Intestinal coccidian parasites as an underestimated cause of travellers’ diarrhoea in Polish immunocompetent patients

Abstract

Intestinal coccidian parasites are intracellular protozoa most frequently transmitted during food-borne and water-borne infections. This group of parasites is responsible for acute diarrhoeal illnesses especially among immunocompromised patients. However, they are more frequently detected in immunocompetent individuals including travellers, and they should also be considered as important etiologic factors of travellers' diarrhoea. We examined 221 immunocompetent patients hospitalized due to acute or chronic diarrhoea and other gastrointestinal symptoms after returning from international journeys to hot climates. A basic microscopical examination and acid - fast staining of stool samples was performed. Each patient was also a part of the epidemiological investigation to define potential risk factors of tropical gastrointestinal infections. Intestinal coccidiosis was confirmed in 12 out of 221 successively hospitalized patients (5.4%). The most common coccidian parasite was Cryptosporidium spp., detected in nine Polish travellers (4.1%). Cyclospora spp. was diagnosed in three cases (1.4%), including two mixed infections with Cryptosporidium spp., and Cystoisospora spp. in two other cases (0.9%). The study has revealed that intestinal coccidian parasites are a significant threat to immunocompetent travellers and should be always considered in the differential diagnosis of gastrointestinal disorders. Therefore, it is necessary to perform specialized diagnostic methods for the detection of Cryptosporidium spp., Cystoisospora spp., and Cyclospora spp. oocysts in reference parasitology laboratories. Clinical observations demonstrated simultaneously an insufficient level of knowledge in Polish tourists concerning the main risk factors of intestinal parasitic diseases during international travels, particularly to developing countries with lower economic and sanitary conditions.

Epidemiology of Cryptosporidiosis in France from 2017 to 2019

“…In addition, the proportion of cases occurring in immunocompetent patients in France is probably still largely underestimated because of the limited number of private laboratories in the network and because diarrhea etiologies (especially parasitological ones) are rarely investigated in minor forms. This underestimation of Cryptosporidium cases in immunocompetent patients is probably encountered worldwide and, finally, immunocompetent cases are often only described through outbreaks, chronic digestive disorders, or in travelers [ 19 , 20 , 25 , 26 ].…”

Cyclospora cayetanensis infection in humans: biological characteristics, clinical features, epidemiology, detection method and treatment

“…Cyclospora cayetanensis is also an important pathogen causing traveler's diarrhea, especially in industrialized regions (Shields and Olson, 2003; Mansfield and Gajadhar, 2004). International travel or expatriate relocation to developing countries with disease-endemic areas or poor sanitation might be a risk factor for cyclosporiasis in humans (Fryauff et al ., 1999; Pandey et al ., 2011; Kłudkowska et al ., 2017).…”

Massive Cryptosporidium infections and chronic diarrhea in HIV-negative patients

“…Protozoa of the genus Cryptosporidium are considered as one of the etiologic agents of persistent diarrheal illness in immunocompromised patients (Clemente et al 2000 ; Werneck-Silva and Bedin Prado 2009 ). However, they are more often detected also in HIV-negative humans, as a cause of travelers’ diarrhea, in immunocompetent children or in man infected with the hedgehog genotype (Kłudkowska et al 2017 ; Tallant et al 2016 ; Kváč et al 2014 ).…”