Management of the febrile child without a focus of infection in the era of universal pneumococcal immunization.
Should strategies of management of invasive disease in the febrile child without focus of infection (occult bacteremia) be reconsidered in communities with universal immunization of infants with the conjugate vaccines for Haemophilus influenzae type b and Streptococcus pneumoniae (PCV7)? The incidence of occult bacteremia is likely to decrease with the virtual elimination of H. influenzae type b and vaccine serotype pneumococcal invasive diseases. The number of children with fever coming to physicians' offices, however, is unlikely to change. The challenge of distinguishing the febrile child with invasive bacterial disease who requires aggressive therapy from the febrile child who has a viral infection and requires only symptomatic therapy will persist. The bacteriology of invasive disease in infants and young children in 2002 will include pneumococcal serotypes not in PCV7; serotypes in PCV7 that occur in the unimmunized, partially immunized or fully immunized child (vaccine failures); Neisseria meningitidis; Salmonella spp., group A Streptococcus, Staphylococcus aureus and gram-negative enteric bacilli. Management plans published in the 1990s suggested an aggressive diagnostic approach to the febrile child 3 to 36 months old who was toxic or had a temperature of >39 degrees C. Diagnostic tests included white blood cell counts, cultures of blood and urine and chest radiograph and lumbar puncture as indicated by clinical signs and administration of parenteral ceftriaxone. Although PCV7 was extraordinarily effective in prevention of serotype-specific invasive pneumococcal disease in clinical trials, pediatricians need to know whether the results based on 38,000 enrollees will be maintained as millions of children are immunized. In addition questions about change in serotype of pneumococci causing invasive disease (serotype switching), herd immunity and durability of protection after immunization need to be answered. Until more experience is available to answer these questions, the febrile child without focus of infection should be managed without consideration of immunization with PCV7. Evaluation of the organism (serotype) and the host (acute and convalescent sera) should be undertaken for each case of invasive pneumococcal disease in this era of universal pneumococcal immunization.