The Argentine Ministry of Health has confirmed to the Pan American Health Organization (PAHO) that legionella has been the cause of the outbreak of pneumonia cases associated with a health clinic in the province of Tucumán, in northwestern Argentina. A total of 11 cases have been identified to date, including four deaths in patients with comorbidities. Legionella, particularly the bacterium L. pneumophila, is associated with outbreaks of severe pneumonia. The most common form of transmission is inhalation of contaminated aerosols produced along with water sprays, jets or mists. Infection can also occur from aspiration of contaminated water or ice, particularly in susceptible patients in hospital settings. Treatment includes the administration of antibiotics for several weeks or months. Until now, the Ministry of Health had ruled out Covid and influenza A and B as causes. “We are studying the origin of the outbreak and the epidemiological link, we are still in the process of investigation,” explained the minister this Wednesday. Once the origin is detected, the Argentine Ministry of Health and the provincial health authorities are working to identify the source and implement the appropriate control measures. To do this, they are collecting environmental samples, conducting risk assessments and developing actions in the health care clinic related to the outbreak. For its part, PAHO is providing support to the Argentine health authorities from its Headquarters and the PAHO Representation in Argentina to investigate and characterize the outbreak. The Representative of PAHO and the World Health Organization in Argentina, Eva Jane Llopis, today accompanied the Minister of Health of Argentina, Carla Vizzotti, on a visit to the site. In agreement with national and provincial authorities, PAHO will also send a multidisciplinary team of experts next week to support surveillance, infection control measures within hospital care, and identification of the origin of the outbreak at the hospital infrastructure level.