1.1. Viruses and Environmental Virology Environmental virology may be defined as the study of viruses that can be transmitted through various environments (water, sewage, soil, air, or surfaces) or food and persist enough in these vehicles to represent a health threat. A wide variety of different viruses, representing most of the families of animal viruses, can be present in human and animal fecal wastes and urine. Especially important are a variety of nonenveloped human and animal enteric pathogenic viruses that can enter the environment through the discharge of waste materials from infected individuals; contaminate food products and drinking and recreational waters; and be transmitted back to susceptible individuals to continue the cycle of infection (Table 6.1). It is estimated that billions of cases of gastrointestinal illness occur annually worldwide (Parashar et al., 1998; Oh et al., 2003). A good deal of these diarrheal cases are to some extent the result of fecal contamination of the environment (Cabelli et al., 1982; Koopman et al., 1982; Fattal and Shuval, 1989; Moore et al., 1994) while outbreaks of hepatitis A and E are associated with water, shellfish, and crops (Melnick, 1957; Reid and Robinson, 1987; Halliday et al., 1991; Bosch et al., 1991, 2001). The significance to human health of many of the non-human animal viruses present in environmental samples is less well understood and remains uncertain or unknown for many of them. It is remarkable, however, that zoonotic viruses infecting humans continue to be discovered or appear to reemerge as important human pathogens. One example of an emerging disease is severe acute respiratory syndrome, or SARS, reported in November 2002 (Ksiazek et al., 2003). The primary mode of transmission of the SARS coronavirus appears to be direct mucous membrane contact with infectious respiratory droplets and/or through exposure to fomites. Several coronaviruses are known to spread by the fecal-oral route, but there is no current evidence that this mode of transmission plays a key role in the transmission of SARS, although there is a considerable shedding of the virus in stools (Tsang, 2003). As a scientific discipline, environmental virology was born after a large hepatitis outbreak occurred in New Delhi between December 1955 and January 1956. The origin of the outbreak, which was attributed to hepatitis A at the time but now confirmed to be hepatitis E, was the contamination
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- Publication year
2006
- Venue
Viruses in Foods
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Unknown publication date
- Fields of study
Medicine, Environmental Science
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