Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 33-03: Pneumococcal Infections + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Productive cough, fever, rigors, dyspnea, early pleuritic chest pain Consolidating lobar pneumonia on chest radiograph Lancet-shaped gram-positive diplococci on Gram stain of sputum +++ General Considerations ++ The most common cause of community-acquired pyogenic bacterial pneumonia Predisposing factors Alcoholism Asthma HIV infection Sickle cell disease Splenectomy Hematologic disorders + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ High fever, productive cough, occasional hemoptysis, and pleuritic chest pain Rigors may occur initially but are uncommon later in the course Bronchial breath sounds are an early sign Differentiating pneumococcal from other bacterial pneumonias is not possible clinically or radiographically because of significant overlap in presentations +++ Differential Diagnosis ++ Pneumonia due to other causes, eg, Haemophilus influenzae, influenza Aspiration pneumonia or lung abscess Pulmonary embolism Myocardial infarction Acute exacerbation of chronic bronchitis Acute bronchitis Hypersensitivity pneumonitis + Diagnosis Download Section PDF Listen +++ +++ Laboratory Tests ++ A rapid urinary antigen test for Streptococcus pneumoniae, with sensitivity of 70–80% and specificity > 95%, can assist with early diagnosis A good-quality sputum sample (less than 10 epithelial cells and more than 25 polymorphonuclear leukocytes per high-power field) shows gram-positive diplococci in 80–90% of cases Blood cultures are positive in up to 25% of selected cases and much more commonly so in HIV-positive patients +++ Imaging Studies ++ Chest radiograph shows findings of consolidation, often with a lobar distribution, infiltrates, pleural effusion + Treatment Download Section PDF Listen +++ +++ Medications ++ Initial antimicrobial therapy of pneumonia is empiric pending isolation and identification of the causative organism (Table 9–8) +++ OUTPATIENT ++ Amoxicillin, 750 mg twice daily orally for 7–10 days Cephalosporins may also be used Cefpodoxime, 200 mg orally twice daily Cefdinir, 300 mg twice daily Alternatives include Azithromycin, one 500-mg dose orally on the first day and 250 mg orally for the next 4 days Clarithromycin, 500 mg twice daily orally for 10 days Doxycycline, 100 mg twice daily orally for 10 days Levofloxacin, 750 mg orally for 5 days Moxifloxacin, 400 mg orally for 7–14 days +++ INPATIENT ++ Aqueous penicillin G (susceptible strains), 2 million units every 4 hours intravenously Ceftriaxone, 1 g every 24 hours intravenously For a highly penicillin-resistant strain, vancomycin, 1 g every 12 hours intravenously Alternatively, a fluoroquinolone (eg, levofloxacin, 750 mg) can be used Total duration of therapy is not well defined but 5–7 days is appropriate for patients who have an uncomplicated infection and demonstrate a good clinical response Corticosteroid use remains controversial in community-acquired pneumonia and should not be administered routinely +++ Therapeutic Procedures ++ Pleural effusions developing after initiation of antimicrobial therapy usually are sterile, and thoracentesis need not be performed if the patient is otherwise improving Thoracentesis is indicated for an effusion present prior to initiation of therapy and in the patient who has not responded to antibiotics after 3–4 days + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ Repeat chest radiograph 6–8 weeks after treatment to ensure resolution of infiltrate +++ Complications ++ Parapneumonic effusion is common cause of recurrent or persistent fever Empyema occurs in ≤ 5% Pneumococcal pericarditis (rare) Pneumococcal endocarditis usually involves aortic valve and often in association with meningitis +++ Prevention +++ PNEUMOCOCCAL VACCINE ++ 23-valent purified polysaccharide from most common serotypes of S pneumoniae Current recommendations Table 30–7 Patients at increased risk for developing severe pneumococcal disease (eg, asplenic patients, those with sickle cell disease) Chronic illnesses (eg, cardiopulmonary disease, alcoholism, renal disease, cancer) Persons over 65 years of age Elderly individuals with unknown immunization status should be immunized once Revaccination Recommended regardless of age for those with the highest risk of fatal pneumococcal disease (eg, asplenic patients, nephrotic syndrome or renal failure, HIV, leukemia, lymphoma, myeloma, immunosuppressive medications, transplant patients) 65 years of age if primary vaccine was at least 5 years before High-risk individuals previously immunized with 14-valent vaccine +++ Prognosis ++ Mortality rates remain high in cases of Advanced age Multilobar disease Hypoxemia Extrapulmonary complications Bacteremia +++ When to Refer ++ All patients with suspected pneumococcal endocarditis or meningitis to an infectious disease specialist Extensive disease Seriously ill patient with pneumonia, particularly in the setting of comorbid conditions (eg, liver disease) Progression of pneumonia or failure to improve on antibiotics +++ When to Admit ++ All patients in whom pneumococcal endocarditis or meningitis is suspected or documented should be admitted for observation and empiric therapy All patients with pneumococcal pneumonia that is multilobar or associated with significant hypoxemia Failure of outpatient pneumonia therapy, including inability to maintain oral intake and medications Exacerbations of underlying disease (eg, heart failure) by pneumonia that would benefit from hospitalization + References Download Section PDF Listen +++ + +Galán-Ros J et al. Bacteremic pneumococcal pneumonia in adults. Arch Bronconeumol. 2018 Jan;54(1):54–5. [PubMed: 28757279] + +Uranga A et al. Duration of antibiotic treatment in community-acquired pneumonia: a multicenter randomized clinical trial. JAMA Intern Med. 2016 Sep 1;176(9):1257–65. [PubMed: 27455166] + +Wunderink RG et al. Advances in the causes and management of community acquired pneumonia in adults. BMJ. 2017 Jul 10;358:j2471. [PubMed: 28694251]