At least five people have died and 28 others have fallen ill in a mysterious disease outbreak in Burundi, the World Health Organization (WHO) has said.

The outbreak is centred on the Mpanda district in Burundi’s north, near to the border with the Democratic Republic of Congo.

Symptoms of the unidentified disease include fever, vomiting, diarrhoea, and blood in urine, with jaundice and anaemia reported in some severe cases, the WHO said in a statement that was published on Thursday before being taken down without explanation.

The WHO and the local health authorities are racing to identify the disease.

Initial testing ruled out Ebola and Marburg, two haemorrhagic fevers with extremely high mortality rates that have caused outbreaks in the region in the past.

Investigators are now testing for a range of pathogens including Rift Valley fever, dengue, yellow fever, Crimean-Congo haemorrhagic fever and leptospirosis, the WHO said.

Investigators are hoping to clarify whether the virus behind the outbreak is a mutation of a known disease or an emerging threat.

Test results will determine whether current containment measures are sufficient or whether cross-border coordination will be needed to prevent further spread to other regions, the WHO said.

The cases, first reported on 30 March, have so far been limited to members of the same household and their close contacts. 

The WHO said it is currently supporting the Ministry for Health in Burundi to “strengthen disease surveillance, field investigation, clinical care, and laboratory diagnosis”.

A spokesperson for Gavi, the organisation which provides vaccines for the developing world, said it was working with the WHO to support the investigation.

“Outbreaks such as these underscore the critical importance of preparedness and investing in the systems that enable rapid response,” the spokesperson said.

A joint UN-supported team of experts has been deployed to contain the spread and coordinate a response. 

It is not the first time Burundi has reported an outbreak of an unidentified pathogen.

In 2023, at least three people died in an outbreak of a disease which killed rapidly, with symptoms including nose bleeds, abdominal pain, high fever, headache, dizziness and vomiting.

The cases led to the town of Baziro, in Burundi’s north west, being quarantined and surveillance measures being introduced. It is still not clear what disease caused the outbreak.

Burundi remains at risk of infectious disease outbreaks despite recent improvements in sanitation.

The country is currently facing a resurgence of cholera, with over 3,500 cases reported last year and continued transmission this year. 

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