Shamonda virus infects a human for the first time, patient in Lyon dies

French health authorities have detected for the first time in a human the Shamonda virus, which causes disease in cattle and was until now believed not to spread to humans. The infected man was a severely immunocompromised patient who was being treated at the Lyon university hospitals (Hospices Civils de Lyon) for a serious illness, and died in early October.

According to a joint statement issued on Thursday by the French ministries of agriculture and health, the brain complications that developed before his death were very likely linked to the viral infection. It is still being investigated, however, whether the virus caused his death or merely contributed to it. The ministries describe it as an “exceptional case” and stress that they currently see no risk to the population as a whole. No alert has therefore been issued, but the World Health Organization (WHO) and the European Centre for Disease Prevention and Control (ECDC) have been notified.

According to the authorities, the most likely explanation is that the man was bitten by an infected biting midge in eastern France, where the virus spread widely among cattle in spring and summer. This is so far only a hypothesis: clinical, laboratory and epidemiological investigations are still ongoing, and according to the ECDC it is not even known which midge species transmitted the pathogen. According to Connexion France, the authorities do not expect further human cases. Experts say the case is particularly unusual because the virus has been circulating in Africa and Asia for decades without a single human infection ever having been recorded. The man's severely weakened immune system may explain why his body was unable to stop the pathogen. However, none of the sources provide information on whether symptomatic infection could also occur in healthy people.

The Shamonda virus was discovered in Nigeria in the mid-1960s, and has since been detected sporadically in cattle in West, East and Southern Africa, as well as in Japan. It belongs to the orthobunyaviruses and is a close relative of the Schmallenberg virus, which emerged in Germany in 2011 and also caused significant damage to livestock farming at the time. According to information from the French Ministry of Agriculture, the virus is mainly transmitted by biting midges of the genus Culicoides, the same insects that spread bluetongue disease. It does not spread directly between animals, except from a pregnant mother to her fetus. Infected cattle develop fever and diarrhea, and their milk production drops sharply. In pregnant cows, it can also cause miscarriage and severe fetal developmental abnormalities. There is no vaccine or treatment, but according to the authorities, the meat and milk of infected animals can still be safely consumed.

In Europe, the virus was first identified this summer, in late July, in Germany, Switzerland and France, and has since spread rapidly. According to the French agricultural publication Réussir, it is now present in 51 French departments. According to a Euronews compilation, it has also been detected in Austria, Belgium, Ireland, Italy, Liechtenstein, Luxembourg, the Netherlands, Portugal, Spain and the British Crown dependency of Jersey. In addition to cattle, infections have also been found in sheep, goats, horses and alpacas. The epidemic is also causing severe losses for farmers; a breeder in Haute-Savoie told France 3 in July that he had lost four thousand liters of milk in ten days, around a tenth of his production. As recently as August, the French ministry was still stating that the virus could not be transmitted to humans and therefore had no public health impact. The case in Lyon has now disproven that assumption, although the authorities still consider it an extremely rare exception.

Ugar