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Not only ticks carry dangerous borreliosis Bacterial pathogens also in mosquitoes
According to estimates, up to 200,000 people in Germany suffer from Lyme disease each year. The disease is usually transmitted by a tick bite. German scientists have now but also found in native mosquitoes bacteria that can trigger Lyme disease.
Even mosquitoes can transmit Lyme disease
Ticks carry serious illnesses such as tick-borne encephalitis (TBE) or Lyme disease. That's been known for a long time. But they are obviously not the only carriers. German scientists have now found out that even native mosquitoes carry some bacteria that could cause Lyme disease. According to current knowledge, the mosquitoes play at most a minor role in the transmission of the pathogens.
It has long been known that ticks transmit borreliosis. Scientists have now found in mosquitoes bacteria that can trigger Lyme disease. (Image: nechaevkon / fotolia.com) Borrelia in german mosquitoes
According to a press release of the Senckenberg Gesellschaft für Naturforschung, a research group headed by Sven Klimpel from the Biodiversity and Climate Research Center and the Goethe University Frankfurt has detected Borrelia in German mosquitoes for the first time. The three identified types of bacteria can cause Lyme disease in humans. The researchers also showed in their recent study in the journal "Ticks and Tick-borne Diseases" published study that the pathogens survive the transformation of the mosquito larva to the pupa and finally to the adult animal. For the first time, they were able to detect Borrelia DNA in wild-caught mosquitoes hatched and raised under laboratory conditions. "The fact that we have found the DNA of the pathogens in the reared mosquitoes is amazing and shows that the Borrelia can survive the transformation of the larva to the pupa and finally to the adult animal," said Klimpel.
Little data available on the spread of the disease
Among the symptoms of the disease include general symptoms such as fatigue, night sweats, fever and nonspecific joint and muscle pain. The so-called "walking red" is indeed a 100 percent symptom, but occurs only in half of the patients. The disease can be controlled by taking antibiotics, otherwise it can take a chronic course. A vaccine against the disease is not available. "Although Lyme disease is considered the most common vector-borne disease in Europe and can cause severe damage, data on their prevalence, as well as the causes and consequences, are inadequate." Sven Klimpel. "This is mainly because of the fact that a reporting obligation of Lyme disease exists only in a few states and the basics of reporting obligations are not uniform." In Germany, the annual numbers are between 40,000 and 214,000 people who are infected with Lyme disease pathogens.
Mosquitoes can transmit numerous infectious diseases
As a well-known carrier of the Lyme disease pathogens acts in Germany, the common wood buck from the family of Schildzecken. The team of scientists around Klimpel has now also examined mosquitoes for their transmission potential. The Frankfurt parasitologist said: "Mosquitoes are known carriers of numerous infectious agents such as malaria, the dengue virus or the currently rampant Zika virus. We wanted to see if the insects could theoretically transmit borreliosis-causing borrelia. "
Three Borrelia species identified
For their investigation, the researchers caught more than 3,600 mosquitoes at 42 German sites. They found that ten different mosquito species from four genera carried Borrelia in 11 locations. "We have identified certain Borrelia-specific genes using molecular biological methods and were thus able to identify the Borrelia species Borrelia afzelii, Borrelia bavariensis and Borrelia garinii," added Klimpel. The three Borrelia species are considered in Germany and Europe as the most important pathogens of Lyme disease, all can infect humans.
"No reason to panic"
Despite the findings, Klimpel had reassuring words: "There is no need to panic," said the expert. "According to our current knowledge, mosquitoes as transmitters of Lyme disease-causing pathogens are only partially suitable. If anything they play a subordinate role. "The main transmitter is and remains the tick. According to the Robert Koch Institute (RKI), on average every fifth tick bears Borrelia. However, only very few people (up to six percent) become infected after a tick bite. The pathogen can not be transmitted from person to person. (Ad)