Sylvatic plague is an infectious disease that is caused by Yersinia pestis. It primarily infects rodents, but is also the same bacterium that causes bubonic and pneumonic plague in humans. The bacteria is transmitted via flea bites and contact with infected tissue or fluids. The plague has been pushing the population of the black-footed ferret to the edge of extinction. Not only are the ferrets susceptible, but their primary food resource, the prairie dog, have had mortality rates as high as 90 percent in some populations from the plague. The ferrets each require about 100 acres of prairie dogs to provide for their offspring, but are falling short as the plague spreads.
Researchers have designed a plan to use oral immunize the prairie dogs by spreading 350,000 vaccine baits over 1,200 acres to reduce the impact of the plague, on both the prairie dog and ferret. They hope that by eliminating the plague in prairie dogs, the black-footed population will make a comeback from near extinction. A recent preliminary study showed that the oral immunization method was effective, with 90% of the bait consumed in field tests. However, the researchers needed a faster way to distribute the vaccine over a wide range, having each bait about 30 meters apart, to prevent the baits being eaten by one prairie dog. For the delivery of the oral vaccine, the researchers are developing the technology needed to release the bait uniformly from the drones. After it is developed, there will be a public comment period and other assessments before the plan can be approved. Wildlife managers had previously sprayed pesticides into the prairie dog burrows to try and combat the fleas, but it proved to be too time consuming and labor intensive, as well as ineffective after the fleas developed a resistance to the pesticide.
The idea of using a drone to distribute the vaccine is interesting, but it might not be the most cost effective measure. Although it will be decided when they release the estimated cost of using drones versus more traditional methods, such as the airplane delivery system that is used to distribute the oral vaccination for the rabies virus.