Burmese pythons, native to Southeast Asia, have become established as an invasive species in regions like southern Florida, especially within Everglades National Park. This establishment is due to the release of pet pythons into the wild, where the climate and lack of natural predators allow them to thrive. While often perceived as a direct danger, their impact on human health is multifaceted, encompassing rare direct encounters and more widespread indirect ecological consequences.
Direct Physical Hazards
Burmese pythons are capable of biting and constricting humans, with sharp, rearward-curving teeth. A bite from a larger python can cause significant lacerations and pain. While smaller pythons are less dangerous, adults can grow to lengths exceeding 18 feet and weigh over 200 pounds, making them capable of subduing large prey.
Unprovoked attacks on humans are uncommon, especially for the general public. Most reported incidents involve biologists working in remote, flooded areas, where snakes might strike due to mistaken identity, mistaking human movement for prey. In these rare instances, the pythons often abort their strike upon realizing the size of the human.
Disease Transmission Risks
Burmese pythons can carry various pathogens, with Salmonella bacteria a primary concern for human health. Reptiles, including pythons, commonly carry Salmonella as part of their normal gut flora, and an estimated 6% of human Salmonella infections annually in the United States are linked to reptile or amphibian contact.
Transmission to humans can occur through direct handling of the snake or indirectly through contact with contaminated surfaces or feces. Symptoms of reptile-associated salmonellosis in humans primarily involve the gastrointestinal tract, but can also include fever and central nervous system issues. Proper hygiene, such as washing hands after handling reptiles or cleaning their environments, is important to minimize transmission risk.
Ecological Disruption and Public Health
The presence of Burmese pythons in areas like the Florida Everglades has disrupted native ecosystems, with indirect yet significant consequences for public health. These invasive snakes have caused declines in native mammal populations, including raccoons, opossums, bobcats, and rabbits, with reductions ranging from 85% to 100% in some areas.
This decimation of native wildlife can lead to shifts in the food web and alter disease transmission dynamics. For instance, the reduction of larger mammals has led mosquito populations to shift their feeding preferences towards other available hosts, such as rodents like the hispid cotton rat. This increase in mosquito feeding on rodents, which can act as “reservoir hosts” for certain pathogens, can lead to a higher prevalence of zoonotic diseases circulating in mosquito populations, such as Everglades virus (EVEV). Such ecological changes can indirectly elevate the risk of human exposure to these mosquito-borne illnesses.
Coexistence and Safety
Living in areas with established Burmese python populations requires awareness and safety measures. Securing properties by eliminating potential hiding spots, such as dense brush or debris piles, can help deter snakes. Keeping pets on leashes and supervised in python-prone areas is also an important precaution, as large pythons are capable of preying on domestic animals.
If a python is encountered, it is important to maintain a safe distance and contact local wildlife authorities or licensed python removal agents. Attempting to capture or handle a large python without proper training and equipment can be dangerous. While the direct risk of an unprovoked attack on humans is low, the presence of these large predators can cause concern among residents.