河南猪隐孢子虫病流行病学调查及动物感染试验

Epidemiological Survey of Pig Cryptosporidium in Henan and Artificial Infections with the Strain SUCP

为了掌握河南猪隐孢子虫（Cryptosporidium）的感染情况，用饱和糖溶液漂浮法和改良抗酸染色法调查了郑州、许昌、漯河和禹州等地市6个猪场共417份粪样，并进行了固始品种雏鸡和昆明系小白鼠和长大二元杂交仔猪的动物感染试验．结果表明，根据形态大小初步鉴定为小球隐孢子虫（Cryptosporldium parvum），平均感染率为10．95％。20日龄以前的仔猪未感染，21～40日龄的的仔猪感染率为12．20％，41～60日龄的仔猪感染率为21．19％；猪源隐孢子虫分离株（suep）不感染5日龄固始品种雏鸡和18日龄正常的昆明系小白鼠，但是能感染免疫抑制小白鼠，对4日龄仔猪有较强的致病性，并且出现严重的拉稀、脱水等症状．组织切片用H．E染色观察结果显示，sucp株寄生在小白鼠的十二指肠、空肠和回肠以厦仔猪的盲肠、结肠和直肠。

417 Faecal samples were randomly got from 6 hoggeries among Zhengzhou, Luohe, Xuchang and Yuzhou regions were examined by using the Sheather＇ s sugar flotation technique and the modified Ziehl-Neelsen technique to determine the situation of Cryptosporidium infections in Henan. In addition, we made crosstransmission studies on porcine original oocysts in Gushi chicken, Kunming strain mice and Cryptosporidia-free dualistic crossbreed piglets. Results show that Cryptosporidium parvum was identified among the less than 2-month old experimental piglets with an average infection rate of 10.95 %. The infection rate of the 21 ～ 40-day-old piglets and that of the 41 ～ 60-day-old piglets were 12.20% and 21.19% respectively. Piglets of less than 20 days old were negative of Cryptosporidium. Porcine original Cryptosporidium oocyst was lack of infectivity to 5-day-old Gushi chickens and to 18-day-old Kunming mice, but able to infect immuno-suppressed mice and with a strong power to cause disease to 4-day-old piglets with severe clinical signs including watery diarrhoea, dehydration, depression, inappetence and vomiting. In addition, through routine histotomy and H. E staining technique, SUCP strains of cryptosporidia were observed parasitizing in caecum, colon and rectum of piglets and in the small intestine of mice, including duodenum, jejunum and ileum.