Rwanda is battling its first-ever outbreak of Marburg virus disease, a deadly illness related to Ebola. The disease does not have any approved vaccines or treatments. As of October 6, the outbreak had infected 56 people and killed 12 of them, according to Rwanda’s Ministry of Health. With support from the Africa Centers for Disease Control and Prevention (Africa CDC) and other partners, the Rwandan government is implementing rigorous testing, contact tracing and quarantine measures to contain the outbreak. A clinical trial of a vaccine candidate from Sabin Vaccine Institute will soon get underway following the delivery of about 700 doses on request by the Rwandan government.But challenges remain, including the disease symptoms’ similarity to those of malaria, the need for more rapid diagnostic tools and the fact that the majority of known infected people are healthcare workers.
The Rwandan government, the Africa CDC and others are working to contain the outbreak and are currently tracing the contacts of about 400 individuals with possible exposure to the virus. Cases have been identified in eight of the country’s 30 districts, with health care workers representing a staggering 80 percent of those confirmed to be infected. Concerns about possible international spread were heightened when Germany revealed that a medical student who had traveled to Rwanda and his partner had had contact with a confirmed case, but both later tested negative.
“Marburg virus is known to be associated with a very high mortality rate, if not the first, maybe the second deadliest virus that is so far known in terms of affecting people’s body and destroying the immune response and leading to mortality,” says Rwanda’s minister of health Sabin Nsanzimana. He describes the high proportion of cases among health care workers as an unfortunate reality. “They’re the first to be affected by such diseases because they face sick people from different places, different backgrounds,” Nsanzimana says.
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Jean Kaseya, director-general of Africa CDC, emphasizes the need to assist Rwanda by decentralizing testing capabilities and ensuring adequate supplies. “We need to prevent widespread community transmission,” in which a disease spreads among people with no known contact to other infected individuals. “The government is doing its best with testing, and our role is to ensure Rwanda doesn’t run out of supplies,” Kaseya adds. “Since there’s no rapid test available yet, we are working to decentralize PCR [polymerase chain reaction] testing so that all regions can respond quickly.”. (These PCR tests are highly accurate molecular assays for the virus.)
Nsanzimana, who is leading the charge to stop the Marburg outbreak, spoke to Scientific American about its current state and Rwanda’s containment measures.
[An edited transcript of the interviews follows.]
What steps is Rwanda taking to prevent the international spread of Marburg virus, especially with possible cases emerging in far-away countries such as Germany?
We’ve implemented several strategies to prevent the virus from spreading beyond our borders. Key among these is expanding our contact-tracing and quarantine efforts. We are testing individuals regularly and have intensified screening at both entry and exit points. The more contacts you explore, the better because you exhaust all possibilities of the virus or the outbreak to spread.
We issued a travel notice to further enforce these protocols. This ensures that no potential cases travel internationally, such as the recent case involving a student who had contact with a confirmed case. The student tested negative before leaving Rwanda and again upon arrival in Germany. This cooperation under international health regulations demonstrates the effectiveness of our measures. We are also focusing on strengthening exit screening, especially for those in the incubation phase of the virus, to minimize any risk of transmission. We are going to stop this outbreak before it affects other places in the country, in the region or even beyond.
What challenges have you faced in controlling the outbreak?
The initial challenge in identifying the Marburg cases was the similarity of its symptoms to those of malaria, a common disease in the region. Symptoms of both diseases include high fever, severe headache, muscle pain, and joint pain and fatigue—and later on gastrointestinal symptoms, nausea, vomiting, which are very common with malaria.
How extensive is the outbreak at this point, and how is Rwanda managing it?
At the moment we are primarily tracking one significant cluster of cases. This cluster is concentrated in a single hospital department, particularly within the intensive care unit (ICU), where the initial patient was treated. Unfortunately, several doctors and nurses were infected while performing resuscitation and other critical procedures. We’ve identified about 400 contacts and are tracing them diligently to ensure we don’t miss any potential cases.
The cases have largely remained confined to this ICU cluster, and we have not observed a widespread extension beyond that. To further mitigate the risk, we’ve ramped up community surveillance and are screening anyone with symptoms resembling Marburg virus, such as high fever, headaches and muscle pain. Given the overlap of these symptoms with malaria, our screening efforts are cautious but comprehensive to avoid missing even a single case.
What resources are needed for Rwanda to effectively control the outbreak, and how quickly are you able to detect cases?
Our primary method of testing has been through polymerase chain reaction [PCR], which provides results in eight to 10 hours. This turnaround time has been instrumental in identifying cases quickly, especially given the urgent need to contain the outbreak. As we collect more samples from community surveillance, however, our labs are becoming stretched.
To enhance our response, we need rapid diagnostic tools, which would ease the burden on our PCR testing facilities. Right now we are also working to further expand our PCR capabilities. We’re in the process of decentralizing testing, ensuring that more regions have the capacity to test and respond swiftly.
In terms of genomic epidemiology, we have been building up our genomic sequencing infrastructure. This will help us track the virus more effectively. While we already have a solid foundation, our teams are currently prioritizing case identification to ensure we capture every positive case. As we make progress, we will begin sharing genomic data that will provide deeper insights into the outbreak.
Rwanda already has strong genomic sequencing infrastructure. Why haven’t we seen faster genomic analysis during this outbreak?
While we have indeed developed significant genomic sequencing capabilities, our priority has been on rapidly testing and identifying positive cases. Our teams are working around the clock to ensure no case is missed, but we are now beginning to analyze and generate genomic data. As we continue to gain a clearer picture of the virus’s genetic makeup, we will share more information with our partners and the public.
Is the outbreak currently under control?
The outbreak is under control but not yet fully contained. We’re making progress daily, and we remain vigilant in our efforts to screen and monitor all potential cases. Our main priority is ensuring the virus doesn’t spread beyond the current cluster. With continued testing, quarantine efforts and community surveillance, we are confident we can keep the situation contained.
There are no approved vaccines available, but can you share any information about a potential vaccine clinical trial?
We’ve opted for a protocol for vaccination for this trial that will allow us to catch up with time—a fast-track, rapid protocol that also fulfills all the requirements.
