An Outbreak of Type C Botulism among Waterfowls in a Pond in Tokyo

Abstract

In the Shinobazu Pond of Ueno Park in Tokyo, death occurred to almost one half of the aquatic fowls inhabiting in June, 1984, and to more than 60 migratory wild ducks in fall and winter up to March, 1985. Dead birds were found to have manifested motorial paralysis characteristic of botulism as a main symptom. Clostridium botulinum type C1 toxin was demonstrated in the blood of 7 ducks and wild ducks which died in June. C. botulinum type C was isolated from the contents of the gizzard in two of the seven. The toxin was also demonstrated in the blood of 23 wild ducks which died in November, December, and January, and this organism isolated from the contents of the gizzard and cecum of 7 and 14 waterfowls, respectively. Botulinum toxin type C1 was also recognized in mud almost all over the pond in July and February.