Infants

Most babies born to women carrying group B strep are healthy. But the few who are infected by group B strep during labor can become critically ill.

In infants, illness caused by group B strep can take two forms: early onset or late onset.

Early-onset group B strep disease. A baby with early-onset group B strep disease becomes sick within one week after birth. Signs and symptoms may include:

• Fever
• Difficulty feeding
• Lethargy

Late-onset group B strep disease. Late-onset group B strep disease develops within a week to a few months after birth, usually within the first month. Signs and symptoms may include:

• Difficulty breathing
• Fever
• Difficulty feeding
• Lethargy
• Irritability

Adults

If you're like many adults, you may carry group B strep in your body, usually in your bowel, vagina, rectum, bladder or throat. Most adults simply carry the bacterium and have no signs or symptoms.

In some cases, group B strep may cause a urinary tract infection or more serious infections such as blood infections (bacteremia) or pneumonia.

Many healthy people carry group B strep bacteria in their bodies. Group B strep bacteria aren't sexually transmitted, and they're not spread through food or water. You may carry group B strep in your body for just a short period of time, it may come and go, or you may always have it.

Group B strep can spread to a baby during a vaginal delivery if the baby is exposed to — or swallows — fluids containing group B strep.

Some individuals, such as older adults and those with chronic health conditions, can develop a more serious infection from group B strep. However, the reason this occurs in some people but not others isn't known.

Infants

An infant is at increased risk of developing group B strep disease if:

• The mother carries group B strep in her body
• The baby is born prematurely (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 have been detected in the mother's urine (bacteriuria) during pregnancy (either her current pregnancy or previous pregnancies)
• The mother's temperature is greater than 100.4 F (38 C) during labor
• The mother previously delivered an infant with group B strep disease

Adults

You're at increased risk of a group B strep infection if:

• You have a medical condition that impairs your immune system, such as diabetes, HIV infection, cancer or liver disease
• You're older than 65, particularly if you live in a nursing home

Group B strep infection can lead to life-threatening complications in infants, including:

• Inflammation of the lungs (pneumonia)
• Inflammation of the membranes and fluid surrounding the brain and spinal cord (meningitis)
• Infection in the bloodstream (bacteremia)

If you're a pregnant woman, group B strep can cause:

• 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)

If you're an older adult or you have a chronic health condition, group B strep bacteria may cause complications such as:

• 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)
• Inflammation of the membranes and fluid surrounding the brain and spinal cord (meningitis)