Learning About Legionella: What You Should Remember

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New and future mothers in Darlington Memorial Hospital are less likely to shower in the maternity ward. Those planning water birth before September may need to change their plans or their facility for now.

The hospital recently announced that it detected high levels of Legionella during one of the routine water exams. It needs to use a filter to keep Legionella out of the water system until a new shower and cold-water taps equipment become available.

Now, what is Legionella, and why is it such a big deal? What does it have to do with showers or even the ventilation system, and why do some reports link it to the COVID-19 pandemic?

Defining Legionella

Legionella is actually a genus of a type of Gram-negative bacteria where Legionella pneumophila belongs. It is the cause of a cluster of conditions known as legionellosis.

Two of the most common types of legionellosis are Pontiac fever and Legionnaires’ disease. The former refers to a mild, non-fatal flu-like condition that affects the upper respiratory system. Legionnaires’ disease is the more severe between the two.

So named after a 1976 American Legion convention, Legionnaires’ disease is a kind of atypical pneumonia, which means that the pathogen that caused the infection of the lungs isn’t the more common one. Thus, it is less likely to be responsive to popular antibiotics such as penicillin and sulfonamide.

However, people with this illness may exhibit the same symptoms as anyone with pneumonia. These include high fever, headaches, muscle pain, vomiting, diarrhoea, nausea, shortness of breath, and coughing. These may develop between two and ten days after exposure.

bacterial cultures

How Dangerous Is It?

Outbreaks led to the discoveries of both Pontiac fever and Legionnaires’ disease, but that was so long ago. Today, these problems are often isolated cases. Should they affect a group of people, they will likely be in small clusters like schools, healthcare facilities, and multiple-occupant buildings.

But that doesn’t mean this isn’t dangerous. According to Medscape, its mortality rate can range from 5 to 80 percent, depending on the patient’s risk factors. People with weakened or compromised immune systems could experience more serious and life-threatening symptoms. The same goes for kids, particularly those below a year old and the elderly.

One of the probable reasons for its potential harm is the bacteria’s ability to replicate inside the body. Legionella can introduce as many as 300 toxins, and the pathogen can manipulate each of those to guarantee survival. These include a toxin called SidJ.

In a 2019 European research, the team discovered that this substance can modify the human protein to allow the bacteria to enter into the human cells and grow there.

Now, when the body senses the presence of a pathogen, the immune system gets to work. It can initiate a process called autophagy wherein white blood cells, which act as soldiers, destroy the invader by gobbling it up.

But a 2017 study revealed that Legionella might be able to avoid that by creating a molecule called RavZ. This one disrupts autophagy by cutting and breaking another molecule, LC3-PE, which makes the sac engulf the bacteria.

How the Bacteria Find Their Way to Humans

Pathogens are still living organisms, so they need the ideal environment to thrive. In Legionella, the bacteria prefer to live in standing or stagnant water in the plumbing system. This explains why the UK hospital has detected it in the shower and faucet.

However, they can breed just as well in the cooling towers, which may then be connected to heating, ventilation, and air-conditioning (HVAC). When these droplets of water circulate, the pathogen can already find its way into many homes and expose many humans to them.

For this reason, health experts suggest that homes and buildings that might have been shut down for prolonged periods because of the COVID-19 pandemic should consider ventilation ductwork cleaning and HVAC inspection and monitoring. Prolonged periods may be defined as weeks or months, according to the US CDC.

Legionella is a kind of bacteria that can develop in stagnant water, including those left out for long because of the pandemic. It can lead to a severe form of pneumonia and may be deadly to people with known risk factors such as age and pre-existing conditions.

It doesn’t have a vaccine, and it may not respond effectively to common antibiotics for pneumonia. The good news is that outbreaks are not frequent, and it doesn’t spread from human to human easily. Moreover, with regular monitoring on the quality of water, improving HVAC, and preventing stagnation, the bacteria will fail to thrive.

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