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

ENTEROCOLITIS DUE TO CLOSTRIDIUM DIFFICILE 1351987). Hemorrhagic necrotizing enteritis in neonate foals is usually caused by otherclostridia, such as C. perfringens types B and C, and C. sordelli. Some cases may bedue to C. difficile. C. difficile was isolated from four foals that died at three ranches,and the presence of the cytotoxin was also confirmed (Jones et al., 1988). A case oftyphlocolitis was also described in an adult horse (Perrin et al., 1993). Traub-Dargatz and Jones (1993) recently reviewed the literature on the disease in horses.Chronic diarrhea due to C. difficile was described in dogs; it was successfullytreated with metronidazole (Berry and Levett, 1986).A rabbit breeder observed green, watery diarrhea in approximately 25% of his130 animals. Upon autopsy, lesions (of varying intensity) were found only in thececum. The total loss was 40 rabbits. A study confirmed that the feed was contaminatedby a food meant for swine, to which lincomycin had been added (permittedonly in feed for pigs and fowl). The situation returned to normal when the feed waschanged (Thilsted et al., 1981).Hamsters (Mesocricetus auratus) are very susceptible to C. difficile and are usedas model animals. Proliferative ileitis is seen in young animals; in adult hamsters,the disease is characterized by chronic typhlocolitis with hyperplasia of the mucosa(Rehg and Lu, 1982; Chang and Rohwer, 1991; Ryden et al., 1991).Outbreaks of typhlitis not induced by antibiotics also occur in guinea pigs. Anoutbreak occurred in a colony of 400 female specific-pathogen free guinea pigs,maintained gnotobiologically with mice; 123 animals became ill, died, or were sacrificed.The disease was attributed to deficient intestinal flora (Boot et al., 1989).Source of Infection and Mode of Transmission: Diarrhea due to C. difficileoccurs in both man and animals absent any association with antibiotics. However,the use of antibiotics and the resulting imbalance in the normal intestinal flora is apredominant factor inducing pseudomembranous enteritis or diarrhea varying fromslight to profuse and hemorrhagic. The implicated antibiotics are, in particular,clindamycin and lincomycin, but other antimicrobials may also be responsible(ampicillin and cephalosporins). An intraperitoneal injection of ampicillin given tomice increased the rate of C. difficile fecal isolates from 19.4% to 63.6% (Itohet al., 1986).The main reservoir of C. difficile seems to be infants in the first months of life.The carriage and excretion of cytotoxigenic strains in diarrheal dogs may also be anadditional zoonotic source of infection (Berry and Levett, 1986; Weber et al., 1989;Riley et al., 1991).Another aspect to consider is that C. difficile forms spores that are resistant toenvironmental factors. Environmental contamination by C. difficile plays an importantrole in the epidemiology of the disease, in both hamsters and man. C. difficilewas isolated from 31.4% of the environmental samples from a hospital ward (Kaatzet al., 1988). Studies conducted with epidemiological markers demonstrate crossinfection between nosocomial patients and hospital acquisition of the infection, aswell as a direct relationship between symptoms and the type of C. difficile(Tabaqchali, 1990). A recent study on nosocomial transmission is illustrative in thisregard. Rectal swabs taken from 49 chronic-care patients in a geriatric hospital confirmedthe presence of C. difficile in 10 of them (20.4%). A prospective study tooksamples from 100 consecutive patients admitted to an acute care ward in the samehospital, upon admission and every two weeks thereafter. Two patients (2%) were