Streptococcus Group B Infections Clinical Presentation

Group B streptococcal infection in healthy adults is extremely uncommon, except in young and middle-aged women. Group B streptococcal infection is almost always associated with underlying abnormalities, with diabetes most commonly associated with infection in some series. This association, which the authors have observed over the last 25 years, is unexplained. Malignancy was the most common association in a series from an institution with a large population of patients with cancer. Cardiovascular and genitourinary abnormalities have also been identified as major factors that predispose to group B streptococcal acquisition. Other conditions associated with group B streptococcal infection in adults include neurologic deficits, cirrhosis, steroids, AIDS, renal dysfunction, and peripheral vascular disease. In elderly people aged 70 years or older, group B streptococcal infection is strongly linked with congestive heart failure and being bedridden.

Group B streptococcal pneumonia is rare and has few unique features. It is observed in elderly people with diabetes and with neurologic deficits and may result from aspiration of group B streptococci that colonize the upper airway. In one series, group B streptococcal pneumonia appeared to be associated with a high rate of bacteremia.

Group B streptococcal meningitis, a common manifestation of neonatal infection, is uncommon in adults. It is almost always associated with anatomical abnormalities contiguous with, or of, the CNS, usually as a result of neurosurgery.

Group B streptococcal bacteremia is common. While a genitourinary, soft-tissue, or line-related source of infection is possible, no source of infection can be identified in most cases. Bacteremia with an unknown source accounts for approximately 25% of all cases of invasive group B streptococcal disease in some studies.^[4] Group B streptococcal pneumonia in elderly people has been associated with bacteremia. Endocarditis should always be strongly considered in cases of bacteremia without an identified source. Often, the diagnosis becomes obvious because group B streptococcal endocarditis is very destructive and frequently necessitates valve replacement for valve insufficiency.

Other manifestations of group B streptococcal infection include skin and soft-tissue infection, osteomyelitis, arthritis, discitis, and colonization of diabetic foot infections and decubitus ulcers. For an unclear reason, many patients who develop such manifestations have diabetes. Although medical therapy should cure many group B streptococcal infections, those involving skin, soft tissue, and bone may not be cured with antibiotics alone and may require surgical intervention. Group B streptococcal infections leading to necrotizing fasciitis and toxic shock syndrome have been documented.^{[6, 4]}

Chorioamnionitis, endometritis, and the full spectrum of urinary tract infections (from asymptomatic bacteruria to cystitis and pyelonephritis with bacteremia) are observed with group B streptococcal infection. These are common complications often related to childbirth in young and middle-aged women. Urinary tract infections with group B streptococci also are observed in elderly men and women, often those with diabetes or genitourinary abnormalities.

• Pneumonia in bedridden elderly patients with neurologic deficits and fever, shortness of breath, chest pain, pleuritic pain, or cough
• Meningitis in the neurosurgical patient with fever, headache, nuchal rigidity, or confusion
• Bacteremia, line-related infection, sepsis, or endocarditis in the patient with fever, malaise, confusion, chest pain, shortness of breath, myalgia, or arthralgia
• Skin and soft-tissue infection, osteomyelitis, or septic arthritis in patients with diabetes or in elderly patients with fever, malaise, localized pain, cellulitis, arthralgia, arthritis, or weakness
• Urinary tract infection or pelvic abscess in the postpartum woman or older man or woman with fever, dysuria, flank pain, or pelvic pain

• Pneumonia in bedridden elderly patients with neurologic deficit and fever, lung consolidation, pleural effusion, tachypnea, tachycardia, or hypotension
• Meningitis in the neurosurgical patient with fever, confusion, hypotension, headache, nuchal rigidity, or changing mental status
• Bacteremia, line-related sepsis, or endocarditis in the patient with fever, murmur, evidence of an embolic event, hypotension, phlebitis, tachycardia, tachypnea, splenomegaly, or evidence of heart failure
• Skin and soft tissue infection, osteomyelitis, septic arthritis, or discitis in diabetic or elderly patients with fever, cellulitis, arthritis, arthralgia, localized pain, decubitus ulcer, vascular insufficiency of the lower extremity, back pain, wound infection, or neurologic dysfunction
• Urinary tract infection or pelvic abscess in the postpartum woman or older man or woman with fever, flank pain, pelvic pain, or abdominal pain