Streptococcal bacteria are extremely versatile and common. Able to invade almost any part of the body, streptococci cause a host of diseases. These microbes are divided into more than a dozen different groups, based on the proteins they harbor in their cell walls and their characteristics as determined by laboratory tests.
A list of some of the most troublesome categories or species of streptococcus and the diseases for which they are well known includes:
- Group A: strep throat, scarlet fever, rheumatic fever, impetigo, toxic streptococcal syndrome, streptococcal kidney disease, blood infections
- Group B: blood infections in newborns, meningitis, childhood fever
- Groups C, D, G, H, K: urinary tract infections, heart infections, meningitis, upper and lower respiratory tract infections
- Streptococcus mutans: dental caries (cavities)
- Streptococcus pneumonia: pneumonia, ear infections, meningitis, sinus infections
There are more than 80 known types of Group A streptococcus, which can cause more than a dozen different illnesses. Some of the more well-known Group A strep afflictions include upper respiratory disease such as strep throat and scarlet fever, skin disorders such as impetigo, and inflammatory diseases such as rheumatic fever or kidney disease.
In addition, blood infections due to Group A strep are a serious and frequent complication of wounds or surgery.
Group A strep infections are treatable with antibiotics, the drug of choice being penicillin. Other antibiotics, such as erythromycin and various cephalosporins, are effective alternatives for patients allergic to penicillin.
Strep throat (streptococcal pharyngitis) is probably the most well known Group A strep infection. Although strep throat can occur at any age and at any time of the year, it mainly affects school-age children during the winter and spring.
The many symptoms of strep throat include an extremely red and painful sore throat, ear pain, fever, enlarged and tender lymph nodes in the neck, white spots on the tonsils, or dark red spots on the soft palate.
Strep throat is highly contagious among children because they are in close contact with one another. In addition, they have not developed resistance to many of the strains as adults have.
Lurking behind several types of strep infections is the possibility of rheumatic fever. Although much less common a disease now than it was a few decades ago, the effects of rheumatic fever are serious enough to warrant concern. Signs of rheumatic fever include a red rash, pea-sized lumps under the skin, tender joints, fever, involuntary jerky movements, heart palpitations, chest pain, and in severe cases, heart failure.
As many as 3 percent of untreated cases of strep throat can develop into rheumatic fever. But antibiotic treatment, even if it is not started until several days after the onset of symptoms, can squelch the possibility of rheumatic fever.
When Group A streptococci literally get under the skin, they can foster a common skin disease known as impetigo. This contagious disease frequently afflicts mainly children during the summer, when insect bites, cuts and scrapes are prevalent. These skin infringements serve as portals of entry for the streptococci.
Group B streptococcus agalactiae is the leading cause of prenatal infection. In newborns and young infants, these infections include congenital pneumonia and meningitis. Pregnant women should be screened for group B strep (GBS) infection. Those women who carry the GBS bacterium and who have certain risk factors - premature labor, premature or prolonged rupture of the membranes, a previous child who had the infection, fever during labor, or multiple births - should be given antibiotics to prevent passing the infection on to their child.