A mystery illness that kills within 48 hours has claimed 53 lives in two outbreaks in the Congo and there are fears it could spread to the UK. Two separate villages in the Congo’s Equateur province have reported outbreaks of the disease since January 21, with 419 cases so far.

Experts do not know what the disease is or how it spreads – but have ruled out both Ebola and Marburg. The villages are 120 miles apart.

Patients reported pain in the neck and joints, sweating and shortness of breath, intense thirst and in children, persistent crying.

The first victims were children in a village who died within 487 hours of falling in, the World Health Organisation (WHO) said. Dr Zania Stamataki, Associate Professor in Viral Immunology at the University of Birmingham, said: “It is possible that we will see more cases.The incidents are currently correctly treated like an outbreak of infection, but it is not known how infection is transmitted, which makes it more difficult to contain.

“The best way to contain the outbreak is to isolate patients and stop travel in affected regions to prevent transmission. While infected, a person could feel well enough to travel and mix with others in social events, which aids transmission.”

Dr Stamataki added: “Infections know no borders and do not respect country lines. People travel and infections travel with them, either hitching a ride in a person or in animal carriers, so one cannot exclude spread outside of a country’s borders.

“In the UK and in other countries we need to remain vigilant and watch for symptoms. Symptoms of a haemorrhagic fever-type disease should be reported to the UK Health Security Agency via a registered medical practitioner.”

Congo’s Ministry of Health said most of the patients have similar symptoms including fever, chills, body aches and diarrhoea. Death occurs within 48 hours in most cases.

The WHO is investigating a number of possible causes, including malaria, viral hemorrhagic fever, food or water poisoning, typhoid fever and meningitis. Half of the patients have tested negative for malaria.