Researcher from Johns Hopkins University School of Medicine had said in a research finding to be published in The New England Journal of Medicine that the disease called Rocky Mountain spotted fever may spread faster than people thought possible, to cause an outbreak.
The research highlights the importance of the recent outbreak in Arizona, US, as the first confirmed cases that could be traced back to ticks carried into to the state on feral dogs, an animal group whose population has markedly increased. And, as the number of dogs has increased, so have the number of ticks.
According to the research, the disease, most often marked by a telltale spotty rash that appears five to 10 days after the first signs of infection, has been largely confined to the South Central and Southeastern United States, although sporadic cases have been reported in all 48 continental states, mostly North Carolina.
The scientist also reports that the number of people infected with Rocky Mountain spotted fever, which is fatal in up to 10 percent of those who contract it, has peaked for the third known time this century, with more than 1,800 cases reported nationally in 2003 and 2004. However, scientists believe the number of unreported cases is much greater.
Growing awareness among physicians about the disease's early signs and symptoms may be the best means of curbing the potentially deadly impact of the disease, which can be effectively treated with specific antibiotics if caught early.
In the study, government researchers took blood and skin tissue samples from 16 patients across Southeastern Arizona suspected of having the infection. Laboratory tests, including immuno-histochemical staining, confirmed that 11 had the disease, while the remaining five were still probable cases. Ticks were found in the cracks of stucco walls on patients' homes, in crawl spaces under these homes and on furniture placed outside for children and pets. All patients owned and had come in contact with dogs with the infected ticks. Four of the patients had a recent history of tick bite. Tests of the dogs' blood confirmed their infection with the spotted fever bacterium.
Initial treatment for adults, he says, involves immediate, twice daily 100-milligram doses of the oral antibiotic doxycycline (a version of the common tetracycline) until the patient's fever subsides. Patients continue to take the medication for an additional five days to prevent the disease from rebounding. Infected children would receive the same drug, but at a lower dose.