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ProMED翻訳情報(220回) ~アメリカでのコウモリからの感染疑い~



狂犬病-USA (New Mexico)コウモリ、ヒト曝露
Date: Fri 4 Oct 2013
Source: WRAL, Associated Press (AP) report [edited]
A total of 6 students at an Albuquerque [New Mexico] middle school are being treated for rabies exposures because they were found playing with a bat that later tested positive for rabies. The school districts sent warnings to the homes of additional students at Polk Middle School because officials are concerned there could be more students who were exposed. A teacher captured the bat, and tests confirmed it had rabies.

The 6 students who were identified as having played with the bat on Wednesday [2 Oct 2013] have received the 1st of several rounds of vaccine. A state Department of Health epidemiologist said the 6 students don’t show evidence of bites. However, Dr. Chad Smelser says bat teeth are so small that people sometimes don’t feel it when they’re bitten.
コウモリで遊んでいた6人の生徒は水曜日(2013年10月2日)に特定され、複数回にわたるワクチン接種のうち一回目のワクチンを受けた。州の保健疫学者のChad Smelser氏は、6名の生徒に咬まれた痕跡は無かったが、コウモリの歯は非常に小さく、時に咬まれた事に気づかない人がいると述べている。

Communicated by: ProMED-mail <promed@promedmail.org>

[Rabies is a zoonotic disease caused by RNA viruses in the family _Rhabdoviridae_, genus _Lyssavirus_. Virus is transmitted in the saliva of rabid mammals via a bite. After entry to the central nervous system, these viruses cause an acute, progressive encephalomyelitis. The incubation period usually ranges from 1 to 3 months after exposure, but can range from days to years. In the United States, animal rabies is common. In a recent study, approximately 23 000 persons per year were estimated to have been exposed to potentially rabid animals and received rabies post-exposure prophylaxis (PEP). Prompt wound care and the administration of rabies immune globulin (RIG) and vaccine are highly effective in preventing human rabies following exposure. A variety of empirical schedules and vaccine doses have been recommended over time, based in part on immunogenicity and clinical experience in areas of the world with enzootic canine or wildlife rabies. As more potent vaccines were developed, the number of vaccine doses recommended for PEP has decreased, and studies aimed at further revision and reduction of PEP schedules and doses in humans have been encouraged. By the latter half of the 20th century, a 4- to 6-dose, intramuscular regimen using human diploid cell vaccine (HDCV) or purified chick embryo cell vaccine (PCECV) was being recommended. In the United States, a 5-dose PEP vaccine regimen was adopted during the 1980s. In 2007, when human rabies vaccine was in limited supply, an ad hoc National Rabies Working Group was formed to reassess the recommendations for rabies prevention and control in humans and other animals.
In 2008, a smaller Advisory Committee on Immunization Practices (ACIP) Rabies Workgroup was formed to review rabies vaccine regimen options. It recommended a 5-dose regimen for rabies PEP in previously unvaccinated persons. However, new recommendations have reduced the number of vaccine doses to 4. The reduction in doses recommended for PEP was based in part on evidence from rabies virus pathogenesis data, experimental animal work, clinical studies, and epidemiologic surveillance. These studies indicated that 4 vaccine doses in combination with rabies immune globulin (RIG) elicited adequate immune responses and that a 5th dose of vaccine did not contribute to more favorable outcomes. For persons previously unvaccinated with rabies vaccine, the reduced regimen of 4 1-mL doses of HDCV or PCECV should be administered intramuscularly. The 1st dose of the 4-dose course should be administered as soon as possible after exposure (day 0).
2008年にはより小規模の免疫診療諮問委員会(ACIP)狂犬病検討委員会が設置され、狂犬病ワクチン処方のオプションが再検討された。委員会によれば、狂犬病ワクチンをこれまで受けた事の無い人に対しては5回投与を勧めていたが、新しい提言ではワクチン投与回数を4に減少させている。曝露後予防の推奨投与量を減らすことは、狂犬病ウイルスの発症機序データ、動物実験、臨床試験、疫学調査などから得られた証拠の一部に基づいている。これらの研究は、4回のワクチン投与と狂犬病免疫グロブリン(RIG)を同時に用いることによって十分な免疫反応が得られ、5回目のワクチンを接種してもそれ以上の結果を望めないことを示した。これまでに狂犬病ワクチンを受けたことの無い人には減量法のHDCVまたはPCECV 1mlの4回投与を筋肉内注射で行うべきである。4回投与コースにおける最初の投与は曝露から出来るだけ早期に行うべきである。(当日に)


Additional doses then should be administered on days 3, 7, and 14 after the 1st vaccination. ACIP recommendations for the use of RIG remain unchanged. For persons who previously received a complete vaccination series (pre- or post-exposure prophylaxis) with a cell-culture vaccine or who previously had a documented adequate rabies virus-neutralizing antibody titer following vaccination with noncell-culture vaccine, the recommendation for a 2-dose PEP vaccination series has not changed. Similarly, the number of doses recommended for persons with altered immunocompetence has not changed; for such persons, PEP should continue to comprise a 5-dose vaccination regimen with 1 dose of RIG. Recommendations for pre-exposure prophylaxis also remain unchanged, with 3 doses of vaccine administered on days 0, 7, and 21 or 28. Prompt rabies PEP combining wound care, infiltration of RIG into and around the wound, and multiple doses of rabies cell-culture vaccine continue to be highly effective in preventing human rabies. [For further information, see:
Recommendations and Reports March 19, 2010 / 59(RR02);1-9

In view of the prompt initiation of PEP following recognition of the exposure of the 6 Albuquerque middle school pupils to a rabid bat, it is likely that all 6 will be protected. It has yet to be established if any other individual was exposed to this animal prior to this incident. – Mod.CP