Fachbereich Veterinärmedizin



    Epidemiological investigations on the public health significance of Cryptosporidium parasites in livestock and people in the Ismailia Canal Zone of Egypt (2014)

    Mohamed, Yosra Ahmed Helmy Abdelsamad (WE 11)
    Berlin: Mensch und Buch Verlag, 2014 — VI, 80 Seiten
    ISBN: 978-3-86387-542-8
    URL (Volltext): http://www.diss.fu-berlin.de/diss/receive/FUDISS_thesis_000000097884
    Institut für Tierschutz und Tierverhalten

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    Abstract / Zusammenfassung

    Cryptosporidiosis is an underestimated problem in livestock animals and humans in Egypt. To provide a valid estimate of the frequencies and distributions of Cryptosporidium species and their subtypes in both animals and humans, a sample of smallholder cattle/buffalo herds in the districts of Ismailia province and of diarrheic children attending the province’s district hospitals was investigated.
    A total of 804 animal samples from 191 herds and 165 human samples were investigated by the Copro-antigen RIDA®QUICK test, followed by PCRs (animals: all RIDA®QUICK test positive + 10% negative) targeting the 18S rDNA and Gp60 genes and PCR-RFLP assays for amplification and differentiation of Cryptosporidium spp.
    Detailed analyses were carried out for prevalence, distribution, risk factors, and infection dynamics of cryptosporidiosis and involved Cryptosporidium species and subtypes.
    Results of molecular diagnostic methods were co-analyzed with epidemiological information. Cryptosporidiosis was found to be common in Ismailia province; within herd prevalence was 73.3%, individual animal prevalence 32.2% and prevalence in diarrheic children 49.1%.
    The pattern of cryptosporidiosis is unique, distinct and multilayered in the province.
    Two independent transmission cycles exist. Anthroponotic transmission is due to C. hominis. Infection hotspots, however, are not urban but rather rural areas along the province’s major irrigation canal. The zoonotic scenario is characterized by 5 Cryptosporidium species involved, with C. parvum dominating, and by 4 C. parvum subtypes, not all identical in animals and humans. The surprising dominance of the IId allele family in animals and humans points to a likely adaptation of a typical subtype of small ruminants. An endemic cryptosporidiosis situation in livestock is likely, maintained by the predominant smallholder husbandry system, where the frequent exchange between herds reshapes the existence of several Cryptosporidium species and subtypes in animals.
    This animal scenario is principally mirrored in zoonotic cryptosporidiosis (C. parvum) of humans. Development of control strategies should take notice of the special features identified in animal and human cryptosporidiosis.
    Strategies will have to be long-term, include hygienic measures at any setting and behavioral change of people, both rural and urban.
    The introduction of routine testing of stool specimens of diarrheal patients is a realistic short term option.