Interview
“The WHO reacted in time”
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Fabian Leendertz is director of the Helmholtz-Institute for One Health in Greifswald. Picture: HIOH/Johanna Eberhard
The current outbreak of the Mpox virus originated in Central Africa. A first case has now been discovered in Europe. The WHO has declared the highest alert level. Fabian Leendertz, Director of the Helmholtz Institute for One Health, puts the events in context.
The topic of Mpox was already in the media in 2022. What's different this time?
We're dealing with a new clade, a type we haven't seen before. In general, there are two large groups in Mpox: A West African group (group 2) and a Central African group (group 1). The milder West African Group 2 moved around the world in 2022. The more aggressive Group 1 is now on the move in Africa. A few strains of this have been known to cause smaller outbreaks, and from time to time a major outbreak. Various strains with smaller outbreaks are also circulating there right now, all of which of course originate from the animal kingdom. But now a new type has emerged, clade 1B in the east of the Democratic Republic of Congo. It seems to spread more easily from person to person. Certain genetic characteristics appear to help it to spread rapidly. However, as is always the case with a relatively new disease, the data is still thin on the ground.
Is Mpox 1B also more aggressive in its health effects?
The Central African variants are generally more dangerous for humans. Whether 1B also has a higher mortality rate is not yet known. It doesn't look like it at the moment, but the data is still lacking. If someone is infected in our country or, as in the only known case to date, in Sweden, i.e., in countries with very good medical care, the chances of survival are far better than in countries with a lower quality of medical care.
You say there is still a lack of data. So why has the WHO already declared the highest alert level?
I would say that the WHO declared the highest alert level in good time. I don't think it makes sense to always wait until the pathogen has actually spread throughout the world and only then ask: “What do we do now?” You should put out a fire before it spreads too far.
What does the WHO's highest alert level mean?
It means that countries are paying particular attention, that laboratories are taking care of their diagnostic capabilities. That doctors are sensitized. That awareness is being raised. Another effect is that the global community will hopefully mobilize to provide as much vaccine as possible and send it to the affected areas. The aim is to contain the outbreak faster and better at a regional level in order to reduce the global risk.
So that Western countries don't dismiss Mpox as an African problem until it's just around the corner?
Exactly, Mpox is a prime example. Because no matter whether you use epidemic or pandemic, we know that the virus exists, we've known about it for a very long time, we've only ever been interested in major outbreaks in Africa and there we only followed the severe cases. We never looked at it: How does it spread? Can it also cause mild symptoms? The latter was the reason why Mpox was able to spread around the world. The combination of a partially non-existent health infrastructure and the increased mobility of people living there into the world means that these problems are affecting us faster and more and more. This is forcing us to think more globally, which we should have done earlier. It is now becoming so obvious.
How far has the new Mpox virus already spread? Has it arrived in Europe?
We only have one confirmed case in Sweden. Due to the increased attention, more 2B cases are now being reported worldwide, as this strain continues to circulate globally. You have to look very closely at Mpox reports: Is it really this 1B strain or are we talking about Mpox as a whole? Which is not wrong, but it doesn't necessarily have anything to do with the current outbreak in Africa.
What do you expect in terms of the further spread towards Europe and Germany?
The clearer and more drastic the symptoms caused by a virus are, the easier it is to identify, isolate and treat cases in areas with a good healthcare system. And then to find the contact persons and introduce monitoring for them too. A pathogen that causes severe symptoms will not normally get very far in our country. We're not talking about SARS-CoV-2, which can be transmitted through the air even with mild symptoms. Mpox requires fairly close skin contact. The potential for Mpox to spread as widely and quickly as corona is extremely low.
But even a slow spread can have serious consequences...
My big concern is more in the African context. What's going on in the east of the Democratic Republic of Congo, especially on the borders with Uganda, Rwanda and Burundi? There's a civil war there, there can't even be a public healthcare system. We also had an Ebola outbreak in that corner a few years ago. The economic and social situation is the crux of the matter. Medically, Mpox would be easy to get under control there. But the co-factors surrounding it are incredibly difficult.
How long is the incubation period? When do you know that someone has been infected?
According to current knowledge, between five and 21 days. Whereby you become really contagious when blisters appear. With type 2, the virus can also cause just a small pustule, often on the genitals, and then you are already infectious. To be contagious, you don't have to look anything like the drastic pictures you see on the internet. From what we know about 1B so far, the symptoms are clearer, with more pustules. Those affected are more infectious, but also easier to identify.
Infection essentially occurs through physical contact with such pustules?
Yes, through direct physical contact, and mucous membranes are particularly popular entry points for Mpox. Such a small pustule contains an extremely large amount of infectious virus. However, infectious viral material can also be in other areas of the body and can be transmitted by smear infection.
How can you generally prevent it? “Be careful who you have sex with!” - is that the number one rule?
That's always a good thing, but especially now. Many close sexual contacts are a risk factor. I would hope and claim that the community affected by this in our latitudes has a certain level of awareness due to the history of HIV, which just needs to be reactivated. That worked very well in 2022.
What is the situation with the vaccine?
Due to the 2022 Mpox outbreak, more vaccine is now available and countries have built up stocks. Thanks to widespread smallpox vaccination, we managed to eliminate true smallpox from the world in 1980. And I can tell anyone who has had a smallpox vaccination that the vaccine does not provide 100% protection against Mpox, but it will have a positive effect. The new vaccines, which very probably also work against the new variant, are available, which is important for the risk groups and for limiting the spread. We are therefore in a completely different situation to that of SARS-CoV-2 back then.
Who would you advise to get vaccinated?
We should make sure that the vaccine is used where it is most urgently needed and otherwise I would refer to the recommendations of the RKI and the Stiko.
How could such epidemics be avoided?
Our Congolese colleagues have sequenced monkeypox cases from 2018 until now. They have found permanent smaller outbreaks in this huge country. The close human-animal contact is constantly producing new variants. The virus is now spreading much more widely and reaching the big cities, so that in some cases two or three different types are circulating there at the same time and, in the worst case, could even infect a patient together. Among all these virus types that we get from the animal kingdom, there is of course one that is genetically fitter and can adapt better to humans. If we don't want to keep chasing the problem, we need to better understand what is happening and manage to reduce the frequency of transmission. So that we reduce the likelihood of the viruses developing pandemic potential.
Helmholtz-Institut for One Health (HIOH)
The Helmholtz Institute for One Health (HIOH) in Greifswald conducts research at the interface between humans, animals and the environment: as a result of the coronavirus pandemic, for example, it is becoming increasingly clear how closely the health of humans, animals and the earth system are intertwined. At the HIOH, scientists from the research fields of human medicine, veterinary medicine and environmental sciences work together. This innovative research approach is known in the scientific community as “One Health”. It has developed extremely dynamically in recent years. The initiators of the HIOH are the Helmholtz Center for Infection Research (HZI) and the University of Greifswald. Other research partners are the Friedrich Loeffler Institute for Animal Health and the University Medical Center in Greifswald.
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