Research Unit in Epidemiology and Risk Analysis applied to Veterinary Sciences (UREAR), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liege, Boulevard de Colonster 20, B42, 4000 Liege, Belgium.
Vet Microbiol. 2011 May 5;149(3-4):298-306. doi: 10.1016/j.vetmic.2010.11.017. Epub 2010 Nov 19.
As neglected zoonosis for many years, Q fever is now ubiquitous in Japan. Similarly to elsewhere in the world, domestic animals are considered to be important reservoirs of the causal agent, Coxiella burnetii, a resistant intracellular bacterium. Infected animals shed bacteria in milk, feces, urine, vaginal mucous and birth products. Inhalation of bacteria present in the environment is the main route of animal and human infection. Shedding of C. burnetii in milk by domestic ruminants has a very limited impact as raw milk is seldom ingested by the Japanese population. The clinical expression of Q fever in Japan is similar to its clinical expression elsewhere. However clinical cases in children are more frequently reported in this country. Moreover, C. burnetii is specified as one of the causative organisms of atypical pneumonia in the Japanese Respiratory Society Guideline for the management of community-acquired pneumonia. In Japan, C. burnetii isolates are associated with acute illness and are mainly of moderate to low virulence. Cats are considered a significant source of C. burnetii responsible for human outbreaks in association with the presence of infected parturient cats. Since its recognition as a reportable disease in 1999, 7-46 clinical cases of Q fever have been reported by year. The epidemiology of Q fever in Japan remains to be elucidated and the exact modes of transmission are still unproven. Important further research is necessary to improve knowledge of the disease itself, the endogenous hosts and reservoirs, and the epidemiological cycle of coxiellosis in Japan.
多年来一直被忽视的动物源性传染病 Q 热在日本现已无处不在。与世界其他地区一样，家畜被认为是病原体贝氏柯克斯体的重要贮存宿主，这是一种具有抵抗力的细胞内细菌。受感染的动物会在乳汁、粪便、尿液、阴道黏液和分娩产物中排出细菌。吸入环境中存在的细菌是动物和人类感染的主要途径。由于日本人口很少食用生奶，因此家畜在乳汁中排出的 C. burnetii 对人类的影响非常有限。日本 Q 热的临床表现与其他地区相似，但在该国，儿童临床病例报告更为频繁。此外，在日本呼吸学会制定的社区获得性肺炎管理指南中，贝氏柯克斯体被指定为非典型性肺炎的病原体之一。在日本，C. burnetii 分离株与急性疾病有关，主要为中低毒力。猫被认为是导致人类感染的重要传染源，与感染的分娩母猫有关。自 1999 年将其列为法定报告疾病以来，每年报告的 Q 热临床病例为 7-46 例。日本 Q 热的流行病学仍有待阐明，确切的传播方式仍未得到证实。需要开展重要的进一步研究，以增进对日本 Coxiellosis 疾病本身、内源性宿主和贮存宿主以及流行病学循环的了解。
