You've Got What - Rickettsial infections
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The Rickettsiae are a diverse group of bacteria some of which can be transmitted to humans via the bites of fleas, lice, ticks or mites.
Several Rickettsia species present in Australia are capable of causing disease in people. These species include:
Although rickettsial infections are relatively rare, they have been reported along the eastern Australian seaboard, Flinders Island and the east coast of Tasmania, as well as the Fleurieu Peninsula in South Australia and southern coastal Western Australia.
Rickettsia prowazekii (epidemic typhus) is spread by human body lice and can result in outbreaks of disease, but is only seen in conflict settings and refugee camps and is not naturally occurring in Australia.
Rickettsiae are usually injected directly from the saliva of ticks and mites as they feed on humans and, in the case of fleas, by contamination of bite sites by faeces.
There is great variation in the range and severity of symptoms experienced.
Commonly a small, hard, black sore (called an eschar) first appears at the bite site where the infection was introduced.
Other typical symptoms may include:
Less common severe infections can be associated with confusion and breathing difficulties.
Given that these infections are not common and usually mild they can be difficult to diagnose. While signs and symptoms can suggest the diagnosis, a definite diagnosis is made with a blood test or skin biopsy (for example a sample of skin) of the bite site.
(time between becoming infected and developing symptoms)
Between 3 to 10 days.
(time during which an infected person can infect others)
Infections are not transmitted from person to person.
Treatment is usually with the tetracycline antibiotic doxycycline which reduces the duration and severity of infection.