Rickettsialpox is a rickettsial disease that is caused by Rickettsia akari bacteria and spread by infected chiggers (mite larvae) or adult mites.
Rickettsialpox is spread through the bites of infected mites.
Symptoms of rickettsialpox are mild and include a fever with chills and sweating, a headache, sensitivity to light, muscle pains, and a rash.
To diagnose the infection, doctors test a sample of the black scab (eschar) that forms and do blood tests.
Treatment is not needed for rickettsialpox.
Rickettsiae are a type of bacteria that can live and multiply only inside the cells of a host organism, such as an animal or a person, and cannot survive on their own in the environment. The Rickettsia akari bacterium that cause rickettsiosis usually lives in house mice (the host). This bacterium is transmitted to people when they are bitten by an infected chigger (mite larva) or an adult mite. The mites may also transmit the bacterium to house mice and some wild mice.
This photo shows a house mite, which transmits the bacteria that cause rickettsialpox.
CDC
This colorized image shows a chigger (mite larva) on human skin. The bacteria that cause rickettsialpox are spread to people through the bites of infected chiggers.
DENNIS KUNKEL MICROSCOPY/SCIENCE PHOTO LIBRARY
Rickettsialpox occurs in many areas of the United States and in Russia, Korea, and Africa.
Symptoms of Rickettsialpox
Symptoms of rickettsialpox are mild. A small buttonlike bump appears at the site of the bite. It develops into a small sore covered by a black scab (eschar) that leaves a scar when it heals. Nearby lymph nodes may be swollen.
About a week later, people have a fever with chills and sweating, a headache, eye sensitivity to light, muscle pains, and a widespread rash.
Diagnosis of Rickettsialpox
A doctor's evaluation
Biopsy and testing of the eschar
Blood tests
Doctors suspect rickettsialpox in people who develop typical symptoms after being in contact with mice. They look for the black scab (eschar) that develops at the bite site.
To confirm the diagnosis, doctors do an immunofluorescence assay. An immunofluorescence assay is a blood test that detects antibodies to the Rickettsia akari bacteria. Or they remove a sample of the eschar and test it using the polymerase chain reaction (PCR) technique. (See also Tests That Detect Antibodies to or Antigens of Microorganisms.) The PCR technique makes copies of the bacteria's DNA, so that the bacteria can be detected more rapidly. They may also send a sample of the eschar to a laboratory for testing and identification of the bacteria (culture).
Treatment of Rickettsialpox
No treatment needed
People who have rickettsialpox do not need treatment. Rickettsialpox is mild and not fatal.
However, the antibiotic doxycycline taken by mouth for 5 days shortens the duration of some symptoms.
Prevention of Rickettsialpox
Prevention of rickettsialpox involves controlling the mice population and using pesticides to kill the mites.
Making the environment less appealing to mice can help. For example, people can remove wood piles, leaf litter, and trash and clear tall grasses and brush around homes. Mice can hide and live in such places. Holes and other openings where mice can enter homes should be blocked. All food should be stored in mice-proof containers.
Drug Information for the Topic
