What are streptococcal infections?

Causes and Symptoms

Among the many bacteria that belong to the genus
Streptococcus, two groups are distinguished for their pathogenicity, the group A streptococci and the group B streptococci. Group A streptococci, common pathogens found in the throat and skin, cause a variety of symptoms in the body, ranging from skin lesions and sore throat to severe, life-threatening infections. The most common infection caused by the group A streptococci is a sore throat commonly known as strep throat. If untreated, the disease may spread to involve other organs, causing otitis media, sinusitis, or tonsillitis. Some children may exhibit later sequelae such as rheumatic fever, and organs such as the heart and joints may be involved. Scarlet fever
is another manifestation, with a rash that starts on the face and moves downward.
Group A streptococci can also affect the skin and cause impetigo
(yellow-crusted, pus-filled lesions), cellulitis, and even infection with the dreaded “flesh-eating bacteria,” necrotizing fasciitis. These bacteria have also been implicated in toxic shock syndrome, previously thought to be caused only by Staphylococcus bacteria.

Group B streptococci, on the other hand, cause mostly severe diseases and mainly affect newborns and pregnant women. These bacteria, found in the genital and intestinal tracts of 20 to 35 percent of healthy adults, can infect a newborn during the birth process. They are the most common cause of neonatal meningitis and sepsis, can cause pneumonia, and are a cause of neonatal death. Group B streptococci also affect pregnant women and can cause amnionitis, urinary tract infections, and stillbirth. They have also been implicated in causing disease in the elderly and in adults with chronic medical conditions.

Treatment and Therapy

Strep throat is diagnosed readily in the clinic by a rapid strep test and can be treated easily with common antibiotics, such as penicillin or cephalosporins. Prevention is the key to avoiding complications of the disease. Maintenance of hygiene (such as washing one's hands after sneezing or coughing), visiting a doctor to rule out streptococcal disease in cases of severe sore throat, and taking any antibiotics prescribed should keep complications at bay. Keeping all wounds clean should prevent the occurrence of skin infections. Streptococcal toxic shock syndrome is an emergency siuation and requires hospitalized care.

Pregnant women should be screened for group B streptococci, and antibiotics are administered during labor to women who are carriers of these bacteria. This practice is quite effective in preventing neonatal meningitis and sepsis. Babies affected by the disease can be treated effectively with antibiotics and management of symptoms.

Bibliography

Fauci, Anthony S., et al, eds. Harrison’s Principles of Internal Medicine. 18th ed. New York: McGraw-Hill, 2012.

Frazier, Margeret Schell, and Jeanette Wist Drzymkowski. Essentials of Human Diseases and Conditions. 5th ed. St. Louis, Mo.: Saunders/Elsevier, 2013.

"Group A Streptococcal Infections." National Institute of Allergy and Infectious Diseases, Jan. 28, 2010.

"Group B Strep (GBS)." Centers for Disease Control and Prevention, Mar. 16, 2012.

Randall, Brian. "Strep Throat." Health Library, Sept. 30, 2012.

"Streptococcal Infections." MedlinePlus, May 7, 2013.

Tapley, Donald F., et al., eds. The Columbia University College of Physicians and Surgeons Complete Home Medical Guide. Rev. 3d ed. New York: Crown, 1995.