Is Japan sufficiently prepared to deal with bioterrorism?

To the Editor: A wide range of pathogenic microorganisms can be used for bioterrorism. Anthrax bacteria were used for such a purpose in the United States. Other pathogenic microorganisms that can be used for bioterrorism include smallpox virus, plague bacteria, and botulinus toxin. The problem in dealing with infections caused by such microorganisms is that most doctors have no experience in diagnosing and treating such infections.

The use of smallpox virus in a bioterrorist attack could have a devastating impact, since this virus can spread easily by airborne infection and its infectivity is strong. There have been no cases of smallpox in Japan since 1975, and smallpox vaccination was stopped in 1976. Almost 4 million people in Japan therefore have no immunity to smallpox virus. There is still basically no cure for smallpox, and it is estimated that almost 30% of people who have not been vaccinated would die if infected with smallpox virus. Although people who have been vaccinated should not be seriously affected, their immunity to the virus may have been weakened, as 25 years have passed since smallpox virus vaccination was stopped in Japan.

Due to the escalating fear of bioterrorist attacks in recent years, the Ministry of Welfare and Labor in Japan has prepared guidelines for dealing with a bioterrorist attack and has instructed local government bodies to make adequate preparations for dealing with bioterrorism. These preparations include (1) designation of staff of medical institutions who will initially deal with the problem and (2) storage of a sufficient amount of vaccine for vaccination of the people who will initially deal with the problem if there is a likelihood of the occurrence of a bioterrorist attack using smallpox virus. Past experience has shown that vaccination within 1 week after infection with smallpox virus can prevent spread of the virus in the body or alleviate the severity of symptoms caused by the virus. The Ministry of Welfare and Labor has been taking measures since 2001 to increase the production of smallpox virus vaccine, and there is now a sufficient amount of vaccine for 2.5 million people.

Unlike the effects of chemical substances such as sarin, there are incubation periods before the appearance of symptoms caused by infection with pathogenic microorganisms that can be used for bioterrorism, and doctors may treat patients without awareness of infection with such pathogenic microorganisms if there has been no news of a bioterrorist attack. To detect in the early stage unusual outbreaks of infectious diseases, the Ministry of Welfare and Labor has established a system in which symptoms such as skin/mucosa symptoms and respiratory symptoms of all cases of suspected infectious disease are reported to the ministry by designated medical institutions if it is thought that there is a high probability of occurrence of a bioterrorist attack. Appropriate measures taken by staff of medical institutions at which infected patients are first examined are essential for preventing the spread of infection.

Takashi Yokota, MD

Seiichi Kojima, MD

Department of Surgery

National Sanatorium Tohoku Shinseien

Miyagi, Japan

Shu Kikuchi, MD

Hidemi Yamauchi, MD

Department of Surgery

Sendai National Hospital

Sendai, Japan