San Diego zoos effectively prevent bird flu infections

Bird flu has caused widespread issues for many animals worldwide, but San Diego’s zoos have managed to keep their animals safe. The San Diego Zoo, Safari Park, and SeaWorld have not reported infections among their collections since the H5N1 strain was first found in U.S. wild birds three years ago. To protect their animals, zoo officials have changed their feeding practices. They now provide a higher grade of beef to carnivorous birds like California condors and Bengal tigers, as it is seen as safer in light of bird flu concerns. Over the past three years, the parks have implemented new methods to prevent the virus’s spread while maintaining the animals' natural behaviors. Despite 11 dead wild birds testing positive for H5N1 at Safari Park, no animals in the parks have been infected. Officials attribute their success to strong surveillance of wild birds, biosecurity measures, and a bit of luck. Other zoos have not fared as well, losing various animals to the virus. One of the main concerns is the risk of transmission from infected wild birds. To minimize this, staff drain and clean habitats regularly and remove potential nesting areas for wild birds. San Diego is located on the Pacific Flyway, where migratory birds can carry the virus without showing symptoms. Zoo officials adjust their protective measures based on what they learn from bird flu cases. For example, they have stopped sanitizing delivery trucks out of concern for virus transmission from poultry farms. They also focus more on the known transmission routes, like the consumption of raw dairy products. In light of the ongoing threat, SeaWorld previously paused its bird-rescue program to prevent possible infections but has since resumed it with precautions. Staff now wear protective gear when responding to rescue calls. Historically, bird flu has been around for a long time, with severe outbreaks leading to the loss of millions of birds. In recent times, the virus has sickened people in the U.S. as well, prompting ongoing concerns about its impact on global biodiversity. Notably, a wave of California condor deaths in Arizona in 2023 led to the approval of a bird flu vaccine for them. Trials have shown promise, and many condors at San Diego's facilities have already received at least one vaccine dose, with plans to vaccinate more in the future. Overall, while the threat of bird flu remains, the San Diego zoos continue to adapt their measures to protect their animals effectively.