Streptococcus pneumoniae infection: Difference between revisions
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::::: Note: Middle ear infections (otitis media), peritoneum infections (spontaneous bacterial peritonitis), pericardium infections (purulent pericarditis), skin infections (cellulitis) and eye infections (conjunctivitis) caused by Streptococcus pneumonia. | ::::: Note: Middle ear infections (otitis media), peritoneum infections (spontaneous bacterial peritonitis), pericardium infections (purulent pericarditis), skin infections (cellulitis) and eye infections (conjunctivitis) caused by Streptococcus pneumonia. | ||
::* ''' | ==Prevention== | ||
::* '''General principles''' | |||
:::* 1. Pneumovax (23-valent) prevents bacteremia; impact on rates of CAP are modest or nil. | :::* 1. Pneumovax (23-valent) prevents bacteremia; impact on rates of CAP are modest or nil. | ||
:::* 2. Prevnar vaccine for children <2 yrs age | :::* 2. Prevnar vaccine for children <2 yrs age prevents invasive pneumococcal infection in adults by herd effect. Impact is impressive with rates of invasive pneumococcal infection down 80% in peds and 20-40% in adults. | ||
:::* 3. Risk for bacteremia in splenectomy, HIV, smokers, black race, multiple myeloma, asthma. | :::* 3. Risk for bacteremia in splenectomy, HIV, smokers, black race, multiple myeloma, asthma. | ||
===Vaccination in the USA=== | ===Vaccination in the USA=== | ||
In the USA, a heptavalent pneumococcal [[conjugate vaccine]] vaccine (PCV 7) (e.g. [[Prevnar]]) is recommended since 2000 for all children aged 2-23 months and for at-risk children aged 24-59 months. The normally 4-doses series is given at 2, 4, 6 & 12 - 14 months of age. Protection is good against deep pneumococcal infections (especially septicemia and meningitis). Similar 9- and 13-valent vaccines are being tested. Yet, if the child is exposed to a serotype of pneumococcus that is not contained in the vaccine, he/she is not afforded any protection. This limitation, and the ability of capsular-polysaccharide conjugate vaccines to promote the spread of non-covered serotypes, has led to research into vaccines that would provide species-wide protection. | In the USA, a heptavalent pneumococcal [[conjugate vaccine]] vaccine (PCV 7) (e.g. [[Prevnar]]) is recommended since 2000 for all children aged 2-23 months and for at-risk children aged 24-59 months. The normally 4-doses series is given at 2, 4, 6 & 12 - 14 months of age. Protection is good against deep pneumococcal infections (especially septicemia and meningitis). Similar 9- and 13-valent vaccines are being tested. Yet, if the child is exposed to a serotype of pneumococcus that is not contained in the vaccine, he/she is not afforded any protection. This limitation, and the ability of capsular-polysaccharide conjugate vaccines to promote the spread of non-covered serotypes, has led to research into vaccines that would provide species-wide protection. |
Revision as of 16:28, 23 June 2017
Streptococcus pneumoniae infection Microchapters |
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Usama Talib, BSc, MD [2]
Overview
Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, alpha-hemolytic diplococcus bacterium and a member of the genus Streptococcus.[1] A significant human pathogen, S. pneumoniae was recognized as a major cause of pneumonia in the late 19th century and is the subject of many humoral immunity studies.
Despite the name, the organism causes many types of infection other than pneumonia, including acute sinusitis, otitis media, meningitis, osteomyelitis, septic arthritis, endocarditis, peritonitis, pericarditis, cellulitis, and brain abscess.
S. pneumoniae is the most common cause of bacterial meningitis in adults and children, and is one of the top two isolates found in otitis media.[2] Pneumococcal pneumonia is more common in the very young and the very old.
S. pneumoniae can be differentiated from Streptococcus viridans, which is also alpha hemolytic, using an optochin test, as S. pneumoniae is optochin sensitive. The encapsulated, gram-positive coccoid bacteria have a distinctive morphology on gram stain, the so-called, "lancet shape." It has a polysaccharide capsule that acts as a virulence factor for the organism; 91 different capsular types are known, and these types differ in virulence, prevalence, and extent of drug resistance.
