08/12/2013 07:41 EDT | Updated 10/12/2013 05:12 EDT

How Pneumonia Happens: A Strange Case of Friend to Foe

Anyone who has suffered from pneumonia -- or witnessed a loved one battle with the illness -- knows how scary the episode can be. The lungs fill with fluid, breathing becomes difficult and at times impossible, requiring hospitalization, and without proper treatment, the consequences can be dire.

One of the primary causes of pneumonia is the aptly names Streptococcus pneumoniae, better known in some branches of medicine as pneumococcus. This bacterium is considered to be in Ontario one of the top causes of premature mortality. In adults, up to a quarter of pneumonia cases are caused by this microbe. Yet that pales in comparison to children, where 1 out of every 5 children is vulnerable; the pathogen is responsible to over 10 per cent of all deaths in children under 5 years of age worldwide.

With these startling numbers, one might believe that this bacterium should be hunted down, locked up in a Level 4 laboratory and treated the same way as Ebola and SARS. However, S. pneumoniae can be found pretty much anywhere on earth in one of the most unlikely places: your nose and throat.

Contrary to the statistics, S. pneumoniae is normally nothing more than a freeloading bacterium that likes to hang out in an area of the body called the nasopharynx . It's warm, moist and can provide a nice selection of nutrients. Once there, the microbe eventually builds a community, better known as a biofilm and lives in a friendly, communal manner without causing any signs of infection. Researchers looking for this bacterium have fount that up to 95% of us have been 'colonized' at some point in our lives.

However, in the same way as another case of friend turned foe, flesh eating disease, the pneumococcus lives with a Dr. Jekyll and Mr. Hyde duality. For some unknown reason, these good tenants suddenly turn on us and begin to not only make us sick, but put our lives at risk. How this transformation happens has been a mystery with few answers.

Last week, though, a group from the State University of New York offered some incredible clues that might help us all. The team published a study that uncovered just how the change from harmless tenant to raging invader occurs. From studies done both in the petri dish and in the mouse, the team learned that the trigger isn't something that the bacterium does; it's something we do that causes them to go into attack mode. Unfortunately for us, it's not something that we can control.

When a respiratory infection, such as influenza, occurs, our bodies work to fight off the virus using the immune system and a number of other measures, such as starting a fever and releasing stress hormones. These actions are necessary to keep the body fighting the illness until it has been cleared. Yet, this change also creates a hostile environment for other bacteria, including S. pneumoniae. But unlike other microbes, which usually weather out the storm, these bacteria decide that the gig is up and it's time to fight.

Over the course of just a few hours, the bacteria change from settlers working together to individual fighters, heading out from their happy shelter into other areas of the body, including the ears, the lungs and the bloodstream. Shooting toxins and other nasty chemicals into the fray, the bacteria can quickly kill cells and show its dominance over the host. Sadly for us, when that happens, especially if there is another infection, medical attention within a few days is the only way to survive.

Thankfully, over the last few decades, there have been efforts to control the ability of pneumococcus to call our bodies, home. There are currently vaccines available to help reduce the likelihood that a strain with a bad reputation can take residence in the nasopharynx. In addition, with better hygiene practices in place, the spread of the bacterium can also be reduced. As with other respiratory illnesses, such as the flu, handwashing as well as covering coughs and sneezes can go a long way to prevent spread.

Even with these measures, S. pneumoniae isn't going away any time soon and the risks will remain for some time. This means that when it comes to your health, the best advice is to consult with a medical professional when respiratory sickness occurs. While not everyone will develop pneumonia, it is always good to get an idea as to what the cause might be and whether any problems may lie ahead. There may be little we can do to prevent pneumonia in some people, but there are many ways to be proactive so that something as innocuous as a summer cold doesn't turn into a life-threatening experience.