As of May 27, the global number of cases of infection with the monkeypox virus had risen to 401, 21 of which were in Germany. No deaths have been reported to date in Europe, North America, Canada, or Australia, but there is a lot of uncertainty regarding the subject. At a press briefing by the Science Center Germany, experts provided an overview of the available knowledge and ventured a prediction as to how the situation would develop.
First Patient in Germany
Clemens Wendtner, MD, of the Schwabing Clinic in Munich, treated the first patient with monkeypox in Germany. “The diagnosis was made via polymerase chain reaction. The patient was hospitalized on May 20,” said Wendtner. “He is in a clinically very stable condition.” He has no symptoms aside from the typical skin changes.
From a medical point of view, no inpatient treatment was necessary. Since this was a visitor to Germany, however such treatment was still sensible. The patient remained in isolation until the start of June.
Outbreaks in Africa
There is hardly any clinical experience of monkeypox in Europe or North America. Disease outbreaks occur predominantly in African countries. Gérard Krause, PhD, an epidemiologist at the Helmholtz Center for Infection Research, Braunschweig, Germany, was in Nigeria during an outbreak of monkeypox in 2017 and 2018.
“I assume that this will develop in a completely different manner,” said Krause. In Africa, direct correlations with exposure to animals occur on a very frequent basis; human-to-human transmissions are only observed in isolated cases, such as in a prison.
Krause suspects that only a small portion of the current global infection process, possibly at the beginning, can be attributed to exposures to animals. The process is predominantly characterized by transmission between people.
Nevertheless, there are parallels with the situation in Africa. “The cases were spread far apart from each other geographically,” said Krause. “That is now similar on a global scale.” It is even more important, then, to accurately establish a patient’s travel history and trace their contacts.
How High Is the Mortality?
“But what is quite different, and I hope it stays that way, is the death rate,” said Krause. It was significantly higher in the outbreak in Africa than what is being seen right now. “I do not believe that it will proceed in a similarly dramatic manner,” he estimated. The outbreak will not affect the entire population. “At-risk groups can be clearly identified and measures focused,” says Krause.
On the question of who is particularly at risk, Wendtner identified people with limited immunity, such as those with an insufficiently controlled HIV infection, as well as those with tumorous diseases and other diseases associated with a suppressed immune system. Preventive measures are required for these patients, including preventive sexual behavior. He specifically mentioned, as known from the coronavirus pandemic, nonpharmacologic measures, as well as targeted vaccinations for the at-risk groups.
According to Wendtner, the “meager literature” suggests a higher mortality risk for persons younger than 16 years. “But we should be very careful with the figures,” he said. Data have been recorded in the context of healthcare in Africa and cannot simply be transferred to the developed world.
Low R Value
It is unclear how quickly monkeypox will spread. “The R value has been below 1 in estimations from Africa in the last few decades,” said Mirjam Kretzschmar, PhD, of the Dutch National Institute for Public Health and the Environment, Bilthoven, the Netherlands. However, the figures only stem from short-term, smaller outbreaks.
Fewer and fewer people are vaccinated against monkeypox. “The result of this may be that the population’s immune protection is lower and that the R value could increase,” said Kretzschmar. In a hypothetically nonimmunized population, the R value is between 1.0 and 2.5.
“It can be assumed that the majority of all people over the age of 60 in the population will still have some basic immunity from pox vaccinations,” she said. It is estimated that those who are vaccinated have 85% protection. However, younger people are not immunized. Models have shown that it would work currently with an R value below 1. But there are still no concrete data, Kretzschmar pointed out.
Mild Mutation Risks
Roman Wölfel, PhD, of the German Armed Forces Institute for Microbiology, Munich, sequenced the first sample from Germany. He is aware of older genomic data.
“The monkeypox genome is very large, seven times larger than for the coronaviruses,” explained Wölfel. “A lot of information is hiding in there.” However, being DNA viruses, poxviruses would change less than RNA viruses, such as SARS-CoV-2. Mutations are not an issue. “We do not see this with pox in general, nor with monkeypox in particular.”
Samples from Germany are being sequenced, said Wölfel. Major changes have not been found. The potential for small changes, perhaps individual switched bases, is still being studied.
Why the Rapid Increase?
The experts have multiple hypotheses for how the current situation came to be. Wölfel speculated that the virus may have been circulating unrecognized for a while.
Wendtner asked whether, despite the known stability of DNA viruses, a subvariant has perhaps emerged. He described decreasing immunity as a result of the end of systematic pox vaccinations — in 1976 in the Federal Republic of Germany and 1982 in the former German Democratic Republic.
The expert mentioned unprotected sexual contact, in part in conjunction with promiscuous behavior. A new finding is that it is not just smear infections and droplet infections that are significant. This is because researchers have detected the virus in blood and semen. “As a result, we also need to be concerned about a sexually transmissible infection,” said Wendtner. Infections will develop in the event of risky behavior, regardless of gender, according to his hypothesis.
Wölfel still considered there to be unanswered questions here. This is because the skin lesions, which are known to be infectious, may play a role in sexual contact; the role of semen is still unclear.
The Coming Months
How could the next few months look? “A virus can become endemic, even if it is limited to an at-risk group,” Kretschmar pointed out. This was also seen with HIV in Europe, for example. This scenario is conceivable with monkeypox.
“It is also being discussed that the virus adapts to people and becomes easier to transmit, but that is speculative at the moment,” she said. Fortunately, transmission and spread are occurring more slowly than with SARS-CoV-2. Through measures such as contact tracing or quarantine, there is a good chance that the situation will be brought under control. At the moment, Kretschmar does not expect the situation to get out of hand.
Krause saw a potential danger in “certain countries withholding reports due to the stigmatization of patients.” This is a serious problem, because containment measures would be undermined. “I do not see any danger in this regard in Germany,” he added.
This article was translated from the Medscape German edition.