Group B strep positive: do you need antibiotics?

Group B streptococcus is a bacterium that can live harmlessly in the bowel or genital area. A swab may find carriage without an active infection, while a urine test or symptoms may point to a urinary infection. The result needs to be interpreted with the sample type and the reason for testing.

During pregnancy, clinicians may use a positive result to plan care during labour because bacteria can pass to a newborn around delivery. Outside pregnancy, antibiotics are generally considered when there is an infection that needs treatment, rather than for carriage alone.

Contact the clinician who arranged the test and ask which specimen was positive and whether it represents carriage or infection. If antibiotics are prescribed, take them exactly as directed and complete the course unless the prescriber changes the plan. Tell the clinician about allergies, pregnancy, breastfeeding, kidney problems, and medicines you take.

Do not use leftover antibiotics or share them. Keep the result available for future pregnancy or hospital care, and ask whether your partner or household contacts need assessment; this depends on the infection and is not automatic.

Seek urgent medical help for fever with severe weakness, confusion, fainting, trouble breathing, rapidly worsening pain, or signs of a serious allergic reaction such as facial swelling or wheezing. If you are pregnant, contact your maternity team promptly for contractions, waters breaking, or reduced fetal movement, and mention the positive result.

Ask: Which test was positive? Am I carrying group B strep or do I have an infection? Do I need antibiotics now? If I am pregnant, what should happen during labour? What symptoms should make me seek help?