Group B strep infection (GBS) in newborns is a bacterial infection caused by the streptococcus bacteria type B (strep B). Strep B normally lives without causing problems inside our digestive system and, in women, the vagina or birthing canal. Because most of us develop an immunity to strep B, GBS infections mainly affect newborn babies, although GBS infections may occur at any age. About 1 in 5 pregnant women have strep B bacteria in their vagina and/or digestive system. The bacteria can sometimes be passed on to the baby through the amniotic fluid (the liquid that surrounds and protects the baby in the womb). It is also possible for a baby to contract a GBS infection while passing through the birth canal during labor. GBS infections affect 1 in every 2,000 births. Strep B can quickly spread through the baby’s body, causing serious infections such as pneumonia (infection of the lungs), meningitis (infection of the protective outer layer of the brain) and sepsis (infection of the blood). The symptoms of GBS infection in a newborn usually develop between 12 hours and 6 days of life and include being floppy and unresponsive, poor feeding, grunting when breathing, irritability, a very high or low temperature, very fast or slow breathing and a very fast or slow heart rate. In some cases a baby may develop the infection between 1 week and 3 months of age, known as a late-onset GBS infection. The cause of late-onset GBS infection is unknown. Today, pregnant women are screened routinely for strep B between the 35th and 37th week of pregnancy. Depending on these results and other factors, she may be given intravenous antibiotics during labor. The newborn will be watched for symptoms of GBS infection. Prompt medical treatment is required if symptoms develop and may include antibiotics, help with breathing, oxygen, and intravenous fluids. If you suspect your newborn has a GBS infection, please seek medical help immediately.