Covid, flu, influenza A and B, hantavirus and more than 25 other germs were tested on all patients who tested negative for already known diseases. The World Health Organization (WHO) is monitoring an epidemic of pneumonia of unknown origin detected in Argentina, while three of the ten people infected have died. All the cases occurred in a private clinic in San Miguel de Tucumán, in the northwest of the country, according to the Pan American Health Organization (PAHO), the regional office of the WHO. A first report published on Tuesday indicated that five staff members and one patient were infected. Three more cases were reported on Thursday, and one new case was identified on Friday. To read also: 6 cases, 2 dead: a mysterious pneumonia “of unknown origin” discovered in Argentina The three deceased people had comorbidities. Tests performed to try to establish whether the disease was caused by a known virus, bacteria or fungal pathogen were negative, the PAHO said. The disease is manifested by fever, muscle and abdominal pain and breathing difficulties. Read also: Mysterious pneumonia in Argentina: what do we know about the disease which has already killed a third person?