Spotted fever: Description
Spotted fever (also called louse spotted fever or tick spotted fever) is an infectious disease caused by the bacterium Rickettsia prowazekii. The germs are transmitted by blood-sucking clothes lice and tropical ticks.
Spotted fever caused by clothes lice
In some parts of the world, however, spotted fever is still more common today, for example in East Africa and in the Andean valleys of South America. Risk factors for infection are crowding and poor sanitary conditions.
Tick-borne spotted fever
The Hyalomma tick originates from the arid and semi-arid regions of Africa, Asia and southern Europe. In Germany, their numbers are growing: While 35 tropical ticks were counted in 2018, there were already 50 identified specimens in 2019.
Spotted fever should not be confused with typhoid fever. Folk oral terms such as “lice typhus” or “spotted typhus” are misleading. Typhoid fever is an infectious disease caused by salmonella. Misunderstandings can also arise in the Anglo-Saxon language area. There, typhus is referred to as “typhus” or “typhus fever”. Typhus itself is called “typhoid fever” in English.
Spotted fever: symptoms
However, typical spotted fever symptoms are mainly high fever and skin rash. The fever is very characteristic: it rises rapidly to 41 °C during the first two days of illness, often accompanied by chills. It then persists for at least ten days before the fever subsides. This lasts about four to five days.
Other symptoms observed in spotted fever include:
- Restlessness
- trembling (tremor) of the hands
- Speech disorders
- Disturbances of consciousness
- Violence
Secondary infections
Those who contract typhus are susceptible to other infections (secondary infections). Thus, spotted fever favors, among others:
- meningitis (inflammation of the brain)
- Pneumonia (pneumonia)
- Heart muscle inflammation (myocarditis)
Spotted fever: causes and risk factors
Clothes lice are very rare in Germany nowadays. As a result, there are hardly any infections with the spotted fever bacterium caused by clothes lice in this country.
In contrast, the further spread of the tropical tick species Hyalomma could increase the risk of spotted fever in Germany in the medium term. The populations in this country are still low (see above). However, experts assume that about every second Hyalomma tick carries the spotted fever pathogen.
Spotted fever: examinations and diagnosis
To be able to diagnose spotted fever in the case of a suspicious fever and skin rash, the doctor first needs more detailed information about your medical history (anamnesis). To do this, he will ask you the following questions, among others:
- Have you been to Africa or South America recently?
- Have you noticed lice on you or your clothes?
- Have you recently been bitten by a tick?
- How long have you had the fever?
To detect a spotted fever infection, there is a blood test. This looks for specific antibodies that the body has produced against the rickettsiae. This test should be performed by experienced specialized laboratories.
In the past, tissue samples were taken from patients and examined directly for the pathogen. Nowadays, this is generally no longer done, as the testing of tissue samples is unreliable and associated with an increased risk of infection.
- Infections with meningococci
- Abdominal typhoid fever (Typhus abdominalis)
- Hemorrhagic fevers
- Relapsing fever
Once the diagnosis of spotted fever has been established, the physician must inform the responsible public health department – spotted fever is, in fact, notifiable in Germany.
Spotted fever: Treatment
It is also important to ensure that patients maintain a balanced fluid and electrolyte balance. Possible secondary infections (additional illnesses caused by other pathogens) must also be treated with appropriate agents.
Spotted fever: course of disease and prognosis
However, it can take several months for those affected to recover completely. Particularly malnutrition or impaired immune system function significantly prolong the healing time.
Spotted fever: prevention
On the one hand, spotted fever can be prevented by combating the clothes lice that carry the disease. Insecticides, for example, have proven effective here. In addition, when traveling to risk areas, care should be taken to ensure adequate hygiene and no used clothing should be worn unwashed.
There is currently no vaccine available against spotted fever. However, in special cases, for example during humanitarian missions in risk areas, prophylaxis with medication is possible. For this purpose, the antibiotic doxycycline is administered once. However, even in such cases, the best prevention of spotted fever is to avoid contact with clothes lice and ticks as far as possible.