Classification
Streptococcus pneumoniae infections can be classified as:
Streptococcus pneumoniae infection | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Community Acquired Pneumonia | Endocarditis | Sinusitis | Bronchitis | Meningitis | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Laboratory Findings
Depending on the nature of infection, an appropriate sample is collected for laboratory identification. Pneumococci are typically gram positive, cocci, seen in pairs or chains. When cultured on blood agar plates with added optochin antibiotic disk, they show alpha-hemolytic colonies and a clear zone of inhibition around the disk meaning they're sensitive to the antibiotic. Pneumococci are also bile soluble. Just like other streptococci, it's catalase negative. Quellung test to identify specific capsular polysaccharides may also be done.
Laboratory Diagnosis
Diagnosis is generally made based on clinical suspicion along with a positive culture from a sample from virtually any place in the body. An ASO Titre of >200 units is significant.[3] S. pneumoniae is, in general, optochin sensitive, although optochin resistance has been observed.[4]
Atromentin and leucomelone possess antibacterial activity, inhibiting the enzyme enoyl-acyl carrier protein reductase, (essential for the biosynthesis of fatty acids) in S. pneumoniae.[5]
Treatment
- Streptococcus pneumonia treatment
- 1. Lung (Community-acquired pneumonia)[6]
- 1.1 Penicillin sensitive (minimum inhibitory concentration < 2 mcg/ml)
- Preferred regimen: Penicillin G 5-24 MU IV in equally divided doses q4-6h, Amoxicillin 1 g PO tid (+/- macrolide)
- Alternative regimen: Macrolides (Azithromycin (IV) 500 mg IV qd for at least 2 days followed by 500 mg PO qd 7-10 days or Clarithromycin extended-release tablets 1000 mg PO qd for 7 days) and oral Cephalosporins-Cefpodoxime 200 mg PO bd, (Cefprozil 500 mg PO bd, Cefditoren 400 mg PO bd, Cefdinir 300 mg PO bd), OR parenteral Cephalosporins-Ceftriaxone 2 g IV q24h (or Cefotaxime 1-2 g IV q6-8h), Clindamycin 600-1200 mg IV/IM q6-12h, do not give single IM doses > 600 mg; IV infusion rates should not exceed 30 mg/min , Doxycycline 100 mg PO bd, respiratory flouroquniolones.
- 1.2 Penicillin-resistant (Penicillin minimum inhibitory concentration ≥ 2 mcg/ml)
- Preferred regimen: Ceftriaxone 2 g IV q24h (or Cefotaxime 1-2 g IV q6-8h), respiratory Flouroquniolones Levofloxacin (Levaquin) 500 mg IV/PO q24h for 7-14 days or 750 mg IV/PO q24h for 5 days (or Moxifloxacin (Avelox) 400 mg PO/IV over 60 minutes q24h for 7-14 days)
- Alternative regimen: Vancomycin 2 g/day IV q6-12h over at least 60 minutes, Linezolid 600 mg IV/PO q12h for 7-21 days , high-dose Amoxicillin (3 g qd with Penicillin minimum concentration of inhibitory <4 mcg/mL).
- 2.Endocarditis[7]
- Preferred regimen (1): Aqueous crystalline Penicillin-G 6 MU q4-6h IV for 4 weeks
- Preferred regimen (2) (who are unable to tolerate beta lactams therapy): Vancomycin 15 mg/kg IV q12h (target trough concentration, 10-15 mcg/mL); for troughs of 15-20 mcg/mL (MIC, 1 mcg/mL or less), 15-20 mg/kg (actual body weight) IV q8-12h for most patients with normal renal function
- Preferred regimen (3) (If the isolate is resistant (MIC 2 g/mL) to cefotaxime): Cefotaxime 1-2 g q8-12h IV/IM (max dose: 12 g/24 hr) AND Vancomycin 15 mg/kg/day IV q12h AND Rifampin 300 mg IV/PO q8h for 6 weeks, in combination with appropriate antimicrobial therapy
- Alternative regimen (1): Cefazolin 0.5-2 g q8h IV/IM (max dose: 12 g/24 hr)
- Alternative regimen (2): Ceftriaxone 2 g IV q12h
- Note : Streptococcus pneumoniae with intermediate doses minimum inhibitory concentration (MIC) 0.12 g/mL–0.5 g/mL Penicillin resistance (MIC 0.1 to 1.0 g/mL) or high Penicillin resistance (MIC 2.0 g/mL) is being recovered from patients with bacteremia.
