Group B streptococcus is a common bacterium that is usually carried in the intestines or lower genital tract. The condition is usually harmless in adults. However, in newborns and infants it may cause a serious illness called group B strep disease.
Group B strep can also cause infections in adults who suffer from certain chronic medical conditions such as diabetes or liver disease. Healthy adults may not require treatment for group B strep. A positive group B strep during pregnancy may require antibiotic treatment during labor to protect the baby.
Symptoms
Infants
In infants, group B strep can cause illness that can take two forms: early onset or late onset.
Early onset group B strep disease:
- Fever
- Difficulty feeding
- Lethargy
Late onset group B strep disease:
- Difficulty breathing
- Fever
- Difficulty feeding
- Lethargy
- Irritability
Adults
Adults may be carriers of group B strep but have no signs or symptoms. In some cases, group B strep may cause a urinary tract infection or more serious infection such as blood infections (bacteremia) or pneumonia.
Causes
Group B strep bacteria are not sexually transmitted and they are not spread through food or water. Adults may carry the bacteria in the body for a short period, it may come and go or one may always have it.
Group B strep can spread to a newborn baby during delivery or if the baby is exposed to or swallows fluids that contain group B strep.
Older adults and those with chronic health conditions may develop a more serious infection from group B strep.
Risk factors
Risk factors for infants include:
- A mother that carries group B strep
- Premature birth (earlier than 37 weeks)
- The mother’s water breaks 18 hours or more before delivery
- The mother has an infection of the placental tissues and amniotic fluid (chorioamnionitis)
- Group B strep bacteria discovered in the mother’s urine during pregnancy
- The mother’s temperature is greater than 38C during labor
- The mother previously delivered an infant with group B strep disease
Risk factors for adults include:
- A medical condition that impairs the immune system such as diabetes, HIV, cancer or liver disease
- Older than 65
Complications
Complications in infants may include:
- Inflammation of the lungs (pneumonia)
- Inflammation of the membranes and fluid surrounding the brain and spinal cord (meningitis)
- Infection in the bloodstream (bacteremia)
Complications during pregnancy may include:
- Urinary tract infection
- Infection of the placenta and amniotic fluid (chorioamnionitis)
- Inflammation and infection of the membrane lining the uterus (endometritis)
- Infection of the bloodstream (sepsis)
Complications in older adults or people with other chronic health conditions may include:
- Skin infection (cellulitis)
- Infection of the bloodstream (sepsis)
- Urinary tract infection
- Inflammation of the lungs (pneumonia)
- Bone and joint infections
- Infection of the heart valves (endocarditis)
- Meningitis
Prevention
If the individual is pregnant, IV antibiotics may be administered to prevent group B strep from spreading to the baby during labor.
Furthermore, researchers are working on a group B strep vaccine that could help prevent group B strep infections in adults.