For the first time, Ghana is facing the Marburg virus. Thanks to the successful handling in West Africa of the comparable Ebola virus, no major outbreak is expected. It is likely that the virus originated from the Egyptian fruit bat. Professor of tropical medicine at Amsterdam UMC Martin Grobusch was interviewed about this topic by NRC.nl and RTL-nieuws. In this article, Grobusch shares his knowledge on the basis of five questions.
Ghana is officially dealing with an outbreak of Marburg virus, a deadly infectious disease. In mid-July, the laboratory of the Institut Pasteur in Dakar, the capital of Senegal, confirmed the diagnosis. Two patients who became independently infected in late June have since died. No other infections have yet been detected; nearly 100 contacts of the two patients have been in quarantine.
What are the symptoms?
A Marburg infection produces Ebola-like symptoms of illness, with high fever, diarrhea, vomiting and sometimes spontaneous bleeding. Marburg and Ebola are so-called filoviruses that cause hemorrhagic fever, which involves bleeding.
In many people who contract the Marburg virus, it is not initially clear that it is specifically that virus. But in the second instance, the severity of the disease becomes clear. "Then organ failure can occur," says Martin Grobusch, professor of tropical medicine at Amsterdam UMC. " About 50 percent of the people who become very sick die."
How can you catch the Marburg virus?
There is one animal that is known to be the host of the Marburg virus. And that's the bat, says Grobusch. "Bats can transmit it to humans in several ways," he says."First of all if an infected bat touches you. In addition, it can probably happen if you eat fruit that still has bat saliva on it. Or if you eat a bat that's not prepared properly."
So a bat can infect a human. And once that happens, an infected person can also transmit it to another human. "That's then through direct contact with feces or bodily fluids from someone who is sick," Grobusch says. This is similar to Ebola, which is also transmissible from person to person when people come into contact with a patient's body fluids.
In August 2021, one person became infected with the Marbrug virus in Guinea, also in West Africa. And in 2005, there was a major Marburg outbreak in Angola, resulting in nearly 400 infections and 329 deaths. Two years later, researchers in Gabon found genetic material of the virus in Egyptian fruit bats, also called hippo rouettes ( Rousettus aegyptiacus ). The animals, which do not get sick from Marburg themselves, also had antibodies against the virus in their blood. Since then, researchers have assumed that the virus is widely distributed among these animals.
However, it is rare for the virus to spread to humans. This can happen when people visit caves without protection where many thousands of these bats may be. Their droppings are contagious. There is also a risk of infection when the bats are eaten. But neither the man in Guinea nor the two patients in Ghana have any indication that they came into contact with bats in these ways. Grobusch therefore thinks that the infection may have occurred through bat saliva that sat on fruit.
What is the difference between the Marburg virus and Ebola?
Ebola and Marburg virus are hardly distinguishable from each other. In terms of symptoms, they are almost identical. Ebola is also a rare infectious disease that is often accompanied by bleeding in the body.
Grobusch: "The two viruses are genetically close. They have the same hosts (bats, ed.) and come from the same region (West, Central and East Africa, ed.)."
Most people will know Ebola from the major outbreak of between 2013 and 2016 in western Africa. Countries like Sierra Leone, Guinea and Liberia were all hit hard. 28,000 people became infected, 12,000 of whom did not survive. So that's the first difference: Ebola outbreaks tend to be much more extensive than Marburg.
"But do you want to know the most important difference?," Grobusch asks. "Over time, several vaccines have been developed that work well against Ebola. But against the Marburg virus, there is not one."
Will there be another pandemic?
No vaccine available, that doesn't sound good. Still, we don't have to worry about a new pandemic , says Grobusch. "For that, you need a low-threshold way of human-to-human transmission. And that's not the case with the Marburg virus, since you need to make real contact with bodily fluids of others."
And with that, we're not talking about huge infection numbers (yet). In Ghana, two have been counted so far. Those were recorded just a few weeks ago.
"With the Marburg virus, we have to take into account an incubation period of 21 days," says Grobusch. "The two known infections were recorded in late June. That's already more than 21 days ago and yet, as far as is known, no new case has surfaced since then. That is hopeful, although it remains to be seen whether the outbreak will indeed be contained."
Should it remain limited, Grobusch says this is due in part to the experience authorities now have. "It is thanks to the measures taken after the major Ebola outbreak in West Africa that a proper signaling system for hemorrhagic diseases such as Ebola and Marburg has now been established throughout Africa. Early detection can prevent major outbreaks from occurring."
What is the advice for people who are currently in Ghana?
"One of the most important pieces of advice is: be careful eating bushmeat," Grobusch says. That's the meat that comes from hunting wild animals in tropical or warmer areas. Think of bats, for example.
Grobusch: "Also, don't grab fruit you find somewhere. And try to avoid contact with other people's bodily fluids. Furthermore, hand hygiene is always important. But mouth masks, on the other hand, are of no use. Since the Marburg virus spreads in a different way than, for instance, corona."
If it does happen that a Dutch person becomes infected, not all alarm bells go off immediately. "There is always a risk that someone with a highly contagious disease ends up in hospital. Hospital staff always have that scenario in the back of their minds."
"In the Netherlands, people are paying close attention. Hospitals, doctors and the RIVM," says Grobusch. "The situation is monitored and hygiene measures are always observed. And if someone contracts the virus before his or her return trip to the Netherlands, that person simply does not travel. So we can feel safe."
In July 2008, a Dutch tourist became infected with the Marburg virus while visiting a bat cave in Uganda. After returning to the Netherlands, she developed a high fever and was diagnosed with Marburg. The woman died.