ZOONOTIC PARASITES AFFECTING FOOD SAFETY AND PUBLIC HEALTH
Location: Environmental Microbial and Food Safety Laboratory
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 1, 2012
Publication Date: August 1, 2012
Citation: Robertson, L., Fayer, R. 2012. Cryptosporidium. In: Foodborne protozoan parasites. Eds. Robertson L and Smith H. Nova Science Publuishers. NY. Book Chapter. p. 33-64.
Interpretive Summary: This chapter, written in language easily understood by persons with nontechnical backgrounds summarizes all scientific publications related to the presence of the widespread protozoan parasite Cryptosporidium in food. Included are the following sections: Taxonomy; Life cycle, Human disease; Infectious dose and treatment; Incidence; Transmission routes; Foodborne outbreaks; Cryptosporidium in water used for food processing; Cryptosporidium on fruit and vegetables: contamination routes, detection methodologies, and occurrence; Cryptosporidium on meat products: infection, occurrence, detection methods, and inactivation; Cryptosporidium in beverages: outbreaks, occurrence; detection methodologies, survival and decontamination; Cryptosporidium in shellfish: occurrence, detection methodologies and inactivation; Regulations and guidance. This chapter is intended for use by public health specialists worldwide at local to national and global levels for purposes from laboratory identification to environmental and public health policy formulation.
Of nearly 25 named species and numerous genotypes of Cryptosporidium, two are of special importance relative to human health and food safety: Cryptosporidium hominis and Cryptosporidium parvum, the former with a predilection for humans and the latter a promiscuous species. Genetic tools have been essential for identification, naming, and epidemiological studies of the many members of this genus with lifecycle stages similar to apicomplexan coccidia and some genetic traits of gregarines. Cryptosporidiosis has been reported worldwide in all age groups. Infection results primarily in gastrointestinal discomfort, diarrheal disease, and dehydration. Treatment relies primarily on supportive rehydration. Typically, billions of oocysts, produced in the small intestine, are excreted in the faeces; between 10 and 1000 oocysts are sufficient to initiate infection in a susceptible host. Oocyst transmission can be direct, from person to person or animal to person, or indirect through contaminated water or food. Recreational water, irrigation water, wash water, and drinking water have all been found contaminated. Raw fruits and vegetables, milk, apple cider, meat, and shellfish have been found contaminated. Contamination at the sites of production, processing, and preparation have resulted in outbreaks worldwide. Methods of detection, disinfection, and prevention are described herein, as well as the need for regulations and guidance.