Bronchitis

Bronchitis is rumored to be contagious although Bronchitis is the inflammation of the mucus membrane of the bronchial tree. They are of two types, namely acute and chronic bronchitis. The acute bronchitis is primarily due to viral infection which can readily develop to a secondary bacterial infection in a susceptible host. They are contagious. On the contrary, chronic bronchitis is caused by various other reasons like cigarette smoking or exposure to pollution and hence is non-contagious.

Acute bronchitis often follows the infections of the upper respiratory tract. When upper respiratory tract infections are adequately treated, acute bronchitis can be prevented. Apart from infection, inhalation of physical and chemical irritants, gases and other air contaminants can also cause acute bronchial irritation. This irritation causes dry, irritating cough with a scanty amount of mucopurulent sputum. When a culture of this sputum is collected and tested, it will show the growth of certain organisms like Streptococcus pneumoniae, Haemophilus influenzae or Mycoplasma pneumoniae. These organisms are highly contagious.

These organisms spread from one person (infected) to other through air particles while coughing, sneezing, talking, singing, using their fomite and even breathing. Proper disposal of sputum, good hygiene and appropriate medical treatment with antibiotics can prevent the spread of infection. Other symptoms may include sternal soreness from coughing, fever, headache, general malaise and noisy breathing (inspiratory stridor). They are treated with antihistamines, cough expectorants, steam inhalation, vapor therapy and increasing fluid intake.

Unlike acute bronchitis, chronic bronchitis interferes with effective breathing due to accumulation of secretion in the bronchioles and lower respiratory tract. The person is asymptomatic until they become susceptible to infections of the lower respiratory tract. They are easily prone to infections because of the accumulated secretions providing adequate nutrients for the organisms to grow. The major symptom is the presence of productive cough that lasts for 3 months a year for 2 consecutive years.

In chronic bronchitis, the smoke or pollutant irritates the airway which results in hypersecretion of mucus and reduces the function of cilia. Thus mucus coats the bronchioles, clogs and narrows the airway affecting normal air entry. The alveoli nearer to the bronchioles becomes fibrosed and the function of alveolar macrophages is altered, this makes the person more susceptible to infections. All these actions brings about an irreversible change in lungs resulting in emphysema and bronchiectasis. They together contribute to the major lung disease called chronic obstructive pulmonary disease (COPD).

As they are constrained to the lower respiratory tract, they are usually harmless by not being contagious. Cough is the main symptom and no signs of infection noticed in them. Cough is also exacerbated by cold weather, dampness or pulmonary irritants and not by infection. They are treated with oxygen therapy, bronchodilators, postural drainage, chest percussion, hydration and corticosteroids. This confirms they are not contagious.

To summarize, acute bronchitis which is primarily caused due to viral infection is contagious and chronic bronchitis which is caused by various other reasons like cigarette smoking or exposure to pollution are non-contagious.