You are in: eMedicine Specialties > Pediatrics: General Medicine > Infectious Disease Pneumococcal BacteremiaArticle Last Updated: May 15, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Richard G Bachur, MD, Assistant Professor of Pediatrics, Harvard Medical School; Associate Chief and Fellowship Director, Attending Physician, Division of Emergency Medicine, Children's Hospital of Boston Richard G Bachur is a member of the following medical societies: American Academy of Pediatrics, Society for Academic Emergency Medicine, and Society for Pediatric Research Coauthor(s): Marvin Harper, MD, Assistant Professor of Pediatrics, Departments of Emergency Medicine and Infectious Disease, Harvard Medical School; Director, Informatics Program, Children's Hospital of Boston Editors: David Jaimovich, MD, Chief Medical Officer, Joint Commission International and Joint Commission Resources; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Larry I Lutwick, MD, Professor of Medicine, State University of New York, Downstate Medical School; Director, Infectious Diseases, Veterans Affairs New York Harbor Health Care System, Brooklyn Campus; Robert W Tolan Jr, MD, Chief of Allergy, Immunology and Infectious Diseases, The Children's Hospital at Saint Peter's University Hospital; Clinical Associate Professor of Pediatrics, Drexel University College of Medicine; Russell W Steele, MD, Professor and Vice Chairman, Department of Pediatrics, Head, Division of Infectious Diseases, Louisiana State University Health Sciences Center Author and Editor Disclosure Synonyms and related keywords: pneumococcal bacteremia, Streptococcus pneumoniae bacteremia, Streptococcus pneumoniae, S pneumoniae, pneumococcus, gram-positive sepsis, occult bacteremia, OB, meningitis, bacteremia, pneumonia, upper respiratory infection, URI INTRODUCTIONSection 2 of 11
  BackgroundStreptococcus pneumoniae, or pneumococcus, is an encapsulated gram-positive bacterium that is a major cause of common upper respiratory infections and serious invasive infections. In the United States, pneumococcus is responsible for 3,000 cases of meningitis, 50,000 cases of bacteremia, and 500,000 cases of pneumonia per year. Additionally, in the United States, pneumococcus is the most common cause of bacterial meningitis and bacterial pneumonia in children younger than 2 years. Many patients with pneumococcal bacteremia have evidence of focal infection at their initial presentation, but a phenomenon of occult bacteremia (OB) was recognized 3 decades ago and has been the featured topic of pediatric journals since then. The OB phenomenon has been defined clinically as bacteremia occurring in a healthy-appearing febrile child without evidence of focal bacterial infection or signs of sepsis. Although S pneumoniae is the most common cause of OB, much of the research and writing about OB preceded the near elimination (by introduction of an effective vaccine) of another major cause of OB, Haemophilus influenzae type B. The identification of patients at risk for bacteremia and strategies to prevent secondary complications (eg, meningitis, pneumonia, septic arthritis, osteomyelitis, cellulitis) has been the focus of the OB literature. After the introduction of the heptavalent pneumococcal vaccine in the United States, the rates of invasive disease have markedly diminished (an estimated 85% reduction for the 7 serotypes covered by the vaccine). PathophysiologyPneumococcus commonly and asymptomatically colonizes the upper respiratory tract of children. Breakdown of the normal mucosal barriers is considered to be the initial step towards invasion of the bloodstream. FrequencyUnited StatesPrevious studies have suggested that 3-5% of children aged 3-36 months who have a fever higher than 39°C and no source of infection have OB, and a recent estimate of pneumococcal bacteremia in the post–H influenzae era found a prevalence of 1.6%. Since the introduction of the universal pneumococcal vaccination, the incidence has most recently been estimated to be approximately 0.5%. Mortality/MorbidityAlthough the previous writings have indicated that most cases of pneumococcal bacteremia self-resolve, data are insufficient to make such a claim. Only one prospective study reported a no antibiotic treatment group, and 2 out of 5 untreated patients developed meningitis. In retrospective studies, most patients no longer had bacteremia upon reevaluation, but many patients still had fever and were treated subsequently with antibiotics; therefore, one is unable to state that the bacteremia self-resolved. Ten percent of patients with bacteremia develop focal complications. Meningitis is the complication of 3-6% of patients with pneumococcal bacteremia. Of patients who develop meningitis, approximately 15% die, and 25% survive with neurologic deficits. Pneumococcus is a major cause of sepsis in immunocompromised patients, including those with malignancy, asplenia (eg, sickle cell disease), and HIV. AgeOccult pneumococcal bacteremia is most common in children aged 3-36 months. Pneumococcal bacteremia can occur in older patients with focal pneumococcal infection and in immunocompromised patients. CLINICALSection 3 of 11
HistoryApproximately 40% of patients have fever for less than 1 day, and 82% of patients have fever for less than 2 days. PhysicalBy definition, occult pneumococcal bacteremia occurs in a healthy-appearing child with the absence of signs of focal infection or sepsis. Observation scales are not helpful for identifying patients with OB.
