Management of Cystoisospora (Isospora) infections
- Karin Leder, MBBS, FRACP, PhD, MPH, DTMH
Karin Leder, MBBS, FRACP, PhD, MPH, DTMH
- Section Editor — Travel Medicine
- Head of Infectious Diseases Unit
- Monash University, Australia
Cystoisospora belli (formerly known as Isospora belli) is an opportunistic protozoan that in immunocompetent patients can cause self-limited watery diarrhea. However, in immunocompromised patients, such as those with the acquired immune deficiency syndrome (AIDS), it can result in severe debilitating chronic diarrhea with wasting.
The clinical management of patients with Cystoisospora infection will be discussed here. The epidemiology, clinical manifestations, and diagnosis of Cystoisospora infection are discussed elsewhere. (See "Epidemiology, clinical manifestations, and diagnosis of Cystoisospora (Isospora) infections".)
The management of patients with Cystoisospora involves supportive treatment for the dehydration and malnutrition associated with a severe diarrheal illness. For certain patients, especially immunocompromised hosts, antibiotic therapy against the pathogen is also administered. There are special treatment considerations for HIV-infected individuals, such as early initiation of potent antiretroviral therapy and secondary prophylaxis. (See 'Secondary prophylaxis' below and 'Antiretroviral therapy' below.)
Fluid and electrolyte support — Patients with Cystoisospora infection may have evidence of severe volume depletion and electrolyte abnormalities, such as hypokalemia, hypomagnesemia, and bicarbonate wasting. Aggressive fluid resuscitation is critical with intravenous crystalloid, as well as supplementation of potassium chloride and magnesium sulfate. Cardiac monitoring may be necessary for patients with severe electrolyte imbalances. (See "Maintenance and replacement fluid therapy in adults".)
Nutritional support — It is important to address nutritional needs with parenteral nutritional support (where feasible) followed by enteral or oral feeding as soon as the patient’s clinical symptoms improve. Immunocompromised patients (eg, patients with acquired immune deficiency syndrome [AIDS]) who have chronic diarrhea from enteric pathogens often have malabsorption of fats and vitamins, which can lead to elevated prothrombin and low serum albumin levels. Malnutrition can also lead to significant thymic gland atrophy that can affect T cell mediated immune responses .To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
- Savino W, Dardenne M. Nutritional imbalances and infections affect the thymus: consequences on T-cell-mediated immune responses. Proc Nutr Soc 2010; 69:636.
- Drugs for Parasitic Infections. The Medical Letter on Drugs and Therapeutics 2013.
- Panel on Opportunistic Infections in HIV-Infected Adults and Adolescents. Guidelines for the prevention and treatment of opportunistic infections in HIV-infected adults and adolescents:recommendations from the Centers for Disease Control and Prevention, the National Institutes of Health, and the HIV Medicine Association of the Infectious Diseases Society of America. Available at http://aidsinfo.nih.gov/contentfiles/lvguidelines/adult_oi.pdf. (Accessed on July 07, 2017).
- Ud Din N, Torka P, Hutchison RE, et al. Severe Isospora (Cystoisospora) belli Diarrhea Preceding the Diagnosis of Human T-Cell-Leukemia-Virus-1-Associated T-Cell Lymphoma. Case Rep Infect Dis 2012; 2012:640104.
- Marathe A, Parikh K. Severe diarrhoea due to Cystoisospora belli in renal transplant patient on immunosuppressive drugs. Indian J Med Microbiol 2013; 31:185.
- Usluca S, Inceboz T, Unek T, Aksoy U. Isospora belli in a patient with liver transplantation. Turkiye Parazitol Derg 2012; 36:247.
- DeHovitz JA, Pape JW, Boncy M, Johnson WD Jr. Clinical manifestations and therapy of Isospora belli infection in patients with the acquired immunodeficiency syndrome. N Engl J Med 1986; 315:87.
- Pape JW, Verdier RI, Johnson WD Jr. Treatment and prophylaxis of Isospora belli infection in patients with the acquired immunodeficiency syndrome. N Engl J Med 1989; 320:1044.
- Lagrange-Xélot M, Porcher R, Sarfati C, et al. Isosporiasis in patients with HIV infection in the highly active antiretroviral therapy era in France. HIV Med 2008; 9:126.
- Verdier RI, Fitzgerald DW, Johnson WD Jr, Pape JW. Trimethoprim-sulfamethoxazole compared with ciprofloxacin for treatment and prophylaxis of Isospora belli and Cyclospora cayetanensis infection in HIV-infected patients. A randomized, controlled trial. Ann Intern Med 2000; 132:885.
- Weiss LM, Perlman DC, Sherman J, et al. Isospora belli infection: treatment with pyrimethamine. Ann Intern Med 1988; 109:474.
- Nitazoxanide (Alinia)--a new anti-protozoal agent. Med Lett Drugs Ther 2003; 45:29.
- Doumbo O, Rossignol JF, Pichard E, et al. Nitazoxanide in the treatment of cryptosporidial diarrhea and other intestinal parasitic infections associated with acquired immunodeficiency syndrome in tropical Africa. Am J Trop Med Hyg 1997; 56:637.
- Fox LM, Saravolatz LD. Nitazoxanide: a new thiazolide antiparasitic agent. Clin Infect Dis 2005; 40:1173.
- Trier JS, Moxey PC, Schimmel EM, Robles E. Chronic intestinal coccidiosis in man: intestinal morphology and response to treatment. Gastroenterology 1974; 66:923.
- http://www.bhiva.org/OI2011.aspx (Accessed on January 23, 2012).
- Boyles TH, Black J, Meintjes G, Mendelson M. Failure to eradicate Isospora belli diarrhoea despite immune reconstitution in adults with HIV--a case series. PLoS One 2012; 7:e42844.
- Sorvillo FJ, Lieb LE, Seidel J, et al. Epidemiology of isosporiasis among persons with acquired immunodeficiency syndrome in Los Angeles County. Am J Trop Med Hyg 1995; 53:656.
- Guiguet M, Furco A, Tattevin P, et al. HIV-associated Isospora belli infection: incidence and risk factors in the French Hospital Database on HIV. HIV Med 2007; 8:124.
- Anglaret X, Chêne G, Attia A, et al. Early chemoprophylaxis with trimethoprim-sulphamethoxazole for HIV-1-infected adults in Abidjan, Côte d'Ivoire: a randomised trial. Cotrimo-CI Study Group. Lancet 1999; 353:1463.
- GENERAL PRINCIPLES
- SUPPORTIVE CARE
- Fluid and electrolyte support
- Nutritional support
- ANTIMICROBIAL THERAPY
- Approach to treatment
- - Immunocompetent
- - Immunocompromised
- - Alternative agents
- Management of treatment failure
- Secondary prophylaxis
- - Duration of prophylaxis
- ANTIRETROVIRAL THERAPY
- SOCIETY GUIDELINE LINKS
- SUMMARY AND RECOMMENDATIONS