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Environmental sampling codes for investigation and disposal of COVID-19 epidemic (China First edition)

Environmental sampling codes for investigation and disposal of COVID-19 epidemic (China First edition). Standardize environmental sampling operations in epidemic management.

Environmental sampling codes for investigation and disposal of COVID-19 epidemic (China First edition).

1 Purposes

In order to further improve the prevention and control of the COVID-19 pneumonia epidemic in Beijing, and standardize the environmental sampling operation in the treatment of the epidemic, this specification is formulated.

2. Scope of application

Environmental sampling operations in areas such as confirmed cases, suspected cases, asymptomatic infected persons and close contacts, etc., in the residential areas, public places involved, and working places.

3. Basic requirements

(1) The sample transportation unit shall obtain a certificate for transportation of highly pathogenic microorganisms (virus) or samples issued by the administrative department of health.

(2) The sampling personnel should undergo sample collection technology and biosafety training before taking up their posts, and master personal protection requirements, personal protective equipment putting on and taking off methods, sample collection requirements, collection operation procedures, sample storage and transportation requirements and other relevant technical content.

(3) The materials used for sampling shall comply with the requirements of relevant national standards.

4. preparation before sampling

(1) Pre-sampling plan

The content includes: sampling purpose, sampling personnel and division of labor, sampling time, sampling location and location, sampling method, sampling quantity, etc.

(2) Personnel preparation

1. The sample collection staff should have a good division of labor, with no less than 2 people in each group, responsible for sample collection, preparation of sampling sheets and sample numbers on sampling tubes, and disinfection during and after sampling.

2. Before entering the sampling site, the sample collector should take personal protection and select appropriate protective equipment according to the risk level of the sample collection area. Before and after sampling, the personal protective equipment should be put on and taken off according to the requirements of the specification. The same group of people should check whether the personal protection meets the requirements.

(3) Material preparation

1. Personal protective equipment

Sufficient and compliant personal protective equipment should be prepared in accordance with the requirements for epidemic prevention and control and on-site conditions.
When sampling the environment of confirmed cases, suspected cases, asymptomatic infected persons and their close contacts, it should include disposable medical hats, medical protective masks, medical disposable protective clothing, disposable latex gloves or nitrile gloves, and protective clothing. Eyepieces (or disposable face screen) and disposable protective shoe covers.
Other environmental sampling should include disposable medical caps, medical surgical masks, disposable surgical gowns, disposable rubber gloves and disposable protective shoe covers.

2. On-site sampling supplies
It should include a virus collection tube (should be made of polypropylene, the screw mouth can be sealed, and the tightness is moderate. The tube is transparent, has good visibility, and contains a preservation solution that is easy to observe and identify the color), a collection swab (polyester, Nylon and other non-cotton, non-calcium alginate swabs, and the handle is non-wood material. The breaking point is about 3 cm from the top of the swab head, which is easy to break.), sample sampling record sheet, sample label (can be advanced Affixed to the collection tube), signature pen, marker pen, ziplock bag, mobile phone for on-site contact and taking pictures, quality control samples, clean sampling bag, medical waste collection bag, disinfectant (hand disinfectant, environmental disinfectant) and Disinfect utensils.

3. Storage and transportation supplies
It should include cooling gel ice pack (or ice row) and sample transfer box, transfer bucket, cleaning item storage box, and transportation vehicle.

5. sampling frequency

(1) The confirmed cases, suspected cases, asymptomatic infected persons, and close contacts of the residences, public places, and workplaces involved shall be sampled once after the flow of people is controlled and before full professional disinfection. The floors where confirmed cases, suspected cases, and close contacts are located should be single-collected, and other floors can be mixed.

(2) Conduct a recheck sampling of the positive area (recheck sampling is still required after the environment has been fully disinfected).

(3) The frequency of environmental sampling for traceability can be determined according to needs.

