From the Guidelines
Cyclospora cayetanensis infection should be treated with trimethoprim-sulfamethoxazole (TMP-SMX) as the first-line therapy, as recommended by the 2017 Infectious Diseases Society of America clinical practice guidelines 1. The standard treatment for Cyclospora infection is TMP-SMX, commonly known as Bactrim or Septra, administered as one double-strength tablet (160 mg TMP/800 mg SMX) twice daily for 7-10 days. For patients who are immunocompromised, a longer treatment course of 10-14 days may be necessary. Those who are allergic to sulfa drugs present a treatment challenge, as alternative therapies like nitazoxanide have limited data to support their use 1. Symptoms of cyclosporiasis include:
- Watery diarrhea
- Abdominal cramping
- Nausea
- Fatigue
- Weight loss which can persist for weeks to months if untreated, as described in the case definitions for infectious conditions under public health surveillance by the Centers for Disease Control and Prevention 1. The infection is most commonly associated with imported fresh produce, particularly berries, herbs, and leafy greens from tropical and subtropical regions. Prevention involves thoroughly washing fruits and vegetables, though this may not completely eliminate the risk as the parasite is resistant to routine chemical disinfection. Cyclospora is not transmitted directly from person to person, as the oocysts require days to weeks in the environment to become infectious.
From the Research
Characteristics of Cyclospora cayetanensis
- Cyclospora cayetanensis is a coccidian parasite that causes cyclosporiasis, a disease associated with severe watery diarrhea, particularly in infants, and immune dysfunction 2, 3, 4, 5, 6.
- The parasite has a worldwide distribution and is an important cause of foodborne outbreaks of enteric disease in many developed countries 4, 6.
- Cyclospora cayetanensis is transmitted by ingestion of water or food contaminated with oocysts, and the life cycle of the parasite is not fully known 3, 5.
Clinical Features and Diagnosis
- The most characteristic feature of cyclosporiasis is a syndrome of acute or chronic diarrhea, and the disease can be self-limiting in most immunocompetent patients 3, 4, 6.
- Diagnosis of cyclosporiasis is made by direct examination of stool samples, and detection methods based on oocyst morphology, staining, and molecular testing have been developed 2, 5, 6.
- Clinical diagnosis is based on cardinal clinical symptoms and conventional laboratory methods, which usually involve microscopic examination of wet smears, staining tests, fluorescence microscopy, serological testing, or DNA testing for oocysts in the stool 2.
Treatment and Prevention
- Trimethoprim-sulfamethoxazole (TMP-SMX) is the antibiotic of choice for the treatment of cyclosporiasis, and it can effectively cure C. cayetanensis infection 2, 3, 5, 6.
- Ciprofloxacin is less effective than TMP-SMX but is suitable for patients who cannot tolerate co-trimoxazole, and nitazoxanide can be used in cases of sulfonamide intolerance and ciprofloxacin resistance 2, 6.
- Prevention of cyclosporiasis can be achieved by avoiding the consumption of contaminated food and water, and by improving hygiene and sanitation practices 4, 6.
Epidemiology and Risk Factors
- Cyclospora cayetanensis infections are commonly reported in developing countries with low-socioeconomic levels or in endemic areas, although large outbreaks have also been documented in developed countries 4, 6.
- The overall C. cayetanensis prevalence in humans worldwide is 3.55%, and the highest prevalence has been documented in immunocompetent individuals with diarrhea 6.
- Infections are markedly seasonal, occurring in the rainy season or summer, and the risk of infection is associated with travel to endemic areas and the domestic consumption of contaminated food, mainly fresh produce imported from endemic regions 4, 6.