Pneumonia is a serious common infection that causes inflammation in the lung tissue. Pneumonia is commonly caused by the same viruses or bacteria that cause upper respiratory tract infections. The most common cause of pneumonia is a pneumococcal virus.
Pneumonia is often preceded by an upper respiratory tract infection or bronchitis. Pneumonia is often associated with a cough, fever or decline in general condition, i.e. the same symptoms as associated with upper respiratory tract infections and bronchitis, but in the case of pneumonia, the symptoms are usually more intense and have an acute onset.
How is a pneumonia infection transmitted?
Airborne transmission or transmission through contact are the most common ways of transmitting a pneumonia infection. Coughing releases viruses or bacteria in the air, through which they can access the respiratory tract or surfaces that may transmit the infection upon contact.
Maintaining good hand hygiene is an essential mode of preventing an infection. You should wash your hands carefully with soap and dry them well and, if necessary, use a hand sanitiser. Attention should be paid to hygiene when coughing as well. Airborne transmission can be prevented by coughing into your sleeve or a napkin that can be discarded after use. It is also important to wash your hands carefully after coughing.
Vaccines can also be helpful in the prevention of pneumonia infections. Influenza is a major risk factor of pneumonia, so all who belong to a risk group should be vaccinated against influenza every year. You may also want to consider a pneumococcal vaccination in order to prevent the onset of a severe pneumococcal disease and pneumonia.
Smoking is a major risk factor for pneumonia. Quitting smoking can thus reduce the risk of the onset of pneumonia.
Incubation period of pneumonia
Pneumonia can be caused by bacteria or viruses, and the duration of the incubation period of the disease depends on the type of infectant. The cause cannot always be identified. The onset of pneumonia in adults is primarily caused by a bacterium or a combination of a virus and a bacterium. The most common cause of the disease is a pneumococcal bacteria. In such cases, the onset of pneumonia can be very acute and involve severe symptoms that may develop in the space of few hours. The incubation period of a mycoplasma infection is 1–4 weeks.
If the pneumonia is caused by an underlying influenza infection, the incubation period of the influenza varies between 1–7 days. The secretion of an influenza virus may begin 1–2 days before any significant symptoms arise.
Symptoms of pneumonia
Common symptoms of pneumonia include:
• cough and wet sputum
• fever (typically over 38 °C)
• chest pain
Pneumonia is possible if the symptoms listed above develop rapidly, the disease impairs your overall condition, the symptoms of a respiratory tract infection recur or you belong to a risk group, i.e. if you are elderly or have other underlying diseases.
Elderly people, in particular, may experience disorientation, stomach issues or declined medical condition as the only symptoms of a bacterial pneumonia. Pneumonia in the elderly may not necessarily involve fever.
Sequelae of pneumonia
If the pneumonia persists, it may be an indication of a complication, such as a lung abscess or a wet pleuritis. In some cases of a suspected persistent pneumonia, the symptoms are caused by another underlying illness.
How is pneumonia diagnosed?
Pneumonia can often be diagnosed with a simple auscultation of the lungs, but the diagnosis is usually confirmed with a chest X-ray. Due to the wide variety of possible causes of pneumonia, the cause cannot be reliably determined on the basis of symptoms, laboratory tests and the chest X-ray examination. High C-reactive protein (CRP) levels in blood and typical changes in the blood count can indicate a bacterial infection, but they no not provide a completely reliable differential diagnosis. Because of this, pneumonia is always treated with antibiotics.
When should you see a doctor?
If you suspect that you might have pneumonia, you should always see a doctor. The doctor will make a diagnosis on the basis of the symptoms, inflammation marker levels and the chest X-ray.
Treatment of pneumonia
Pneumonia is always treated with antibiotics. The antibiotic treatment will usually become effective in 2–3 days. If there is no response to treatment, the dose is increased and additional examinations are performed in order to rule out the possibility of complications such as lung abscesses or pleuritis.
Depending on the case, antibiotics must be taken at home for 5–10 days. You should re-visit a doctor if your condition becomes worse or if the symptoms do not begin to go away in three days in spite of the antibiotic treatment.
Complete recovery from pneumonia may take several weeks. If the symptoms persist for more than two weeks, an additional X-ray should be taken. An additional clinical and X-ray examination is performed on patients over 50 who smoke eight weeks after the symptoms subside in order to monitor their recovery. If the recovery process does not go according to plan, you should request more examinations and additional treatment.
When can you go back to work, school or daycare?
The duration of sick leave varies between cases and depends on the severity of the disease. In most cases, a sick leave of 1–2 weeks is required, and it is continued whenever necessary.
Expert interviewed for the article: docent, pulmonologist Terttu Harju.