Pneumonia is the inflammation of the lung tissue most often due to an infection. A number of microorganisms may cause pneumonia although bacteria are the most common pathogen.
Pneumonia can affect any person of any age and health status. However, in patients who are chronically ill, debilitated, young children or elderly patients, the possibility of a contracting is significantly high if exposed to the causative pathogen.
Known Risk Factors for Pneumonia
- Elderly > 65 years
- Infants < 2 years
- Cigarette smoking
- Alcohol use (excess)
- Corticosteroid therapy
- Respiratory tract infections, particularly lower tract but also upper
- Pre-existing lung disease
- Air pollution (indoor, work exposure)
- Health Care Facilities and Institutions
- Outpatient visits (clinics)
- Nursing homes
- Other health care institutions
Many of the risk factors relate to impaired or low immune functioning, as seen with age, chronic illnesses and particularly conditions like HIV infection.
Any dysfunction of the cough reflex also increases the risk for contracting pneumonia as mucus containing pathogens cannot be cleared from the respiratory tract effectively. An impaired cough reflex is often seen in cigarette smokers, heavy alcohol consumption, use of sedatives (especially in sedated patients within a hospital/institution setting), and stroke patients.
Pneumonia and Pregnancy
The hormonal changes that occur during pregnancy may hamper immune functioning and aggravate pre-existing nasorespiratory allergic conditions that are marked with mucus hypersecretion, like hay fever. Contracting a viral infection such as a cold or influenza (including H1N1 swine flu) during pregnancy can lead to complications such as pneumonia.
Bacterial pneumonia can occur secondary to a viral respiratory tract infection or it can occur without any prior viral infection. Any person with mucus hypersecretion is at an increased risk of contracting bacterial respiratory infections and this is more pronounced in pregnant women.
There is also evidence to suggest that adverse outcomes like a spontaneous abortion (miscarriage) following viral respiratory tract infections are more likely to occur in cases that complicate into pneumonia. Early antiviral treatment in pregnant women is often considered these days especially after the 2009 H1N1 swine flu pandemic. In this outbreak, fatalities among pregnant women who contracted H1N1 was often linked to pneumonia, among other complications.
Read more on Influenza, Swine Flu and Common Cold during Pregnancy.
Pneumonia in Hospitals
Health care-acquired pneumonia (HCAP) and hospital-acquired pneumonia (HAP) has received much attention in recent years. Previously, ventilator-associated pneumonia (VAP) was the main concern for contracting pneumonia in the hospital setting.
However, with widespread multi-drug resistant (MDR) strains of bacteria, which are more frequently seen in health care facilities, HCAP and HAP have also become a concern even for patients who visit facilities on an outpatient basis. The risk significantly increases with hospitalization, especially after 48 hours. MRSA (methicillin-resistant Staphylococcus aureus) and the more recent NDM-1 strains of Klebsiella pneumoniae and Escherichia coli (E.coli) are of particular concern, especially since the latter is very resistant to new age antibiotics and antibiotic cocktails.
Pneumonia is Nursing Homes and Health Institutions
Pneumonia contracted by patients or residents within homes for the elderly, frail care institutions and health institutions is broadly referred to as institution-acquired pneumonia. Nursing home-acquired pneumonia (NHAP) is often seen because the residents are living in close quarters (a risk for outbreaks) but are also older than 65 years of age (a high risk group). Patients who are heavily sedated, as seen in those who are terminally ill (hospices), addictions (rehab centers) and mentally ill are also at risk due to living in close quarters in addition to being debilitated (weak immune system) and having a suppressed cough reflex.