In fact, there is no simple answer. In general, no, pneumonia is not contagious. However, there are exceptions. A few special types of pneumonia that can be transmitted from one person to another, such as pneumonia viral origin and some forms of bacterial pneumonia.
It should be noted, however, that most people who come into contact with a patient who is ill with a contagious form of pneumonia does not develop pneumonia.
Pneumonia is the name given to infection of the lung tissue, especially the alveoli, which are the microscopic air pockets responsible for passage of oxygen from the lungs to the blood. Each lung has million alveoli, which are completely sterile structures, ie free of the presence of any organism causing disease.
For someone to develop pneumonia is necessary that a fungus, virus or bacteria reaches the alveoli. In general, this is very difficult because the respiratory tract has a complex defense system, ranging from lashes to "sweep" constantly respiratory system even millions of antibodies and immune cells scattered across its surface. The very sneeze and cough reflex are defense mechanisms activated to expel any structure of the innermost portions of the respiratory system.
Individuals who contract pneumonia are often exposed to two factors: a highly virulent germ and a failure in the defense of the airways system.
Pneumonia can be spread through the air after contact with infected persons secretions. This route of transmission, however, is one of the less common and only occurs in some types of pneumonia, as we shall see later. In most cases, the germ that causes pulmonary infection comes from the nasal cavity or oropharynx of the patient. Are bacteria which normally colonize the upper airways responsible for most cases of pneumonia. As the patient's immune system is strong, these bacteria are prevented from migrating to the lungs. But at the first sign of weakness, they may be able to overcome the barrier of defense and settle in lung tissue.
There are more than 100 germs, including viruses, bacteria, parasites and fungi, which can cause pneumonia. However, the vast majority of cases is caused by only 4 or 5 germs that normally colonize our upper respiratory tract.
Elderly, very young children, smokers, malnourished individuals, those with chronic diseases, people with lung diseases or immunosuppressed patients are the group at greatest risk of developing pneumonia, because usually have a weaker immune system and / or a chronically diseased lung. Respiratory viruses, such as those caused by the flu virus or cold, also increase the risk of pneumonia.
Factor in the transmission of influenza pneumonia
Influenza and other respiratory viruses increases the risk of pneumonia in two ways: the first is by airway inflammation, which disrupts the functioning of immune cells and promotes lung invasion by bacteria of the oropharynx. One of the most common complications of influenza is exactly bacterial pneumonia, which generally comes days after the onset of symptoms of influenza. In these cases, what usually happens is a patient who, after a few days of viral infection, begins to show signs of improvement flu, but suddenly back to deteriorate, with rising fever, worsening cough and poor general condition. The second way in which the influenza increases the risk of pneumonia is through a pulmonary infection by influenza virus itself. In most cases, the influenza restricted to the upper airways, but in certain individuals, the virus itself can be the source of influenza pneumonia.
Therefore, influenza is a risk factor for both bacterial pneumonia and for viral pneumonia.
As mentioned above, there are contagious pneumonia and not contagious pneumonia. Pneumonia caused by fungi or parasites are not transmitted directly from one person to another. Have viral pneumonia are usually contagious. Pneumonia of bacterial origin are not contagious in most cases, but there are some exceptions.
Viral pneumonia
The four most common forms of viral pneumonia is caused by influenza virus, Parainfluenza, Respiratory Syncytial Virus and Adenovirus. The first infectious agent is influenza, while the remaining three are viruses that cause cold. In susceptible patients, these viruses can go beyond a simple respiratory virus, causing a viral pneumonia. This situation is very common in the elderly, small children and immunosuppressed people.
Consider viral pneumonia as of infectious origin, but, in fact, who is contagious is the virus. If you have contact with a patient with pneumonia caused by influenza, for example, your greatest risk is of getting the flu. If you have a weak immune system, it can also develop viral pneumonia, but this will be a complication of viral infection you have purchased.
Bacterial pneumonia
Most cases of bacterial pneumonia is not contagious. The major bacterial agent causing pneumonia are: Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. None of these bacteria is usually transmitted from one person to another, bacteria are already present in our body.
In some situations, however, bacteria such as Streptococcus pneumoniae can be contagious. Although not the most common form of contamination, small children and immunocompromised patients can get pneumonia after direct contact with infected people. Importantly, the Streptococcus pneumoniae is much less contagious than any of the respiratory viruses described above, requiring close and prolonged contact to be broadcast.
There is also a group of bacteria which are responsible for a type of pneumonia known as atypical pneumonia. This form of pneumonia is atypical call because the clinical manifestations are usually different. The clinical picture is usually milder and dragged the traditional pneumonia. Mycoplasma pneumoniae and Chlamydophila pneumoniae are two bacteria that group, that can be directly transmitted from person to person through respiratory secretions, just like common viruses are transmitted.
Despite the Mycoplasma pneumoniae is a very contagious bacteria, most people do not develop acquires the disease or have only mild respiratory symptoms. Pneumonia usually only occur in clinically most vulnerable and risk factors for pneumonia patients.
A large number of patients hospitalized with pneumonia do not need to stay in respiratory isolation because the risk of transmission to the medical staff or other patients is very low. Simple hygiene measures such as hand washing and avoiding direct contact of a patient with each other are sufficient. Only in cases of pneumonia caused by Mycoplasma pneumoniae is that it is suggested that the patient be in a separate room and the medical staff must wear breathing masks.
Patients with influenza pneumonia, especially if the infection occurs during frames of new strains epidemics, as recently happened with the H1N1 influenza, also tend to stay in isolation. Masks should be used by the health team and the family who come to visit.
In the case of tuberculosis, the transmission from one person to another is much more common, and respiratory insulation must be even stricter. The patient must be isolated in a special room with negative air pressure and air exchange. The medical team can only enter the room wearing masks with filters.
