A history of mycobacterial infections such as tuberculosis can lead to damage of the airways that predisposes to bacterial colonization. Severe viral infections in childhood can also lead to bronchiectasis through a similar mechanism. Nontuberculous mycobacteria infections such as Mycobacterium avium complex are found to be a cause in some patients. Recent studies have also shown Nocardia infections to been implicated in bronchiectasis. Impaired host defenses
Impairments in host defenses that lead to bronchiectasis may be congenital, such as with primary ciliary dyskinesia, or acquired, such as with the prolonged use of immunosuppressive drugs. Additionally, these impairments may be localized to the lungs, or systemic throughout the body. In these states of immunodeficiency, there is a weakened or absent immune system response to severe infections that repeatedly affect the lung and eventually result in bronchial wall injury. HIV/AIDS is an example of an acquired immunodeficiency that can lead to the development of bronchiectasis. Aspergillosis
Allergic bronchopulmonary aspergillosis (ABPA) is an inflammatory disease caused by hypersensitivity to the fungus Aspergillus fumigatus. It is suspected in patients with a long history of asthma and symptoms of bronchiectasis such as a productive, mucopurulent cough. Imaging often shows peripheral and central airway bronchiectasis, which is unusual in patients with bronchiectasis caused by other disorders. Autoimmune diseases
Several autoimmune diseases have been associated with bronchiectasis. Specifically, individuals with rheumatoid arthritis and Sjögren syndrome have increased rates of bronchiectasis. In these diseases, the symptoms of bronchiectasis usually presents later in the disease course.
Monitoring bodies
Many countries have official bodies that monitor drug safety and reactions. On an international level, the WHO runs the Uppsala Monitoring Centre, and the European Union runs the European Medicines Agency (EMA). In the United States, the Food and Drug Administration (FDA) is responsible for monitoring post-marketing studies. In Canada, the Marketed Health Products Directorate of Health Canada is responsible for the surveillance of marketed health products. In Australia, the Therapeutic Goods Administration (TGA) conducts postmarket monitoring of therapeutic products. In the UK the Yellow Card Scheme was established in 1963. Epidemiology
A study by the Agency for Healthcare Research and Quality (AHRQ) found that in 2011, sedatives and hypnotics were a leading source for adverse drug events seen in the hospital setting. Approximately 2.8% of all ADEs present on admission and 4.4% of ADEs that originated during a hospital stay were caused by a sedative or hypnotic drug. A second study by AHRQ found that in 2011, the most common specifically identified causes of adverse drug events that originated during hospital stays in the U.S. were steroids, antibiotics, opiates/narcotics, and anticoagulants. Patients treated in urban teaching hospitals had higher rates of ADEs involving antibiotics and opiates/narcotics compared to those treated in urban nonteaching hospitals. Those treated in private, nonprofit hospitals had higher rates of most ADE causes compared to patients treated in public or private, for-profit hospitals.MRH is common after hospital discharge in older adults, but methodological inconsistencies between studies and a paucity of data on risk factors limits clear understanding of the epidemiology.