Bronchitis: Symptoms and Contagiousness

Inflammation of the bronchi is called bronchitis.  It is a common form of inflammatory involvement of the airways. It can occur alone or as part of a systemic disease (immune disorders, bronchial asthma, cystic fibrosis).

There are two types of bronchitis:

1. Acute bronchitis – classified as a contagious form. It can be transmitted by droplets of saliva or mucus when sneezing, coughing or talking.
2. Chronic bronchitis – due to a dusty environment or smoking, frequent recurrent acute bronchitis can lead to bronchitis becoming chronic.

Acute bronchitis often occurs in children. The cause of the disease is the massive penetration of pathogenic microorganisms through the defense mechanisms of the respiratory system. Approximately 50-90% of cases of bronchitis are caused by viruses.

It occurs most often in the winter months. Bacterial infection often follows a viral infection.

Complications of bronchitis include:

• Otitis – ear inflammation,
• Sinusitis – inflammatin of the sinuses,
• Bronchopneumonia – an inflammatory disease that affects the bronchi, bronchioles and alveoli of the lungs.

Thus, acute bronchitis is an infectious disease that can be transmitted from person to person. It is therefore a contagious disease. More precisely - infectious/transmissible are the microorganisms that cause the disease and spread in droplet form.

In the case of acute bronchitis, there are many causes. The most common causes of the disease include bacterial and viral infections.

Other causes of the disease include external factors (smog, smoking, chemical gases). These external influences cause inflammation in the airways.

Viruses cause approximately 85 to 95% of cases of acute bronchitis. The most common viral causative agents of the disease include:

• influenza A, B virus
• rhinoviruses - the most common cause of rhinitis
• enterovirus - an important human pathogen
• respiratory syncytial virus (RSV) - attacks the lungs and airways

V In rare cases, human metapneumovirus, coronavirus and adenovirus can cause the disease.

In some cases, bacterial bronchitis may occur after a viral infection. This arises as a result of the action of bacteria:

• Mycoplasma pneumoniae
• Chlamydophila sp.
• Bordetella pertusis (whooping cough)

Causes of chronic bronchitis include a polluted outdoor environment and bacterial or viral infections.

The most common pathogens that cause chronic bronchitis include Haemophilus influenzae, Streptococcus pneumoniae and Moraxella cattarhalis.

Chronic bronchitis is caused by excessive production and excessive secretion (hypersecretion) of mucus by goblet cells (mucosal metaplasia).

Mucus hypersecretion is largely caused by external influences (cigarette smoke) and/or viral or bacterial infection.

In most cases, acute bronchitis starts as a common cold or flu with a typical scratchy throat. After about three days, a dry cough appears. Over time, this changes to a wet cough.

Patients usually cough up yellow to green coloured mucus. The cough subsides within 5 to 10 days. In some cases, breathing problems (labored breathing) may occur.

The most common symptoms of acute bronchitis include:

• weight loss,
• fever,
• chest pain,
• whistling when coughing,
• cough lasting more than 10 days.

In viral bronchitis, the following symptoms appear:

• fatigue,
• weakness,
• sweating,
• subfebrile,
• joint pain,
• muscle pain.

In the case of bacterial inflammation, patients develop the following symptoms:

• fever,
• purulent (i.e. with pus) sputum,
• laboratory - leukocytosis and a higher CRP value.

Acute bronchitis can in some cases progress to chronic bronchitis.  

Chronic bronchitis

The main symptoms of chronic bronchitis include coughing, wheezing and chest tightness. A persistent cough is accompanied by coughing up yellow to green mucus. This cough occurs for at least three months per year for two consecutive years.

In infants and toddlers, bronchitis is often accompanied by varying degrees of bronchial obstruction.

The latter is caused by oedema, hyperaemia of the bronchial mucosa, spasm of the bronchial muscles (bronchospasm) and excessive secretion (hypersecretion) of the bronchial glands. This condition closely resembles an asthma attack.

The doctor makes a diagnosis based on the clinical picture and physical examination. During the examination, certain typical sounds can be heard.

Of the laboratory examinations, microbiological examination of sputum is carried out. To distinguish viral and bacterial infection, the examination of inflammatory parameters is used: sedimentation, CRP and blood count.

When bronchopneumonia is suspected, the doctor sends the patient for a lung X-ray. A chest scan in bronchitis is negative. With pathological findings, a bronchoscopic examination and a CT scan of the chest are recommended.  

The cold-like symptoms of bronchitis are joined by a cough after 3 to 4 days. This is initially dry, irritating and unproductive. Patients describe pain behind the sternum.

After a few days, a dry cough turns into a moist, productive, with excessive mucus secretion. Coughing fits and increased production of secretion, which patients swallow, can cause vomiting. The cough subsides within 5 to 10 days.

What is coughing?

Coughing is characterized as a defensive reflex that is necessary to maintain airway patency. The cause of its occurrence is irritation of the so-called sensitive areas.

Did you know that when you cough, air flows through your airways at 120 m/s?

These sensitive areas are found in the larynx, trachea, bronchi, pleura or external ear canal. Coughing begins with a short inhalation, followed by the closing of the vocal cords and a sharp exhalation.

Learn more:

Wet cough: Causes of productive cough without a temperature?

Dry cough as a symptom: Causes in adults and children