S2053 Iso Painful in My Belli

Abstract

Introduction: The etiology of diarrhea in patients with human immunodeficiency virus (HIV) is broad. Causes include antiretroviral therapy adverse events, opportunistic infections, malignancies, and progressive HIV. CD4 count and HIV viral load are important risk-assessment tools for infection. Stool studies including gastrointestinal pathogen polymerase chain reaction (GI PCR), C. difficile, and ova and parasites testing are instrumental. Microsporidia and Isospora are 2 causes of diarrhea in HIV patients for which testing is not included on GI PCR and ova and parasite testing. We present a case of a 57-year-old male with uncontrolled HIV and diarrhea found to have Isospora belli. Case Description/Methods: A 57-year-old male with a medical history of HIV on Descovy and Prezcovix (CD4 90, VL 154K) presented to the hospital with a 5-week course of watery non-bloody diarrhea with intermittent nausea, vomiting, and a 20 lb weight loss. He reported having up to 5 watery diarrheal movements daily. His last colonoscopy was 2 years prior with no acute findings. On exam, he was afebrile with no abdominal tenderness. Prior to presentation, the patient was seen by his primary care physician for diarrhea, with 2 GI PCR panels and ova and parasite testing negative. Patient was prescribed ciprofloxacin and metronidazole by his physician with no improvement in symptoms. On hospital admission, labs were significant for Na/K/Cl of 130/3.3/110, venous blood gas with pH 7.27, CO2 31, HCO3 14.2, and WBC of 6.0. C-diff, CMV, Cryptococcus and repeat GI PCR were negative. Stool examination was positive for Isospora. Patient was initially treated with Bactrim 800-160 twice daily for 10 days with resolution of his diarrea. His HIV regimen was adjusted from Descovy and Prezcovix to Biktarvy for concern for resistance and nonadherence. Discussion: Patients with HIV who present with diarrhea should be extensively worked up as etiology can be multifaceted with consideration for opportunistic infections, medication side effects, and worsening HIV disease burden. Isospora is an opportunistic protozoan parasite that can cause significant diarrhea and weight loss in HIV patients. It is more common in developing countries such as India and sub-saharan Africa and is rarely diagnosed in the United States. Thus, Isospora is not commonly part of the regular stool ova and parasite culture set and should be tested for in patients with high clinical suspicion.