Questions are being raised after three people in Argentina died from a mystery respiratory illness.
On Thursday (local time), authorities reported the deaths and ruled out any connection to COVID-19 or the flu.
Nine people have contracted the illness in Tucuman, a province in Argentina.
Health officials said the disease is similar to COVID-19 and four people are being treated in hospital for it, Forbes reported.
Samples were sent to the Malbran Institute in Buenos Aires for further testing.
Eight out of the nine people infected with the mysterious illness worked at the Malbran clinic and close contacts of the people infected and their colleagues are being monitored for symptoms which include breathing difficulties, fever, diarrhoea and body aches.
Investigators have not determined whether or not the disease is caused by environmental factors or an infectious agent and are analysing water and air conditioners for possible contamination, Forbes reported.
The World Health Organization (WHO) and The Pan American Health Organization (PAHO) offices in the Argentian region say they are monitoring the situation alongside Argentine health authorities.