- 3. Sinuses (sinusitis)[8]
- Empiric therapy
- 3.1 For initial empiric treatment of acute bacterial rhinosinusitis in adults
- Preferred regimen: Amoxicillin 500 mg/Clavulanate 125 mg PO tid or Amoxicillin 875 mg/Clavulanate 125 mg PO bid for 5 to 7 days recommended by the Infectious Disease Society of America (IDSA)
- Alternative regimen (1): Doxycycline 100 mg PO q12h
- Note: Doxycycline can be used in patients with Penicillin allergy.
- Alternative regimen (2): A respiratory Fluoroquinolone (Levofloxacin or Moxifloxacin) is another recommended drug for Penicillin-allergic patients.
- 3.2 For second-line high-dose therapy for acute bacterial rhinosinusitis in adults
- Preferred regimen: Amoxicillin 2 g/Clavulanate 125 mg PO bid recommended by the Infectious Disease Society of America (IDSA).
- Note: The second line high dose therapy is recommended in adults who have failed initial therapy, in regions of high endemic rates (10% or greater) of invasive Penicillin-nonsusceptible Streptococcus pneumoniae, severe infection.
- 4. Bronchi (acute exacerbation of chronic bronchitis)[9]
- Preferred regimen (1): Amoxicillin 875 mg PO q12h or 500 mg PO q8h
- Preferred regimen (2): Doxycycline 100 mg PO q12h
- 5. CNS (meningitis)[10]
- Empiric therapy
- Preferred regimen: Vancomycin 15 mg/kg/day IV q12h AND a third-generation cephalosporin (Ceftriaxone 2 g IV q12h OR Cefotaxime 2 g IV q4h or 3 g q6h) AND Rifampin 600 mg IV qd in combination with Vancomycin
- Alternative regimen: Meropenem, fluoroquinolones
- Note: Middle ear infections (otitis media), peritoneum infections (spontaneous bacterial peritonitis), pericardium infections (purulent pericarditis), skin infections (cellulitis) and eye infections (conjunctivitis) caused by Streptococcus pneumonia.
Prevention
- General principles
- 1. Pneumovax (23-valent) prevents bacteremia; impact on rates of CAP are modest or nil.
- 2. Prevnar vaccine for children <2 yrs age prevents invasive pneumococcal infection in adults by herd effect. Impact is impressive with rates of invasive pneumococcal infection down 80% in peds and 20-40% in adults.
- 3. Risk for bacteremia in splenectomy, HIV, smokers, black race, multiple myeloma, asthma.
Vaccination in the USA
In the USA, a heptavalent pneumococcal conjugate vaccine vaccine (PCV 7) (e.g. Prevnar) is recommended since 2000 for all children aged 2-23 months and for at-risk children aged 24-59 months. The normally 4-doses series is given at 2, 4, 6 & 12 - 14 months of age. Protection is good against deep pneumococcal infections (especially septicemia and meningitis). Similar 9- and 13-valent vaccines are being tested. Yet, if the child is exposed to a serotype of pneumococcus that is not contained in the vaccine, he/she is not afforded any protection. This limitation, and the ability of capsular-polysaccharide conjugate vaccines to promote the spread of non-covered serotypes, has led to research into vaccines that would provide species-wide protection.
