A Salmonella outbreak at the Bannerghatta Biological Park in Bangalore, India, has resulted in the death of three tigers. The latest victim, a four-year-old female tiger named Minchu, had been critically ill for the past two weeks and died of kidney failure. (Kidney failure is a potential complication of severe intestinal bacterial infections like salmonellosis.) This followed on the deaths of Minchu's older sister Divya and a 45-day-old tiger cub. Fifteen of the remaining 41 tigers are sick, and more deaths would not be surprising.
The source of the outbreak at the Bannerghatta Biological Park hasn't been reported. Likely, it originated from Salmonella in raw meat. Whether the large outbreak indicates a highly contaminated batch of meat, a particularly virulent strain of Salmonella or widespread transmission of Salmonella from an initial case or two is not clear. Regardless, good infection control practices are going to be critical, since the animals' environment is certainly highly contaminated. This poses a risk to all animals and people exposed to the environment. Good infection control is also needed to prevent Salmonella from spreading to other parts of the park. Spread is most likely to occur via peoples' hands or clothing, or through contaminated equipment.
Large Salmonella outbreaks can be very hard to contain. Aggressive infection control, including testing of animals, isolation, thorough cleaning and disinfection, restriction of movement, and re-assessment of various management practices are key aspects of any outbreak control program. Hopefully this outbreak is now under control and Salmonella doesn't "escape" and affect other animals or people at the park.