CausesAlthough S pneumoniae is the most common cause of OB, much of the research and writing about OB preceded the near elimination (by introduction of an effective vaccine) of another major cause of OB, H influenzae type B. DIFFERENTIALSSection 4 of 11
Appendicitis Bacteremia Herpesvirus 6 Infection Meningitis, Aseptic Meningitis, Bacterial Meningococcal Infections Pneumococcal Infections Pneumonia Pyelonephritis Retropharyngeal Abscess Rhinovirus Infection Salmonella Infection Shigella Infection Staphylococcus Aureus Infection Streptococcal Infection, Group A Varicella
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| Drug Name | Penicillin (Pfizerpen, Pen.Vee K, Beepen-VK) |
|---|---|
| Description | Penicillin and amoxicillin are the drugs of choice for outpatients without signs of serious bacterial infection. IV penicillin or ampicillin can be administered parenterally for more serious infections requiring hospitalization. |
| Adult Dose | 500 mg (800,000 U) PO qid 10-30 million U/d IV divided q4-6h |
| Pediatric Dose | 40,000-80,000 U/kg/d PO divided qid or 25-50 mg/kg/d divided qid (250 mg=400,000 U) 100,000-400,000 U/kg/d IV divided q4-6h |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid can increase effects of penicillin; coadministration of tetracyclines can decrease effects of penicillin |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Caution in impaired renal function |
| Drug Name | Amoxicillin (Amoxil, Biomox, Trimox) |
|---|---|
| Description | Can be used when oral outpatient therapy is appropriate. |
| Adult Dose | 1.5-3 g/d PO divided tid |
| Pediatric Dose | 40-60 mg/kg/d PO divided tid High-dose therapy: 60-80 mg/kg/d PO divided tid |
| Contraindications | Documented hypersensitivity |
| Interactions | Reduces the efficacy of oral contraceptives |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Adjust dose in renal impairment |
| Drug Name | Ampicillin (Marcillin, Omnipen, Polycillin, Principen, Totacillin) |
|---|---|
| Description | Can be used when parenteral treatment is required and penicillin resistance is not suggested. |
| Adult Dose | 500-3000 mg IV/IM q4-6h; not to exceed 12 g/d |
| Pediatric Dose | 100-400 mg/kg/d IV/IM divided q6h |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction |
| Drug Name | Ceftriaxone (Rocephin) |
|---|---|
| Description | Can be used in patients with suggested but not proven pneumococcal bacteremia to prevent complications of bacteremia. Long half-life affords antibiotic coverage for outpatients while blood culture is pending. Ceftriaxone also can be used for parenteral treatment of bacteremia. |
| Adult Dose | 1-4 g/d IV/IM divided q12h or qd |
| Pediatric Dose | 50-100 mg/kg/d IV/IM divided q12h or qd |
| Contraindications | Documented hypersensitivity |
| Interactions | Probenecid may increase ceftriaxone levels; coadministration with ethacrynic acid, furosemide, and aminoglycosides may increase nephrotoxicity |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Adjust dose in renal impairment; caution in breastfeeding women and allergy to penicillin |
| Drug Name | Vancomycin (Lyphocin, Vancocin, Vancoled) |
|---|---|
| Description | Should be used in all cases of life-threatening infection caused by S pneumoniae pending results of culture and antibiotic sensitivities. |
| Adult Dose | 2 g/d IV divided q6-12h |
| Pediatric Dose | 60 mg/kg/d IV divided q6h |
| Contraindications | Documented hypersensitivity |
| Interactions | Erythema, histaminelike flushing, and anaphylactic reactions may occur when administered with anesthetic agents; taken concurrently with aminoglycosides, risk of nephrotoxicity may increase above that with aminoglycoside monotherapy; effects in neuromuscular blockade may be enhanced, when coadministered with nondepolarizing muscle relaxants |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Caution in renal failure and neutropenia; red man syndrome is caused by too rapid IV infusion (dose given over a few min) but rarely happens when dose given as 2-h administration or as PO or IP administration; red man syndrome is not an allergic reaction; monitor serum levels to assure adequate therapeutic effect |
| Media file 1: Pneumococcal bacteremia. Algorithm for the reevaluation of outpatients with Streptococcus pneumoniae bacteremia. | |
 | View Full Size Image | Media type: Graph |
Pneumococcal Bacteremia excerpt
Article Last Updated: May 15, 2006
