Pneumonia: causes, treatment and prevention
In Italy, the latest ISTAT data in relation to the year 2018, therefore pre-Covid-19, speak of 13,600 deaths from pneumonia, with an increase in incidence as the age of the population rises
Also according to the latest European Union Statistics Office (Eurostat) data available, as many as 131,450 people died of pneumonia in 2016 within the EU: around 3% of all deaths for the year.
This is not strange when we consider that pneumonia, which strikes at any age, poses a greater threat to the elderly population and is the leading infectious cause of death in children worldwide; responsible for 15% of deaths in children under 5, mainly in underdeveloped countries.
What is pneumonia?
Pneumonia is an inflammation of the lung tissue, usually of an acute nature, which in most cases is caused by infectious causes.
Types of pneumonia
There are several classifications of this pathology, which vary according to the:
anatomical location affected:
– unilateral: one lung only;
– bilateral: to both lungs.
cause of origin:
– bacterial: one of the most common, caused by bacteria reaching the lungs from the upper airways, generating an infection;
– viral: caused by a virus;
– fungal: caused by fungi and mycetes. It is a rare form that mainly affects those with a compromised immune system such as HIV patients;
– inhalation/aspiration (or ab ingestis): by inhalation or ingestion of airborne intoxicants and/or irritants, liquids, gases or gastric juices.
mode of contagion
– community-acquired (CAP): therefore contracted in a community environment, outside healthcare facilities, RSA, inpatient facilities;
– hospital-acquired: contracted by the patient in hospital, after admission;
– from mechanical/invasive ventilation: contracted by the patient after undergoing invasive mechanical ventilation;
– in immunocompromised individuals: occurs in patients with reduced immune system activity due to disease or therapy.
Causes of pneumonia
Pneumonia generally originates from pathogens that cause an infection of the airways.
This can be particularly serious for people with a weak immune system, such as the elderly, but also people with chronic illnesses, alcoholics, smokers, cancer patients or those undergoing therapies that may diminish the activity of the immune system.
The best-known pathogens at the origin of the disease, when it does not remain idiopathic (i.e. with 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 influenza);
– staphylococcus (staphylococcus aureus);
– Moraxella catarrhalis;
– Escherichia coli;
– pseudomonas aeruginosa;
– mycoplasma pneumonia;
– legionella (legionella pneumophila);
– less common chlamydia (chlamydophila pneumoniae or also chlamydophila psittaci).
for viral pneumonia:
– respiratory syncytial virus (RSV);
– influenza A and B viruses;
– Severe Acute Respiratory Syndrome (SARS);
– Middle East Respiratory Syndrome (MERS);
for fungal pneumonia: (more frequent in immunocompromised individuals)
– 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 phlegm. More rarely also with haemoptysis, i.e. the presence of blood);
– difficulty in breathing (dyspnoea) and shortness of breath;
– chest pain that worsens with the urge to cough;
– rapid breathing (tachypnoea);
– chills and sweating.
How to treat
Pneumonia generally heals in most cases, especially in people who are not at risk, if well treated, and is treated with
– antibiotics, in the case of a bacterial form;
– antimycotics in the case of fungal pneumonia.
The choice of antibiotic or antifungal therapy is very important for the course of the disease.
In cases 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 more fragile population or in less simple cases of Covid-19, hospitalisation may be necessary for the use of pharmacological and instrumental therapies, including invasive ones.
Risks of pneumonia
The complications of pneumonia, if not diagnosed and treated in time, can be very serious.
Among these, particular mention should be made of
– pleurisy: inflammation of the membrane (pleura), which lines the lungs and the inner wall of the chest, resulting in an obstruction to breathing;
– pulmonary abscess: a lesion containing pus inside the lungs, which in about 1 in 10 cases requires surgery to clean and remove it;
– septicaemia: if the infection progresses to the bloodstream and spreads throughout the body.
The more fragile population over 65, or those with co-morbidities such as diabetes, cardiovascular disease, renal insufficiency, or oncological diseases, may face a more serious clinical picture with a more significant risk of hospitalisation and, in the most serious cases, mechanical ventilation in intensive care.
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 sort of scaffolding 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 thickened or, in more serious cases, replaced by scar tissue, a barrier is created to the alveoli, which cannot adequately oxygenate the blood and remove carbon dioxide, leading to severe respiratory failure.
Interstitial pneumonia is typical of viral infections, which also characterises Covid-19 due to an overreaction of the immune system which, by generating a very strong inflammation, is able to damage lung tissue.
Post-pneumonia check-ups and plethysmographic booth
After a serious case of pneumonia, such as interstitial pneumonias linked to Covid-19, but not only, checks are appropriate over time:
- specialist and instrumental checks by chest X-ray, CT scan;
- respiratory function tests.
The latter are carried out in a plethysmographic booth, a piece of equipment capable of performing in particular
- Global spirometry: to measure lung volumes such as the amount of air the lungs are able to hold or how much remains in them after exhalation;
- Alveolo-capillary diffusion study of Carbon Monoxide (DLCO): to assess how the exchange of oxygen and carbon dioxide takes place, and therefore to highlight any deficits in oxygen transmission to the tissues.
In addition to this, for patients who have been intubated for a long time and, therefore, have 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 us not forget, is the fuel of our organism.
The pneumococcal and flu vaccine
The 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) or anyone with risk factors such as:
- chronic diseases
- respiratory diseases;
- immune-compromised states’.
There are currently 2 types of pneumococcal vaccine
- 23-valent polysaccharide vaccine: which contains 23 types of pneumococcus and is used in subjects over 2 years old;
- 13-valent conjugate vaccine: which protects against the 13 most common pneumococcal strains and is available from 6 weeks of age.
The flu vaccine, for its part, can also be of indirect help against pneumonia, since by reducing the chances of contracting seasonal flu, it also reduces the chances of developing complications such as pneumonia.