Isolation of Clostridium septicum during a Blackleg Outbreak in Madagascar

Blackleg outbreaks have been reported at various locations in Vakinankaratra area (Madagascar) in 1996 and 1997, and caused the death of 588 head of cattle within seven months. Even animals that had been vaccinated between April and August 1996 were not spared from the disease. After performing bacteriological investigations on samples in March 1997, another blackleg agent, Clostridium septicum, was isolated, and its presence was reported in the country for the first time. The Institute for Applied Biotechnology in the Tropics of Goettingen (Germany) confirmed the diagnosis by the gas chromatography technique in May. An experimental vaccine was developed from that strain in order to fill the lacking valence in the conventional product. The isolation of C. septicum occurred 28 years after the first outbreaks of blackleg caused by Clostridium chauvoei. Its origin is briefly discussed.