GBS infection in adults
GBS is also an important infectious agent able to cause invasive infections in adults. Serious life-threatening invasive GBS infections are increasingly recognized in the elderly and individuals compromised by underlying diseases such as diabetes, cirrhosis and cancer. GBS infections in adults include urinary tract infection, skin and soft-tissue infection (skin and skin structure infection) bacteremia, osteomyelitis, meningitis and endocarditis. GBS infection in adults can be serious and related with high mortality. In general penicillin is the antibiotic of choice for treatment of GBS infection. Gentamicin (for synergy with penicillin G or ampicillin) can also be used in patients with life-threatening invasive GBS. Non-human infections
In addition to human infections, GBS is a major cause of mastitis (an infection of the udder) in dairy cattle and an important source of economic loss for the industry. GBS in cows can either produce an acute febrile disease or a subacute more chronic condition. Both lead to diminishing milk production (hence its name: agalactiae meaning "of no milk"). Outbreaks in herds are common, so this is of major importance for the dairy industry, and programs to reduce the impact of S. agalactiae disease have been enforced in many countries over the last 40 years.GBS also causes severe epidemics in farmed fish, causing sepsis and external and internal hemorrhages, having been reported from wild and captive fish involved in epizootics in many countries.
Prevention of neonatal infection
The only reliable way to prevent EOD currently is intrapartum antibiotic prophylaxis (IAP), that is to say administration of antibiotics during delivery. It has been proved that intravenous penicillin or ampicillin administered for at least 4 hours before delivery to GBS colonized women is very effective at preventing vertical transmission of GBS from mother to baby and EOD. Intravenous penicillin remains the agent of choice for IAP, with intravenous ampicillin as an acceptable alternative. For penicillin allergic women, the laboratory requisitions for ordering antepartum GBS screening cultures should indicate clearly the presence of penicillin allergy.Cefazolin, clindamycin, and vancomycin are used to prevent EOD in infants born to penicillin-allergic mothers. Intravenous vancomycin is recommended for IAP in women colonized with a clindamycin-resistant Group B Streptococcus strain and a severe penicillin allergy.There are two ways to identify female candidates to receive intrapartum antibiotic prophylaxis: a risk-based approach or a culture-based screening approach. The culture-based screening approach identifies candidates to receive IAP using lower vaginal and rectal cultures obtained between 36 and 37 weeks gestation (32–34 weeks of gestation for women with twins) and IAP is administered to all GBS colonized women.