Intestinal Coccidian Infections in Cancer Patients: A Case Series

Introduction Coccidian protozoa and microsporidian fungi are opportunistic pathogens increasingly implicated in infections in immunosuppressed individuals. These parasites typically infect the intestinal epithelium, resulting in secretory diarrhea and malabsorption. The disease burden and timeline are both greater and longer among immunosuppressed patients. Therapeutic options for immunocompromised individuals are limited. As a result, we wanted to better characterize the disease course and treatment efficacy of these parasitic gastrointestinal infections. Methods We performed a single-center, retrospective MedMined (BD Healthsight Analytics, Birmingham, AL, USA) chart review of patients between January 2012 and June 2022 diagnosed with coccidian or microsporidian infections. Relevant data were collected from Cerner's PowerChart (Oracle Cerner, Austin, TX, USA). Descriptive analysis was performed with IBM SPSS Statistics (IBM Corp., Armonk, NY, USA), and Microsoft Excel (Microsoft, Redmond, WA, USA) was used to generate graphs and tables. Results In these 10 years, there were 17 patients with Cryptosporidium infections, four with Cyclospora infections, and no positive cultures for Cystoisospora belli or microsporidian infections. In both infections, the majority of patients experienced diarrhea, fatigue, and nausea, with vomiting, abdominal pain, appetite loss, weight loss, and fever occurring to a lesser degree. Nitazoxanide was the most common treatment for Cryptosporidium, while trimethoprim-sulfamethoxazole or ciprofloxacin were the treatments of choice for Cyclospora. Of the Cryptosporidium infections, three received combination therapy with azithromycin, immunoreconstitution, or IV immunoglobulins. Among the four Cyclospora-infected patients, one received combination therapy of ciprofloxacin and trimethoprim-sulfamethoxazole. Treatment lasted around two weeks, and 88% of Cryptosporidium patients and 75% of Cyclospora patients had a resolution of symptoms. Conclusion The most detected coccidian infection was Cryptosporidium, followed by Cyclospora, with the lack of Cystoisospora or microsporidian infections likely due to diagnostic limitations and prevalence. Cryptosporidium and Cyclospora likely caused their associated symptoms in most cases, with other possible etiologies, including graft-versus-host disease, medications, and feeding tubes. The small number of patients receiving combination therapy prohibited a comparison with monotherapy. In our patient population, though, there was a clinical response to treatment despite immunosuppression. While promising, additional randomized control experiments are required to fully understand the efficacy of parasitic treatments.