6, sampling site

(1) The residences and related public areas of confirmed cases, suspected cases, asymptomatic infected persons and close contacts shall be collected at each of the following points:

1. The contact point of the door handle, doorbell, fingerprint unlocking hand of the residence;
2. Toilets: toilet door handles, various faucet handles, towels, mops, areas frequently contacted by personnel, toilet flush buttons, toilets, floor drains, wall switches, mouthwash cups, toothbrushes;
3. Living room: various remote control surfaces, sofa and coffee table armrests or countertops, window handles, wall switches, telephone (hand contact part) (if any), water cup;
4. Kitchen: kitchen door handles, frozen and refrigerated food remaining in the refrigerator, refrigerator door handles, sinks, cooking utensils, dining tables, etc. often touch locations, knives, chopping boards, wall switches, range hood buttons, trash cans;
5. Bedroom: bedroom door handles, closet door handles, bedside countertops, bed sheets, quilt covers (parts in contact with the human body), lamp switches, drawer handles, pillow towels, tissue boxes, wall switches, remote control switches, etc. which are easily accessible by personnel;
6. Public areas in the residential community: public facilities and equipment in the community, trash cans, old recycling machines, ready-made water dispensers, express cabinets, etc.;
7. The public area of the building where the residence is located: unit door access control, handles, corridor stairs handrails, elevator internal buttons and external buttons on each floor, corridor doors and door handles for residents on each floor, etc.;
8. The public areas of other buildings in the community: elevator internal buttons, sampling at a 30% ratio of the corridor stair handrails, the external buttons of the elevators on each floor, corridor doors and door handles of residents;

(2) The workplaces of confirmed cases, suspected cases, asymptomatic infected persons and close contacts shall be collected at each of the following points:

1. Public toilets: faucets, various door handles, buttons, squatting toilets or toilets, mops, floor drains; (if any) dining area and kitchen in the canteen;
2. Work surface, keyboard, seat armrest, water dispenser button, air conditioner remote control, work utensils, trash can;
3. Door and window handles, express cabinets, fingerprint readers, etc.;

(3) In public places involving confirmed cases, suspected cases, asymptomatic infected persons and close contacts, the key areas shall be determined based on the circulation situation. The following key areas in different public places shall be collected, and other areas shall be sampled at a rate of 30% :

1. Shopping malls and supermarkets: fire exits, various door handles and buttons of shops, escalator handrails, elevator buttons, shelves, cashier counters, clean rooms, toilets, trash cans and other personnel often contact locations;
2. Hotel: every room handle, clean room, toilet door handle, towel, faucet and toilet button, floor drain, various remote controls, switches, air conditioning vents, various door handles in public areas, elevator buttons, trash cans, etc. Touch site
3. Dining room: door handle, cash register, dining table and chair, tissue box, back kitchen chopping board, knives, kitchen utensils, freezer refrigerator handle, inner and outer surfaces and contents, cleaning utensils, trash can;
4. School: all kinds of doorknobs, chalk, blackboard eraser and blackboard, podium, water dispenser buttons, toilets and other public areas, clean rooms, various switches, desks and chairs, sports equipment and teaching utensils, trash cans, etc.

(4) Other places
In other places, sampling points should be reasonably determined according to the length of stay of confirmed cases, suspected cases, asymptomatic infected persons, and close contacts, and contact locations. Sampling should be conducted in areas that are in frequent contact with the human body, especially respiratory droplets, excreta, and vomit, and close contact with hands, lips, and other objects that may be contaminated by viruses.

(5) Description of sampling site
1. Various handles include room door handles, unit door handles, corridor door handles, furniture handles, electrical appliance handles, car door handles, shopping cart (basket) handles, outdoor fitness equipment handles, etc.;
2. All kinds of handrails include staircase handrails, seat handrails, nursing bed handrails, bus handrails, bicycle handlebars, etc.;
3. Switches include lamps, air conditioners, exhaust fans, electrical appliances and other switches;
4. Various types of buttons include toilet buttons, calculator buttons, community water vending machine buttons, car buttons, POS machine password buttons, etc.
5. The sampling personnel should determine other parts that may be at risk according to the flow regulation information to collect samples.

(6) Sampling area and quantity
1. Smear at least an area of 10cm×10cm on the surface of each object to be collected, and collect the entire area if it is insufficient.
2. See the attached table for the sampling number of various objects.

7.collection operation

(1) When performing single-site sampling, your fingers should hold the top of the other end of the collection swab head, dip the virus sampling solution to make the collection swab wet, and evenly apply back and forth on the appropriate part of the surface of the object to be collected while rotating the collection swab . After the application is complete, put the swab head into the tube, place the swab breaking point at the mouth of the tube, break it slightly to make the swab head fall into the liquid in the collection tube, and throw the swab stick in the hand into the medical waste garbage In the bag, screw the tube cap tightly, put a label on the collection tube, mark the sample number (if it has been affixed and numbered in advance, measures should be taken to ensure the traceability of the sample), and place the collection tube on a stable shelf.

