Specimen collection dr manar-nursing
- 1. Specimen collection DR. MANAR AKAS MICROBIOLOGY & IMMUNOLOGY 11/feb/2015 DR. MANAR 1
- 2. Specimen collection: key issues What is your differential diagnosis? What test(s) you should conduct? How to collect appropriate samples ? 11/feb/2015 DR. MANAR 2
- 3. Successful laboratory investigations Advance planning Collection of adequate and appropriate specimens Sufficient documentation Biosafety and decontamination Correct packaging Rapid transport Choice of a laboratory that can accurately perform the tests Timely communication of results 11/feb/2015 DR. MANAR 3
- 4. Transport medium Allows organisms (pathogens and contaminants) to survive Non-nutritive - does not allow organisms to proliferate For bacteria – i.e., Cary Blair For viruses - virus transport media (VTM) 11/feb/2015 DR. MANAR 4
- 5. specimens type ◦ Urine ◦ Stool ◦ Sputum ◦ Wound drainage/puss ◦ Blood 11/feb/2015 DR. MANAR 5
- 6. Why a urine specimen ? Urinary Tract Infection (UTI) ◦ Frequency ◦ Urgency(An immediate unstoppable urge to urinate) ◦ Dysuria (painful urination) ◦ Hematuria(blood in urine) ◦ Flank pain ◦ Fever Culture = ? Bacteria growing Sensitivity = which antibiotics are effective Midstream Urine Sterile Catheter Specimen (never from bag) Random Clean Female ? Menstrual details Tested for: ◦ Specific gravity ◦ pH ◦ Albumin ◦ Glucose ◦ Microscopic exam To lab 15-20min post collection 11/feb/2015 DR. MANAR 6
- 7. Stool Specimen Analysis of fecal material can detect pathological conditions i.e: infection, hemorrhage, tumors. Tests ◦ Occult Blood ◦ Bacteria ◦ Ova & Parasites Note the: 1-Color ◦ Melena (black stools) 2-Odor 3-Consistency Medical aseptic technique To lab on time Labelling /Documentation 11/feb/2015 DR. MANAR 7
- 8. Stool samples for bacteria Timing ◦ during active phase Method ◦ Cary-Blair medium ◦ For Ag detection/PCR – no transport medium Storage ◦ refrigerate at 4oC if testing within 48 hours, store at -15oC for Ag detection and PCR Transport ◦ 4oC (do not freeze); dry ice for Ag, PCR detection 11/feb/2015 DR. MANAR 8
- 9. Stool samples for parasites Timing ◦ as soon as possible after onset Sample amount and size ◦ at least 3 x 5-10 ml fresh stool from patients and controls Storage ◦ refrigerate at 4oC; store at -15oC for Ag detection and PCR Transport ◦ 4oC (do not freeze); dry ice for antigen detection and PCR 11/feb/2015 DR. MANAR 9
- 10. Respiratory Tract Tests to determine infection ◦ Throat cultures ◦ Sputum specimens Upper respiratory/ throat infections Throat swabs ◦ before meal or 1 hr after meal ◦ Wash hands, glove ◦ Tilt head backward ◦ “ah” ( if pharynx not visualized, tongue depressor, anterior 1/3 of tongue) ◦ Don’t contaminate 11/feb/2015 DR. MANAR 10
- 11. Nose & Throat cultures Nose, Oropharynx & tonsillar Sterile swab Insert swab into pharyngeal region Take swab from reddened areas/ exudate Culture determines pathogenic microorganisms Sensitivity determines the antibiotics to which the microorganisms are sensitive or resistant 11/feb/2015 DR. MANAR 11
- 12. Sputum collection Ordered to identify organisms growing in sputum Culture & Sensitivity AFB (acid fast bacilli) 3samples in 3 consecutive days, early morning ◦ Cough effectively,avoid postnasal discharge and saliva ◦ 1 ml minimum volume Record ◦ Color ◦ Consistency (thickness) ◦ Amount ◦ Odor ◦ Document date & time sent to lab. 11/feb/2015 DR. MANAR 12
- 13. Blood for smears Collection Capillary blood from finger prick ◦ make smear ◦ fix with methanol Handling and transport Transport slides within 24 hours Do not refrigerate (can alter cell morphology) 11/feb/2015 DR. MANAR 13
- 14. Blood for cultures Collection Requires aseptic technique Venous blood ◦ infants: 0.5 – 2 ml ◦ children: 2 – 5 ml ◦ adults: 5 – 10 ml Collect within 10 minutes of fever ◦ if suspect bacterial endocarditis: 3 sets of blood culture 11/feb/2015 DR. MANAR 14
- 15. Blood for cultures Handling and Transport Collect into bottles with infusion broth ◦ change needle to inoculate the broth Transport upright with cushion ◦ prevents hemolysis Wrap tubes with absorbent cotton Travel at ambient temperature Store at 4oC if can’t reach laboratory in 24h 11/feb/2015 DR. MANAR 15
- 16. Cerebrospinal fluid (CSF) Collection Trained person Aseptic conditions Lumbar puncture Sterile tubes 11/feb/2015 DR. MANAR 16
- 17. CSF Handling and transportation Bacteria ◦ Medium pre-warmed to 25-37°C before inoculation OR ◦ transport at ambient temperature (relevant pathogens do not survive at low temperatures) Viruses ◦ transport at 4-8oC (if up to 48hrs or -70oC for longer duration) 11/feb/2015 DR. MANAR 17
- 18. Labeling specimens Patient’s name Clinical specimen Unique ID number Specimen type Date, time and place of collection Name/ initials of collector
- 19. Thank you Questions? DR. MANAR AKAS 19