Pneumococcal Pneumonia  Health Article

Definition

Pneumococcal pneumonia is an infection in the lungs caused by a bacteria known as S pneumoniae. S pneumoniae, which is also called pneumococcus, can infect the upper respiratory tracts of adults and children, and can spread to the blood, lungs, middle ear, and nervous system. More than 90 serotypes of the bacteria exist. At any given time, the noses and throats of up to 70% of healthy persons contain pneumococcus. In general, children harbor more of the bacteria than adults. Pneumococcus is transmitted by person-to-person contact through breathing the bacteria into the lungs.

Pneumococcal pneumonia primarily causes illness in children younger than 2 years old and adults aged 65 years old or older. Older adults are especially at risk of becoming seriously ill and dying from this disease. In addition, persons with certain medical conditions (eg, chronic heart, lung, or liver diseases; sickle cell anemia; human immunodeficiency virus infection; acquired immunodeficiency syndrome) or persons who have had organ transplants and are taking immunosuppressant medications are at increased risk of developing pneumococcal pneumonia.

Scope

The CDC estimates that S pneumoniae causes 40,000 deaths and 500,000 cases of pneumonia each year in the United States. Annually, twice as many cases of pneumococcal pneumonia occur in blacks than in whites. The disease is responsible for 3,000 cases of meningitis, 50,000 cases of bacteremia, and 7 million cases of otitis media in the United States.

The incidence among young adults and young children is decreasing because of improved human immunodeficiency virus therapy and the use of a new conjugate vaccine for children. Outbreaks have occurred in institutional settings and child care centers.

Symptoms

Pneumococcal pneumonia can begin suddenly, with a severe shaking chill that is usually followed by these symptoms:

• high fever;
• cough;
• dyspnea;
• tachypnea; and.
• chest pains.

Other symptoms present might include nausea, vomiting, and headache.

Diagnosis

The diagnosis of pneumococcal pneumonia is made on the basis of symptoms, physical examination, laboratory testing, and chest radiography. The presence of S pneumoniae in blood, saliva, or lung fluid helps lead to a diagnosis of pneumococcal pneumonia.