Tada Yuki, Okabe Nobuhiko, Kimura Mikio
Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640, Japan.
Travel Med Infect Dis. 2008 Nov;6(6):368-72. doi: 10.1016/j.tmaid.2008.08.002. Epub 2008 Sep 23.
Country-specific information on the incidence of malaria in travelers provides the most reliable data on which to base the pre-travel risk assessment. Some such studies have been conducted among Western travelers; however, to our knowledge, there have been no reports on Japanese travelers.
Malaria cases that were diagnosed between April 1999 and December 2005 and were reported to the national infectious disease surveillance body were used as the numerators after grouped into countries of disease acquisition. The denominators, the numbers of Japanese travelers visiting individual countries were derived from the recipient countries and obtained through a Japanese organization.
In addition to the well-documented high risks in sub-Saharan countries, our study showed that travelers to Papua New Guinea were exposed to a significantly high risk of malaria. In Asia, Myanmar had the highest risk. Generally, malaria incidence rates among Japanese travelers were lower than those previously reported on Western travelers. However, the rates were rather comparable to the data obtained recently.
These malaria incidence data in travelers should be taken into consideration for pre-travel risk assessment. They need to be constantly updated, and at the same time, limitations in data interpretation that are inherent in various study methodologies should also be clarified.
旅行者中疟疾发病率的国别信息为旅行前风险评估提供了最可靠的数据依据。一些此类研究已在西方旅行者中开展；然而，据我们所知，尚无关于日本旅行者的报告。
将1999年4月至2005年12月期间诊断出并报告给国家传染病监测机构的疟疾病例，按疾病感染国家分组后作为分子。分母，即前往各个国家的日本旅行者人数，来自接待国并通过一个日本组织获取。
除了撒哈拉以南国家存在的高风险已被充分记录外，我们的研究表明前往巴布亚新几内亚的旅行者面临着显著的高疟疾风险。在亚洲，缅甸风险最高。总体而言，日本旅行者中的疟疾发病率低于此前报告的西方旅行者。然而，这些发病率与最近获得的数据相当。
旅行者中的这些疟疾发病率数据应在旅行前风险评估中予以考虑。这些数据需要不断更新，同时，还应阐明各种研究方法中固有的数据解释局限性。
