What is Pneumococcal Disease?

Pneumococcal disease is a term that encompasses diseases caused by the bacterium Streptococcus pneumonia. These bacteria normally live in the upper respiratory tract of many people without incident. Among people with compromised immune systems, the bacteria can spread into the lungs to cause serious cases of pneumonia. There are safe and effective vaccines for this disease that can help prevent susceptible people from contracting this severe form of pneumonia.

Streptococcus pneumonia is frequently found in the nose and throat of healthy adults and children. It is more common when people are confined in close quarters, such as in military barracks or daycare centers. When individuals are healthy, the presence of these bacteria is generally not a problem. Sinus and ear infections are common, but are not generally life-threatening.

When people have an impaired immune system, however, they can become vulnerable to systemic pneumococcal disease. This type of condition is referred to as an invasive infection. Conditions that induce susceptibility include a number of health conditions. Patients with diabetes, AIDS, cancer, alcoholism, sickle-cell anemia, and those who lack spleens are vulnerable, as are the very young and the very old. There is also a high rate of transmission of this communicable disease among hospitalized patients.

Pneumococcal pneumonia occurs when the bacteria migrate from the upper respiratory tract into the lungs. They invade the sacs that are normally filled with air. These sacs become filled with fluid instead, which is the definition of pneumonia. This disease is common, but is quite serious and can be fatal.

From the lungs, the Streptococcus pneumonia bacteria can also invade other parts of the body to cause additional pneumococcal diseases, like meningitis. This is a bacterial infection of the lining of the brain or spinal cord. This organism is the most common causal agent of meningitis in children and adults. Bacteremia is another type of infection that occurs in the blood itself.

For many years, the traditional way to treat pneumococcal disease was with penicillin, but now most strains are resistant to the drug. Third and fourth generation antibiotics are used in treatment, generally intravenously, but advanced antibiotic resistance continues to be a problem. Cephalosporins are frequently used in combination with other antibiotics. A common strategy is to monitor the local strains for their pattern of drug resistance and choose appropriate drugs based on these results.

Pneumococcal disease has serious global consequences, and kills up to 1.6 million people annually, according to statistics from the World Health Organization (WHO). In the United States, invasive cases of this disease kill nearly 5,000 people per year, according to the National Foundation for Infectious Diseases (NFID). Many cases of pneumococcal pneumonia, and other diseases caused by this organism, could be prevented with a pneumococcal vaccine. There are two forms of the vaccine — one for adults and one for children under two years of age. It is strongly recommended that people with risk factors for this disease be vaccinated.