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

68 BACTERIOSES96.1% could be typed using the Penner system and 92.1% could be typed using theLior system. They also conclude that these schemes complement each other and areuseful for epidemiological research.Geographic Distribution: Worldwide.Occurrence in Man: At present, C. jejuni is considered to be one of the principalbacterial agents causing enteritis and diarrhea in man, particularly in developedcountries. In these countries, the incidence is similar to that of enteritis caused bySalmonella. As culture media and isolation methods have been perfected, the numberof recorded cases caused by C. jejuni has increased. In Great Britain, the 200public health and hospital laboratories had been reporting isolations of salmonellasexceeding those of Campylobacter, but beginning in 1981, the proportions werereversed: 12,496 isolations of Campylobacter as opposed to 10,745 of Salmonella(Skirrow, 1982). According to Benenson (1990), campylobacteriosis causes 5% to14% of diarrhea cases worldwide. Based on records from private medical practice,it has been estimated that 20% of office consultations for enteritis in Great Britainwere associated with campylobacteriosis and that there are a projected 600,000cases annually at the national level (Skirrow, 1982). It is harder to establish the incidencein developing countries; because of deficiencies in hygiene, C. jejuni is isolatedfrom 5% to 17% of persons without diarrhea (Prescott and Munroe, 1982) andfrom 8% to 31% of persons with diarrhea. Thus, it is likely that Campylobacter isan important cause of infantile diarrhea in the Third World (Skirrow, 1982).The illness affects all age groups. In developing countries, it particularly affectschildren under the age of 2 years; in developed countries, children and young adultsbecome ill more frequently. Campylobacteriosis is also an important cause of “travellers’diarrhea” (Benenson, 1990). The disease is primarily sporadic, although thereare also epidemic outbreaks. The largest known epidemics originated from commonsources, such as unpasteurized milk or contaminated water from the municipal supplyof two European cities. In countries with a temperate climate, the disease is mostprevalent in the warm months.In Great Britain, the US, Canada, and Switzerland, consumption of unpasteurizedmilk or products prepared with raw milk has caused campylobacteriosis outbreaks.The largest outbreak in Great Britain affected approximately 3,500 people (Jones etal., 1981). Outbreaks may be due to milk contaminated by fecal matter or, less frequently,to milk from udders with mastitis caused by C. jejuni. Another outbreakaffected more than 30 people in a small town in Great Britain. The ensuing investigationshowed that the source of infection was two cows with mastitis caused by C.jejuni that contaminated the bulk milk of 40 cows (Hutchinson et al., 1985). Thesame serotypes of C. jejuni were isolated from the cows, patients’ feces, milk filters,and bulk milk.It is estimated that C. jejuni causes more than 90% of human cases of the disease(Karmali and Skirrow, 1984) and only 10% in other species.Occurrence in Animals: Domestic and wild mammals and birds constitute thelarge reservoir of C. jejuni,but it is difficult to implicate this agent as a cause of diarrhealdisease because a high rate of infection is found in clinically healthy animals.The Disease in Man: Enteritis caused by C. jejuni is an acute illness. In general,the incubation period is from two to five days. The principal symptoms are diarrhea,