Pneumonia is a lung disease that can be caused by a variety of viruses, bacteria, and sometimes fungi. The U.S. Centers for Diseases Control and Prevention (CDC) estimate nearly 90,000 people in the United States died from one of several kinds of pneumonia in 1999. In the United States, pneumonia is the fifth leading cause of death [Natl Vital Stat Report 47 (25), 10/5/1999]. Rates of infection are three-times higher in African Americans than in whites and are 5- to 10-times higher in Native-American adults and 10-times higher in Native-American children [J Infect Dis;170:368-76, 1994].
On an international scale, acute respiratory infection ranks as the third most frequent cause of death among children less than 5 years old and was responsible for approximately 3.5 million deaths in 1998.
What is Pneumococcal Pneumonia?
Pneumococcal pneumonia is an infection in the lungs caused by bacteria called Streptococcus pneumoniae. S. pneumoniae, also called pneumococcus, can infect the upper respiratory tracts of adults and children and can spread to the blood, lungs, middle ear, or nervous system. CDC estimates S. pneumoniae causes 40,000 deaths and 500,000 cases of pneumonia annually in the United States. The yearly incidence of pneumococcal pneumonia is twice as high in African Americans than in whites and is responsible for 3,000 cases of meningitis (inflammation of spinal cord membranes), 50,000 cases of bacteremia (bacteria in the blood), and 7 million cases of otitis media (inner ear infection) [JAMA; 285:1729-1735, 2001].
According to the World Health Organization, S. pneumoniae is the leading cause of severe pneumonia worldwide in children younger than 5 years old, causing more than 1 million deaths in children each year [Pneumococcal Vaccines: WHO Position Paper: Wkly Epidemiol Rec, Vol 74, 177-183, 1999].
Pneumococcal pneumonia primarily causes illness in children younger than 2 years old and adults 65 years of age or older. The elderly are especially vulnerable to getting seriously ill and dying from this disease. In addition, people with certain medical conditions such as chronic heart, lung, or liver diseases or sickle cell anemia are also at increased risk for getting pneumococcal pneumonia as are people with HIV infection or AIDS or people who have had organ transplants and are taking medicines that lower their resistance to infection.
How is Pneumococcus Spread?
The noses and throats of up to 70 percent of healthy people contain pneumococcus at any given time. It is spread from person to person by coughing, sneezing, or close contact. Researchers do not know why it suddenly invades the lungs and the bloodstream to cause disease.
What are the Symptoms of Pneumococcal Pneumonia?
Pneumococcal pneumonia may begin suddenly, with a severe shaking chill usually followed by
- High fever
- Shortness of breath
- Rapid breathing
- Chest painsThere may be other symptoms as well, including:
- Muscle aches
In an otherwise healthy adult, pneumococcal pneumonia usually involves one or more parts of the lungs, known as lobes. Thus, it is sometimes called lobar pneumonia. The remainder of the respiratory system is comparatively not affected. In contrast, infants, young children, and elderly people more commonly develop a relatively mild infection in other parts of the lungs, such as around the air vessels (bronchi) causing bronchopneumonia.
How is Pneumococcal Pneumonia Diagnosed?
A doctor or other health care provider diagnoses pneumonia based on:
- Physical examination
- Laboratory tests
- Chest x-ray
Because a number of bacteria, viruses, and other infectious agents can cause pneumonia, if you have any of the symptoms, you should get diagnosed early and start taking the right medicine if you have any of the symptoms. The presence of S. pneumoniae in the blood, saliva, or lung fluid helps lead to a diagnosis of pneumococcal pneumonia.
How is Pneumococcal Pneumonia Treated?
Health care providers usually prescribe antibiotics, such as penicillin, to treat this bacterial disease. The symptoms of pneumococcal pneumonia usually subside within 12 to 36 hours after treatment has begun. Bacteria such as S. pneumoniae, however, are resisting and fighting off the powers of antibiotics to destroy them. Such antibiotic resistance is increasing worldwide because these medicines have been overused or misused. Therefore, if you are at risk of getting pneumococcal pneumonia, you should talk with your doctor about taking steps to prevent it.
Can Pneumococcal Pneumonia be Prevented?
The pneumococcal vaccine is the only way to prevent getting pneumococcal pneumonia. Vaccines are available for children and adults.
The CDC National Immunization Program (NIP) recommends that you get immunized against pneumococcal pneumonia if you are in any of the following groups.
- You are 65 years old or older.
- You have a serious long-term health problem such as heart disease, sickle cell disease, alcoholism, leaks of cerebrospinal fluid, lung disease (not including asthma), diabetes, or liver cirrhosis.
- Your resistance to infection is lowered due to HIV infection or AIDS; lymphoma, leukemia, or other cancers; cancer treatment with x-rays or drugs; treatment with long-term steroids; bone marrow or organ transplant; kidney failure; nephrotic (kidney) syndrome; damaged spleen or no spleen.
- You are an Alaskan-Native or from certain Native-American populations.
In February 2000, the U.S. Food and Drug Administration approved a pneumococcal vaccine for use in toddlers and children. It is the first pneumococcal vaccine approved for children younger than 2 years old [http://www.fda.gov/cber/inside/annrpt.htm,: CBER Annual Report FY2000 Issued:01-08-01, Posted: 03-15-01, Updated: 04-10-01]. NIP recommends that all children ages 2 to 23 months old get this vaccine.
Does Pneumococcal Pneumonia Cause Complications?
In about 30 percent of people with pneumococcal pneumonia, the bacteria invade the blood stream from the lungs [http://www.cdc.gov/nip/publications/pink/pneumo2.pdf pp. 249-263]. This causes bacteremia, a very serious Pneumococcal pneumonia also can cause other lung problems and certain heart problems.
What Research is Going On?
The National Institute of Allergy and Infectious Diseases (NIAID) supports research on more effective prevention and treatment approaches to control pneumonia and its causes. These include
- Developing and licensing vaccines and treatments for the disease-causing microbes (pathogens) that cause pneumonia
- Stimulating research on the structure and function of these pathogens
- Developing better and more rapid diagnostic tools
- Understanding the long-term health impact respiratory pathogens have in various populations
- Examining the effect of vaccines in high-risk populations
- Determining how pneumococcus becomes resistant to antibiotics
The recently approved pneumococcal conjugate vaccine for children is partially the result of crucial NIAID research in the early development of the vaccine. This vaccine helps prevent pneumococcal diseases in babies and toddlers and is the latest advance in developing vaccines against common bacterial infections. This effort was led in large part by NIAID for more than 30 years.
NIAID supports studies to develop improved pneumococcal conjugate vaccines for children worldwide. In one such study, NIAID researchers are working with The Gambia Government and scientists from several international research institutions to test a pneumococcal conjugate vaccine in The Gambia, West Africa. Health care experts have consistently identified pneumococcus as the most common cause of bacterial pneumonia in The Gambia. In a pattern typical of many developing areas, infant and child mortality rates in The Gambia are high, acute respiratory infections are a leading cause of death, and pneumococcus is the most common cause of these infections.
Source: National Institute of Allergy and Infectious Diseases
Last Updated May 20, 2003.
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