EPIDEMIOLOGIC DATA ON CRYPTOSPORIDIUM-PAR VUM INFECTION OF MAMMALIAN DOMESTIC-ANIMALS IN HUNGARY

Epidemiologic, diagnostic and therapeutic experiences are reported abo ut cryptosporidiosis of young mammalian domestic animals (calves, lamb s, goats, pigs, rabbits and dogs), based on investigations directed to enteric diseases. Data reported here (Table I) are based on microscop ic, electronmicroscopic (and occasional immunofluorescence) studies on ileal samples of animals that had died or were euthanized because of diarrhoea. The main data of these studies were reported at different i nternational conferences (9, 11, 12), except for pigs, rabbits and dog s. Based on morphological properties, the cryptosporidia proved to be C. parvum. Cryptosporidiosis of calves has been studied on 649 calves from 56 herds from where the small intestine of at least 3 diarrheal c alves has been tested by bacteriological, microscopic and electron mic roscopic methods. These investigations indicated that cryptosporidia w ere the third most frequent (21%) pathogens, following rotavirus and c oronavirus. They were detected in 70% of the herds.The calves showed d iarrhoea at 5-14 days of age characterized by putrid odor, mucoid (som etimes, blood tingled faeces), not responding to antibiotic therapy. C ryptosporidia were the sole or prime agent only in 4 herds. In about h alf of the cases, cryptosporidia could be detected together with other enteric pathogens. The average age of the calves infected only with c ryptosporidia was 12 days, while that of the calves also infected with other enteric pathogens was about 7-10 days. Antibiotic therapy (oxyt etracycline, furazolidone, neomycine, sulfaquinoxaline) of cryptospori diosis in diarrheal calves was unsuccesful. However, in cases when sul faquinoxaline treatment (160 mg/kg bwt plus vitamins K-1 and B-12 adde d) was initiated before the clinical signs of cryptosporidiosis (i.e. in case of 2-3 days old calves with enteric colibacillosis and cryptos poridiosis), and the treatments were continued for for 5-10 days, the frequency of cryptosporidia and death has dropped essentially (Table 2 ). These results were confirmed by the results of metaphylactic sulfaq uinoxaline (100 mg/kg bwt/day) treatment of goat kids infected experim entally with C. parvum of calf origin (Table 3).Lambs were investigate d in 14 herds (53 diarrheal animals) from which cryptosporidia could b e detected from 4 herds. In 3 of these herds there were other enteric pathogens (K99(+) E. coli, coccidia, rotavirus) present. Cryptosporidi a occured in 22.6% of the diarrheal animals. Diarrhoea started usually at 4-7 days of age. Studies were made on 128 goat kids from 3 herds. It was observed, that in colostrum fed goat kids cryptosporidia cause diarrhoea mostly at the end of the first week and at the beginning of the second week, characterized by soft and pasty faeces, followed by s pontaneous recovery in a few days. Cryptosporidiosis was complicated i n about 50% of the cases by rotavirus and/or coccidial infection. Cryp tosporidia were detected in 37.5% of the 96 diarrheal goat kids (in ha lf of the cases with rotavirus), while the infection rate of nondiarrh eal kids of that age was 3/32. Developmental stages and their localiza tion was Studied by electron microscopy (Figs 1 and 2). Cryptosporidia were detected in pigs during investigations of newborn and postweanin g diarrhoea. They were present in 3/388 (2%) of newborn and in 1/92 (1 %) of weaned pigs, indicating their negligible significance. In harmon y with these results, cryptosporidiosis of weaned pigs did not aggrava te experimental enterotoxic E, coli (ETEC) diarrhoea. ETEC bacteria ad hered to the microvillus membrane at the presence of cryptosporidia (F ig. 3). In diarrheal weaned rabbits (40 animals) cryptosporidia were p resent - sometimes in strikingly high numbers - in 25% of the animals in almost all cases with coccidia and/or rotavirus or E, coli. Infecti on rate of nondiarrheal weaned rabbits was 12.2%. In enteric diseases of 36 dogs (almost all city dogs) there were protozoa present - usuall y in few numbers - resembling C. parvum. Protozoa with the size of C. muris were detected in the small intestine of two diarrheal calves, on e lamb and of two rabbits without early indications of pathological si gnificance. Based on these data it seems that in enteric diseases of y oung ruminants and rabbits a pathological significance can be attribut ed to C. pavrum primarily as a predisposing secondary infection. In ca se of immunocompetent pigs and dogs the significance of cryptosporidio sis is much less.