosed and was treated with medications as clinically prescribed - antiretroviral therapy was initiated and he was discharged in due course. A total of five protozoal infections were documented affecting a single person - newly diagnosed immunocompromised male, which by sheer qualitative count of patient case histories, indeed is a rare case reported in the medical literature.

INTRODUCTION

Human immunodeficiency virus (HIV) infected patients are vulnerable to various infections, of which parasites are one of the important and common causes leading to increased morbidity and mortality. Parasitic opportunistic infections (OIs) can be divided into protozoal and helminthic. These infections are not only associated with symptomatic HIV-infected patients with low CD4 cell count but also constitute acquired immunodeficiency syndrome (AIDS) defining illnesses.[1] Cryptosporidiosis, isosporidiosis, and microsporidiosis are the main enteric protozoal infections causing diarrhea in HIV patients although amoebiasis and giardiasis are also important. Leishmaniasis and toxoplasmosis are the main systemic protozoal infections reported.[2] The aim of this case report is to highlight that- multiple OIs can present together in a single HIV-infected individual, so these must be thoroughly searched for so that timely therapy can be initiated.

PATIENT INFORMATION

A 64-year-male patient was admitted in our hospital with chronic diarrhea for 6 months associated with abdominal pain, bloating sensation, nausea, and anorexia. There was a history of occasional episodes of fever. The stool was semisolid in consistency and frequency was 6–8 episodes per day, but was not associated with passage of blood. He was a known hypertensive and ischemic heart disease patient on medication, but nondiabetic. He gave a past history of coronary artery bypass graft done 10 years back at the time of which he had received blood transfusion. There was no other significant history. He was investigated in a private diagnostic center and referred to our hospital and found to be Integrated Counselling cum Testing Centre (HiV1 Reactive) ICTC reactive. He had no history of any high-risk behavior.

CLINICAL FINDINGS, DIAGNOSTIC ASSESSMENT AND TIMELINE

He was evaluated in our hospital and his serum sample was confirmed to be reactive for antibodies to HIV1. His routine blood investigations revealed mild anemia, hypoalbuminemia, and rest parameters are within the normal limits. Chest X-ray and ultrasonography of the abdomen were within the normal limits. Sputum cartridge-based nucleic acid amplification test for tuberculosis was negative. His CD4 count was found to be 17 cells/mm³. Eye referral was done and chorioretinitis was excluded from the study. His HBsAg and Anti-hepatitis C virus were nonreactive. He had oral candidiasis for which tablet fluconazole was given. His urine had plenty of pus cells and culture showed growth of Klebsiella pneumoniae for which injection piperacillin and tazobactam course was given.

Stool samples of the patient were collected in dry sterile wide-mouthed screw-capped containers and sent to check for the presence of ova, parasites, and cysts. Saline and LCB (diluted lactophenol cotton blue) wet mounts of stool sample were made and cysts of Entamoeba histolytica and Giardia lamblia were noted. As a routine measure in the institution, formol-ether concentration technique also was adopted to look for ova–parasite-cysts. No ova were found. As the patient was severely immunocompromised, modified Z-N stain was done thinking of intestinal coccidian parasites. Modified acid-fast stain revealed plenty ofoocysts of Cryptosporidium species and Cystoisospora belli [Figure 1].

Figure 1.

Pictures showing different protozoa in stained preparations and unstained wet mount, (a) Modified acid-fast staining showing Cryptosporidium species oocysts. (b) wet mount preparation showing oocyst of Cystoisospora belli (c) stained smear showing oocyst of Cystoisospora belli (d) Wet mount showing oocysts of the coccidian parasite. (e) Wet mount showing trophozoites and cyst of Entameba histolytica (f) Giardia lamblia cyst in unstained wet mount

THERAPEUTIC INTERVENTION

Patient was treated with tablet metronidazole, tablet nitazoxanide, and tablet cotrimoxazole DS tablets in appropriate dosages and duration as per standard treatment guidelines.

His serum Toxoplasma IgG was also found to be positive in high titer although his brain imaging contrast-enhanced computed tomography and magnetic resonance imaging did not reveal any significant abnormality. Other OIs were excluded such as cryptococcosis and Cytomegalovirus.

