Reevaluation of outpatients with Streptococcus pneumoniae bacteremia.

Abstract

To the Editor. The findings of Drs Bachur and Harper1 in their report, “Reevaluation of Outpatients With Streptococcus pneumoniae Bacteremia,” should cause them to rethink their emergency department's policy of using the complete blood count (CBC) to screen febrile children for occult bacteremia (OB).Their protocol targets children 3 to 36 months old with a temperature ≥39°C and no identifiable source for the fever to have a blood culture, CBC, and urine culture when appropriate. They recommend that those children with a white blood cell count (WBC) >15 000/μL be given a single dose of ceftriaxone (although in their study it appears that approximately 50% of these patients received an oral antibiotic instead and a number were given no antibiotic at all—nearly half of the 73 patients in the “no antibiotic” group with a median WBC of 14.6). The use of 15 000 as a cutoff for obtaining blood cultures was recommended by experts for practical reasons, “… because WBC counts are more easily obtained in many physicians' offices and are less expensive than a blood culture and because such a strategy reduces the number of children treated empirically.”2In Bachur and Harper's study the greatest percentage of patients with significant complications came from the “no antibiotic” group: persistent bacteremia in 20% versus 2.6% and 0% in the oral and parenteral antibiotic groups, respectively; meningitis in 4.6% versus 0.9% and 1.5%, respectively. The 3 “no antibiotic” patients with meningitis had WBCs of 7.5, 12.6, and 16.4 (×1000/mm3).Because there has been no data to suggest that a patient with occult bacteremia and a WBC <15 000 has any better outcome than one with a count >15 000 and their data demonstrates a skew of complications among untreated patients below this value, then if the clinician chooses to diagnose and treat OB,3 the 13%4of patients with OB and a WBC <15 000 should not be excluded from consideration.In a busy emergency department it is far more efficient to make a decision on OB based on the demographics of age, immunization status, and temperature height,5 rather than waiting for the CBC, calling the patient's pediatrician back to discuss the result (which is the norm in many community EDs) and most importantly using the extra 0.5 to 1 mL of blood that is obtained to increase the yield of the blood culture. This study supports the practice of not obtaining a CBC in evaluation of febrile children.In Reply. The objective of our article was to evaluate the follow-up management of outpatients with a known positive blood culture forStreptococcus pneumoniae. Dr Reingold has used the opportunity to comment on the appropriate initial evaluation of highly febrile young children at risk for S pneumoniae bacteremia; although related, we believe that his comments deserve another forum for complete discussion. Nevertheless, he does point out that most complications occurred among patients who did not receive antibiotic treatment at the initial evaluation and who had lower white blood cell counts (WBCs) at the initial evaluation. The lower WBCs and lack of antibiotic use are the result of a thoughtful management strategy—those patients with higher WBCs are treated empirically with an antibiotic pending the result of blood culture. In our emergency department, our clinicians use a strategy to give empiric antibiotics only to those patients at an elevated risk of occult bacteremia as judged by a WBC ≥15 000/mm3. This strategy identifies 80% of patients with S pneumoniae bacteremia.1Treatment at the initial visit is intended to prevent the development of complications before notification of the positive blood culture. Because the WBC was used as a determining factor for which patients received antibiotic therapy, it cannot be evaluated as an independent predictor of complications. Dr Reingold also states that for pragmatic reasons he uses some less sensitive and specific parameters for determining which children are at risk for occult pneumococcal bacteremia. It is not clear from his comments whether he empirically treats all patients felt to be at risk for bacteremia or whether he waits for the growth in the blood culture. We find that the WBC is particularly useful for excluding patients from being treated empirically with antibiotics. Additionally, when faced with an unexpectedly elevated WBC, we reconsider what infectious foci we may have missed by examination alone (eg, urinary tract infection, pneumonia).2,3 It is likely that our approach to the initial management of febrile children will change after widespread use of the conjugate pneumococcal vaccine, but until then, we find our current strategy to be efficient and logical. Nonetheless, regardless of the initial management, clinicians occasionally still will be faced with patients having been identified as having S pneumoniaebacteremia. We hope that our article provides useful data to help properly care for these children.