Cryptosporidium in Piglets

Cryptosporidium Species in Pigs

Cryptosporidia are single-celled parasites that exhibit low host specificity in some cases and are highly infectious. The oocysts represent the inactive, infectious, persistent form of the parasite. They are excreted in the feces of infected animals and are highly resistant in the external environment. In the absence of proper barn hygiene, they constitute a permanent source of infection and thus a decisive factor in the pathogenesis of diarrhea. After oral ingestion of Cryptosporidium oocysts, their vegetative, reproductive forms—the sporozoites—are released and multiply within the intestinal epithelial cells of the microvillus layer. Severe infestation of the microvilli with Cryptosporidium can lead to malabsorption.

Course of Disease and Mixed Infections

Various Cryptosporidium species are pathogenic to pigs. Monoinfections in piglets can lead to chronic, asymptomatic infections, sometimes with a high rate of oocyst shedding; however, in cases of secondary infections with other enteropathogenic pathogens, such as rotaviruses, may result in a dramatic increase in clinical diarrhea symptoms and the severity of the disease.

Zoonotic Risk from C. parvum

Cryptosporidia are single-celled intestinal parasites that attach apically to the enterocytes of the small intestine without penetrating the cell; this results in microvillus loss, villus atrophy, and a reduced absorption surface area. In pigs, the host-adapted species Cryptosporidium suis and Cryptosporidium scrofarum predominate, while the zoonotically relevant Cryptosporidium parvum occurs less frequently. The environmentally resistant oocysts represent the persistent infectious form and are excreted in feces.

Transmission and Barn Hygiene

Transmission occurs via the fecal-oral route. In piglets, primary infections are often subclinical or mild, sometimes accompanied by high oocyst shedding. Cryptosporidia are clinically significant primarily as a factor in the diarrhea complex: in combination with other enteropathogenic pathogens, such as rotaviruses, the severity and duration of the disease can increase significantly. C. parvum has zoonotic potential and must be taken into account in farm hygiene.

Diagnosis of Cryptosporidium

Since a clinical etiological diagnosis is not possible, the detection of antigens in feces helps to identify the spectrum of pathogens and assess the hygiene status of the herd.

The Fassisi® PiDia test cassette detects Cryptosporidium parvum along with rotavirus and Clostridium perfringens in the feces of young animals, thereby aiding in the identification of single and mixed infections from a single sample.

References are listed on the References page.