Cap
Upcoming SlideShare
Loading in...5
×

Like this? Share it with your network

Share
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
1,569
On Slideshare
1,569
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
13
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Binax NOW ® RTI Products 義大醫院 2008.06.13 1 臨床病理科
  • 2. WHO comments:– “More than any other infectious disease, pneumonia remains the number one killer worldwide.”– Streptococcus pneumoniae and Haemophilus influenzae are the top two bacterial causes of acute respiratory infections.– Both viral and bacteria respiratory infections present the same clinical symptoms and can often only be distinguished by laboratory tests– 80% of pneumonia patients may unnecessarily be given antibiotics - contributing to antibiotic resistance 2 2
  • 3. Case Review• Respiratory Tract Infection (RTI) cases – very large cases – several diseases with similar symptoms• Target cases – Community-acquired pneumonia – Nosocomial pneumonia cases – Acute ‘Flu-like’ cases 3 3
  • 4. Community - Acquired Pneumonia~12 million cases treated annually worldwideS. pneumoniae is the leading cause ofbacterial pneumonia -up to 65% of cases in some studiesLegionella also a leading cause of community-acquiredpneumonia - up to 15%S. pneumoniae and Legionella pneumonia have highmortality rates - as high as 30% 4 4
  • 5. Acute ‘Flu-like’ Cases• Clinical symptoms of lower RTI diseases (pneumonia, acute influenza and acute bronchitis) similar• Bacterial pneumonia can be a complication of acute influenza or acute bronchitis• Significantly increases overall case potential 5 5
  • 6. Disease Overview 6 6
  • 7. Causative Agents ofCommunity-Acquired PneumoniaBacterial ViralStreptococcus pneumoniae Influenza A & BLegionella pneumohila RSVHaemophilus influenza type B AdenovirusNon typable Haemophilus Para InfluenzaStaphlococcus aureusMoraxella catarrhalisPseudomonas aeruginosaChlymydia pneumonia 7Mycoplasma pneumonia 7
  • 8. Community-Acquired Pneumonia CAP • S. pneumoniae is the leading cause of bacterial pneumonia and CAP - up to 65% of all cases in some studies • Legionella also a leading cause of community-acquired pneumonia - up to 15% • S. pneumoniae and Legionella pneumonia have high mortality rates - as high as 30% • Bacterial infections can occur as a complication of influenza 8 8
  • 9. Community-Acquired Pneumonia• Transmission: person to person by direct contact with infectious secretions • Risk groups • Symptoms – elderly – fever, chills – children under 2 and / – chest pain, pleurisy, or attending day care difficulty breathing – patients with – blood-tinged sputum underlying illness – headache – immunocompromised – cough (often non- patients productive) 9 9
  • 10. Community-Acquired Pneumonia• Treatment – Pathogen-specific diagnosis - • help direct the most cost-effective treatment • minimizes the risk of increasing antibiotic resistance – Empirical treatment • may not always be the most cost-effective treatment • increases the risk of antibiotic resistance 10 10
  • 11. Community-Acquired Pneumonia• many strains of S. pneumoniae have intermediate sensitivity and resistance to penicillin and resistance to single or multiple broad-spectrum antibiotics (Goldstein and Acar, 1996)• accurate diagnosis required allowing specific antibiotic therapy 11 11
  • 12. Diagnostics 12 12
  • 13. Diagnostics• Blood Culture• Sputum Culture• Sputum Gram Stain• PCR / DFA• NOW® ICT Urinary Antigen Test 13 13
  • 14. Diagnostics• Blood Culture – Advantages • positive = confirmation patient is bacteremic • allows for drug susceptibility testing – Disadvantages • only 10-30% of all pneumonia cases are bacteremic - positive culture result in only 25% of cases (Musher, 1992) • potential errors by technician 14 14
  • 15. Diagnostics• Blood Culture – Disadvantages • can also be positive in patients with meningitis, otitis media, septic arthritis, etc • 24-48 hours incubation • requires experienced technicians to perform and interpret results • expensive – technician time – instrumentation (incubators) • invasive for the patient 15 15
