寄生于人体的钩虫主要有十二指肠钩虫和美洲钩虫2种,其分布为世界性,惟多见于热带及亚热带地区。在我国,华北地区气候干燥寒冷,虽有钩虫存在,一般感染较轻,华东、华中、华南及华西某些地区,则为农村及矿区重要的寄生虫病,流行区的感染率高达70～84.2%。十二指肠钩虫分布较为普遍,美洲钩虫则以海南岛、广东及四川南部等地区最多,许多地区则是两种钩虫混合感染。部队主要见于来源于上述地区的农村新战士和从事农业生产的部队。钩虫主要寄生在十二指肠至空肠下部或回肠前部,有报告盲肠亦可见钩虫附着。钩虫以肠粘膜和血浆为食料,以其口囊咬住肠壁,食管腺分泌乙酰胆碱脂酶、蛋白酶等溶解肠粘膜而形成1～5mm直径的散在溃疡和出血点。由于钩虫善食新鲜肠粘膜,不断更换叮咬部位,故可造成多处肠粘膜损伤;钩虫的头腺又分泌抗凝素,能延长凝血酶元时间,致损伤的肠粘膜出血时间延长,而引起大出血。 Hookworms parasitic on the body mainly have two kinds of hookworm duodenal and hookworm, its distribution is worldwide, but more common in tropical and subtropical regions. In our country, the climate in North China is cold and dry. Although hookworm exists, the infection is generally mild. In eastern, central, southern and western China, it is an important parasitic disease in rural areas and mining areas. The infection rate in endemic areas is as high as 70-84.2 %. The distribution of duodenal hookworm is more common, while the American hookworm in Hainan Island, Guangdong and southern Sichuan and other regions most, and in many areas are two kinds of hookworm mixed infection. The troops are mainly found in the rural new fighters and troops engaged in agricultural production from the above areas. Hookworms mainly parasitic in the lower part of the duodenum or jejunum or ileum in the front, there are also reports of cecal attachment hookworm. Hookworms to intestinal mucosa and plasma as food material, with its mouth bite intestinal wall, esophageal gland secretion of acetylcholinesterase, protease and other dissolved intestinal mucosa to form a diameter of 1 ~ 5mm scattered ulcers and bleeding. Hookworm feeding fresh intestinal mucosa, constantly changing the bite site, it can cause multiple intestinal mucosal injury; hookworm’s gland secrete anticoagulant, can extend the prothrombin time, causing damage to the intestinal mucosal bleeding time, which caused Bleeding.