The homosexual and bisexual population is 10 times more at risk of infection by meningococcal group C in France. A study shows that sexual transmission is possible.
Group C meningococcus circulates in France. In some populations, more than others. This is no coincidence: a published study conducted by the Instituts Pasteur (France) and Robert-Koch (Germany) shows that the bacterium has evolved. She adapted to a route of sexual transmission, researchers explain in the journal PLOS One.
Several strains compared
In 2013, in France, several outbreaks of invasive meningococcal infections were reported among men who have sex with men (MSM). The situation also affects Germany and the United States. According to the High Council for Public Health (HCSP), the risk of being infected with meningococcal disease is 10 times higher than in the general population. This is also why vaccination is recommended for MSM.
But why does the bacterium circulate so well? This is the question posed by researchers at the French and German meningococcal reference centres. They have indeed spotted genitourinary infections. To answer their question, they therefore studied the genome of the strains sent to them during the epidemic. Then they compared the proteins expressed with those found in other patients.
flexible bacteria
In Germany and France, meningococci taken from MSM have evolved. This variant can grow without oxygen, an ability that is found in gonococci. This strain is also able to multiply better in the blood, which makes it more virulent.
“The emergence of this strain reveals that meningococci are extremely flexible and that they modify their phenotype very quickly in order to adapt effectively to new conditions”, comments in a press release Ulrich Vogel, head of the reference laboratory for meningococci at the University of Würzburg.
This finding suggests that meningococci have adapted for a genitourinary route of transmission. Usually, the bacterium is transmitted by droplets emitted during breathing.
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