CRYPTOSPORIDIUM GENOTYPING IN ISRAEL

Background

Cryptosporidium is associated with gastrointestinal illness. In immune-compromised individuals the infection may develop into a prolonged life-threatening disease. Cryptosporidium infection is a mandatory reported disease in Israel but little is known about its prevalence and associated morbidity. Laboratory detection is challenging, therefore the disease is probably underreported. The parasitology reference lab has introduced molecular tools for epidemiological surveillance. Here we overview for the first time Cryptosporidium species and genotypes found in Israel, especially during two outbreaks.

Methods

The molecular epidemiology of cryptosporidiosis in Israel between 2015 and 2018 was explored, including genetic analysis of Cryptosporidium subtypes. Stools received for parasitology examination at the Haifa and Western Galilee Clalit Laboratory were tested for Cryptosporidium using a combination of commercial real-time PCR, Immunochromatograpy and microscopy after acid-fast staining. Other clinical labs use copra-antigen assays and microscopy on physician`s request. Available stool samples received at the reference center were confirmed positive using in-house real-time PCR (established by the CDC) targeting the 18S gene. The Cryptosporidium genotype was determined by further analysis of the 18S rRNA gene. Subtype was determined by analyzing the gp60 gene.

Results and conclusions

Two outbreaks were detected at the Northern Clalit lab, between 2015 and 2017. Infection rates peaked between August and November. Most of the patients were children between the ages of 1 and 5. Stool samples available from outbreak patients were genotyped and subtyped, along with additional samples from infected patients elsewhere in Israel. C.hominis appears to be the dominant species in Israel the zoonotic species C.parvum was identified as well. The data suggest that Cryptosporidium subtypes are shared with neighboring countries more than with Europe.