我国非疫区人布鲁菌病首例病例流行情况

Epidemic situation of first case of human brucellosis in non endemic areas of China

布鲁菌分6型:羊型、牛型、猪型、犬型、森林鼠型和绵羊附睾型,前4种可引起人类疾病。布鲁菌含有20余种蛋白原和脂多糖,其中脂多糖(内毒素)在致病中起重要作用。传染源为布鲁杆菌,是一组球杆状的革兰阴性菌。以羊,牛、猪为主,病原菌主要存在在病畜的组织、尿、乳液、产道分泌物、羊水、胎盘及羔体内。布鲁菌病可由直接接触受染动物的肉、皮毛、分泌物和排泄物,饮用未经消毒的牛奶、羊奶或食入含有活的布鲁杆菌的奶制品(如黄油和奶酪)而引起,罕有人与人间传播。布鲁杆菌经皮肤或黏液侵入人体后,可在局部被消灭,或在淋巴结中生长繁殖而形成感染灶,后侵入血循环。由于细菌和内毒素同时侵入可出现菌血症、毒血症等急性症状,病原菌侵入血循环后,易在网状内皮系统如肝、脾、骨髓、淋巴结等处形成新的感染灶,并可多次侵入血循环而导致复发。人群对布鲁菌普遍易感,特别是从事密切接触布鲁菌的相关职业,如兽医、畜牧、屠宰、肉食品加工、皮毛加工、疫苗、诊断制品生产、从事布鲁菌病防治的工作人员及动物科研人员等是感染该病的高危人群。以往布鲁菌病大多在内蒙、新疆、青海等疫区流行,但随着人们生活水平的提高,以及对牛、羊肉和奶制品营养的认可和需求,由接触受感染牛、羊和饮用消毒不够彻底的奶制品而引发的布鲁菌病也越来越多,特别是三聚氰胺事件后,由饮用羊奶和养殖山羊引发的布鲁菌病病例显著增加,在非疫区也逐渐流行。

Brucella is divided into 6 types： sheep,cattle,pig,dog,forest rat and sheep epididymis types,and the first 4 types can cause human diseases. There are more than 20 species of protein and lipopolysaccharide in brucella,in which lipopolysaccharide（endotoxin）plays an important role in the pathogenesis. The source of infection is brucella,which is a group of ball shaped gram negative bacteria. Pathogenic bacteria mainly exists in sick animals＇ tissue,urine,emulsion,vaginal discharge,amniotic fluid,placenta and lamb body,especially for those sick sheep,cattle and pigs. Brucellosis can be caused by contacting directly with infected animal meat,fur,secretion and excretion;drinking unpasteurized milk and goat＇s milk or ingestion of those dairy（such as butter and cheese）contained with live brucella,there are rare cases for the transmission of this disease from human to human.After invading the body through the skin or mucus,brucella can be destroyed in the local,or grow and reproduce in the lymph nodes and form the foci of infection,and then invade into the blood circulation. Due to the intrusion of the bacteria and endotoxin at the same time can cause some acute symptoms of bacteremia and toxemia,after invading the blood circulation,pathogenic bacteria can form the new foci of infection easily in the reticuloendothelial system such as liver,spleen,bone marrow and lymph nodes,and then make multiple invasion of blood circulation and cause those disease relapsing. Generally,human can be infected easily by brucella,especially those group people with the occupation,which have closer contact with brucella,such as veterinary medicine,animal husbandry,slaughter,meat dish processing,fur processing,vaccines and diagnostic products production and engaged in the prevention of brucella,animal researchers etc,they are all at high risk of the infection of this disease. In the past,brucella was endemic mostly in Inner Mongolia,Xinjiang,Qinghai and other epidemic areas,but with the improvement of people＇s living standard,as well as the recognition and demand of the nutrition of beef,mutton and dairy products,brucellosis caused by contacting with infected cattle,sheep and drinking not completely disinfected dairy is also increasing. Especially,after＂Melamine Milk Incident＂happened in China,the brucellosis cases caused by drinking goat＇s milk and goat breeding is also increasing and endemic in non epidemic areas.