An 'unprecedented' good news story about a potentially deadly viral outbreak

Marburg virus is notorious for its killing ability. In past outbreaks, as many as 9 out of 10 patients have died from the disease. And there are no approved vaccines or medications.

That was the grim situation in Rwanda just over a month ago, when officials made the announcement that nobody wants to make: The country was in the midst of its first Marburg outbreak. 

Now those same Rwandan officials have better news to share. Remarkably better.

“We are at a case fatality rate of 22.7% — probably among the lowest ever recorded [for a Marburg outbreak],” said Dr. Yvan Butera, the Rwandan Minister of State for Health at a press conference hosted by Africa Centers for Disease Control and Prevention on Thursday.

There’s more heartening news: Two of the Marburg patients, who experienced multiple organ failure and were put on life support, have now been extubated — had their breathing tubes successfully removed — and have recovered from the virus.

“We believe this is the first time patients with Marburg virus have been extubated in Africa,” says Tedros Adhanom Ghebreyesus, director general of the World Health Organization. “These patients would have died in previous outbreaks.”

The number of new cases in Rwanda has also dwindled dramatically, from several a day to just 4 reported in the last two weeks, bringing the total for this outbreak to 66 Marburg patients and 15 deaths.

“It's not yet time to declare victory, but we think we are headed in a good direction,” says Butera. Public health experts are already using words like “remarkable,” “unprecedented” and “very, very encouraging” to characterize the response.

How did Rwanda — an African country of some 14 million — achieve this success? And what can other countries learn from Rwanda’s response?

Doing the basics really well

Rwanda is known for the horrific 1994 genocide — one of the worst in modern times. Since then, the country has charted a different path. In 20 years, life expectancy increased by 20 years from 47.5 years old in 2000 to 67.5 years old in 2021 — about double the gains seen across the continent. And Rwanda has spent decades building up a robust health-care system.

“The health infrastructure, the health-care providers in Rwanda — they're really, really great,” says Dr. Craig Spencer, an emergency physician and professor at Brown University School of Public Health. Spencer specializes in global health issues and has been following the Rwandan outbreak closely.

There are well-run hospitals and well-trained nurses and doctors, he says. There are laboratories that can quickly do diagnostic testing. There is personal protective equipment for medical workers.

For this outbreak, there was the know-how and infrastructure to set up a separate Marburg treatment facility. That's been a boon for other patients and medical staff, preventing exposure to the virus — which crosses over from bats to humans and can be transmitted through bodily fluids like blood, sweat and diarrhea.

And even though there aren't approved medications to treat Marburg, patients in Rwanda have received good supportive care for all their symptoms — like the IV fluids critical for symptoms like high fevers, nausea, vomiting and diarrhea.

This stands in stark contrast to the response in past Marburg scenarios. For example, the Democratic Republic of Congo — next door to Rwanda — had an outbreak between 1998 and 2000. Dr. Daniel Bausch, a pronow fessor at the London School of Hygiene and Tropical Medicine and an expert in tropical diseases like Marburg, provided care in that outbreak. He says what the country’s health centers were able to offer patients was rudimentary at best.

“We called it a care center or treatment center, but really it was a separate mud hut that people were placed in. We didn't have really anything available to us,” he remembers. “People were lucky that they got paracetamol, or Tylenol, and some fluids to drink, if they could get them down without the nausea and vomiting preventing them.”

That outbreak had a fatality rate of 83% with 154 cases and 128 deaths.

In the world's 18 recorded Marburg outbreaks, the mortality rate varies considerably. Several small outbreaks have had fatality rates below 30% but the largest outbreak — in Angola in 2004 and 2005 — had a case fatality rate of 90% with 252 cases and 227 deaths.

Rwanda’s “more modern medical centers” make a big difference, Bausch says.

Getting to patients lickety-split

It wasn’t just the caliber of care that made a difference. It’s also the speed with which patients get care.

As soon as the outbreak started, Rwandan officials jump-started a major operation to trace the contacts of those who were infected, monitoring the health of over 1,000 family members, friends, health-care workers and others at risk. They also started door-to-door surveillance in neighborhoods where there might have been an exposure.