(2) When performing mixed sampling, multiple objects of the same kind can be combined and collected as a mixed sample according to the site conditions. When sampling, collect the remaining swabs in sequence according to the above-mentioned collection method, and put the collected swabs into the same collection tube with gentle movements to avoid splashing of liquid in the tube. After collecting multiple swabs continuously, tighten the tube cap to prevent spillage. You can also apply the same swab to multiple parts in sequence. There should be no more than 10 mixed mining locations, and the information of all collection locations should be recorded in the collection record to ensure traceability.

(3) Precautions for sample collection

1. Sample contamination caused by human factors should be avoided during the collection process. Sampling personnel should keep their hands clean. Except swabs during the sampling process, hands and other parts of the body should not touch the sampling location. The swab part touched by fingers and fingers should not touch the mouth and inner wall of the collection tube. During the sampling process, the hands of the sampling personnel, the ziplock bag containing the virus collection tube, and the transfer barrel should be disinfected at any time.
2. Disinfection of the collection tube
Wipe the outer surface of the collection tube with 75% ethanol or 1000 mg/L chlorine-containing disinfectant (such as using a marker for sample identification, do not use 75% ethanol to avoid ambiguity in the sample identification).
3. Sample identification and records
The sample identification should be clear and unique; the relevant information on the sample collection record sheet should be accurate and without omission to ensure one-to-one correspondence with the sample and traceability. The sample collection record sheet should be placed in a ziplock bag and sealed, or the sample collection record sheet can be photographed and sent to the laboratory in electronic form. The paper record sheet should be properly disposed of as medical waste.
4. Sample packaging

(1) Put the collection tube into a transparent plastic sealed bag and seal the mouth of the bag tightly, spray the outside of the sealed bag with 75% ethanol or 1000 mg/L chlorine-containing disinfectant.

(2) Put the sealed bag in the transfer bucket, and spray it with 75% ethanol or 1000 mg/L chlorine disinfectant after sealing.

(3) Put the transfer bucket into a sample transfer box that meets the requirements, and place a cooling gel ice pack or ice row between the transfer bucket and the transfer box. The transfer bucket should be fixed in the transfer box to keep the sample upright.

(4) After sealing the transfer box, spray the outer surface of the transfer box with 75% ethanol or 1000 mg/L chlorine disinfectant.

8. Medical waste treatment

The protective equipment taken off by the sample collector and the garbage generated during the sample collection process should be placed in a medical waste garbage bag, tighten the garbage bag, and spray the outer surface of the garbage bag with 75% ethanol or 1000 mg/L chlorine disinfectant. Put it into the second medical waste garbage bag and fasten it tightly, and dispose of it properly according to the medical waste.

9. Sample storage and transportation

(1) The collected swab should be immediately placed in a virus preservation solution that meets the requirements, and placed in a cryogenic container for temporary storage as soon as possible. It is strictly forbidden to store the swab in a liquid that does not meet the testing requirements such as distilled water, and it is strictly forbidden to expose the sample to a high temperature environment.

(2) The samples should be transported to the testing agency as soon as possible in a container that can be kept low temperature. Samples that can be tested within 24 hours can be stored at 4°C, and samples that cannot be tested within 24 hours should be stored at -70°C or below ( Or store at -20°C, but the storage time at -20°C shall not exceed 7 days), and avoid repeated freezing and thawing.

(3) The samples must be in accordance with the latest version of the “New Coronavirus Pneumonia Sample Collection, Packaging, Transportation and Testing Specifications” and the latest version of the “New Coronavirus Infection Pneumonia Prevention and Control Plan” “New Coronavirus Infection Pneumonia Laboratory Testing Technology” The “Guide” and other related accessories shall be packaged and transported as required, and the transfer box should be prevented from tilting or inverting during transport.

10. Quality control

(1) Blank on site

Before sampling, clean objects that have not been contaminated by the new coronavirus are sealed in clean packaging in the laboratory and brought to the site as a blank sample on site. Blank objects and other objects to be tested are collected on site at the same time, packaged together, and transported to the testing organization. The test results are used to check whether the sample is contaminated during the collection process. At least one on-site blank sample shall be set for each batch of samples.

(2) Transportation blank

Before sampling, put the swab that has been smeared on the clean area into the collection tube and seal it, and take it to the site as a transport blank sample. Keep it in a sealed state during sampling, and transport it to the testing organization with the sample. The test result is used to check whether the sample is contaminated during transportation. At least one transport blank sample shall be set for each batch of samples.