The gram-positive coccus Streptococcus pneumoniae.
Person to person through close contact via respiratory droplets.
Occurs worldwide, but prevalence is higher in developing than in industrialized countries. Risk is highest in young children, the elderly, and those with chronic illnesses or immune suppression.
Sudden onset of fever and malaise, cough, pleuritic chest pain, purulent or blood-tinged sputum. In the elderly, fever, shortness of breath, or altered mental status may be initial symptoms. Pneumococcal meningitis may present as a stiff neck, headache, lethargy, or seizures.
Isolation from blood or cerebrospinal fluid, but most patients do not have detectable bacteremia. Pneumococcal urine antigen test can be used in adults. Infection can be suspected if a sputum specimen contains gram-positive diplococci, polymorphonuclear leukocytes, and few epithelial cells. High white blood cell counts should raise suspicion for bacterial infection.
Empiric therapy depends on the syndrome. Many strains are resistant to penicillin, cephalosporins, and macrolides, so definitive treatment should be targeted on the basis of antimicrobial susceptibility results. In the United States and other countries where β-lactam resistance is common, the initial regimen for pneumococcal meningitis might include vancomycin or a fluoroquinolone, plus a third-generation cephalosporin.
The 13-valent pneumococcal conjugate vaccine (PCV13) is recommended for all children aged <5 years and children aged <72 months with chronic medical conditions; the vaccine may also be given to children aged <18 years with immunocompromising conditions. A 23-valent pneumococcal polysaccharide vaccine (PPSV23) is recommended for adults aged ≥65 years and people aged 2–64 years with underlying medical conditions. Adults with immunocompromising conditions, functional or anatomic asplenia, cerebrospinal fluid leaks, or cochlear implants should receive PCV13 followed by PPSV23. See www.cdc.gov/vaccines/pubs/ACIP-list.htm#pcv.
CDC. Licensure of a 13-valent pneumococcal conjugate vaccine (PCV13) and recommendations for use among children—Advisory Committee on Immunization Practices (ACIP), 2010. MMWR Morb Mortal Wkly Rep. 2010 Mar 12;59(9):258–61.
CDC. Prevention of pneumococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1997 Apr 4;46(RR-8):1–24.
Fedson DS, Scott JA. The burden of pneumococcal disease among adults in developed and developing countries: what is and is not known. Vaccine. 1999 Jul 30;17 Suppl 1:S11–8.