Is Bronchitis Contagious ?

Bronchitis, an inflammatory condition of the bronchus, has many interesting facts to be known about. Various causes of inflammation and irritation in the bronchus can lead to the condition.

In the US alone, more than 10 million people had chronic bronchitis in 2011^{[1, 2]}. It was also noted that women had chronic bronchitis at double the rate of men (6.8 Million women Vs. 3.3 Million men), and that the risk of chronic bronchitis increased with age ^{[1, 2]}.

What is Bronchitis? Definition

It is actually ‘Bronch’ + ‘itis’. ‘Bronch’ is the bronchus and ‘itis’ refers to inflammation. The inflammation of bronchial tissue is Bronchitis. It results in mucous formation in the lumen of the bronchii ^[3], and swelling of the bronchial tissues which in turn leads to the narrowing of the airways.

Once the airways are narrow, breathing becomes difficult. When less O2 is available for the body functions, the different tissues start being affected.

Image 1: Above image shows the gross difference between a normal bronchus and an inflamed bronchus. You can see the yellowish mucous lining inside the bronchial tube.

 

Image2:  Here you can find how the changes due to bronchitis are affecting the air passage through the bronchial tube.

The lining of the respiratory tubes is by ciliated columnar epithelium. ‘Cilia’ are minute hair like structures. Whenever any particles or organisms get into the respiratory path, they are collected and pushed out by the cilia^[4].

In case of bronchitis, they are lodged within the tract and are not pushed out as the mucous covering the lining prevents the cilia from acting effectively. This results in the infection of already inflamed tubes.

What are the types of Bronchitis?

Acute and Chronic bronchitis are though having some similarities, are completely different in their cause and presentation ^[3].

What causes Bronchitis?

Acute bronchitis

• Acute bronchitis is mainly caused by infective agents such as bacteria and viruses. Influenza virus, Parainfluenza virus, Adenovirus, Mycoplasma pneumonaie, Streptococcus pneumoniae, Hemophilus influenza, Bordetella pertussis, Moraxella catarrhalis etc. are few of those that can cause the condition.^{[3, 5, 15]}
• It can also be cause by cigarette smoke, dust, fumes, polluted air etc. which damages the cilia that lines the respiratory epithelium.^{[3, 5]}
• It is more common in children than the chronic variety.^{[3, 6]}
• Duration- Few days to 3 weeks^[6]

Chronic bronchitis

• Cigarette smoking is said to be the main cause for chronic bronchitis.^[7]
• Exposure to fumes, toxic gases, dust and pollution can also predispose to the condition.
• Long standing infections in the lung can exacerbate chronic bronchitis.^[3]
• Stays for longer duration of time than 3 months and exacerbates whenever there is a triggering factor.
• Treatment is different from that of acute bronchitis.

Is bronchitis contagious?

Surely it is contagious, but not all bronchitis is contagious. The infective agents like viruses and bacteria which causes acute bronchitis, can spread from person to person.

Can bronchitis by virus spread?

Viral bronchitis is highly contagious as it can spread through the air in form of droplets which are expelled from the infected person by means of coughing, sneezing or talking.

Is bronchitis contagious through kissing?

Acute bronchitis caused by virus or bacteria can spread by direct contact. The infective organisms maybe present on the suffering partners mouth and lips. This can easily get transferred to his/her partner while kissing.

Is Bronchitis deadly?

Acute bronchitis can be treated with ease and recovers well. But, if it is not treated, it advances to pneumonia, or sometimes chronic bronchitis. Both of them can be potentially dangerous. ^[10]

What are the symptoms in Bronchitis?

As said earlier, acute and chronic bronchitis differ in their symptoms too. If any of the following symptoms are seen, it is pertinent to visit your family doctor for diagnosis and treatment. ^{[8, 9]}

Acute bronchitis	Chronic bronchitis
Productive cough with Yellow or greenish mucous	Productive cough with or without streaks of blood
Painful chest due to cough	Wheeze
Sore throat	Fatigue
Fever	Headache
Wheeze	Difficulty in breathing
Fatigue	Color change in lips may occur to blue
Weakness	Pedal oedema- Swelling in the ankles or feet

How is bronchitis diagnosed?

• The doctors take a detailed history of the onset of the symptoms and how it has progressed. Further, examination of the chest with a stethoscope to see if any change in the breath sounds will be done. During the evaluation, doctor may hear wheezing from the chest. ^{[11, 15]}
• Sputum- Sputum can be taken in the lab for microscopy and culture. The test will help in identifying the organism according to which an antibiotic can be started if required.^{[11, 12, 13]}
• Chest X-ray- Whenever there is an infection, cough, or pain in the chest, this test is necessary to be done. It helps in excluding conditions like pneumonia, tuberculosis, sarcoidosis or growth inside the lungs as in case of tumors.^{[12, 13, 15]}
• Pulmonary function tests- As the name implies it helps in determining whether the function of lung is done adequately or not. Spirometry is the usual test utilized to analyse different lung capacities. ^{[11, 12, 13, 15]}

What is the treatment for bronchitis?

