1 / 29

LABORATORY DIAGNOSIS OF SYPHILIS

LABORATORY DIAGNOSIS OF SYPHILIS. Lab diagnosis is essential because of the asymptomatic phase in the disease. And also to asses the cure after treatment. IT is done mainly by demonstration of Spirochetes under microscope Antibodies in serum or CSF. MICROSCOPY.

morwen
Download Presentation

LABORATORY DIAGNOSIS OF SYPHILIS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LABORATORY DIAGNOSIS OF SYPHILIS

  2. Lab diagnosis is essential because of the asymptomatic phase in the disease. • And also to asses the cure after treatment. • IT is done mainly by demonstration of • Spirochetes under microscope • Antibodies in serum or CSF

  3. MICROSCOPY • Specimens collected –infectious.so care required PROCEDURE: • Lesion first cleaned with gauze soaked in warm saline & margins-gently scraped so that superficial epithelium is abraded. • Gentle pressure applied at base of lesion & serum that exudes is collected • Wet mount is prepared & observed under DARK GROUND MICROSCOPE

  4. SLENDER SPIRALS

  5. CONTD.. • Treponema pallidum is identified by its slender SPIRAL structure with spiral ends & pointed ends. IMPORTANCE: • Useful in primary , secondary and congenital syphilis. NOTE: Negative results don’t exclude diagnosis of syphilis because of its low sensitivity.

  6. CONTD.. DFA-TP: • Direct fluorescent antibody test-better & safe for diagnosis. • Smears fixed with acetone & sent to laboratory • Requires fluorescent tagged anti –Treponemal antiserum. • More reliable-Specific monoclonal antibody

  7. SEROLOGICAL TESTS • The serological tests that are in practice are: • Standard test for Syphilis – test for antibodies reacting with cardiolipin antigen. • Tests for antibodies reacting with group specific Treponemal antigen • Tests for specific antibodies to pathogenic Treponema

  8. REAGIN ANTIBOBY TESTS • Antigen – CARDIOLIPIN (or) LIPOIDAL antigen • Wassermann complement fixation test(1906) • Modificated method by PANGBORN(1945) • Tube flocculation test of KAHN • Venereal disease research laboratory test(VDRL) • Rapid plasma reagin test(RPR)

  9. VDRL TEST • Slide flocculation test • Term-REAGIN • Principle: patients suffering from syphilis produce antibodies that react with antigen CARDIOLIPIN to produce flocculation that is read by microscope.

  10. Requirements: • VDRL antigen • VDRL diluant • VDRL slide • Microscope • Micropipette16 guage syringe • Water bath • Tips

  11. VDRL antigen: alcoholic solution of composed of 0.03% cardiolipin,0.21% lecithin,0.9% cholesterol. • VDRL slide: glass slide having eight depressions.

  12. SAMPLE PREPARATION: • serum is separated from patient’s blood that is collected & is inactivated . • Sample is allowed to reach room temperature. ANTIGEN PREPARATION: • 4.5ml VDRL diluant is taken & added to vial drop by drop by thorough mixing. • Use limited to 18-24 hours.

  13. Procedure: • VDRL slide is taken. To test well,serum sample is added.(0.05ml) • Positive & negative controls added to their respective wells.(50microL) • With the help of 16 guage syringe,1ml of prepared antigen is added to all wells drop by drop

  14. Antigen & specimen mixed thoroughly using separate tips. • Now,slide is placed on VDRL rotator & rotated for 4min,observed under microscope • Negative & positive controls are observed first to verify the quality of antigen. • No flocculation -negative test well • Flocculation – positive well

  15. If flocculation is observed,screening test is considered REACTIVE.accordingly,it is termed reactive,weaklyreative & non-reactive. • further confirmed by semiquantitative assay • To say it reactive,minimum of 1/8 titre is required. • Non-reactive- less than 1/2 titre.

  16. CONTD..

  17. CONTD.. RPR test : • Antigen – VDRL antigen with fine CARBON particles Advantages: • Evident to naked eye • Time accessible since serum collected does not require heating NOTE:CSF is not recommended testing with the help of this method

  18. CONTD…

  19. CONTD… • BFP TESTS: biological false positive • Reason :cardiolipin is present in mammalian tissue too • Positive in about 1% individuals

  20. CONTD… BFP REACTIONS: • Acute-only for few weeks or months • Due to acute infections,injuries,inflammation • Chronic-greater than 6months • Seen in SLE,leprosy,malaria,relapsingfever,infectiousmononucleosis,hepatitis,tropical eosinophilia

  21. CONTD… REAGIN ANTIBODY : detectable 7-10 days after appearance of primary chancre

  22. CONTD… • Reagin tests are preferred mostly because they become negative on treatment.

  23. GROUP SPECIFIC TREPONEMAL TESTS • Tests using cultivable treponemes as antigen • Reiter protein complement fixation test • Antigen-lipopolysaccharide protein complex derived from treponeme • Sensitivity & specificity-low

More Related