The UK's top scientists are on high alert after a "mystery pneumonia strain" killed two people in Argentina.
The unknown virus has infected the Northwest region of Tucuman after three people, who were already in hospital, contracted the disease.
Three others have since fallen ill with the virus, taking the total of patients hospitalised to six.
In addition, the two people who died, alongside five of those in hospital with the virus, all work in health care.
Cases of the virus were first identified on August 18, but scientists have already ruled out it being related to Covid, influenza and hantavirus, reports the Daily Star.
However, the exact symptoms are unknown to the public - with UK scientists closely monitoring the virus.
Dr Katherine Russell, Head of Emerging Infections and Zoonoses at UKHSA, said: “We are aware of an outbreak of pneumonia of unknown origin in Argentina.
“We continue to monitor the situation closely as further information becomes available through the investigations by Argentina’s health authorities.”
The epidemic intelligence team at the European Centre for Disease Control has admitted to tracking the cases since Tuesday, August 30.
Meanwhile, the World Health Organisation (WHO) are also monitoring cases.
Health officials in Argentina, however, are already puzzled by the new virus.
Luis Medina Ruiz, Tucumán’s Minister of Health said: "What these patients have in common is the severe respiratory condition with bilateral pneumonia and compromise in x-ray images very similar to Covid.
"But that is ruled out, as has cold, influenza of both types A + and B +, Hantavirus and 25 other germs.
“We have that technology in Tucumen, which examines 25 germs between viruses and bacteria, he also tested negative.
"(Having isolated the patients) we are prioritising the health of the community.
"We do warn that an issue may arise and it can spread and lose control.
“These are scientific and epidemiological backed measures. This shows our vulnerability to pathogens.”
