At least eight people have been infected and five are dead (including one healthcare worker) in a new outbreak of the Marburg virus in Tanzania, according to a Monday statement from the World Health Organisation. It is Tanzania’s first-ever confirmed outbreak of the deadly disease.
Yet even so, the country has quickly sprung into action to respond to the Marburg emergence, said the WHO. Tanzania’s National Public Health Laboratory was able to test and confirm all eight cases. Officials identified 161 contacts of the infected, and the country’s public health authorities are monitoring those potentially exposed people for symptoms, as well as working to identify a source of the disease. The three surviving infected people are receiving treatment, according to the WHO.
“The efforts by Tanzania’s health authorities to establish the cause of the disease is a clear indication of the determination to effectively respond to the outbreak,” said Matshidiso Moeti, WHO’s regional director for Africa, in the news release. In addition to national efforts to contain and investigate the outbreak, the WHO noted it is also deploying its own emergency team and working with local officials to scale up Tanzania’s response.
The new emergence in East Africa is the second outbreak of the Marburg virus to pop up so far in 2023. A separate confirmed outbreak was first reported by the WHO in Equatorial Guinea on February 13. That ongoing outbreak is also the Central African country’s first. So far, testing has only confirmed one case in Equatorial Guinea, but there’ve been at least 11 suspected cases, according to statements from the country’s health ministry, all of which have resulted in death.
Last year, Ghana also had its first Marburg outbreak, which spanned from July to September. Three cases were confirmed, and two people died in that instance. In 2005, the largest-ever Marburg outbreak occurred in Angola, and hundreds of people died from the disease.
Marburg virus is a filovirus, like its cousin Ebola. Marburg appears to be even rarer than Ebola, with fewer than 500 people confirmed to have ever had the disease. Symptoms are similar to Ebola and include fever, vomiting, rash, and pain. Frequently, symptoms become increasingly severe and lead to systemic problems like organ failure, internal bleeding, jaundice, and death. The disease has a case-fatality rate somewhere between 23% and 90%, depending on the outbreak, with an average rate of 50% mortality, per the WHO.
Though rare in humans, Marburg is thought to be much more common in animal hosts. Its natural reservoir is an African fruit bat called the Egyptian rousette bat, which doesn’t show apparent signs of illness when carrying the virus. Non-human primates are also known to become infected and sick.
The first human cases of Marburg occurred in Germany and Serbia in the 1960s, when laboratory workers were infected by captive African green monkeys. Since then, there’ve been 16 more documented outbreaks, including the latest one in Tanzania, almost all originating in Africa.
Currently, there is no vaccine or anti-viral treatment approved for Marburg virus (unlike for Ebola), however, multiple vaccines are in development. Recent outbreaks could offer a small silver lining in the opportunity to collect real-world data on vaccine efficacy in people. If researchers have the opportunity to test vaccines, and they prove effective, high-risk healthcare workers and others could be granted some form of protection. A vaccine wouldn’t help those already infected or exposed to Marburg, but it could save countless lives down the line.