Acute bronchitis mostly resolves by itself. Sometimes specific treatments may be required, which varies from person to person ^[14].

• Antibiotics- Only in bacterial infection ^[17]
• Bronchodilators
• Anti-inflammatory drugs
• Pain killers
• General measures such as drinking plenty of fluids, avoid smoking, adequate rest, steam inhalation, breathing exercise etc. can also help in improving the condition.

Chronic bronchitis is little more difficult to treat. They may require oxygen support, appropriate positioning of the patient, bronchodilators, periodic nebulization, antibiotic therapy and corticosteroids according to necessity ^{[18, 19]}.

In severe cases, pulmonary rehabilitation, lung volume reduction surgery or even lung transplant may be required ^{[18, 19]}.

Is bronchitis contagious even after taking antibiotics?

Antibiotics are useful only in cases of bronchitis caused by bacteria. The organism stops spreading within 3-4 days of starting antibiotics in those cases where the disease is caused by bacteria. But remember, it can still be contagious if it is caused by viruses.

How long does bronchitis remain contagious?

Acute bronchitis by bacteria responds to antibiotic therapy. It might take 2-3 days to completely stop spreading the infection by the bacteria. So we can safely say that, 3-4 days after starting antibiotics, bacterial acute bronchitis stops spreading.

What happens if bronchitis is not treated in time?

In most conditions, acute bronchitis resolves by itself. But few may require the supportive treatment. In few people, acute bronchitis may progress into pneumonia or chronic bronchitis if left untreated.

Chronic bronchitis can result in Cor pulmonale (A condition in which health of heart is affected by disease in the lung) or respiratory failure.

How long does it take to recover from bronchitis?

Acute bronchitis may resolve within a period of few days to 3 weeks ^[6]. Chronic bronchitis has a longer outlook. Generally it stays until the patient dies. Whenever an exacerbation of the symptoms occurs, appropriate treatment is given for recovery.

Is there any way we can prevent bronchitis?

General measures such as washing hands and face frequently, drinking plenty of fluids, avoid smoking, protective masks while traveling outside home, adequate rest and nutrient rich food to boost the immunity can help to prevent bronchitis to a limit.

References:

1. Summary of health statistics for U.S. adults: National health interview survey, 2012. (2014, February). Retrieved from http://www.cdc.gov/nchs/data/series/sr_10/sr10_260.pdf
2. Trends in COPD (chronic bronchitis and emphysema): Morbidity and mortality. (2013, March). Retrieved from http://www.lung.org/finding-cures/our-research/trend-reports/copd-trend-report.pdf
3. McIntosh and Webberley, “Bronchitis: Causes, Symptoms and Treatments”, Medical News Today, January 9, 2016
4. “The Respiratory System”, National Heart, Lung, and Blood Institute, July 17, 2012
5. Worrall, G. (2008). Acute Bronchitis. Canadian Family Physician, 54(2), 238–239
6. Bronchitis,” NHS Choices, August 3, 2016
7. Madell and Sullivan, “Understanding Chronic Bronchitis,” Healthline, January 29, 2016
8. Ehrlich, “Bronchitis,” University of Maryland Medical Center, December 19, 2015
9. “Bronchitis,” Johns Hopkins Medicine Health Library
10. Mayo Clinic, Bronchitis Complications, April 1, 2014
11. “How Is Bronchitis Diagnosed?” National Heart, Lung and Blood Institute, August 4, 2011
12. “Chronic Bronchitis Diagnosis,” University of California San Francisco Medical Center
13. Mayo Clinic Staff, “Bronchitis Tests and Diagnosis,” Mayo Clinic, April 1, 2014
14. https://www.webmd.com/lung/understanding-bronchitis-basics#3
15. Albert, RH (1 December 2010). “Diagnosis and treatment of acute bronchitis.”. American family physician. 82
16. “What Causes Bronchitis?”. August 4, 2011
17. Smith, Susan M.; Fahey, Tom; Smucny, John; Becker, Lorne A. (2017). “Antibiotics for acute bronchitis”
18. Fauci, Anthony S.; Daniel L. Kasper; Dan L. Longo; Eugene Braunwald; Stephen L. Hauser; J. Larry Jameson (17th ed.).
19. Spencer, S; Karner, C; Cates, CJ; Evans, DJ (2011). “Inhaled corticosteroids versus long acting beta(2)-agonists for chronic obstructive pulmonary disease”.