Anyone who lives with COPD (emphysema, chronic bronchitis, and refractory asthma) wants to avoid exacerbations (severe attacks of coughing, increased mucus, and difficulty breathing) that lead to emergency room visits or hospitalization. These events are not only uncomfortable, but they also interrupt daily life up to 8 weeks or more. Even then, patients might not recover their former level of respiratory functioning.
During the past 20 years, clinical research has shown that three bacteria—non‐typeable Haemophilus influenzae (NTHi), Moraxella catarrhalis (Mcat), and Streptococcus pneumoniae—are strongly linked to COPD exacerbations. The first two, together, cause at 50-80% of acute attacks. Persons with COPD and those who care for them could benefit from understanding this process which lies at the center of the progress of the disease.
How Bacterial Infections Cause Exacerbations
Both NTHi and Mcat are bacteria that occur only in humans and cause respiratory and other infections (especially middle ear infections in children). Colonies of these bacteria routinely appear in the upper nasal or sinus areas and can then migrate to infect the ears or the lower respiratory tract. Lower respiratory infections occur primarily in adults and can accelerate the progression of COPD in persons with damaged lung and bronchial tissue or with weakened immune systems.
Most healthy adults are able to counter infection by means of their immune system that causes the bacteria to disintegrate and their bronchial cells that work to expel bacteria-laden mucus by coughing. Many epithelial cells have tiny filaments (cilia) that move the mucus containing dead bacteria up through the bronchia where they can be expelled.
Individuals with COPD suffer from weakened immune systems and damaged epithelial cells that become overloaded with infectious bacteria. The more the infection progresses, the more damage done to lung tissue. That makes it ever more difficult for the body to cope successfully, resulting in extreme attacks of coughing, wheezing, and difficulty breathing.
How to Reduce Infection
Since ITHi and Mcat are both found to some extent in most persons, prevention of infection can be difficult. Experts are not sure of all the causes of weakened immune systems. There may be some genetic factors involved, and exposure to some substances during infancy might contribute to infection later.
Nevertheless, it is clear that not smoking is most important for preventing ITHi and Mcat infection. The reason is simple: smoking damages ciliated epithelial cells so that it becomes ever more difficult to clear the lungs of infected tissue and mucus. Second-hand inhalation of smoke also causes cell damage that allows infection.
Several antibiotics have proven effective against ITHi and Mcat. But continued effectiveness might be in jeopardy because of over-prescription of antibiotics and the ability of bacteria, by creating new strains, to develop resistance to the effects of antibiotics.
Moreover, after patients have been treated with antibiotics, infections frequently recur. Deeper research shows that ITHi and Mcat bacteria can actually invade healthy cells and therefore become shielded from the effects of antibodies. These bacteria can also linger in the respiratory tract in crevices between cells, thereby escaping the effects of antibodies. When treatment ceases, the remaining bacteria reinfect the patient.
Effective actions to help prevent infection include following a healthy diet, exercising appropriately, and practicing basic hygiene. As in the case of COVID-19, you should wash your hands often, keep a hand sanitizer with you, and wear a mask in public or when you visit your doctor’s office. Use an N95 or KN95 mask whenever possible.
Hope for a Vaccine
As frustrating as recent efforts to fight COPD-related bacterial infections have been, there is hope for developing a vaccine. Success depends on surmounting three challenges:
- Since these bacteria are found only in humans, testing for effective antigens in animals (mice) is extremely difficult. Therefore, much clinical research has focused on in vitro models.
- Any vaccine should be able to prevent infection by all three bacteria: ITHi, Mcat, and S. pneumonia. Since each bacterium exhibits different properties, developing a comprehensive vaccine will take time.
- Before clinical trials on humans can begin, the effectiveness and safety of potential vaccines must be demonstrated to the satisfaction of government agencies.
Nevertheless, the search for a vaccine is under way.
In the meantime, if your doctor prescribes an antibiotic to fight infection, be sure to take the medication exactly as directed and to complete the full course. Otherwise, the infection could return more quickly.