Headlines - A New Tick-Borne Bacterium

The Department of Internal Medicine and Infectious Diseases at Mâcon Hospital has reported a case of Candidatus Neoehrlichia mikurensis bacteremia to the Cire. This bacterium, discovered in Japan in 2004, has been detected in ticks (which act as vectors) and rodents (which act as reservoirs) in Europe and Asia. The first human cases were reported in 2008 in Europe and in 2012 in China. A study conducted in France by the French National Institute for Agricultural Research (INRA) on 276 voles captured near residential areas in the Ardennes showed that 5 of them were infected with this bacterium, which had the same genotype as the bacteria that caused disease in humans or animals (a dog in Germany) in other European countries. Studies on ticks (Ixodes ricinus) in Europe have revealed tick contamination rates ranging from 0 to 10%. A few human cases in Sweden, Germany, Switzerland, the Czech Republic, and Denmark have been reported, presenting with recurrent fevers, erysipelas-like rashes, arthralgia, and thromboembolism. Cases have also been reported more recently in China. These primarily involve immunocompromised individuals. This report confirms that France is affected by this bacterium, which should be added to the list of tick-borne infectious agents that have rarely been described to date.