And they did a lot of testing – over 6,000 tests, especially among health-care workers, who’ve comprised 80% of the Marburg patients in this outbreak.

Spencer says many of these capabilities were built up during the COVID pandemic and could be rolled out rapidly. “In Rwanda, you have providers able — within hours really of this outbreak being declared — to get tested,” says Spencer, who has worked with Doctors Without Borders treating Ebola patients. “[Rwanda’s testing is] absolutely remarkable in terms of the response.”

This surveillance and testing allowed “us to detect cases quickly and provide them with treatments in the very, very early phases of their diseases,” explains Butera. He says that caring for patients before they become critically ill likely helped lower the mortality rate.

Embracing experimental vaccines and medications

Rwanda’s speed carried over into other anti-Marburg efforts.

“Everything I have witnessed was really expedited,” says WHO’s Ghebreyesus, who visited Rwanda last week and said what he saw was “very, very encouraging.”

While there are no vaccines or treatments approved for Marburg, Rwanda acted quickly to get experimental vaccines and treatments to people at the center of the outbreak.

“I can't imagine another scenario in which a country went from identifying this outbreak to just over a week later having investigational [experimental] vaccines in country already being provided to frontline health-care workers,” says Spencer, who adds the doses started being administered the same day they arrived in the country. The nonprofit Sabin Vaccine Institute provided the doses, which were developed with major support from the U.S. government.

“I rarely, rarely use the word unprecedented in global health response” Spencer says, but this speed was “unprecedented.”

The vaccine itself is still in development. Testing has shown that it’s safe — but not whether it actually works. Nonetheless, Rwanda decided to inoculate those at risk, hoping that it would help.

Those officials also decided to vaccinate without a randomized controlled trial, where a segment of the recipients get a placebo. Some in the international scientific community say this was a missed opportunity to start learning whether the vaccine is effective — although they concede that it’s far more complicated and slow to roll out a trial. And the size of the outbreak was unlikely to yield enough data to be conclusive.

Did the vaccines help stop the spread or reduce the mortality rate? It’s impossible to know, says Bausch. He points out that in the first recorded Marburg outbreak — in 1967 in Marburg, Germany and what was then Yugoslavia — the mortality rate was 23% with only good supportive care.

Meanwhile, in Rwanda, the next round of vaccines will go to at-risk groups, including mine workers who are in close proximity to the fruit bats that can spread Marburg; that vaccine effort will be randomized.

In addition to the vaccines, Rwanda very swiftly started giving patients two medications — an antiviral called Remdesivir and a monoclonal antibody. As with the vaccine, they hoped these treatments would help even though they haven’t been approved for Marburg.

An early stumble, a course correction

In addition to the speed and high-quality patient care, there’s another less glamorous — but equally important — dimension to quashing Marburg and other viruses, says Bausch. It’s infection control: basically, ensuring Marburg patients don’t infect others. In the hospital, this means that staff take precautions like wearing gowns, masks and double gloves. In public, it can mean sanitizing shared items like motorcycle helmets and installing handwashing stations in public places, as Rwanda has done.

Rwanda stumbled early on with infection control. That’s because it took a couple weeks to diagnose the disease in the individual who is considered the first patient in this outbreak — and the first known Marburg case in the country.

That individual, who likely contracted the virus from exposure to fruit bats in a mining cave, also had a severe case of malaria. Clinicians did not determine that Marburg was also present until other people around that patient started falling ill. As a result, many health care workers were exposed before infection control measures were improved.

While Rwanda rapidly improved their infection control once officials understood what they were dealing with — and not just in health facilities. The mining community linked to the initial patient has seen several cases. So surveillance needs to be sure to cover those populations, says Rob Holden, WHO’s incident manager for Marburg.

“As we go forward, we fine tune, we refine, we reinforce all our surveillance systems, our contact follow ups, our investigations, and we leave no stone unturned,” he says. “If we let our guard down, then I think we'll end up with some nasty surprises and a very long tail on this outbreak.”

Spencer agrees. But he is optimistic. He says that Rwanda’s robust health infrastructure and speedy response has helped protect the rest of the world from a much bigger Marburg outbreak.