getty The mysterious pneumonia outbreak in Tucuman, Argentina, that I covered yesterday for Forbes, isn’t so mysterious anymore. According to an update from the Pan American Health Organization (PAHO), Argentina’s Ministry of Health has confirmed that the Legionella bacterium is the cause of the outbreak that has now left 11 people sick and four dead. Here’s a PAHO tweet with the update: The update specifically mentioned Legionella pneumophila, which is one of a legion of different species of Legionella bacteria that also includes L. longbeachae, L. feeleii, L. micdadei and L. anisa. Legionella can be found in amoebae living in wet environments, such as air conditioning systems, cooling towers, hot tubs, plumbing systems, humidifiers, ice makers, fountains, misting systems, hot tubs, fans, potting mixes and compost. This is yet another reason why you shouldn’t shove potting mix or compost up your nose. When the bacteria enter your lungs through breathing in contaminated droplets of water or soil, the result can be a milder illness called Pontiac Fever with symptoms developing a few hours to 3 days after exposure to the bacteria. Or a more serious illness, called Legionnaires’ Disease, with symptoms developing two to 10 days after exposure. The severity of illness in this outbreak suggests that it was an outbreak of Legionnaires’ disease. It’s called Legionnaires’ Disease not because it will turn you into a Legionnaire and make you wear those hats they wear. Instead, as I described for Forbes in 2018, it was named after the place where the bacteria were first identified: at a three-day American Legion convention at the Bellevue-Stratford Hotel in Philadelphia, Pennsylvania, in 1976. Not everyone exposed to Legionella bacteria will get sick. You are more likely to develop Legionnaires’ disease if you have a weaker immune system (eg, age 50 or older, have a chronic disease, or take drugs that suppress the immune system) or weaker lungs (eg, have chronic obstructive pulmonary disease). That doesn’t mean you have to say, “bring it on,” to Legionella bacteria. Even if you are perfectly healthy, you can get Legionnaires’ disease, although the chance would be significantly lower. The key to treating Legionnaires’ disease is getting the right antibiotics as soon as possible. As reported by the World Health Organization (WHO), the overall mortality rate from Legionnaires’ disease is between 5 and 10%. However, this mortality rate can jump up to 5 to 30% if you have a weaker immune system, and even more up to 40 to 80% if you don’t get the right treatment in time. That’s why doctors should look for evidence of Legionella in your urine, blood, or sputum as soon as Legionnaires’ disease is suspected in any way. So the good news about this pneumonia outbreak in Tucuman, Argentina, is that it’s not an outbreak, oh my god. Instead, it’s a 1976 outbreak in Philadelphia. It is also not common for an infected person to spread Legionella to another person, although there has been a documented case of this happening in the past. Therefore, the chances of Legionella spreading wildly through the population are very, very small. This is definitely not a situation where you should panic and start collecting toilet paper. (In general, it’s unlikely that health authorities will ever say, “Okay, everyone’s hoarding toilet paper now.”) This Legionella outbreak is not the same as the Covid-19 pandemic situation. Or the monkeypox epidemic situation. In other words, this Legionella outbreak is not likely to spread far and wide. That said, the authorities are not going to say something like YOLO and not continue to act urgently. Now, they are trying to find the source of the outbreak as soon as possible to prevent other people from getting sick. After all, you don’t want a water system to keep spraying Legionella into the air like a fog machine at a Phantom of the Opera performance. Argentina’s health ministry and local health authorities are collecting environmental samples in and around the private clinic in San Miguel de Tucumán in northwestern Argentina where health workers affected by the outbreak worked. This can help identify what needs fixing. They will want to make sure that there is no more “venting” on the part of the Legionella bacteria.