Patient was then started on antiretroviral therapy (ART) - tenofovir, lamivudine, and dolutegravir.

FOLLOW-UP AND OUTCOMES

His diarrhea was resolved. Patient was discharged in hemodynamically stable condition - The clinical condition of the patient improved and repeat stool examination was found negative for ova, parasite, and cysts.

DISCUSSION

HIV infection and its end-stage AIDS, is now a pandemic disease. Parasitic OIs in addition to other OIs often constitute important cause of morbidity and mortality in these patients although they present as mild or asymptomatic illnesses in immunocompetent people. Enteric protozoal infections causing chronic diarrhea can lead to dehydration, malabsorption worsening the quality of life. Studies conducted in India show a prevalence rate of >50% intestinal parasite in HIV patients, most common of them being Cryptosporidium and Cystoisospora infections.[3,4,5,6] Progressive loss of immunity in HIV patients with low CD₄ count makes them vulnerable to multiple infections. In developing countries, patients usually present late in course of the disease being underdiagnosed for long time, making situation worse.[7] Hence, a clinician must be well aware and thorough enough to look for all possible infections in a newly diagnosed HIV patient so that early initiation of prompt therapy can lead to improvement in quality of life avoiding complications both due to OI progress as well as prevent immune reconstitution inflammatory syndrome which may occur if ART is initiated without ruling out and addressing the OIs.

HIV/AIDS patients are at increased risk for invasive amoebiasis than immune-competent persons. The standard ova and parasite examination is the recommended procedure for the identification of E. histolytica in stool specimen. Microscopic examination of a direct saline wet mount may reveal motile trophozoites which may contain red blood cells (RBCs). The presence of ingested RBCs clinches the diagnosis of E. histolytica. Although the concentration technique is very much helpful for parasite demonstration, the most important technique for recovery and identification is the permanent stained smear. A minimum of three specimens should be collected over a time frame within 10 days.[8] immunoassay procedures can be used for species identification. Cyst morphology does not differentiate between E. histolytica and E. dispar. Cyst formation occurs only within the GI tract. Serologic test for antibody may or may not be positive in intestinal disease and is much more likely to be positive in extraintestinal disease.

G. lamblia– trophozoite form is teardrop shaped with flagella. Cysts are round-to-oval with long axonemes and curved median bodies. Cysts can be seen and identified on wet mount preparation from concentrated material and confirmed using permanent stained smear. In contrast to E. histolytica, G. lamblia inhabiting the duodenum tends to adhere very tightly to the mucosa and so can be difficult to recover. For this, sometimes, entero-string capsules, duodenal aspirates, or biopsy may have to be used. Fecal immunoassays can also be used for identification and are more sensitive than stool examination for ova, parasites, and cyst.[9]

In immunocompromised persons, a presumptive diagnosis of toxoplasmosis can be made by an elevated serologic titer (both IgM and IgG) and clinical signs/symptoms including neurological findings.[10]

In immunocompromised persons, due to the auto-infective nature of life cycle, Cryptosporidium sp. infection is not self-limiting like in normal hosts, can produce huge fluid loss with diarrhea, and may cause multisystem involvement. Cryptosporidium is now classified as two separate species-C. parvum which affects mammals including humans and C. hominis affecting primarily humans. Species differentiation is not possible based on oocyst morphology. Molecular tests and immunoassay procedures are more sensitive than the acid-fast stains and can differentiate between the species.[9,11,12,13,14,15]

For Cystoisospora belli, wet preparation examination of freshly passed stool either as direct smear or as concentrated sample is recommended rather than permanent stained smear. Although these organisms can be stained by auramine-rhodamine stain, they should be confirmed by wet smears or modified acid-fast stain.[9,16,17,18,19]

PATIENT PERSPECTIVE

Patient was discharged in hemodynamically stable condition after 2 weeks. The patient was satisfied with our management as his clinical symptoms resolved with therapy.

Informed consent

Informed consent was obtained with proper knowledge of the patient.

Ethical clearance

Anonymity of the patient was maintained. Ethical clearance was taken from institutional ethics committee.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.