What Is Community-Acquired Pneumonia?
Pneumonia is an inflammation of one or both of the lungs caused by a bacterial, viral or fungal infection. The word “community” means that the infection was not contracted while the patient was in the hospital. This infection causes the air sacs (called alveoli) in the lungs to fill with fluid, interfering with your lungs’ ability to move enough air throughout your body. As a result, oxygen has trouble reaching the blood. If there is too little oxygen in your blood, your body cannot function properly.
People of any age can develop pneumonia, but the risk is greater in those over 60 years of age and in patients who are ill or in a weakened condition. People who smoke or suffer from diabetes or alcoholism are also at greater risk for developing community-acquired pneumonia. The signs and symptoms of community-acquired pneumonia may include sudden chills followed by sustained high fever, chest pain, productive cough with thick, possible rust-colored sputum (mucus), and rapid and/or difficult breathing.
How Do Germs Infect the Lungs?
Your body has the innate ability to fight off germs. A cough or even a sneeze is your body’s way of fighting off germs. Your body also produces white blood cells, which help to ward off infection. These cells need oxygen in order to work properly.
Sometimes bacteria and viruses can overwhelm your germ-fighting defenses. When the alveoli in your lungs fill up with fluid, the oxygen has trouble reaching the bloodstream, making it difficult for your white blood cells to defend your body against infection.
What Causes Pneumonia?
Pneumonia is triggered when a person’s defense system is weakened. Organisms that cause pneumonia are the important factors. Bacteria are the most common causes of pneumonia, but other microbial organisms can also produce infections.
Usually these organisms enter the lungs after being inhaled into the airways. Sometimes the normally harmless bacteria present in the mouth may be aspirated (swallowed) into the lungs, usually if the gag reflex (coughing) is suppressed. Pneumonia may also be caused from infections that spread to the lungs through the bloodstream from other organs.
The four most common causes of pneumonia are:
- Bacteria: Bacterial pneumonia can attack people of any age, from infants to the elderly. If left untreated, bacterial pneumonia can sometimes result in death, especially in the elderly and those who also have other diseases. The infection can spread to other parts of the lung, and the bacteria may invade the bloodstream.
- Viruses: Viruses causes almost half of all pneumonia cases. Viral pneumonia often starts out feeling like flu, attacking the nose and throat before working its way down into the lungs.
- Fungi: Pneumocystis carinii pneumonia (PCP) is caused by a fungus and mostly strikes people with AIDS, Hodgkin’s disease or other conditions that weaken the immune system.
What is Hospital-Acquired Pneumonia?
Hospital-acquired pneumonia, also called nosocomial pneumonia, is an infection that patients get while they’re in the hospital. This means the infection is not present at the time a patient is admitted to the hospital. Patients already in the hospital for another illness are vulnerable to bacterial infections, particularly the following patients:
- Patients more than 65 years of age
- Patients with weakened immune systems
- Patients breathing with the aid of a ventilator
- Patients in intensive care units (ICUs)
Symptoms may include fever, shortness of breath, and a cough that produces yellow, green, or gray phlegm from the respiratory tract. Because nosocomial pneumonia is such a serious infection, patients may need to receive more than one type of antibiotic to treat it. Getting pneumonia while in the hospital may prolong the hospital stay, and intravenous (I.V.) antibiotic treatment can last for several weeks. If patients begin to feel better, they may be switched from I.V. treatment to oral (tablet) treatment.