COLLECTION AND HANDLING OF SPECIMENS FOR MICROBIOLOGICAL AND IMMUNOLOGICAL INVESTIGATIONS:

At the end of this seminar, the following should be understood:  Concept of proper specimen collection  Handling of collected specimen  Proper transportation of specimen  Rejection criteria for mishandled specimen.

 Specimen collection is a prior procedure towards a better diagnosis.  Collection should be of a quality, that means; right specimen, collected at right time and transported at a right way to the right laboratory.  Collection should be from a right patient.  Handling ensures right collection and quality of specimen as specified by SOP.

The specimen collected must be labelled and date the container appropriately in the request form. Other details to be included in the request form during the collection include:- Patient full name Patient address Patient sex Date of birth Date and time of specimen collection and ordering. Relevant medication history.

 Apply strict aseptic techniques throughout the procedure.  Wash hands before and after collection.  Collect the specimen at the appropriate phase of disease.  Collect and place specimen aseptically in a sterile and appropriate container.  Ensure that the outside of the specimen container is clean and uncontaminated.  Close the container tightly to prevent leaking of contents.

 Some of the specimens collected in microbiology laboratory -blood -Cerebral spinal fluid -sputum -urine -stool -throat swab -bone marrow -rectal swab -vaginal swab

BLOOD -Collect blood during early stage of disease. -Collect blood during paroxysm of fever since the number of bacteria is higher. -Collect blood in the absence of antibiotic administration for the case of bacterial infections.

Age Volume <2years 2ml 2-5years 8ml 6-10years 12ml >10years 20ml

 Whole blood is required for bacteriological examination  Serum separated from blood is used for serological techniques  Skin antisepsis is IMPORTANT at time of collection of blood sample.

Key; LIGHT BLUE-EDTA Light purple- EDTA ORANGE-ACD solution B RED- GREEN-heparin PURPLE-EDTA

 Essential for diagnosis of any patient with evidence of meninged irritation or affected cerebrum.  Three to 5 millilitres are collected and part of it is used for biochemical,immunological and microscopic examination.

Collect CSF before antimicrobial therapy is started. Collect CSF in a screw capped sterile container. Do not delay transport Store at 37C if delay is in processing is inevitable.

 Sputum is processed in the laboratory for aetiological investigation of bacteria and fungal infections of the lower respiratory tract.Eg MTB.  During collection -Select a good wide mouthed sputum container. -Give the patient a sputum a container with the laboratory serial number written in it. -Instruct the patient to inhale deeply 2-3 times,cough up deeply from chest and spit in the sputum container.

Urine is sterile under normal circumstances. Lower part of urethra and the Genitalia are normally colonized by bacteria which may also cause UTI’s For microbiological examination urine must be collected as a “clean catch-mid-stream” specimen.

Collected for diagnosis of acute infection diarhoeas aetiologies. Collected prior adminstration of antimicrobial. Faeces specimens should not contaminate with urine. Do not collect the specimen from the bed pan 1 to 2g is sufficient. Fresh stool specimen should be received 1- 2hrs of after passage. Store at 2-8C. Modified cary and Blair medium is recommended as a good transport medium

 Depress the tongue with a tongue blade.  Swab the inflammed are of the throat,pharynx or tonsils with a sterile swab taking care to collect the PUS.

 COLLECTED by a doctor and a well trained personell.  Decontaminate the skin overlaying the site from where specimen is to be collected.  Aspirate 1ml or more of bone marrow.  Collect in a sterile screw-cap tube.  Send to laboratory immediately.

 Insert swab at least 2.5cm beyond the anal sphincter so that it enters the rectum.  Rotate it once before withdrawing.  Transport in Cary and Blair transport medium

 Every specimen collected should be considered as a potentially hazardous.  Those delivering,receiving and examining specimens must be informed when a specimen is likely to contain highly infectious.  Such specimen should be labelled HIGH RISK  SIGNS/SYMBOLS such as a red dot,star or triangle to recognize the dangerment of specimen.

 Example of specimens of HIGH RISK include; -sputum for Microbacterium tuberculosis -faecal specimen for vibrio cholerae -fluid from ulcers that contain anthranx bacilli -specimens from patients with suspected HIV infections.

 Specimens require special attention during transportation to the laboratory.  Specimens should be placed UPRIGHT.  For long distance transport it should be placed in three containers -A primary container which has the specimen and is leak proof. -A secondary container which is durable,water proof and made of metal and plastic with a screw cap. -A tertiary container is ussually made of wood or cardbox

 " html /loose.dtd  Cheesebrough M.District Laboratory practice in tropical countries,Volume 2.