Researchers have discovered why people infected with the chikungunya virus still experience joint pain despite being cured.
Between 30 and 60% of people infected with the chikungunya virus suffer from joint pain similar to arthritis. In some patients, this persists between three and four years after the other symptoms have cleared. Researchers at the University of Washington School of Medicine have hypothesized that the virus persists in the body in undetectable forms. In PLOS Pathogens, they managed to confirm it. Cells infected with chikungunya are able to remain in the body long after infection.
#WashUMed researchers have developed a method for fluorescently tagging cells infected with #chikungunya virus, allowing scientists to track how cells may harbor the virus months after infection. https://t.co/kt1NDrYBtB
— Washington U. Med (@WUSTLmed) August 29, 2019
A study conducted on mice
Mice were used in this study: the researchers inoculated them with the chikungunya virus, previously genetically modified to become fluorescent during infection. Several months after the infection of the mice, the red blood cells of their cells still contained the DNA of the virus. “No one had managed to locate the cells that contained the DNA of the virus, explains Marissa Locke, lead author of the study. This is really important because if we do not find the cells, we cannot study them. “
The virus is still present more than three months after infection
The virus lodges in muscle cells and in the connective tissues of the skin and muscles. “The infected cells were still in the muscles and joints 114 days after infection, specifies the researcher, and they still contained the DNA of the virus.” According to the team of scientists, this is what triggers the chronic inflammation and causes the symptoms of arthritis.
For the time being, researchers must continue their research before they can work on a drug. “We are still a long way from being able to offer people a treatment, says Deborah Lenschow, co-author of the study. The first step before developing a therapy is to understand the cause of the symptoms, and this technique allows us to do that. “
A global epidemic
The chikungunya virus is transmitted by the tiger mosquito. In general, the first symptoms appear between 4 and 7 days after the bite, in particular fever or headaches. No treatment can cure the disease, doctors can only act on the symptoms. Today, the virus would be present in about sixty countries.
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