  • 16. Diagnostics• Sputum Culture – Advantages • supplies and reagents relatively inexpensive • non-invasive for the patient • allows for drug susceptibility testing – Disadvantages • samples must be taken prior to antibiotic therapy • sample required from lower respiratory tract; difficult to obtain (non-productive cough, children, elderly) 16 16
  • 17. Diagnostics• Sputum Culture – Disadvantages • samples must be processed immediately – delays reduce isolation rates of the organism – high false positive rates (carrier) – low sensitivity and specificity • normally 48 hours for positive identification 17 17
  • 18. Diagnostics• Sputum Culture – Disadvantages • expensive – technician time – equipment – experienced personnel are needed to perform and interpret results • Difficult to identify infecting organism 18 18
  • 19. Diagnostics• Sputum Gram Stain – Advantages • inexpensive reagents and supplies • non-invasive for the patient • rapid test time – Disadvantages • requires sample from lower respiratory tract; difficult to obtain • samples must be processed immediately 19 19
  • 20. Diagnostics• Sputum Gram Stain – Disadvantages • high false positive rate • low sensitivity and specificity; large numbers of organisms must be present • does not allow for drug susceptibility testing • requires experienced personnel 20 20
  • 21. Diagnostics• PCR / DFA – Advantages • same day results • specificity – Disadvantages • requires sample from lower respiratory tract; difficult to obtain • expensive - equipment, skilled technician • sensitivity 21 21
  • 22. Diagnostics• NOW® ICT Urinary Antigen – Technology • detects antigen, which is a common component of the cell wall within the species – S. pneumoniae - C-polysaccharide antigen, common to all serotypes within the species – Legionella - lipopolysaccharide portion of the serogroup 1 cell wall • rabbit anti-species antibody as capture component • rabbit anti-species antibody conjugated to colloidal gold as detection component 22 22
  • 23. Technology• Absorbent• Control Line--Goat anti-rabbit IgG• Sample Line--Rabbit anti-S. pneumoniae antibody• Conjugate Pad• Sample Pad( patent No. 91/214051). 23 23
  • 24. Intellectual Property• 12 Issued Patents – 4 ICT platform – 7 Magnetic particles – 1 Meningitis test• 11 Patents Applied For – respiratory, meningitis, and bacteria screen area 24 24
  • 25. Diagnostics• NOW® ICT Urinary Antigen – Advantages • rapid results - 15 minutes • non-invasive sample - urine • easy test to run and interpret results • accurate – Limitations • Susceptibility cannot be performed • Single bacteria test 25 25
  • 26. 26 26
  • 27. Diagnostics• NOW® ICT Urinary Antigen – Performance Data • S. pneumoniae – Sensitivity 86% – Specificity 94% • Legionella – Sensitivity 95% – Specificity 95% 27 27
  • 28. DiagnosticsComparison of Streptococcus pneumoniae Test Methods Methods Sample Type Sensitivity Specificity Time 1 1 Binax NOW® Urine 86% 94% 15 mins PCR Blood 52% 100% 4 hrs 2 Blood Culture Blood 10-30% >95% 48 hrs Sputum Culture Sputum 50-60% 50-80% 48 hrs Sputum Gram Stain Sputum 50-60% 50-80% 15 mins 1-Retrospective study data -- blood culture used as reference method. 2-Numbers reflect percent of pneumonia patient population estimated to be bacteremic. Note: Sensitivity and specificity data on blood culture, sputum culture, and sputum Gram stain taken from various published studies. References available upon request. 28 28
  • 29. Positioning• NOW® ICT Features – Easy to run – Rapid test - only 15 minute tests for S. pneumoniae and Legionella available – Uses non-invasive sample – No special equipment needed – Easy to interpret resul 29 29
  • 30. – Accurate results– U.S. FDA cleared products– Multiple applications for S. pneumoniae test - pneumonia, CSF and otitis media 30 30
  • 31. NOW® ICT S. pneumoniae additional applications 31 31
