To set the scene, it’s 1967 in the city of Marburg, Germany. Scientists were working to find a Polio vaccine. It’s common practice for scientists to use animals in the processes of finding and testing vaccines, and these particular scientists animal of choice: African Green Monkeys from Uganda. Unfortunate for them, the monkeys were infected with a virus (known today as the Marburg Virus), which inturn infected 31 people and caused 7 deaths. The Marburg Hemorrhagic Fever is considered one of the deadliest diseases in the world; with a fatality rate averaging around 50%, but has gotten as high as 88% in previous outbreaks according to the WHO.
The virus is from the family Filoviridae, and has a well known cousin – Ebola. Marburg is a zoonotic virus, meaning it’s transmitted through animals rather than vectorborne where it’s transmitted through arthropods. Fruit bats native to Africa are the natural hosts of the virus and can be transmitted to humans through the bats or from human to human. For someone to get the virus they need to come in direct contact with an infected humans bodily fluids or any materials that have been contaminated by their bodily fluids (ex: clothing). Deceased people can still infect others if their blood still carries the virus. Fortunately, transmission cannot happen during the incubation period (the time between becoming infected and becoming symptomatic), which can last from anywhere between 2-21 days.
Death occurs most often between days 8 and 9 after symptoms begin; The time spent between incubation and death can get quite gruesome. Symptoms come on very suddenly, starting with headache, fever, muscle pains, and malaise (feeling generally unwell and fatigued). These symptoms are very similar to other infectious diseases, like malaria, and lab testing is needed to confirm what it the cause. Diarrhoea, vomiting, abdominal pain, nausea, and cramping usually start at symptomatic day 3. Also a non-itchy rash has been observed on some patients between days 2-7. At about day 5-7 the severe Haemorrhagic Fever begins, blood coming out in vomit or faeces and patients start bleeding from their gums, vagina, and nose for example. Changes in behaviour can occur, like irritability or confusion, due to the central nervous system malfunctioning. In fatal cases, death usually is from the blood loss and shock to the body.
The virus can stay immune-privileged sites of some people that have recovered from the virus, including: inside the eye, testicles, in the fetus/placenta of a pregnant woman, and also breast milk. In a few rare cases, re-infection has occurred through the virus staying in these immune-privileged sites. Unfortunately, there is no known treatment or cure for Marburg virus; Quarantine and supportive care helps improve survival rates and stop the disease from spreading. Scientists are testing some treatments in the hope of decreasing the likelihood of death, but I don’t believe they are close to any sort of cure, like a vaccine yet. Moral of the story, don’t spend too much time in caves in Africa or test on animals!