After confirming the first two deaths, Ghana has just recognized the first Marburg outbreak in its history: an outbreak of almost a hundred people. This hemorrhagic fever, related to Ebola, has mortality rates between 24% and 88% depending on the outbreak, the virus strain and case management.
Despite this, it has never been a cause for special concern because the outbreaks have been limited and sporadic: hence we do not have a treatment or a vaccine. However, the spread of the virus in recent years is beginning to make international authorities wonder what is going on.
What is Marburg virus?. In 1967, there were simultaneous outbreaks of a rare hemorrhagic fever in three laboratories in three European cities, Marburg, Frankfurt, and Belgrade. For days, the illness began abruptly with fever, headache and generalized myalgia, but immediately led to massive bleeding. Eventually the virus (a filovirus of the Ebola family) was identified and the outbreaks were linked to a group of African green monkeys from Uganda (with whom they were working in the labs)
Since then, outbreaks have been confined to Africa. Specifically to Angola, Kenya, the Democratic Republic of the Congo and South Africa. In general, with the Marburg we are lucky: it is not only that, to get it from the bats, you need to come into direct contact with open lesions, blood or body fluids; is that cases that are infected from animals tend to have a slower evolution and a relatively low lethality. The problem is that, from there, with the spread from humans to humans, the virus gains speed and virulence.
Speed, speed and speed. And, in this sense, “the health authorities [ghanesas] they have responded quickly, anticipating the preparation of a possible outbreak. This is good because, without immediate and decisive action, the Marburg virus can easily get out of hand,” the World Health Organization said.
What is a virus like you doing in a place like this? The good news ends there because the fact that the virus has reached Ghana raises questions that we are not sure we can answer. There is no doubt that all the hemorrhagic fevers related to Ebola (including the Spanish cousin of Lloviu) attract media attention due to their lethality: but unlike viruses such as SARS-CoV-2, they have a very low contagion capacity. That is our main asset against them.
The problem is that with its appearance in Ghana, experts are beginning to wonder what are the dynamics (natural or not) that have brought the virus to this West African country. Not so much because it’s weird (between 1980 and 2010, the annual number of infectious disease outbreaks worldwide tripled, and the diseases they cause almost doubled), but because of what they can tell us about the future.
As Stephen Morse has already written, there are fundamental factors that are driving the global emergence of infectious diseases: environmental changes (whether caused by the evolution of agricultural and livestock practices, changes in aquatic ecosystems, deforestation or climate change) combined with the growth of people, travel and commerce.
Where are we going? What does the extremely rapid spread of Zika tell us, the hantavirus pulmonary syndrome epidemic in the southwestern United States in 1993, or the cholera outbreak in Haiti in 2010 after the earthquake? What is the growth of diseases such as Argentine hemorrhagic fever (or stubble disease), schistosomiasis or Rift Valley fever telling us? What does the Marburg outbreak in Ghana tell us? That is the big question that we have to answer because they contain the central elements of the ‘Age of Pandemics’ in which we are already installed.
Image | WHO