Ivreplication And Host Range

Humans are the only known reservoir of the NLV pathogens. Chimpanzees can be experimentally infected with NLVs. They can shed virus in their stools and seroconvert, but are refractory to onset of clinical symptoms and disease (25,31). Although some animal caliciviruses have genetic and morphological similarities to human NLVs, foodborne zoonotic infection of humans by animal cali-civiruses has not been demonstrated to date (35-39). However, zoonotic transmission of animal caliciviruses is not unprecedented, since nonfoodborne transmission of the San Miguel sea lion virus to a laboratory worker has been reported (40). Efforts to propagate human caliciviruses in vitro have been unsuccessful, and there is no practical laboratory animal which can be used to culture the virus in vivo. Consequently, the only source of NLVs are the stools of infected individuals. Virus shedding occurs as early as 15 hours postinfection and peaks between 25 and 72 hours (41). However, virus shedding for as long as 2 weeks postinfection has been demonstrated (42).

Unlike enteric bacterial pathogens in foods, NLVs do not replicate within foods. Therefore, NL illness does not result from temperature abuse of food products. Exactly how much virus constitutes an infectious dose of NLV is not known; however, the amount of virus required to elicit illness is likely to be only 10-100 virus particles (35).

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  • Rebekah
    What is host in food poisoning?
    6 years ago

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