What we know about deadly Marburg virus as feared Germany cases test negative

Two people feared to have the deadly Marburg virus after developing flu-like symptoms on a train in Germany have tested negative, local media has reported.

On Wednesday, a train station platform in central Hamburg was cordoned off, after a couple showed flu-like symptoms on board an ICE train to the city.

According to local media outlet Hamburger Abendblatt, one of the couple, a medical student, had treated a person infected with the Marburg virus in Rwanda, where at least 11 people have died and 36 cases confirmed amid a concerning outbreak.

According to the German dpa news agency, the medical student who had contact with an infected person will continue to be monitored until the end of the incubation period of up to 21 days.

It follows new measures taken by the World Health Organization (WHO) earlier this week to curb the spread of the highly infectious virus in Rwanda. Officials in the Rwandan capital Kigali are understood to be attempting to trace about 300 people thought to have been in contact with those infected.

At least one is understood to have travelled to Belgium.

The WHO has advised against all travel to Rwanda, which is understood to be experiencing the disease for the first time.

Previous outbreaks have seen a fatality rate of about 50%, but among those with existing poor health it has risen to almost 90%.

According to a report in Nature journal, researchers are now racing to deploy vaccines and treatments.

Read the full story below or click the links to skip ahead

> What is Marburg virus?

> What are the symptoms of Marburg virus?

> Have there been Marburg virus outbreaks before?

> How is Marburg virus spread?

> Is Marburg virus deadly?

> How do you treat Marburg virus?

> Is there a vaccine for Marburg virus?

What is Marburg virus?

According to the WHO, Marburg virus disease is a highly virulent disease that causes haemorrhagic fever.

It is in the same family as the virus that causes Ebola.

What are the symptoms of Marburg virus?

Illness caused by Marburg virus starts "abruptly", according to the WHO, with high fever, severe headache and severe malaise. People may also experience muscle aches and pains.

Symptoms including severe watery diarrhoea, abdominal pain and cramping, nausea and vomiting can start on the third day and diarrhoea can last for a week.

According to the WHO: "The appearance of patients at this phase has been described as showing 'ghost-like' drawn features, deep-set eyes, expressionless faces and extreme lethargy."

Patients can also experience a non-itchy rash. Within a week many patients suffer from bleeding from multiple areas including the nose and gums.

In fatal cases, death usually occurs between eight and nine days after onset, the WHO says, usually preceded by severe blood loss and shock.

The US Centers for Disease Control and Prevention (CDC) says symptom onset is sudden following an incubation period of five to 10 days, and is marked by fever, chills, headache, and myalgia (muscle pain).

It says a rash can start around the fifth day, followed by nausea, vomiting, chest pain, a sore throat, abdominal pain and diarrhoea.

Symptoms become increasingly severe and can also include jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive haemorrhaging, and multi-organ dysfunction.

The CDC adds: "Because many of the signs and symptoms of Marburg haemorrhagic fever are similar to those of other infectious diseases such as malaria or typhoid fever, clinical diagnosis of the disease can be difficult, especially if only a single case is involved."

In an effort to curb the spread, Rwanda's health minister has temporarily banned hospital visits and put restrictions on attending funeral services. However, reports of possible cases have also been received in border areas of DR Congo, Tanzania and Uganda.

Have there been Marburg virus outbreaks before?

Marburg virus was initially recognised in 1967 following two large outbreaks that occurred simultaneously in Marburg and Frankfurt in Germany, and in Belgrade, Serbia, according to the WHO.

The outbreak was associated with laboratory work using African green monkeys (Cercopithecus aethiops) imported from Uganda.

Since 1967 there have been at least 12 major Marburg outbreaks, mostly in southern and eastern Africa.

In 2008, two independent cases were reported in travellers who visited a cave inhabited by Rousettus bat colonies in Uganda.

In 2021, Guinea recorded the first Marburg death in West Africa, where further outbreaks were also reported in 2023.

Last year also saw cases in the Kagera region of Tanzania, which borders Rwanda.

The latest outbreak is believed to be the first time the virus has been officially observed in Rwanda.

Outbreaks have also previously been reported in Angola, Congo, Ghana, Kenya and South Africa.

How is Marburg virus spread?

Marburg virus is transmitted to humans from fruit bats and then spreads via bodily fluids.

According to the WHO, Marburg can spread through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with those fluids.

According to the European Centre for Disease Prevention and Control (ECDC), both European Ebola and Marburg virus diseases are not airborne diseases and are generally considered not to be contagious before the onset of symptoms.

It says: "Transmission requires direct contact with blood, secretions, organs, or other bodily fluids of dead or living infected people or animals.

"Therefore, the risk of infection is considered to be very low if appropriate infection prevention and control precautions are strictly followed."

According to the WHO healthcare workers have previously been infected while treating patients with suspected or confirmed cases of Marburg, while burials which involve direct contact with the body of a victim can also contribute to transmission.

Of the current outbreak in Rwanda, more than 70% of cases are understood to be among healthcare workers from just two health facilities in Kigali, the capital.

Is Marburg virus deadly?

Marburg case fatality rates can be up to 88%, with past outbreaks varying from 24% to 88% depending on virus strain and case management, according to the WHO.

However, the US CDC puts the case-fatality rate at 23-90%.

How do you treat Marburg virus?

According to the WHO, there is no proven treatment yet available for Marburg virus disease, although treatments including blood products, immune therapies and drug therapies are being explored.

Treatment for specific symptoms as well as rehydration with oral or intravenous fluids can improve chances of survival, the WHO says.

Is there a vaccine for Marburg virus?

According to WHO director-general Dr Tedros Adhanom Ghebreyesus, there is currently no licensed vaccine for Marburg, although vaccines are under development.

Plans for a vaccine trial were mooted during last year's outbreaks, but were not enacted, however it is hoped a system known as 'ring vaccination' - which involves immunising contacts of infected people - could be tested this time in Rwanda, after the approach proved promising during the 2014-16 Ebola outbreak in Guinea.

Plans to trial vaccines as well as other anti-viral treatments, have previously been approved by the WHO.

In July, the University of Oxford said they had launched the first-in-human clinical trial to test for a vaccine. Professor Teresa Lambe OBE, the trial’s Lead Scientific Investigator and Professor of Vaccinology at Oxford Vaccine Group and the Pandemic Sciences Institute, University of Oxford said: "Although outbreaks of Marburg virus have historically been small, this devastating disease has started to spread even further and the potential to cause a pandemic and inflict suffering on many is a real concern.

"With no approved treatments for Marburg, developing a vaccine is critical. This Oxford trial is a first step towards developing a safe and effective vaccine to protect people from future outbreaks."

On 30 September, the WHO said it was working closely with the Rwandan government to provide information and access to available candidate vaccines and therapeutics for a possible clinical trial.

On 3 October, Rwandan health officials said they were poised to start vaccine and therapeutic clinical trials within weeks.