Transmission routes of atypical pneumonia

Pneumonia is a disease that is very easy to get, especially atypical pneumonia. This type of pneumonia is actually quite contagious. If it is not well controlled, it will spread more and more widely, eventually making your symptoms more severe, leading to severe pneumonia, and then your physical condition will take a turn for the worse. In this case, you must get treatment as soon as possible.

Pneumonia refers to lung inflammation caused by different pathogens or other factors. Bacterial pneumonia is the most common pneumonia. It is an ancient disease. Evidence of the disease was found on ancient Egyptian mummies as early as 1200 BC. Before the advent of antibiotics, about one-third of people with pneumonia would die. The emergence of antibiotics once significantly reduced the mortality rate of pneumonia, but in recent years, despite the use of powerful antimicrobial drugs and effective vaccines, the overall mortality rate of pneumonia has no longer decreased and has even increased. The reasons for the increase in morbidity and mortality are related to the aging of the population, smoking, underlying diseases and impaired immune function. They are also related to the changes in pathogens, the increased incidence of hospital-acquired pneumonia, the difficulty in etiological diagnosis, and the irrational use of antibiotics leading to increased bacterial resistance.

Normal respiratory immune defense mechanisms keep the airways below the tracheal carina sterile. Whether pneumonia occurs is determined by two factors: pathogens and host factors. Pneumonia may occur if the number of pathogens is large, the virulence is strong, and/or the host's local respiratory tract and systemic immune defense systems are damaged. Pathogens cause pneumonia through the following routes: 1. Inhalation of air; 2. Hematogenous spread; 3. Spread to nearby sites of infection; 4. Aspiration of bacteria colonizing the upper respiratory tract. Pneumonia may result from aspiration of bacteria from the gastrointestinal tract (gastroesophageal reflux) and from aspiration of environmental pathogens through an artificial airway. After the pathogens reach the lower respiratory tract directly, they multiply and cause congestion and edema of the alveolar capillaries, fibrin exudation and cell infiltration in the alveoli. Except for Staphylococcus aureus, Pseudomonas aeruginosa and Klebsiella pneumoniae, which can cause necrotic lesions in lung tissue and easily form cavities, pneumonia usually leaves no scars after recovery, and the structure and function of the lungs can be restored.

1. Lobar (alveolar) pneumonia is mainly caused by Streptococcus pneumoniae. The lesions involve more than one lung segment and are acute inflammation characterized by diffuse fibrin exudation in the alveoli. The lesions begin in local alveoli and quickly spread to the entire lung segment or lobe.

2. Lobular (bronchogenic) pneumonia is a focal acute suppurative inflammation with the pulmonary lobule as the unit. Because the lesions are mostly centered in the bronchioles, it is also called bronchopneumonia. The lesions start in the bronchi and spread to the surrounding alveoli.

3. Interstitial pneumonia is an inflammation mainly affecting the lung interstitium. It mainly invades the bronchial wall, alveolar wall and its supporting tissue, especially the peribronchial blood vessels, causing alveolar wall hyperplasia and interstitial edema. It can be caused by bacteria, mycoplasma, chlamydia, virus or Pneumocystis.