Pneumonia as a misconception

When we were kids, Pneumonia was taken to mean cold in the lungs, during a cold weather, if you were running around playing without covering yourself up with a sweatshirt your Moma will come yelling, do you want cold to enter your body [and give you pneumonia].
But that was when we were kids.
Now that we are adults, things haven't changed that much; you still see adults, even learned ones, still referring to Pneumonia as cold, and associating it with the same. Example, a doctor diagnose someone as having Pneumonia and in defence he says, but I didn't sleep out in the cold.

Image credit pixabay

Question is, if Pneumonia was due to cold weather, why then is it more prevalent in the tropics than in the temperate regions; why is the burden of Pneumonia much more in Africa with all it's scorching climatic conditions, and far less in the West even with winter coming around every other season?
Surely those that lives in the Arctics would be shaking hands, and winning and dinning with the Pneumonias . But it isn't so.
What then is Pneumonia?

Pneumonia is an infection, a chest infection involving the lower respiratory tract, from the smallest air ducts to the air sacs including the Lungs. It involves inflammation of the lungs, with resultant exudation of fluid and pus into the air sacs which is coughed up as sputum.
Suffice it to say that Pulmonary tuberculosis is a bad kind of Pneumonia. That's right, I guess that paints a better picture.

FEATURES OF PNEUMONIA
Depending on the virulence wickedness of the infecting organism, quantity of the inoculum size of the infective organism introduced, and the host immunity, Pneumonia can run a fairly benign course or alternatively it can constitute a life-threatening medical emergency.
Overall, the symptoms include:

• Cough
• Fever
• Shaking chills
• Chest pain
• Difficulty breathing
• Loss of appetite
• Muscle aches

In the elderly, it is usually severe and may present with just fever and mental confusion without as much as cough.
In children, cyanosis [bluish discolouration], diarrhoea and vomiting may be thrown into the mix.

CAUSES OF PNEUMONIA

Pneumonia is mainly caused by Micro organisms, including:

• Bacteria
• Fungi
• Viruses
  Rarely, a Pneumonia-like condition is caused by harmful chemicals when aspirated into the chest [example stomach acid from vomitous] or inhaled. In such setting it is called pneumonitis.

Image credit wikimedia commons

SOURCE OF INFECTION
This is usually by inhalation of infected droplets let into the atmosphere by a sufferer.
Other sources include;

• Spread of organisms from the blood into the lungs.
• Direct inoculation of organisms, eg from a stab wound.
• Contiguous spread from an infected area near the chest.
• Aspiration of microbes from the digestive tract.

RELATIONSHIP WITH COLD WEATHER?

In as much as Pneumonia is not cold entering the body, there may be some correlation between cold weather and the pneumonias.
But like they say in Epidemiology, correlation does not translate to causology ; it may merely be just an association.
The association between cold weather and Pneumonia may be explained by the following:

1. LOW HUMIDITY

Cold air is associated with low humidity, and may "dry up" the respiratory tract reducing the potency of the muco-cilliary escalator mechanism, predisposing to respiratory tract infections.
The Muco-cilliary escalator is an ingenious protective machinery possessed by the respiratory tract. The sticky mucus traps dust particles and other foreign bodies including infectious nuclei, and the whip-like activity of the cilia of respiratory epithelium sweeps the trapped dirt upwards so that one removes it by clearing the throat and spitting it out as sputum.
The modus operandi of this machinery requires humidity, as aridity would impair it's function.
Compare with what is obtainable in Immotile Cilia Syndromes [Eg Kartagener's ].

1. RESPIRATORY VIRUSES
   These thrive better in cold environment, hence the high preponderance of virus-mediated upper respiratory tract infections in cold weather.
   Little wonder these infections are termed "Common cold" or simply "the cold".
   This also predisposes to Lower respiratory tract infections, hence Pneumonias.

CONCLUSION

Make no mistakes, Pneumonias still occur in weather conditions as hot as hell. The Pneumonias while they may have an association with cold weather are not due to cold perse but are a group of potentially serious chest infections which can occur in all weather/climatic conditions.
Good news however is that they are treatable; with good course of organism-specific antibiotic therapy they are toast.

REFERENCES
1 pneumonia
2 pathogenic bacteria
3 Epidemiology of pneumonia
4 viral pneumonia

Thank you for reading