Public health officials across the world are monitoring the spread of a deadly virus ominously known as "bleeding eye disease". But what exactly is it?
At least 66 people have been infected and 15 people have died from an outbreak of Marburg virus disease (MVD) in Rwanda as of November 29, according to an update from the country's Ministry of Health.
MVD, which is frequently fatal and is related to the much better-known Ebola virus, is sometimes known as "bleeding eye disease" because it damages people's blood vessels, causing them to bleed from various orifices including their eyes.
In October the WHO warned against all travel to Rwanda, while the UK's national public health agency warned travellers visiting Rwanda to avoid a host of activities such as participating in burial rituals or coming into contact with wild animals.
The outbreak now seems to have slowed, with Nov 29 marking 28 days without a new case and 22 days since the last patient was discharged from hospital, although there is long incubation period, according to Rwandan officials.
However, the disease is just one of several viruses that have concerned global health experts in recent weeks, with further cases of monkeypox (often shortened to "Mpox") identified in the UK and California.
Ebola’s nasty twin
The Marburg virus was first described by scientists in 1967 following an outbreak in the German cities of Marburg and Frankfurt, and the-then Yugoslavian capital of Belgrade.
It's part of a family of microrganisms known as filoviruses, which also includes the deadly Ebola. In fact, the two are "clinically almost indistinguishable", according to the UK's government-run Travel Health Pro website.
MVD is thought to be generally spread to humans via fruit bats, and can incubate quietly in a person's body without symptoms for up to 21 days (the average is five to nine days).
After up to five days of fever, patients begun to suffer damage to their blood vessels, which can cause internal bleeding, psychological symptoms such as confusion and aggression, and persistent bleeding from the nose, gums, vagina, eyes, mouth, or ears.
Without treatment it is usually lethal, with an estimated case fatality rate of about 62 percent. Partly for that reason, the WHO has classified MVD as having high pandemic potential.
Although there is no specific antiviral therapy known to be effective, there is a potential vaccine under research, which has been administered to more than 1,500 health workers in Rwanda as part of a clinical trial.