  • 32. CSF application• Anti-microbial therapy often initiated empirically because causative agent not identified in advance• Sensitivity of CSF gram staining is 75% - decreases to 50% in patients given anti-microbial therapy• Latex bacterial antigen assays have low sensitivity in CSF• Streptococcus pneumoniae is typically the second most common causative agent of community-acquired acute bacterial meningitis• Increasing rates of pneumococcal resistance to penicillin and third generation cephalosporins 32 32
  • 33. CSF application• NOW® ICT S. pneumoniae test – 100% sensitivity and specificity with CSF sample – published studies • New Rapid Antigen Test for Diagnosis of Pneumococcal Meningitis. Marcos et al, The Lancet 357: 1499-1500, 2001. • Using the NOW test in Cerebrospinal Fluid for the Rapid Diagnosis of Pneumococcal meningitis. Samrai et al, ASM: 114, 2001. 33 33
  • 34. CSF application• NOW® ICT S. pneumoniae test – additional application to support bringing the test into a hospital lab – only accurate rapid test for detection of a critical pathogen for bacterial meningitis 34 34
  • 35. Otitis Media application• NOW® ICT S. pneumoniae test – Rapid Detection of S. pneumoniae in the Airways of Children with Acute Otitis Media. Faden et al, ASM: 113, 2001. • Sensitivity – 90.0% (18/20) versus culture positive nasopharangeal samples • Specificity – 86.9% (21/23) versus culture negative nasopharangeal samples – one of three leading causes of otitis media 35 35
  • 36. Reference• Published Studies - S. pneumoniae – Evaluation of a Rapid Immunochromatographic Test for the Detection of Streptococcus pneumoniae Antigen in Urine Samples from Adults with Community-Acquired Pneumonia Murdoch et al, ASM: 112, 2001 – Detection of Streptococcus pneumoniae Antigen by a Rapid Immunochromatographic Assay in Urine Specimens Dominguez et al: Chest, 119: 243-249, 2001 – Diagnostic Utility of a Rapid Urine Pneumococcal Antigen Assay Neuman et al, 2001 Pediatric Academic Societies Meeting 36 36
  • 37. • Published Studies - S. pneumoniae – Evaluation of Binax NOW®, an Assay for the Detection of Pneumococcal Antigen in Urine Samples, Performed among Pediatric Patients Dowell et al, Clinical Infectious Diseases, 32: 2001 – New Rapid Test for Detecting S. pneumoniae in Lower Respiratory Tract Infections Lienhard et al, Clinical Microbiology and Infection 7: 101 37 37
  • 38. Detection of Streptococcus pneumoniae Antigen by aRapid Immunochromatogrphic Assay in Urine Samples CHEST, 119: 243-249, 2001 J.Dominguez et al ♦ Conclusions (1) Now® S. pneumoniae test is sensitive and specific (2) Now® S. pneumoniae test is a valuable tool for diagnosing pneumococcal pneumonia cases, especially nonbacteremic cases, which are often not diagnosed. (3) Blood culture is only useful in approximately 25% of pneumococcal pneumonia cases (i.e. that is the percent of the population that is bacteremic). (4) Sputum cultures only provide a probable diagnosis due to difficulties associated with methodology (obtaining reliable samples, etc.) and samples for culture are rarely taken invasively due to concerns with the techniques that must be used. 38 38
  • 39. Evaluation of a Rapid Immunochromatographic Testfor the Detection of Streptococcus pneumoniae Antigen in Urine Samples from Adults with Community- Acquired Pneumonia ASM: 112, 2001 Murdoch et al, The authors conclude : “ The Now® S. pneumoniae antigen test is a useful adjunct to culture for determining the etiology of community-acquired pneumonia in adults.” 39 39
  • 40. 40 40
  • 41. Immuno-Chromatographic Test v.s. Latex Agglutination Test Now Wellcogen 108 CFU/ml* Positive 108 CFU/ml Positive 107 CFU/ml Positive 107 CFU/ml Negative 106 CFU/ml Positive 106 CFU/ml Negative 105 CFU/ml Positive (weak) 105 CFU/ml Negative 104 CFU/ml Negative 104 CFU/ml Negative * Adjust cell suspension of S. pneumoniae to 0.5 McFarland ( 108 CFU/ml ) 資料來源:林口長庚兒童醫院臨床檢驗組 90.01.05 測試者王碧娥組長 41 41