Experts extremely concerned as mystery illness kills 53 people just days after feeling symptoms

Dozens of people have died from an unknown disease in the Democratic Republic of the Congo.

As of February 15, it was reported that 53 people have died from the mysterious illness in the country's northwestern Équateur Province.

Some of the deaths have occurred within 48 hours of the onset of symptoms, says the World Health Organization (WHO).

It said that, since January, there's been over 400 cases of people suffering from fever, vomiting, diarrhea, muscle aches, headaches, and fatigue.

With this in mind, the unknown disease 'poses a significant public health threat', the WHO warned.

The WHO has issued a stark warning about an outbreak in the Congo (Thomas Fuller/SOPA Images/LightRocket via Getty Images)

The WHO went on to say in a bulletin released on February 16: "The exact cause remains unknown, with Ebola and Marburg already ruled out, raising concerns about a severe infectious or toxic agent.

"Key challenges include the rapid progression of the disease, with nearly half of the deaths occurring within 48 hours of symptom onset in one of the affected health zones, and an exceptionally high case fatality rate in another."

"Urgent action is needed to accelerate laboratory investigations, improve case management and isolation capacities, and strengthen surveillance and risk communication," it went on.

"The remote location and weak healthcare infrastructure increase the risk of further spread, requiring immediate high-level intervention to contain the outbreak."

The disease is affecting people in a northwestern region of the Democratic Republic of Congo (Getty Stock)

The outbreak has affected two communities in particular in the Équateur Province — Bomate and Boloko.

The latest outbreak in Bomate Village was initially reported to provincial health authorities on February 9, while the cluster of cases that took place in the Boloko village were first reported on January 21.

Investigations traced the disease back to three community deaths among children under five years old. Reportedly the children in question had consumed a bat carcass prior to onset of signs and symptoms.

There's been over 400 reported cases (World Health Organization)

Speaking about the prospect of the disease being new, Michael Head, a senior research fellow in global health at the University of Southampton in Britain, said, as per Washington Post: "A genuinely new illness, as we saw with covid-19, of course can happen but is very rare.

"Usually, it’s a bug that we know about but haven’t yet diagnosed in that particular outbreak."

To determine what the disease is, the WHO says that 'metagenomic sequencing and additional investigations are ongoing to determine the cause of illness and deaths in the two health zones' — those zones being the Bolomba Health Zone and Basankusu Health Zone where the two affected villages are located.