History
History
GBS infection in healthy adults is becoming more prevalent in nonpregnant adults and is almost always associated with underlying comorbidities, with diabetes and obesity being the most common in some series. [12] This association, which the authors have observed over the last 25 years, is unexplained. Malignancy was the most common association in a study from an institution with a large population of patients with cancer.
Cardiovascular and genitourinary abnormalities have also been identified as major factors that predispose individuals to GBS infection. Other conditions associated with GBS infection in adults include neurologic deficits, cirrhosis, steroids, AIDS, renal dysfunction, and peripheral vascular disease. In elderly people aged 70 years or older, GBS infection is strongly linked with congestive heart failure and being bedridden.
GBS pneumonia is rare and has few unique features. It is observed in elderly people with diabetes or with neurologic deficits and may result from aspiration of group B streptococci that colonize the upper airway. In one study, GBS pneumonia appeared to be associated with a high rate of bacteremia.
GBS meningitis, a common manifestation of neonatal infection, is uncommon in adults. It is almost always associated with anatomic abnormalities contiguous with, or of, the central nervous system, usually as a result of neurosurgery.
Multiple studies have shown that GBS bacteremia is one of the most common clinical manifestations of invasive GBS disease. [9] Although 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 GBS disease in some studies. [8] GBS pneumonia in elderly people has been associated with bacteremia. Endocarditis should always be strongly considered in patients with bacteremia without an identified source. Often, the diagnosis becomes obvious because GBS endocarditis is very destructive and frequently necessitates valve replacement for valve insufficiency.
Other manifestations of GBS infection include skin and soft-tissue infection, osteomyelitis, arthritis, diskitis, and colonization of foot infections and decubitus ulcers in patients with diabetes. Although medical therapy should resolve many GBS infections, those involving skin, soft tissue, and bone may not be resolved with antibiotics alone and may require surgical intervention. GBS infections leading to necrotizing fasciitis and toxic shock syndrome have been documented. [8, 14]
Chorioamnionitis, endometritis, and the full spectrum of urinary tract infections (from asymptomatic bacteriuria to cystitis and pyelonephritis with bacteremia) are observed with GBS infection. These are common complications often related to childbirth in young and middle-aged women. Urinary tract infections with group B streptococci are also observed in elderly men and women, often those with diabetes or genitourinary abnormalities.
Pneumonia may occur in bedridden elderly patients with neurologic deficits and fever, shortness of breath, chest pain, pleuritic pain, or cough.
Meningitis may be seen in the neurosurgical patient with fever, headache, nuchal rigidity, or confusion.
Bacteremia, line-related infection, sepsis, or endocarditis may develop in patients with fever, malaise, confusion, chest pain, shortness of breath, myalgia, or arthralgia
Skin and soft-tissue infection, osteomyelitis, or septic arthritis may occur in patients with diabetes or in elderly patients with fever, malaise, localized pain, cellulitis, arthralgia, arthritis, or weakness.
Urinary tract infection or pelvic abscess may develop in the postpartum woman or older man or woman with fever, dysuria, flank pain, or pelvic pain.
Physical
Physical examination may reveal the following conditions:
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Pneumonia in bedridden elderly patients with neurologic deficit and fever, lung consolidation, pleural effusion, tachypnea, tachycardia, or hypotension
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Meningitis in the neurosurgical patient with fever, confusion, hypotension, headache, nuchal rigidity, or changing mental status
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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
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Skin and soft tissue infection, osteomyelitis, septic arthritis, or discitis in elderly patients or those with diabetes who have fever, cellulitis, arthritis, arthralgia, localized pain, decubitus ulcer, vascular insufficiency of the lower extremity, back pain, wound infection, or neurologic dysfunction
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Urinary tract infection or pelvic abscess in the postpartum woman or older man or woman with fever, flank pain, pelvic pain, or abdominal pain