Pneumococcal polysaccharide vaccine (Pneumovax™ is one brand) gives at least 85% protection in those under 55 years of age for five years or longer. Immunization is suggested for those at highest risk of infection, including those 65 years or older, and generally should be a single lifetime dose (high risk side effects if repeated). The standard 23-valent vaccines are ineffective for children under two years old.
The current guidelines of the American College of Physicians call for administration of the immunization between ages 2 and 65 when indicated, or at age 65. If someone received the immunization before age 60, the guidelines call for a one-time revaccination.
Revaccination at periodic intervals is also indicated for those with other conditions such as asplenia or nephrotic syndrome.
Vaccination in the UK
It was announced in February 2006 that the UK government would introduce vaccination with the conjugate vaccine in children aged 2, 4 and 13 months.[11][12] This is expected to start on September 4, 2006 and is to include changes to the immunisation programme in general.[13]
Vaccination Worldwide
Pneumococcal vaccines Accelerated Development and Introduction Plan (PnemoADIP) is a program to accelerate the evaluation and access to new pneumococcal vaccines in the developing world. PneumoADIP is funded by the Global Alliance for Vaccines and Immunization (GAVI). Thirty GAVI countries have expressed interest in participating by 2010. PneumoADIP aims to save 5.4 million children by 2030.[14]
References
- ↑ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0-8385-8529-9.
- ↑ Dagan R. "Treatment of acute otitis media - challenges in the era of antibiotic resistance". Vaccine. 19 Suppl 1: S9–S16. PMID 11163457.
- ↑ Siemieniuk, Reed A.C. (Nov 2011). "The persisting burden of invasive pneumococcal disease in HIV patients: an observational cohort study" (PDF). BMC Infectious Diseases. 11: 314. doi:10.1186/1471-2334-11-314. PMC 3226630. PMID 22078162. Unknown parameter
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ignored (help) - ↑ Pikis, A; Campos, JM; Rodriguez, WJ; Keith, JM (2001). "Optochin resistance in Streptococcus pneumoniae: mechanism, significance, and clinical implications". Journal of Infectious Diseases. 184 (5): 582–590. doi:10.1086/322803. PMID 11474432.
- ↑ Zheng CJ, Sohn MJ, Kim WG. (2006). "Atromentin and leucomelone, the first inhibitors specific to enoyl-ACP reductase (FabK) of Streptococcus pneumoniae". Journal of Antibiotics. 59 (12): 808–12. doi:10.1038/ja.2006.108. PMID 17323650.
- ↑ Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC; et al. (2007). "Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults". Clin Infect Dis. 44 Suppl 2: S27–72. doi:10.1086/511159. PMID 17278083.
- ↑ Baddour LM, Wilson WR, Bayer AS, Fowler VG, Bolger AF, Levison ME; et al. (2005). "Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America". Circulation. 111 (23): e394–434. doi:10.1161/CIRCULATIONAHA.105.165564. PMID 15956145.
- ↑ Chow AW, Benninger MS, Brook I, Brozek JL, Goldstein EJ, Hicks LA; et al. (2012). "IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults". Clin Infect Dis. 54 (8): e72–e112. doi:10.1093/cid/cir1043. PMID 22438350.
- ↑ Bartlett, John (2012). Johns Hopkins ABX guide : diagnosis and treatment of infectious diseases. Burlington, MA: Jones and Bartlett Learning. ISBN 978-1449625580.
- ↑ Tunkel AR, Hartman BJ, Kaplan SL, Kaufman BA, Roos KL, Scheld WM; et al. (2004). "Practice guidelines for the management of bacterial meningitis". Clin Infect Dis. 39 (9): 1267–84. doi:10.1086/425368. PMID 15494903.
- ↑ "Children to be given new vaccine" BBC News, February 08, 2006, retrieved August 25, 2006
- ↑ "Pneumococcal vaccine added to the childhood immunisation programme" February 08, 2006
- ↑ "Changes to the immunisation programme in the UK" Meningitis Research Foundation, retrieved August 25, 2006
- ↑ "PneumoADIP website"