It is generally believed that there are no important reservoirs or alternative hosts for FCV.
Humans are not susceptible to FCV infection. Interestingly, apart from the existence of a
specific canine calicivirus, FCV-like viruses have also been isolated from dogs (Hashimoto et
al., 1999; Martella et al., 2002; Roerink et al., 1999). Their role in the epidemiology of FCV
in the cat (and dog) is uncertain (Binns et al., 2000; Helps et al., 2005), but is not thought to
be significant.
The virus is shed predominantly with oral and nasal secretions in acute disease. On recovery,
many cats continue shedding, most of them for at least 30 days post-infection, a few for
several years (Wardley, 1976). A small proportion of cats may be resistant to infection
(Coyne et al., 2006a), which is probably dependent on host and virus strain factors.
Feline calicivirus infection is widespread in the general cat population. The prevalence is
broadly proportional to the number of cats in the household, with the highest prevalenceusually seen where large groups are housed together. The prevalence in household cats kept in
small groups is generally low (~10%; Wardley et al., 1974). In contrast, cats living in colonies
or shelters have a high chance of being infected, with prevalence figures between ~25% and
40% (Wardley et al., 1974; Coutts et al., 1994; Bannasch and Foley 2005; Helps et al., 2005).
The prevalence within individual colonies is variable, ranging from low (Radford et al., 2001;
Coyne et al., 2006a) to high (50-90%) values (Radford et al., 2003; Coyne et al., 2006a).
Infection generally occurs through direct contact with secretions from acutely infected and
carrier cats. However, the virus can also persist in the environment and remains infectious for
up to one month on dry surfaces at room temperature, and longer in colder weather conditions
(Doultree et al., 1999; Duizer et al., 2004; Clay et al., 2006). Indirect transmission can
therefore occur, especially within the close confines of a cattery, where secretions may
contaminate cages, feeding and cleaning tools or personnel. Direct contact between
susceptible individuals and FCV shedding carriers is probably the most common way of
transmission (Wardley, 1977).