Rocky Mountain spotted fever (RMSF) is a rickettsial disease, meaning it’s carried and spread by ticks. RMSF symptoms include rash, fever, headache, abdominal pain, vomiting, and muscle pain. An RMSF infection can be fatal if not treated immediately.
Now, researchers have discovered that RMSF can spread from one animal to another in just ten minutes. But there’s a catch: only ticks who had recently fed on other animals were able to spread RMSF that quickly.
“The current literature, including medical textbooks and guidelines for the general public, has repeatedly advised that an infected tick requires a minimum feeding period varying from two to 10 hours to transmit Rickettsia rickettsii — the bacterium that causes Rocky Mountain spotted fever — to humans,” noted Marcelo Labruna, a health researcher at the University of Sao Paulo in Brazil.
To study RMSF, which is known as Brazilian spotted fever in Labruna’s country, Labruna’s team examined how RMSF-infected ticks fed on guinea pigs and rabbits. The researchers found that animals exposed to unfed adult ticks were not infected — even after ten hours of exposure.
However, those guinea pigs that were exposed to ticks who had recently fed on rabbits were infected after just ten minutes had passed.
It’s a significant finding because it means the most dangerous ticks could be found on other animals, like dogs — which are often targeted by the small arachnids.
“Our results highlight that dogs are much more important than previously thought in the epidemiology of Rocky Mountain spotted fever in Brazil,” Labruna said. “Within endemic areas, efforts to keep dogs free of ticks should be much more intensive.”
