zoonoses and communicable diseases common to ... - PAHO/WHO

126 BACTERIOSESbreaks of diarrhea, with no other pathogen detected. Blood or mucus do not generallyappear in the feces, but may be found in the stool of some animals. Diarrhea isaccompanied by a mild fever (Taylor, 1992). Swine that are carriers of Y. enterocoliticaserotypes that infect man have been noted primarily in countries where theincidence of human disease is higher, such as in the Scandinavian countries,Belgium, Canada, and Japan. The rate of isolation from swine varies from one herdto another and depends on the level of contamination in each establishment. On onefarm the agent may be isolated only sporadically and at a low rate, while on another,isolations may be continuous and reach 100% of the groups examined (Fukushimaet al., 1983).Y. enterocolitica has been isolated from young sheep with enterocolitis in NewZealand and also in southern Australia. The sheep from 14 herds in New SouthWales from which the agent (serotypes 2, 3) was isolated had diarrhea and someshowed delayed growth and died (Philbey et al., 1991). In Great Britain, Y. enterocoliticawas thought to have caused abortions in sheep. The etiologic agent was isolatedfrom sheep fetuses and most of the serotypes were 6,30 and 7, which did nothave the plasmid that determines the markers to which virulence is attributed(Corbel et al., 1990). An O:6,30 strain isolated from the liver of an aborted sheepfetus was inoculated intravenously in a group of sheep that had been pregnant forapproximately 90 days; the infection produced a necrotizing placentitis and abortions(Corbel et al., 1992).Abortions have been described in association with Y. enterocolitica in cattle in theformer Soviet Union and Great Britain and in buffalo in India. In the latter country,serotype O:9 was isolated from nine buffaloes that aborted; this serotype sharescommon antigens with Brucella and gives serologic cross reactions with that bacterialspecies (Das et al., 1986).Serotypes of Y. enterocolitica were isolated from 5.5% of 451 dogs in Japan(Kaneko et al., 1977) and from 1.7% of 115 dogs in Denmark (Pedersen andWinblad, 1979). In contrast, the incidence of canine carriers in the US and Canadais low. The disease seems to occur rarely in dogs, but it should be borne in mind thatmany clinical cases are not diagnosed because isolation is not attempted. In twocases of enteritis described in Canada, the dogs manifested neither fever nor abdominalpains, but they had frequent defecations covered with mucous and blood(Papageorges and Gosselin, 1983). Y. enterocolitica has also been isolated fromapparently healthy cats. Serotypes O:8 and O:9 are among the types isolated fromdogs and cats.Infection caused by Y. enterocolitica has been confirmed in several monkeyspecies. In one colony of patas monkeys (Erythrocebus patas) in Missouri (USA),two monkeys died less than one month apart from a generalized infection caused byY. enterocolitica. The remaining 20 monkeys were examined and the agent was isolatedfrom rectal swabs taken from five of the clinically normal monkeys (Skavlenet al., 1985).Source of Infection and Mode of Transmission (Figure 10): The epidemiologyof enterocolitic yersiniosis is not entirely clear. The agent is widespread in water,food, many animal species, and man. Of interest is the fact that the serotypes isolatedfrom water and food often do not correspond to the types that produce diseasein man. This is also true of the serotypes found in the majority of animal species,