わが国における<I>Vibrio vulniificus</I>感染症患者誌上調査

Abstract

Vibrio vulnificus is found globally in marine coastal waters. Infection with this organism, via ingestion of raw shellfish or exposure to marine water, can cause necrotizing fasciitis and sepsis, which have high mortality and short latency. In Japan, many cases have been reported since 1980, mainly from hospitals in western prefectures. However, because of the sporadic nature of infection outbreaks, a thorough epidemiologic survey has not been done. We studied the epidemiological and clinical characteristics of Vibrio vulnificus infections reported in Japan from 1975 to 2005. We identified 185 cases using the medical article search engines Ichushi (Japan Medical Abstracts Society), CiNii (Citation Information by National Institute of Informatics), and PubMed over 30 years. The median age of patients was 59. The number of male patients was eight times the number of female patients; however, no significant difference in mortality was found between genders. In yearly distributions of patients, 20 cases were reported in 2001, a year in which we experienced more rainfall and a longer rainy season in Northern Kyushu. In monthly distribution, about 80% of cases were reported from July to September when sea water temperatures rise. About 40% of cases were reported in four prefectures around the Ariake Sea. The underlying disease indicated liver dysfunction in 90% of patients, but mortality was the same regardless of the infection pathway (oral ingestion or wound). Because of its rapid aggravation and high mortality rate, public education is important to prevent new cases. It is also highly recommended that patients with preexisting liver dysfunction avoid raw fish and limit exposure to marine water during the summer.