Rickettsialpox
May 12, 2004 12:48 PM
New York City Department of Health and Mental Hygiene Bureau of Communicable Disease
Rickettsialpox
What is Rickettsialpox?
Rickettsialpox is a mild mite-borne disease caused by the bacterial organism Rickettsia akari. This is a primarily urban disease and was first discovered in New York City in 1946. Since then a few cases are reported in NYC each year. Case reports have increased since the fall of 2001 since the early signs of this disease look very similar to cutaneous anthrax, which had heightened awareness among medical providers. In 2001, there were 15 cases reported among New York City residents (rate of 0.2 cases per 100,000 persons)
Who gets rickettsialpox?
Anyone bitten by infected mites can get rickettsialpox. Patients often report exposure to rodents in the home or workplace. Most people who get infected experience only very mild illness or no illness at all.
How is rickettsialpox spread?
Rickettsialpox is spread by the bite of an infected house mouse mite. Unlike ticks, mites do not attach and feed for long periods of time, so most people do not notice the mite or recall being bitten by an insect. Mites become infected by feeding on infected mice, but infected adult mites can also pass the infection to their eggs.
Where and when does rickettsialpox transmission occur?
Rickettsialpox occurs in urban areas, usually where rodent infestation is common. House mouse mites only tend to feed on people where rodent infestation is severe, or where rodent control is being done (because the mites leave their dying mouse hosts and feed on people.) There is no apparent seasonality to rickettsialpox infection.
What are the symptoms of rickettsialpox?
Initially, patients infected with R.. akari develop an eschar (a painless, dry thickened scab with a black center) at the site of the mite bite. This is followed by fever, headache and a rash, which may last for several days to a week.
How soon after infection do symptoms appear?
The incubation period for rickettsialpox is not known, but symptoms probably develop days to weeks following infection.
Does past infection with rickettsialpox make a person immune?
It is likely that infection confers long-term immunity.
How is rickettsialpox diagnosed?
Diagnosis is based on symptoms and either a positive antibody test or a biopsy of the affected skin.
What is the treatment for rickettsialpox?
Antibiotics such as tetracycline or doxycycline have been effective in treating this disease.
How can rickettsialpox be prevented?
The key to prevention is rodent control. To reduce rodent infestation, remove and secure trash around the home and workplace. Extermination may be necessary if infestation is severe. Mite control may also be necessary during rodent extermination in areas where rickettsialpox is known to occur. March 2003New York City residents: For more information on Rickettsialpox, call 212-788-4204 during normal business hours (Monday-Friday, 9:00am-5:00pm). For people residing outside of New York City, please contact your state or local health department.
