Just over 10 days ago, the World Health Organization warned of the appearance of a epidemic caused by the marburg virus in a remote and border area between Gabon and Cameroon. Spain was put on alert, but this Friday the protocol was activated in the event of a suspected case. This is a 34-year-old patient from Valencia who recently traveled to Equatorial Guinea, where, a few days ago, an epidemic of this viral diseasesimilar to Ebola. The man is isolated in the high-level isolation unit of the La Fe University and Polytechnic Hospital in Valencia.
What is the Marburg virus and how is it transmitted?
There Dr Natalia Rodriguez Valerospecialist in internal medicine and tropical medicine from the Department of International Health and Tropical Medicine of the Hospital Clínic, explains it in four steps:
“Marburg virus is a filovirus, very similar to Ebola, which causes hemorrhagic fevers which can be severe and in some cases result in the death of the infected patient.”
“It is transmitted by contact between people & rdquor ;.
“The virus has an incubation period of 28 days.”
“It starts with symptoms that make it difficult to distinguish what disease it is. After a few days, bleeding occurs, especially gastrointestinal, which is the most typical symptom of Marburg.”
What are the symptoms of this disease?
The symptoms of infection caused by this virus could be summarized in three phases:
At first, the infected patient presents with fever, severe headache, muscle aches and general malaise.
Three days after the first discomfort, others may appear, such as diarrhea, abdominal pain, nausea and vomiting.
Finally, many patients experience severe bleeding 5 or 7 days after infection.
But the symptoms and course of the disease, as explained by the WHO, would be as follows:
It begins abruptly, with high fever, intense headaches and great malaise, as well as frequent muscle pain.
On the third day, intense watery diarrhea, abdominal pain and cramps, nausea and vomiting may appear.
Diarrhea may persist for a week.
In this phase, patients have been described as having a “phantom appearance” due to sunken eyes, lack of facial expression, and extreme lethargy.
In the 1967 European epidemic, most patients developed a nonitchy rash 2 to 7 days after symptom onset.
Many patients have severe bleeding manifestations within 5-7 days.
Fatal cases often present with some form of hemorrhage, often in multiple organs.
The presence of fresh blood in vomit and stool is often accompanied by bleeding from the nose, gums and vagina.
Spontaneous bleeding at venipuncture sites where fluids are administered or blood samples are taken can be particularly problematic.
During the severe phase of the disease, patients have a persistent high fever.
Central nervous system involvement can cause confusion, irritability and aggression.
Occasional cases of orchitis (inflammation of one or both testicles) have also been described in the late phase of the disease (15 days after its onset).
In fatal cases, death usually occurs 8 or 9 days after the onset of symptoms and is usually preceded by severe blood loss and shock.
How is the virus transmitted and when did it appear?
The natural host of the virus is thought to be the fruit bat (Rousettus aegyptiacus, family Pteropodidae) and in fact the migratory movements of these animals are being studied to see where the disease could spread. Other animals like the green monkey can also transmit Marburg.
To find cases of Marburg virus infection in Europe, we must go back to 1967. These infections were produced by laboratory experiments on these animals. The virus is transmitted from these bats to humans and spreads directly between them, since, as Dr. Rodríguez Valero explains:
“Once a person is infected and develops symptoms, they can transmit the disease to others through direct contact with their damaged skin or mucous membranes, as well as through secretions such as blood or bodily fluids & rdquor ;.
Moreover, as with Ebola, the Marburg virus can be transmitted sexually “even months after the infected person has recovered”.
Finally, Marburg can also be transmitted through indirect contact with contaminated surfaces and clothing such as bedding and medical equipment from people with symptoms.
A disease without treatment
As the specialist in tropical diseases at the Hospital Clínic explains, there is still no treatment for the disease caused by the Marburg virus. What does exist are “vaccines that have been successful in animal models and could be used in humans in the experimental phase”.
So, the only thing left for health workers when it comes to treating people infected with this virus is to treat the symptoms.
“The biggest problem is the great loss of fluids suffered by the patient. In intensive care units of hospitals in high-income countries, it is easy to adjust this water balance, but in rural and low-income areas, where the disease affects, it is much more complicated and, therefore, it is more likely that the disease is complicated. So far, rehydration and early treatment of symptoms have been shown to reduce mortality.”
Should we in Europe be worried about this epidemic?
The first Marburg affair was detected in Uganda in 1967 with 24 cases and caused a mortality of 20%. That same year, cases of the virus were reported in Frankfurt (Germany) and Belgrade (Serbia), associated with laboratory experiments on African green monkeys imported from Uganda.
Later, smaller shoots appeared. But the biggest outbreaks to date occurred in the Democratic Republic of Congo in 1998, with 154 people infected and causing 83% mortality. Seven years later, there was another case in Angola, with 250 patients and generating 90% mortality. Since then, there have been sporadic cases.
It is estimated that the first contagion of the epidemic which is active at the moment “could have occurred in January, but all epidemics in Marburg have been limited compared to Ebola, which in 2014 generated the largest epidemic and the most complex since the discovery of the virus.” virus in 1976 & rdquor ;, details the expert.
So, can infections occur in Europe as happened with the coronavirus? Dr. Rodríguez Valero replies: “With any virus, to ensure that there are no secondary cases, 4 weeks must have passed since a case was detected, and 42 days for declare a controlled epidemic. The number of cases is still not well known, but it is going fast.”
Moreover, the zone in which this epidemic declared itself can also influence its extension. “That it affects a rural area implies that it is an isolated area with fewer people, and therefore it is positive in terms of the number of infections. In addition, movement restrictions are applied in Africa There are more than 4,000 people in quarantine, already around 20 are being monitored for close contact with infected people.
So, “we have to wait to see how the virus evolves, but for the moment we should not be alarmed; moreover, the COVID pandemic has left a lesson: a better capacity to respond and manage current epidemic situations. and future”.