Shamonda virus: France reports first human case, Spain and Portugal urge calm

A first human case in France

French authorities reported the first known human infection with the Shamonda virus, and the patient died. According to the ECDC, the patient was severely immunocompromised and died in early October, and the case became public on 22 October. Officials said it was an exceptional case in a patient with a seriously compromised immune system and that there is currently no risk to the public. The patient was being treated for a serious illness at a hospital in Lyon and developed neurological complications that were considered very probably linked to the virus, based on initial findings. Health and agriculture ministries said on Thursday, 22 October, that the patient is believed to have been bitten by an infected midge in eastern France, where animal cases had first been identified in spring. Investigators are still working out how the virus reached a human.

Signals from the WHO and ECDC

The World Health Organization has not yet carried out its own formal risk assessment, but the information available on similar diseases suggests this is an isolated case. WHO spokesman Christian Lindmeier said a wider spread is currently improbable, and an assessment of that kind can take weeks or months. The ECDC is working with French and European partners to investigate the case. WHO also noted that the ability of midge-borne viruses to spread generally falls in the colder months of the year. Until now, the Shamonda virus had been considered not transmissible to humans, even after decades of circulation in Africa and Asia.

The virus and its vector

The Shamonda virus is an orthobunyavirus closely related to the Schmallenberg virus, which has been observed in Europe since 2011. It has been known since the 1960s in Africa and mainly affects cattle, although cases have also been recorded in sheep, goats, alpacas and horses. Infected dairy herds can show fever and diarrhoea and produce less milk. Sara Epis, a parasitology professor at the University of Milan, told Adnkronos that the vectors are tiny biting midges called Culicoides, which are also present in Italy. She stressed that the evidence is still limited:

There is still no experimental demonstration that this virus is transmitted by Culicoides.

Epis said Culicoides obsoletus, a widespread species that feeds mainly on ruminants but can also bite humans, is one of the most promising candidates. The key dates of the human case and the livestock detections are set out below.

Spain and Portugal respond

Spain's Ministry of Agriculture, Fisheries and Food said it is monitoring the situation after detections in livestock in at least six provinces in recent weeks. The national reference laboratory in Algete confirmed Shamonda virus type 1 on farms in Córdoba, Toledo, Ávila, Madrid and Girona, where three dairy cattle farms were affected on 20 October, while Cantabria certified type 2. In Andalusia, regional agriculture councillor Ramón Fernández-Pacheco said the two foci in Córdoba and Cádiz had self-regulated, calling the case isolated and the situation perfectly normal. The farm group Unión de Uniones urged caution and reliance on official sources, and asked the ministry for better communication and funding for animal disease research. Catalonia's public health secretary Esteve Fernández said the virus does not put the region on alert, and he admitted that it is unknown whether the virus caused the death:

We do not know if it caused the death, if it contributed in any way, or how the infection happened.

In Portugal, agriculture minister José Manuel Fernandes said there is no reason for alarm, that the virus has infected cattle including one herd in Planalto Mirandês, and that it does not cause animal deaths. He said no plan exists yet, with monitoring and prevention as the current response, and called for faster EU-scale research into effective and affordable vaccines:

We are not going to raise an alarm, which at this moment is not justified.

Earlier, a local veterinarian from the ADS Palaçoulo told Lusa that analyses of cattle for the virus cost more than 30 euros, a significant outlay for a herd of 50 cows where symptoms appear.