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Background. There is concern that Japanese travelers are poorly protected against travel-associated infectious diseases including vaccine-preventable infections. This prompted us to study Japanese travelers for measures taken to reduce their risk of acquiring an infectious disease and their immunization uptake. Methods. During April 2007 to May 2008, a questionnaire study was conducted using the European Travel Health Advisory Board (ETHAB) protocol and targeting Japanese group tour clients as well as individual travelers to developing countries. Results. A total of 302 returned questionnaires were analyzed. While the majority (87.4%) sought general information on their destination, few (38.7%) sought the travel health information. Very few (2.0%) got the health information from travel medicine specialists. More than half were either unaware of the risks or thought there was no risk of hepatitis A, hepatitis B, and typhoid fever in their destination. Only half (50.7%) thought vaccines provided sufficient protection and very few (13.6%) believed that vaccines were safe. For most of the vaccine-preventable diseases, only fewer than 10% had received the vaccines. Conclusions. There is a need for specialized travel health services in Japan and health professionals should be encouraged to expand these services. Japanese travelers should be made aware of the importance of seeking pre-travel health advice and information on the health risks at their destination. Travel health professionals should provide a balanced view of the risks and benefits of immunization, and misperceptions about immunization should be addressed. [ABSTRACT FROM AUTHOR]

Background. Malaria poses a significant threat to military personnel stationed in endemic areas; therefore, it is important to examine the risks of military operations, particularly in areas where malaria-related data are scarce. The recent deployment of Japan Ground Self-Defense Force (JGSDF) for a peacekeeping operation in East Timor provided an opportunity to investigate these risks. The results of these studies may be translated into chemoprophylactic strategies for travelers. Methods. A total of 1,876 members were deployed between April 2002 and September 2003. They consisted of three battalions; each remained for 6 months and was put on mefloquine prophylaxis. Malaria infection was investigated, including exposure to Plasmodium falciparum sporozoites, assessed by seroconversion for anticircumsporozoite (anti-CS) protein antibodies. Adherence to and adverse events (AEs) of mefloquine were studied via questionnaires. Results. Four members were evacuated: one each with optic neuritis, lung cancer with brain metastasis, IgA nephropathy, and psychotic reactions that may have been precipitated by mefloquine. Six clinical episodes of Plasmodium vivax occurred, including one relapse, but there were no clinical cases of P falciparum, yielding a crude malaria attack rate of 0.32% for the 6-month period. Overall, 3.1% of the study population seroconverted for the anti-CS protein antibodies, with some regional differences noted. About 24% of questionnaire respondents, reported AEs; however, none of the AEs was severe. The AEs tended to emerge during the initial doses of chemoprophylaxis. Conclusions. The implementation of mefloquine prophylaxis among JGSDF personnel in East Timor, where P falciparum constitutes a moderate risk, appears to have been a success. Mefloquine prophylaxis was generally safe for Japanese unless predisposed to neuropsychiatric illness. However, given that mefloquine is the only chemoprophylactic agent available, a risk-benefit analysis tailored to the traveler is required for visits to countries such as East Timor. [ABSTRACT FROM AUTHOR]

Reviews the epidemiologic situation and clinical management of malaria in Japan. Role of the Research Group on Chemotherapy of Tropical Diseases; Statistics of malaria cases; Blood donor selection; Malaria checks at international airports.

The effect of various H-2-subregion differences on graft-versus-host (GVH) autoimmunity in mice was investigated by testing a variety of GVH combinations in which non-irradiated adult F1 hybrid mice were injected with parental strain lymphoid cells. As with previous results, the superiority of Class-II H-2 antigen (I-A/I-E) differences to other kinds of H-2 incompatibilities, such as Class-I H-2 antigen (H-2K/H-2D) differences, was largely confirmed. Anti-nuclear antibodies were produced significantly across Class-I as well as Class-II H-2 differences. However, the productions of anti-erythrocyte and anti-thymocyte autoantibodies were mainly confined to GVH reactions induced across Class-II H-2 antigens. Elevated proteinuria was elicited only in the GVH combination that included the differences at Class-II H-2 antigens. GVH autoimmunity, however, did not always result in the significant occurrence of elevated proteinuria. The level of in-vitro IgG production by GVH spleen cells correlated closely with the degree of autoimmunity. [ABSTRACT FROM AUTHOR]