Pneumonia causes

Pneumonia: causes, treatment and prevention

Also according to the latest available data from the European Union Statistics Office (Eurostat), no less than 131,450 people died of pneumonia in 2016 in the EU, i.e. around 3% of all deaths in the EU. ‘year.

This is not surprising considering that pneumonia, which strikes at any age, poses a greater threat to the elderly population and is the leading infectious cause of death among children worldwide; responsible for 15% of deaths of children under 5, mainly in underdeveloped countries.

What is pneumonia?

Pneumonia is an inflammation of the lung tissue, usually acute in nature, which in most cases is caused by infectious causes.

Types of pneumonia

There are several classifications of this pathology, which vary according to:

anatomical location affected:
– unilateral: one lung;
– Bilateral: to both lungs.

root cause:
– bacterial: one of the most common, caused by bacteria reaching the lungs from the upper respiratory tract, generating an infection;
– viral: caused by a virus;
– fungal: caused by fungi and fungi. This is a rare form that mainly affects people with weakened immune systems, such as HIV patients;
– inhalation/aspiration (or ab ingestis): by inhalation or ingestion of intoxicants and/or irritants in suspension in the air, liquids, gases or gastric juices.

mode of transmission
– Community Acquis (CAP): therefore contracted in the community, excluding health establishments, RSA, hospitals;
– nosocomial: contracted by the patient in hospital, after admission;
– mechanical/invasive ventilation: contracted by the patient after undergoing invasive mechanical ventilation;
– in immunocompromised people: occurs in patients whose immune system activity is reduced due to illness or treatment.

Causes of pneumonia

Pneumonia usually comes from pathogens that cause infection in the respiratory tract.

This can be particularly serious for people with weakened immune systems, such as the elderly, but also people with chronic illnesses, alcoholics, smokers, cancer patients or those on therapies that may decrease blood pressure. immune system activity.

The best known pathogens causing the disease, when it does not remain idiopathic (i.e. of unknown causes) are for example

for bacterial pneumonia
– pneumococcus (streptococcus pneumoniae): this is the main cause of pneumonia;
– haemophilus influenza (which has nothing to do with the flu);
– Staphylococcus (staphylococcus aureus);
– Moraxella catarrhalis;
– Escherichia coli;
– Pseudomonas aeruginosa;
– Mycoplasma pneumonia;
– Legionella (Legionella pneumophila);
– less common chlamydia (chlamydophila pneumoniae or chlamydophila psittaci).

for viral pneumonia:
respiratory syncytial virus (RSV);
– influenza A and B viruses;
– Severe Acute Respiratory Syndrome (SARS);
– Middle East Respiratory Syndrome (MERS);
– Covid19.

for fungal pneumonia: (more common in immunocompromised people)
– candida albicans;
– pneumocystis jirovecii.


The most common symptoms of pneumonia, which are sometimes also typical of other respiratory diseases, are

– dry or productive cough (with transparent or non-transparent mucus. More rarely also with hemoptysis, that is to say presence of blood);
– difficulty in breathing (dyspnoea) and shortness of breath;
– fever;
– chest pain that worsens with the urge to cough;
– tachycardia;
– rapid breathing (tachypnea);
– Chills and sweating.

How to treat

Pneumonia is usually cured in most cases, especially in people who are not at risk, if treated well, and are treated with

– antibiotics, in the case of a bacterial form;
– antifungals in case of fungal pneumonia.

The choice of antibiotic or antifungal treatment is very important for the evolution of the disease.

In the case of viral pneumonia, on the other hand, if the situation is not serious, treatment is generally based on rest and supportive therapy.

In more serious cases of pneumonia, on the other hand, especially in the most fragile population or in less simple cases of Covid-19, hospitalization may be necessary for the use of pharmacological and instrumental therapies, including invasive ones.

Risks of pneumonia

Complications of pneumonia, if not diagnosed and treated in time, can be very serious.

Among these, particular mention should be made

– Pleurisy: inflammation of the membrane (pleura) that lines the lungs and the inner wall of the chest, causing obstruction to breathing;

– Lung abscess: lesion containing pus inside the lungs, which in about 1 in 10 cases requires surgery to clean and remove it;

– sepsis: if the infection progresses through the bloodstream and spreads throughout the body.

The more fragile population over the age of 65, or with comorbidities such as diabetes, cardiovascular disease, kidney failure or oncological disease, may face a more serious clinical picture with a greater risk of hospitalization and , in the most serious cases, mechanical accidents. intensive care ventilation.

Acute interstitial pneumonia and Covid-19

Acute interstitial pneumonia occurs when pneumonia affects the interstitium: the part of the lungs made up of connective tissue that forms a kind of scaffold on which the alveoli are arranged.

The alveoli are small elastic sacs in which oxygen is introduced into the blood and carbon dioxide is expelled.

As the interstitium becomes inflamed and sometimes thickens or, in more severe cases, is replaced by scar tissue, a barrier is created for the alveoli, which cannot adequately oxygenate the blood and eliminate carbon dioxide, resulting in severe respiratory failure.

Interstitial pneumonia is typical of viral infections, which also characterizes Covid-19 due to an excessive reaction of the immune system which, by generating a very strong inflammation, is capable of damaging the lung tissue.

Post-pneumonia check-ups and plethysmography cabin

After a serious case of pneumonia, such as interstitial pneumonia linked to Covid-19, but not only, checks are required over time:

  • specialized and instrumental controls by chest X-ray, computed tomography;
  • respiratory function tests.

The latter are carried out in a plethysmography cabin, equipment capable of carrying out in particular

  • Global spirometry: to measure lung volumes such as how much air the lungs are able to hold or how much they have left after exhalation;
  • Study of alveolar-capillary diffusion of carbon monoxide (DLCO): to assess how the exchanges of oxygen and carbon dioxide take place, and therefore highlight any deficits in the transmission of oxygen to the tissues.

In addition to this, for patients who have been intubated for a long time and who have therefore experienced a weakening of the respiratory muscles as well as the loss of automatic breathing, a rehabilitation course is essential in order to restore a functional flow of oxygen. which, let’s not forget, is the fuel of our organism.

The pneumococcal and influenza vaccine

Pneumococcal vaccination is an important tool for the prevention of bacterial pneumonia in all age groups, but especially in children and the elderly (≥ 65 years old) or anyone with risk factors such as:

  • chronic diseases
  • cardiovascular
  • respiratory diseases;
  • immunocompromised states”.

There are currently 2 types of pneumococcal vaccine

  • 23-valent polysaccharide vaccine: which contains 23 types of pneumococci and is used in subjects over 2 years of age;
  • 13-valent conjugate vaccine: which protects against the 13 most common pneumococcal strains and is available from 6 weeks.

The flu vaccine, for its part, can also be an indirect help against pneumonia, since by reducing the risks of contracting the seasonal flu, it also reduces the risks of developing complications such as pneumonia.

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