What Do You Know About Streptococcal Infections?

Infections caused by GAS can be mild to severe. Mild GAS infections include strep throat and minor skin infections such as impetigo. When GAS bacteria get into or invade certain tissues of the body, life-threatening infections can occur. Although rare, two severe invasive GAS infections are necrotizing fasciitis and streptococcal toxic shock syndrome. Necrotizing fasciitis is also known as “flesh-eating bacteria.”

GAS infections are spread through direct contact with saliva or nasal mucus. They also can be spread through direct contact with an infected skin wound. A person with strep throat is generally not considered contagious after taking an antibiotic for at least 24 hours.

GAS infections are rare in children younger than 3. GAS skin infections are most common in children ages 3 to 6. Strep throat is most common in children ages 5 to 15. Others at risk include people with weakened immune systems and elderly adults with cellulitis, diabetes, blood vessel disease, or cancer.

It's important to thoroughly wash hands after coughing or sneezing. A person with a confirmed case of strep throat should stay home until 24 hours after starting an antibiotic.

GBS is the most common cause of life-threatening infections in newborns. This bacterium also can cause illness in pregnant women, elderly adults, and adults who have diabetes or liver disease.

About half of cases of GBS disease in newborns occur in the first week of life. Although premature infants are more susceptible to GBS infection, most of the cases of GBS occur in babies who are full term. Late-onset GBS disease, a rare form of GBS, occurs several months after birth, most often in the form of meningitis. In pregnant women, GBS can cause infections of the bladder and uterus, and stillbirth. Among men and among women who are not pregnant, the most common diseases caused by GBS are blood infections, skin or soft tissue infections, and pneumonia.

Other conditions that increase the risk include contracting GBS late in pregnancy; rupture of membranes 18 hours or more before delivery; and labor or rupture of membranes before 37 weeks.

The CDC recommends routine GBS screening for all pregnant women between their 35th and 37th week of pregnancy.