Question

1- what are the outpatient collection area using POCT?

2- recommendation of a safe efficient testing area for COVID-19

3- what are the precautions used to prevent COVID-19 infection

Answer 1

1) The outpatient collection area using the POCT are :-

- outside the hospital

- onsite or home self collection

2) Steps to be followed for specimen collection using aseptic method:

1. Nasal swab and/or throat swab specimens is to be collected as per GOI

guidelines.

2. Sample collection area should be kept clean and table or work surface

should be properly disinfected with surgical spirit.

3. Collect required details from the patient and fill the sample collection form.

4. Ensure that patient is seated in a comfortable seating position.

5. Clearly explain the sample collection procedure to ensure full cooperation from the patient.

6. Wear appropriate personal protective equipment (PPE) such as gloves, apron, N95 mask, head cap, goggles before starting the procedure.

7. Label the specimen collection vial containing VTM with the unique participant/ sample ID.

8. Specimen should be collected under good illumination.

9. Throat/ oro-pharyngeal swab collection

a. Gently tilt the patient’s head back

b. Steady the chin

c. Ask the patient to open his/her mouth

d. Use a disposable tongue depressor to hold the tongue well

e. Insert a sterile swab

f. Swab both the tonsils and the posterior pharynx vigorously with a rotating motion, till the patient starts to gag

g. Remove the swab without touching the tongue.

h. The swab is then placed in the labelled tube containing VTM

i. The applicator stick is broken off at the indicated mark (if provided) or at below the level of the tube opening

j. Close and tightly screw cap the tube.

10. Nasal swab collection

a. Take a fresh sterile swab

b. Gently tilt the patient’s head Backwards and steady the chin

c. Insert the swab into the nostril parallel (1-2 cm) to the palate until the resistance is met at turbinate

d. Hold the swab in that position for few seconds and then withdraw slowly in a firmly rotating motion (5 times clockwise and 5 times anticlockwise).

11. Appropriate precautions should be taken in collecting specimens since this may expose the lab technician/ sample collector to respiratory secretions from the patient.

12. Specimens from both nostrils are obtained with the same swab vigorously, irrespective of nasal congestion if any.

13. The nasal swab is placed in the same VTM tube containing throat swab. The applicator stick is broken off as done for throat swab and the tube is screw capped tightly.

14. The vial is then placed in the cool box containing tube rack in between the frozen gel packs.

3. Sample handling at collection site:

1. A unique specimen ID is written/ pasted on each VTM sample by the lab technician.

2. VTM containing samples are to be kept in cool box immediately after collection.

3. VTM tube IDs are cross checked with the details in the filled sample collection form.

4. If the specimens cannot be sent to the laboratory within specified time frame

(refer table on page 1), they should be stored at or below –70°C in ultra-low freezer.

5. Repeated freezing and thawing must be avoided.

4. Transportation of samples from field site to testing laboratory:

1. Samples should be transported at 2-8°C within specified time frame to the testing laboratory.

2. Samples should be kept in proper standing position in appropriate test tube rack.

3. The VTM containing part of the tube should be in direct contact with frozen gel packs.

5. Precautions:

1. Always use personal protective equipment (PPE) e.g. Laboratory apron/ gown, face mask, gloves and goggles.

2. Wipe gloves thoroughly with a disinfectant (e.g., surgical spirit) before and after taking the sample.

Current testing modalities for laboratory diagnosis of COVID-19

1. Real Time PCR testing is the recommended testing for COVID-19 diagnosis.

2. Viral RNA is extracted from the Nasal/ throat swab specimen in VTM.

3. Initial Screening RT PCR involves detection of ‘E’ gene (coding for SARS-CoV-2 viral envelope)

4. Confirmation of samples positive in screening PCR involves detection of one of the following two gene targets:

o RdRp gene (coding for SARS-CoV-2 RNA dependent RNA Polymerase)

o ORF gene (coding for SARS-CoV-2 Open Reading Frame)

3. Prevention methods :-