Avian botulism, the reason for deaths of migratory birdsDate: 23 November 2019 Tags: Biodiversity
The mass death of migratory birds at the Sambhar Lake in Rajasthan occurred due to avian botulism according to the report of Bareilly's Indian Veterinary Research Institute.
Bird-watchers and other visitors to the lake discovered thousands of birds dead or dying around Sambhar Lake, which is India’s largest inland saltwater body.
C. botulinum produces the toxins in anoxic, i.e. low-oxygen, conditions, which effectively implies the state government will have to clean up Sambhar Lake.
Botulism outbreaks are likely to become more frequent as climate change alters wetland conditions to favour bacteria and pathogens.
Avian Botulism is a strain of botulism that usually affects wild and captive bird populations, most notably waterfowl. This is a paralytic disease brought on by the Botulinum neurotoxin (BoNt) of the bacterium Clostridium botulinum.
Avian botulism is the result of deadly toxins secreted by Clostridium botulinum bacteria. Upon ingestion, they cause paralysis, which then interferes with critical functions and causes death.
The bacteria is commonly found in the soil, river, and sea water. There are around eight types A, B, C1, C2, D, E, F, and G of botulinum toxin and they are distinguishable when diagnosed. But all types of toxins attack the neurons, which leads to muscle paralysis.
Avian botulism is not contagious in that it is not spread from bird to bird. Instead it is spread to birds through their consumptions of maggots infected with the toxin.
When an infected bird dies the maggots that feed off of it become infected themselves. These maggots are in turn consumed by additional birds.