Strep B Test
Strep B, also known as group B strep (GBS), is a type of bacteria commonly found in the digestive tract, urinary tract , and genital area.
Strep B, also known as group B strep (GBS), is a type of bacteria commonly found in the digestive tract, urinary tract , and genital area. Many healthy people have GBS bacteria in their bodies. Most of the time, GBS bacteria are not harmful and do not make people feel sick or have any symptoms. But in rare cases, these bacteria cause certain infections, known as GBS disease. This is more likely in people who are age 65 and older, have certain chronic health problems, or have a condition that weakens their immune system . And sometimes GBS infections can be very serious, or even life-threatening, in newborns. In most cases, it is not known how people spread GBS bacteria to others. If you are pregnant, you can pass the bacteria to your baby during a vaginal delivery . GBS is usually found in the vagina and rectum, so. the baby can be exposed to the GBS bacteria during labor. It is rare, but it can cause serious illness in the baby. There are two types of GBS infections in babies. The types are based on the age of the infant when signs and symptoms begin to show: In early-onset GBS disease , the signs and symptoms start during the first six days of life In late-onset GBS disease , the signs and symptoms start during between 7 to 89 days of life. The source of late-onset GBS infection is unknown. In newborns, GBS can cause: Bacteremia (infection in the bloodstream) Pneumonia (inflammation of the lung) Meningitis (inflammation of the thin tissue that surrounds the brain and spinal cord) Other serious illnesses GBS bacteria are a leading cause of meningitis and bloodstream infections in a newborn's first three months of life. If you are pregnant, GBS can cause: Bacteremia Chorioamnionitis (infection of the placenta and amniotic fluid) Endometritis (infection of the membrane lining the uterus) Urinary tract infections In older adults and people with chronic health conditions, GBS bacteria can cause: Bacteremia Urinary tract infection Pneumonia Bone and joint infections Endocarditis (infection of the heart valves ) Meningitis Skin or soft-tissue infections A group B strep test checks for GBS bacteria. If you are pregnant and the test shows that you have GBS, taking antibiotics during labor can protect your baby from infection. Other names: group B streptococcus, group B beta-hemolytic streptococcus, Streptococcus agalactiae , beta-hemolytic strep culture
Why is this test ordered? You may need a strep B test if you are pregnant. The American College of Obstetricians and Gynecologists recommends GBS testing if you are pregnant. Testing is usually done between 36 and 38 weeks of pregnancy. If you go into labor earlier than 36 weeks, you may be tested at that time. Symptoms depend on the part of the body that is infected. Symptoms of GBS disease are different in newborns compared to people of other ages who get GBS disease. Most newborns who get sick in the first week of life (early onset) have symptoms on the day of birth. In contrast, babies who develop disease later (late onset) can appear healthy at birth and during their first week of life. A baby may need a group B strep test if he or she has symptoms of infection. These include: High fever Trouble with feeding Trouble breathing Lack of energy (hard to wake up) Irritability Blue-ish skin color Unstable blood pressure (a pattern where the blood pressure suddenly spikes and then falls back to normal) Kidney problems If you are pregnant, you usually do not feel sick or have any symptoms of GBS. Symptoms of bacteremia include: Fever Chills Low alertness Symptoms of pneumonia include: Fever Chills Cough Rapid breathing or trouble breathing Chest pain Skin and soft tissue infections often appear as a bump or infected area on the skin that may be: Red Swollen or painful Warm to the touch Full of pus or other drainage Fever, in some cases Bone and joint infections often appear as pain in the infected area and might also include: Fever Chills Swelling Stiffness or being unable to move the affected joint(s)
Clinical Interpretation
If you are pregnant and results show you have GBS bacteria, you will be given antibiotics intravenously (by IV) during labor, at least four hours before delivery. This will prevent you from passing the bacteria to your baby. Taking antibiotics earlier in your pregnancy is not effective, because the bacteria can grow back very quickly. It's also more effective to take antibiotics through your vein (by IV), rather than by mouth. You may not need antibiotics if you are having a planned cesarean delivery (C-section). During a cesarean delivery, a baby is delivered through the mother's abdomen rather than vaginally. But you still should be tested during pregnancy because you may go into labor before your scheduled cesarean delivery. If your baby's results show a GBS infection, he or she will be treated with antibiotics. If your provider suspects a GBS infection, he or she may treat your baby before test results are available. This is because GBS can cause serious illness or death. If you have questions about your results or your baby's results, talk to your provider. Learn more about laboratory tests, reference ranges, and understanding results .
Clinical Protocol & Patient Advice
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You don't any special preparations for group B strep tests.
Usage Guidance
- Reference ranges vary by laboratory. Always discuss your specific results with a qualified healthcare professional.
Source: MedlinePlus, National Library of Medicine. View the original.