A mysterious outbreak that sickened 11 people in Argentina, killing four, has been solved.
Health authorities said the illness was likely caused by Legionella, the bacteria responsible for Legionnaire’s disease.
The outbreak was contained at a health clinic in San Miguel de Tucumán, which is the capital of Tucumán province and is located 670 miles northwest of Buenos Aires.
Health Minister Carla Vizzotti told a news conference on Sunday that four samples – including blood, respiratory and tissue samples – from the deceased patients had tested positive for the bacteria.
“The Legionella bacteria genome has been detected,” she told reporters. “It is suspected to be Legionella pneumophila.”
However, she said the results are preliminary and further testing is underway.
Legionnaires’ disease is a severe form of pneumonia caused by inhaling the bacteria in small water droplets or by accidentally ingesting water containing Legionella.
The disease is not contagious, but outbreaks can spread if the bacteria enters a building’s water supply, including showerheads, sink faucets, hot water tanks, radiators and other plumbing systems.
Although most people recover from Legionnaires’ disease with antibiotics, some patients — including those who are immunocompromised or have chronic lung conditions — can develop life-threatening complications.
According to the World Health Organization, the cases emerged between August 18 and 25, with patients complaining of fever, muscle aches, abdominal pain and difficulty breathing as well as symptoms of pneumonia.
Of the 11 cases, eight involved clinic health workers and three patients. Three of the four deaths occurred among health workers.
The median age of cases is 45 and seven are male, according to the WHO. Ten people had underlying conditions that put them at risk of serious illness, including all four deaths.
As of September 3, four people remained in hospital and three were recovering at home.
Argentinian health authorities said they were conducting a search for contracts to prevent further spread of the disease. Of the contacts who have been identified so far, none have developed symptoms.
“Sporadic outbreaks of Legionnaires’ disease pneumonia have already been reported in Argentina,” the WHO said in a statement. “Robust surveillance activities are implemented in the affected health facility.”
The statement continued: “Nevertheless, in the absence of an identified source of Legionella bacteria, the risk of developing Legionnaires’ disease for people working or hospitalized in the same health care facility is currently moderate.”