In Rwanda, ten people have died as a result of the highly contagious disease Marburg virus29 cases have been confirmed, the country’s health ministry reported on Tuesday, just days after the country declared an outbreak fatal hemorrhagic fever that does not have an approved vaccine or treatment.

“Marburg is a rare disease,” said Health Minister Sabin Nsanzimana on Sunday. “We are increasing contact tracing and testing to stop the spread.”

He said the cause of the illness has not yet been determined.

Previous Marburg cases and outbreaks have been recorded in Tanzania. Equatorial Guinea, Angola, Congo, Kenya, South Africa, Uganda and Ghana, according to the World Health Organization.

Here’s what else you should know about the disease.

What causes Marburg virus?

How EbolaThe origin of the Marburg virus lies in flying foxes. It can spread between people through close contact with the body fluids of infected people or with surfaces such as contaminated bedding, clothing, needles or medical equipment.

The World Health Organization states that the Marburg virus does not spread through the air.

The rare virus was first identified in 1967 after it caused simultaneous outbreaks of disease in laboratories in Marburg, Germany, and Belgrade, Serbia. Seven people died after being exposed to the virus while conducting research on monkeys.

Symptoms of Marburg virus

According to the Centers for Disease Control and Prevention, symptoms of Marburg virus include:

• Fever
• chills
• Headache
• Muscle pain
• rash
• Chest pain
• Sore throat
• Diarrhea
• Vomit
• Stomach pain
• unexplained bleeding or bruising

“In later stages of the disease, bleeding may occur in various places such as the gums, nose and anus. Patients may suffer from shock, delirium and organ failure,” says the WHO.

Without treatment, Marburg can be fatal in up to 88% of those affected. There are currently no approved vaccines or treatments specifically for this virus.

It can take between three days and three weeks for a person infected with the virus to show symptoms, Nsanzimana added.