Portugal says risk from Shamonda Virus is very low

A virus recently detected in Portuguese livestock is being closely monitored by health authorities, but officials say there is so far little reason for the general public to be concerned.

By Kam Heskin, in News, Health · 27 Oct 2026, 14:33 · 0 Comments

Portugal’s Directorate-General of Health (DGS) has assessed the risk of human infection from the Shamonda virus as very low, following the discovery of the first known human case in France.

Although the virus has been identified on Portuguese livestock farms, no suspected or confirmed human infections have been reported to the DGS.

The announcement follows growing international attention surrounding Shamonda, a virus that until recently was known primarily for affecting farm animals.

Shamonda is not a newly discovered virus. It was first identified in cattle in Nigeria in 1965 and has since been recorded in parts of Africa and Japan.

During the summer of 2026, the virus was detected in Europe, including Switzerland, Germany and France. Following its discovery, it has since been identified in several other countries, including Portugal.

According to the World Health Organization (WHO), Shamonda primarily affects livestock such as cattle, sheep and goats, although infections have also been recorded in horses.

It is thought to spread mainly through the bites of tiny insects known as Culicoides midges. These are small biting flies, rather than the larger mosquitoes people may be more familiar with.

In cattle, infection can cause fever, diarrhoea, and reduced milk production. The consequences can be more serious for pregnant animals, with the virus associated with miscarriages and abnormalities in developing offspring.

Portugal’s Directorate-General for Food and Veterinary Affairs (DGAV) is monitoring the situation in animals and sharing the information with public health officials.

Possibility of transmission

The first documented human infection was reported in France earlier this month.

The patient had a severely weakened immune system and was already receiving treatment for a serious medical condition. The individual died in early October.

French authorities are investigating how the infection occurred and whether the Shamonda virus contributed to the death.

The European Centre for Disease Prevention and Control (ECDC) has confirmed that it is following the investigation alongside French and other European health authorities.

However, one reported infection does not establish that the virus poses a widespread threat to people.

There is currently no evidence that Shamonda spreads from person to person, and scientists still have very limited information about how infection might affect humans.

The WHO has also emphasised that further research is needed to understand the virus’s potential impact on human health.

What does this mean for Portugal?

For now, the DGS is maintaining its existing public health surveillance arrangements and has not issued special instructions to healthcare professionals.

Portugal already has systems for identifying and investigating infectious diseases, including the National Epidemiological Surveillance System (SINAVE) and the laboratory network involving the National Health Institute Doutor Ricardo Jorge.

The DGS says these services are working alongside veterinary and environmental authorities to monitor developments.

As a general precaution, people are advised to protect themselves from insect bites, particularly in areas where biting midges are present.

Suitable insect repellent and clothing that covers exposed skin can help reduce contact with these insects.

The DGS has also advised people with weakened immune systems to contact their medical team if they develop a fever or other unexplained symptoms.

Scientists are still learning about the European strains of Shamonda, including how widely they may be circulating and what risks they present to animals and people.

According to the DGAV, there is currently no vaccine against the virus, making insect control and veterinary monitoring particularly important for livestock farmers.

For the wider population, however, Portugal’s health authorities have not identified evidence of an immediate public health threat.

The DGS says it will continue reviewing developments and update its advice if new scientific evidence changes the assessment.

For now, the message is one of continued monitoring rather than alarm.