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Ticks transmit new bacterial disease

Ticks transmit new bacterial disease

Ticks are carriers of a new bacterial disease

New tick-borne disease discovered. Swiss researchers at the University of Zurich have identified a previously unknown disease transmitted by tick bites and identified the greater Zurich area as a special risk area. So-called neoehrlichiosis is caused by the bacterium Candidatus Neoehrlichia mikurensis and can be treated reliably with antibiotics, according to the University of Zurich.

The scientists around Dr. Guido Bloemberg from the Institute of Medical Microbiology at the University of Zurich discovered the first infection with the bacterium Candidatus Neoehrlichia mikurensis in humans in the Zurich region in 2009. A total of six cases of neoehrlichiosis from Europe were known up to a year ago, Bloemberg and colleagues report in the journal "Journal of Clinical Microbiology". Researchers at the University of Zurich have now identified two other infections in the Zurich area. In addition, the microbiologists used a new test procedure to examine almost 2,000 ticks that were caught in the forests around Zurich. They were able to detect bacteria in up to eight percent of the ticks Candidatus Neoehrlichia mikurensis at individual locations.

Eight people in Europe have contracted new tick disease to date. The bacterium Candidatus Neoehrlichia mikurensis was first identified in 1999 in ticks and rodents in Europe and Asia. In 2010, the scientists around the head of molecular diagnostics at the Institute of Medical Microbiology, Dr. Guido Bloemberg, together with colleagues from Sweden and Germany, the world's first human infection and named it "Neoehrlichiosis". In November 2011 and January 2012, the Swiss researchers were again able to detect two infections using the patient blood of two people from the Zurich region. Thus, of the eight neoehrlichiosis diseases known so far across Europe, three affected the greater Zurich area. For the scientists, this is a clear indication that there is an increased risk of infection with the newly discovered disease after a tick bite.

Zurich risk area of ​​the newly discovered disease In order to determine whether Zurich should actually be assessed as a risk area for neoehrlichiosis, the scientists caught 1,916 ticks in four forests from the area of ​​the previously infected patients. When examining the nymphs, females and males, it was shown that between 3.5 percent and eight percent of the animals carried the pathogenic bacterium Candidatus Neoehrlichia mikurensis, the Swiss microbiologists write. The results of the study suggest that "the greater Zurich area is a risk area for neoehrlichiosis, especially for immunocompromised people," emphasized Florian Maurer from the Institute for Medical Microbiology at the University of Zurich. Almost all previously ill patients had an already weakened immune system, which apparently favored the onset of neoehrlichiosis. However, infections in patients with a healthy immune system have recently been reported from China. So far, seven patients in China have developed neoehrlichiosis.

Rapid test enables detection of neoehrlichiosis
According to the Swiss researchers, the number of actual infections with Candidatus Neoehrlichia mikurensis bacteria may be significantly higher than previously thought. "Because the bacteria that cause neoehrlichiosis have not yet been cultivated in the laboratory and, accordingly, there were no rapid tests available, many infections may have gone undetected," said Dr. Guido Bloemberg. The rapid test that has now been developed provides a remedy here and can provide information about a possible infection within a day. If a neoehrlichiosis disease is suspected, a clear diagnosis can be made using clinical samples such as blood or bone marrow.

Successful treatment with antibiotics The tick-borne Candidatus Neoehrlichia mikurensis bacteria cause recurrent high fever (relapse fever) of up to 40 degrees Celsius, massive weight loss and general malaise. However, antibiotic therapy enabled swift healing in Swiss patients. A few weeks after the start of treatment, the bacteria were no longer detectable in the patient's organism, Bloemberg and colleagues report. However, it is still unclear whether the treatment prospects are similarly good if the pathogen remains undetected for a long time. It also needs to be clarified "how well the bacterium is transmitted to humans by an infected tick if it is bitten," continues Bloemberg.

Growing health risks from ticks In any case, the newly discovered neoehrlichiosis increases the health risk of a tick bite. In many regions of Germany, the blood-sucking arachnids already transmit the bacterium Borrelia burgdorferi, which can cause Lyme disease, and viruses that can lead to early summer meningoencephalitis (TBE). Both diseases pose health risks that should not be underestimated. In the worst case, the TBE can even be fatal. Drug treatment is not possible with TBE. In the case of Lyme disease, promptly initiated antibiotic therapy often shows the desired success, but in the worst case the bacterial infectious disease can become chronic and cause considerable health problems for the patient. A typical feature of Lyme disease is conspicuous redness around the bite site, but this is far from being observed in all patients. If you suffer from a headache, body aches and fever after a tick bite, you should urgently see a doctor, as these can be signs of Lyme disease as well as TBE. If the two diseases known to date cannot be determined, neoehrlichiosis should also be considered in the future and a corresponding test should be carried out using the rapid test. (fp)

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Video: Emerging Tickborne Diseases (September 2020).