Sciensano is responsible for the epidemiological surveillance of rickettsioses in Belgium. For this, we collect data via various surveillance systems. These enable us to describe the occurrence of the disease, to follow trends over time and to identify potential risk factors for infection.
Rickettsioses are vector-borne diseases caused by bacteria of the Rickettsia genus. The symptoms of rickettsioses can vary greatly depending on the bacterial species and the individual patient. The most well-known rickettsiosis is probably typhus. Until now, all rickettsiosis cases confirmed in Belgium have been travel related.
Groups of rickettsioses
In general, rickettsioses can be subdivided into 3 groups:
- The spotted fever group, caused by at least 18 different species and primarily transmitted through ticks.
- The typhus group, including epidemic and endemic (murine) typhus. Epidemic typhus is caused by the bacterium Rickettsia prowazekii and is transmitted by body lice. Endemic typhus or murine typhus is caused by the bacterium Rickettsia typhi and is transmitted by rat fleas.
- The scrub typhus group, caused by Orientia tsutsugamushi. Although these bacteria are now regarded as a new genus, the diseases are still frequently counted among the rickettsioses. Transfer occurs through mites.
The symptoms of rickettsioses can vary greatly depending on the species and the patient. In most cases, the patient becomes sick around 1 to 2 weeks after infection.
The main symptoms are fever and generally feeling unwell. This can be coupled with a rash, a necrotic wound at the site of inoculation and localized swollen lymph glands.
Although most rickettsioses are transmitted by vectors through the skin (fleas, lice, mites and ticks), transmission sometimes occurs by inhaling the bacterium or via the conjunctiva.
Human-to-human infection does not occur.
Diagnosis of rickettsioses is based on serological tests or on the detection of genetic material through PCR.
Rickettsioses are treated with antibiotics.
Risk groups and prevention
As no autochthonous cases have yet been confirmed in Belgium, the primary risk group concerns people who have come into contact with potential vectors in an endemic area.
Avoiding contact with the vectors in endemic areas is therefore also the predominant prevention strategy.