In addition to Great Britain, other countries reported cases of monkeypox in humans on Thursday. In Germany, the RKI warns doctors to be vigilant, the WHO calls for contact tracing. What is behind the rare viral infection? An overview.

The number of people infected with monkeypox is increasing. After the virus infection first appeared in Great Britain in early May, Sweden, Spain, Portugal, Italy and the USA have now also reported the first cases.

The WHO called for rigorous contact tracing of monkeypox patients on Wednesday. Clinics and the population would have to be made aware of the need for an unusual skin rash to be examined by specialist staff. If monkeypox is suspected, patients should be isolated immediately. Health workers should also take the usual hygiene precautions to protect themselves from infection in the event of droplet infections, writes the WHO in a statement.

What is behind the suddenly increasing number of cases? Where does the virus come from? And how is it expressed? FOCUS Online answers the most important questions.

Monkeypox is a so-called zooonosis. That is, the virus is transmitted from animals to humans. “Infections can be transmitted through contact with the secretions of infected animals,” explains the RKI. It has now been observed for the first time that an infected person has infected other people with the virus.

In this case, the transmission probably takes place via a droplet or smear infection on contact with body fluids or crusts. In addition, sexual transmission of the smallpox virus is possible, writes the RKI. However, compared to influenza viruses, monkeypox is less infectious.

Contrary to what the name might suggest, monkeypox is not only transmitted by primates, but mainly by rodents such as rats, which carry the pathogen. Experts suspect that the monkeypox pathogen circulates in rodents, while monkeys are so-called false hosts – reports the Tagesschau. False hosts are a suboptimal host organism for the virus. The false host can be infected, but the virus cannot develop in it.

The viral disease usually causes only mild symptoms, but can also have severe courses. The infection often begins with a rash. Soon after, red patches form, which spread from the face all over the body and can become red, fluid-filled bumps. The rash can look different depending on the stage of the disease and can resemble chickenpox or syphilis.

According to the UK Health Security Agency (UKHSA), the disease also manifests itself through the following side effects:

So far, five European countries have reported cases of monkeypox. Great Britain recorded the first case in early May, and monkeypox has now also been registered in Spain, Portugal, Italy and Sweden.

According to the health authorities, eight people in the Spanish capital Madrid are said to have been infected with the virus. According to media reports, there are already 20 infected people in Portugal. Italy, the next country in Europe to report the first monkeypox case on Thursday. According to the National Institute for Infectious Diseases (INMI), a young man tested positive after a trip to the Canary Islands. He reported to a hospital in Rome and was immediately isolated afterwards. He was said to be in good condition. There is also a suspicion of two other people – they are also in quarantine.

And Sweden also recorded its first case on Thursday. As the local health authority announced, one person in the greater Stockholm area is infected. The US health authority CDC also reported the first case in the United States on Wednesday. In Canada, too, health authorities are already investigating dozens of suspected cases, reports the Süddeutsche Zeitung.

So far, no cases have been reported in Germany. Due to the high number of cases, the Robert Koch Institute (RKI) is now also sensitizing doctors in Germany to the virus infection. Monkeypox should therefore also be considered as a possible cause in the case of unclear smallpox-like skin changes if those affected have not traveled to certain areas in Africa.

Homosexual men who have recently had sexual intercourse with other men should also seek medical care as soon as possible if they notice any unusual skin changes, the authority writes in a report on its website.

Since a major vaccination campaign in 1980, smallpox in humans has actually been said to have been eradicated worldwide. As the RKI explains, large parts of the world’s population no longer have vaccination protection. The virus was able to spread again, especially in West and Central Africa. The first person affected in Great Britain had also entered the country from Nigeria. According to the WHO, monkeypox has increased in people in Nigeria since 2017. There are already 558 reported suspected cases here, 241 have been confirmed and eight people have died.

As the Tagesschau reports, monkeypox in humans has only been identified three times outside of Africa: in 2003 in the United States and in 2018 in the United Kingdom and Israel. More than 30 people were infected in the United States at the time after the virus was introduced by transporting 800 small mammals from Ghana. Contrary to what was initially assumed, those affected are said not to have contracted the animals directly, but through contact with prairie dogs that were kept near the infected animals.

The probability of infection with monkeypox is generally considered to be rather low. The virus is usually only transmitted from animals to humans through direct contact. According to experts, the newly observed human-to-human transmissions also take place via a droplet or smear infection.

There is currently no specific vaccine against monkeypox, as smallpox is believed to be virtually eradicated. According to general practitioner Christoph Specht, a general smallpox vaccination also reliably protects against monkeypox, although the two are not related – the doctor tells RTL. This would give a kind of immunity to the majority of the population. Since the smallpox vaccination was mandatory until 1976 (in the GDR even until 1982), all those born before that could assume good protection, the doctor reassured.

How likely is it that the virus will still spread in this country? “So far there has been no reason to be very afraid that we will suddenly get monkeypox here in Germany,” Specht assures RTL. “But: The Robert Koch Institute has already asked the doctors to take a close look and be vigilant.” You also have to keep an eye on whether the severity of the symptoms changes as a result of the possible new transmission route from person to person.

“The current outbreak indicates a change in human-to-human transmissibility,” Leif Sander, head of the Department of Infectious Diseases at the Berlin Charité, wrote on Thursday describes monkeypox as less pathogenic than smallpox, but it is “nevertheless a serious and in some cases fatal disease”. Sander sees “certainly no reason to panic” at the moment: However, the outbreak shows “how much infectious diseases in a globalized world are a represent a constant danger for which we must better prepare”.