Spotted Fever
Spotted fever is an example of Rickettsiosis. This is an infection caused by a bacterium from the Rickettsia group. This harmful bacterium can be transmitted by ticks. Reason enough to wear tick-resistant clothing when going for a nature walk. Below you will find more information about spotted fever and the diagnosis and treatment of this bacterial infection.
What are Rickettsia bacteria?
Rickettsia is the collective name for a group of bacteria that can only live in the cells of another organism. In order to multiply, these bacteria also need the cells of a host. For some Rickettsia, humans are the most important host. However, most Rickettsia parasitize animals. Rickettsia are transmitted from these animals to humans via, among other things, the bites of ticks, mites, fleas, lice and rats (the so-called vectors).
There are several types of spotted fever that are caused by a specific Rickettsia bacterium. Some examples, with the bacterium from the Rickettsia group as the associated pathogen in brackets:
Rocky mountain spotted fever (R. rickettsii)
Mediterranean spotted fever (R. conorii)
Helvetica spotted fever (R. Helvetica)
Queensland tick typhus (R. australis).
In all four of these variants of spotted fever, the bacteria are transmitted to humans by a tick.
What is spotted fever?
Spotted fever is an infection by a Rickettsia bacterium and is therefore an example of a Rickettsiosis. In humans, Rickettsia bacteria infect the cells on the inside of the small blood vessels. These blood vessels become blocked or inflamed as a result. They can also start to bleed. The blood then ends up in the surrounding tissue. The location of the infection in the body determines the symptoms.
What are the symptoms of spotted fever?
Spotted fever initially presents with the same symptoms as all other Rickettsia infections:
fever
severe headache
skin rash
feeling sick.
Later on the following symptoms may also occur:
confusion
coughing
breathing problems
vomiting
diarrhea
The specific symptoms of spotted fever can vary by type of this Rickettsiosis. As an example, we mention the symptoms of Rocky Mountain spotted fever:
fever
rash
headache
nausea
vomiting
abdominal
pain muscle pain
decreased appetite
eye inflammation
This spotted fever can be very serious and occurs mainly in North America. Most symptoms are the same as those of other Rickettsiosis infections. However, this infectious disease is a serious variant. Patients with Rocky Mountain spotted fever usually have to be admitted to a hospital. Despite treatment, three to five percent of patients die. This disease can also be accompanied by the following complications:
brain inflammation
pneumonia
heart
failure kidney failure
death of fingers and/or toes.
How is spotted fever diagnosed?
The first symptoms of spotted fever resemble those of flu. In order to determine whether there is more going on than a harmless viral infection such as flu, it is important to determine whether the patient has been bitten by a vector of a Rickettsia bacterium. Such as a tick, mite or flea. Such a bite can be an indication of a Rickettsia infection, especially in areas where this infection is common. Unfortunately, most people cannot remember a bite. If the patient develops a skin rash, this is also an indication of Rickettsiosis. Further investigation must then show whether there is indeed a Rickettsiosis (such as spotted fever) and if so, which bacteria it is.
There is (as yet) no laboratory test that can quickly and unambiguously identify a Rickettsia bacterium that causes spotted fever in the blood. The patient cannot wait for long-term (blood) examination. Treatment cannot be delayed and must therefore be based on a suspected diagnosis of spotted fever.
Blood tests can detect antibodies to the R. rickettsii bacteria, which is the bacteria that causes Rocky Mountain spotted fever. This bacteria can also be detected in microscopic skin examinations.
How is spotted fever treated?
A Rickettsia such as spotted fever is an obligate intracellular bacterium. This means that it hides in the cells of its host. This makes it difficult for our immune system to reach and fight the bacterium. For the same reason, not all antibiotics work for spotted fever.
Rickettsiosis is best treated early with one of the following three antibiotics:
tetracycline
doxycycline
chloramphenicol
These antibiotics can be taken orally. If the patient is so ill that oral administration is not possible, these drugs can be given intravenously.
After treatment with one of these antibiotics, the patient will feel better very quickly and the fever will disappear within three days. The course of antibiotics will last for at least a week and longer if the fever persists. The later treatment is started, the slower the improvement will occur and the longer the fever will persist.
Failure to start treatment or starting it too late can have fatal consequences for a patient with rickettsiosis.