点耳用薬液中の結核菌の増殖能力—中耳結核の集団発生に関連して

A STUDY OF VIABILITY OF MYCOBACTERIUM TUBERCULOSIS IN EAR DROPS: IN REFERENCE TO OUTBREAKS OF THE MIDDLE EAR TUBERCULOSIS

　I．はじめに

　最近，同一耳鼻科医の患者の間に中耳結核が集団発生したことが報じられている。約5年前にもほぼ同規模の小児の中耳結核の集団発生が日本の某地で発生している。

　三重大学の鵜飼ら^1）は，1979年，中耳結核について次のように報告している。1959〜1978年に日本で報告された中耳結核76例中，41％が最近5カ年の報告で，原発性中耳結核の報告例が最近散見されるようになった。幼児7例を含む中耳結核48例の自験例中85％が過去2年間に集中発生していた。41例は原発性中耳結核であって，39例は中耳結核診断前に他の耳鼻科に通院しており，複数の同一施設から多発していた。ほとんどが経外耳道的院内感染によって生じた原発性中耳結核であったと考られる，と。

　The middle ear tuberculosis has become very rare in Japan. Nevertheless, endemic outbreak have recently occurred. Suspension of 1mg/ml of mycobacterium tuberculosis was mixed with one-tenth volume of a vial content of each of five kinds of ear drops consisting of antibiotics and others Immediately after, 1, 3 and 6 hours, and 1, 3 and 17 days after. 0.1 ml of each mixture was cultured in Ogawa's culture medium. After five weeks, the presence of colonies of mycobacterium tuberculosis was observed. The results were as follows ; Chloromycetin ear drops containing chloramphenicol 5mg/ml showed negative results in all stages, but colimycin F, predex and rinderon-A, which include fradiomycin 3.3~3.5 mg/ml showed the positive results similar to the control at least until the third di y, and only rinderon-A gave positive results even after 17 days.

　The above results revealed that use of one dropper of each ear solution contaminated with mycobacterium tuberculosis in m any patients may cause endemic outbreak of em tuberculosis. It is desirable to use disposable dropper for each instillation of ear solution to avoid such complication.