1. 刚地弓形虫 toxoplasma-gondii 赵振江 黄永兴 杨雨 周颖

2. Introduction Sarcocystidae （肉孢子虫 科） Toxoplasma （弓形体属） Host: human, swine, dog, cat, etc. Site: intestine,retina （视 网膜）,placenta （胎盘） microscopical feature of tachizoity( 速殖子，又称滋养体 )

3. Morphology

4. Cyst （包囊） Oocyst( 卵囊 )

5. Life cycle

6. Epidemiology T. gondii has been found worldwide in many species, including carnivorous and herbivorous mammals and birds. Toxoplasmosis is a worldwide, predominantly asymptomatic protozoal infection of humans and animals that is due to Toxoplasma gondii. Its frequency of occurrence varies with geographical region and dietary habits. It has also been found in every population group of humans investigated. In the United States, most infection occurs through ingestion of contaminated meat, especially pork and lamb. One survey of pigs in the US found a seroprevalence( 血清阳性率 ) of 42% in breeder pigs and 23% in market pigs. Another study in the 1960s found T. gondii in 32% of pork chops and 4% of lamb chops in grocery stores. In humans the seroprevalence is 22.5% at the national level, according a study of 17,658 people from 1988 to 1994. Because there is the extra concern of congenital infection in mothers, additional attention given to the prevalence in women of child- bearing age. The seroprevalence in the group of 15 to 44 year old women was reported to be 15%.

7. Intermediate hosts :vertebrates such as humans,swines,mice and cats 人及猪、鼠、猫等 多种脊椎动物 Definitive host: cats.

8. Signs or Symptoms In Swine 1. Synochus( 稽留热） 2. Nasal discharge( 脓性鼻涕）， dyspnea （呼吸困 难）， decreased appetite （食欲减退） 3. Constipation （便秘）， diarrhea （下痢）， cacosmis feces （恶臭粪便） 4. Inguinal lymph node tumefaction （腹股沟淋巴结 肿大）， congestion patch （淤血斑）， cyanosis （发绀）

9. Lesions （病变） Lymph node tumefaction （淋巴结肿大）， lung edema （肺水肿）， spleen tumefaction （脾脏肿大）， heart-sac dropsy （心包积水） Focal necrostic hepatitis （局灶性坏死性肝 炎）， lymphadenitis （淋巴结炎）， apyogenous meningoencephalitis （非化 脓性脑膜炎）， pneumonedema （肺水 肿）， interstitial pneumonia （间质性肺炎）

10. Diagnosis initial diagnosis ： according to its epidemiologic feature and signs definite diagnosis : stool examination （粪便常规检查）, staining of organ smear （脏器涂片 检查）， animal inoculation （动物接 种） immunology method :IHA or ELISA

11. Control Sulfadiazine,SD( 磺胺嘧啶 ) + trimethoprim, TMP （甲氧苄氨嘧啶）， albendazole( 丙硫 苯咪唑 ) Periodic inspection, Enhance excrement management （加强粪便的管理）， regularity disinfect （定期消毒） Make use of vaccine （疫苗）

12. References 李国清. 兽医寄生虫学 ( 双语版 ). 北京 : 中国农业大学 出版社,2006 http://www.google.com.hk