Con el fin de guiar a varias localidades para llevar a cabo el trabajo de detección de recolección mixta de COVID-19 y mejorar aún más la capacidad y eficiencia de detección de ácido nucleico., El Equipo de Rescate Médico del Mecanismo Conjunto de Prevención y Control del Consejo de Estado dio a conocer recientemente el “Especificaciones técnicas para la recolección y detección mixta 20 en 1 de ácidos nucleicos COVID-19”.
los “Especificación” se divide en 10 parts, mainly including: sample collection consumables specifications, collection site requirements, proceso de cobranza, specimen submission, laboratory reception, specimen testing and quality control, test result processing, post-test sample processing, technicians Basic requirements, biosafety protection, etc.. The technical specifications are as follows…
Sample Collection Consumables
1. tubo de muestreo de virus. The cap and body should be made of polypropylene, with a sealable screw opening and moderate tightness. The tube body is transparent and has good visibility. The height of the collection tube (including the cap) es (100±5) mm, the capacity is 20-30ml, and the volume contains 11-12ml of guanidine salt or other effective virus inactivator preservation solution. The preservation solution should have a color that is easy to observe and identify (such as pink), and maintain a certain fluidity for easy sampling.
2. Collection swabs. Swabs made of non-cotton and non-calcium alginate materials such as polyester and nylon should be used, and the handle should be made of non-wood materials. The breaking point is located about 3cm from the top of the swab head, which is easy to break.
Collection Site Requirements
Choose an open and well-ventilated site as a centralized collection site for large-scale population screening. According to the original site conditions, it is divided into a waiting area, a collection area, a buffer area and a temporary isolation area to effectively disperse the density of people to be inspected. First aid equipment should be provided for backup.
1. Waiting area. Pedestrian passages are set up, and a one-meter line is set up to ensure the protection and safety of waiting staff. Equipped with thermal insulation, cooling, shading, rain and other facilities according to weather conditions. The elderly, niños, pregnant women and others with limited mobility are given priority for collection.
2. Collection area. According to the climatic conditions, it is equipped with tents, cooling/heating fans, appropriate tables and chairs to ensure that medical staff work in a relatively comfortable environment. Equipped with disinfection supplies for collection, hisopos, virus collection tubes, and prepared tissues, vomit bags and masks for the inspected personnel. If the specimen cannot be transported to the laboratory in time, a 4°C refrigerator or a low-temperature storage box should be prepared for temporary storage. Emergency plans to prevent the spread and infection of pathogenic microorganisms should be formulated.
3. Buffer. The space should be relatively airtight, allowing the collection personnel to replace personal protective equipment, and place protective equipment that matches the size of the sampling site, disinfection supplies for collection, swabs and collection tubes, and outdoor sterilization equipment.
4. Temporary isolation area. Used to temporarily isolate suspected patients or high-risk groups found during collection.
Collection Process
1. Identification and information registration.
(1) Registration process. The staff assigns 20 subjects to a group before collection, collects and registers relevant information of the subjects (including name, género, ID number, contact number, collection location, collection date and time) before collection, according to the group Carry out the collection tube numbering. Due to the relatively large number of 20 gente, in order to avoid confusion among different groups of people, a 2-meter line can be used to strictly separate the next group of waiting people from the group being collected. Group personnel can enter the sampling area in an orderly manner.
(2) Registration requirements. It is recommended to use information means such as ID card readers and QR code barcodes to correlate the subject’s information to improve the efficiency and accuracy of information reading.
2. Método de recolección. The head of the person being collected is slightly tilted, the mouth is wide open, and an “ah” sound is made, exposing the pharyngeal tonsils on both sides. Wipe the back wall up and down at least 3 veces. After the operation, put the swab head into the tube, place the swab breaking point at the mouth of the tube, and break it with a little force so that the swab head falls into the liquid in the collection tube, discard the broken swab rod, and tighten the tube. cover and place the collection tube on a stable rack. After the collection of each case, the collection personnel should disinfect their hands.
3. Mixed swabs. The remaining 19 swabs were collected in sequence according to the above collection method, and the collected swabs were placed in the same collection tube with gentle movements to avoid the generation of aerosols. After collecting 20 swabs in a row, tighten the cap to prevent spillage. Note that the throat swab needs to be immersed in the preservation solution. If there are less than 20 swabs in the collection tube, special marks should be made and recorded.
Specimen Submission
1. Check the information. Check the label of the collection tube and the information on the mixed collection registration form to ensure that it is accurate and complete, and the numbering is consistent.
2. Specimen placement requirements. Put the checked collection tube into a transparent plastic sealed bag (one-layer container) and seal the bag tightly, and spray the outside of the sealed bag with 75% ethanol. Put the sealed bag into a two-layer container (optional packaging box with an appropriate amount of hygroscopic material or double-layer medical garbage bag), and spray with 75% ethanol for disinfection after sealing. Put the second-layer container into a special specimen transfer box with the “biohazard” label (it is recommended to use a transfer box that conforms to the UN2814 standard for the transport of Class A items in the “Technical Rules for the Safe Transport of Dangerous Goods by Air”). Place a cooling gel ice pack. The secondary container should be secured in the transfer box to keep the specimen upright. After sealing the transfer box, spray and disinfect with 75% ethanol, and the surface of the transfer box is clean and free from pollution.
3. Specimen transfer requirements. Standard transfer boxes should be transported by specialized specimen transporters. Specimens should be sent to the laboratory within 2-4 horas de recogida. If it cannot be sent for inspection immediately, a special refrigerator or freezer shall be provided for preservation, and the specimen reception and preservation registration shall be made. Specimens can be stored at 4°C within 24 hours after collection.
Laboratory Reception
1. Specimen receipt. Shipping and receiving personnel should double sign for specimens. The receiving personnel check whether the transfer box and the second-layer container are damaged.
2. The specimen is opened. The transfer box should be opened in the core area of the biosafety secondary laboratory, and the secondary container should be taken out. Open the two-layer container in the biological safety cabinet, spray or wipe with 75% ethanol for disinfection, take out the sealed bag, spray or wipe with 75% ethanol reagent for disinfection, and check whether the seal is intact.
3. Examination of specimens. Take out the collection tube and check whether the tube wall is damaged or leaking at the nozzle. After confirming that there is no damage or leakage, spray or wipe with 75% ethanol for disinfection. If there is any damage or leakage, the operation should be stopped immediately, covered with absorbent paper, and then disinfected with 0.55% chlorine-containing disinfectant, and the unqualified registration should be completed before destruction.
4. Preservation of specimens. Specimens that cannot be detected in time should be stored in a special refrigerator. Specimens tested within 24 hours can be stored at 4°C. Specimens that cannot be detected within 24 hours should be stored at -70°C or below. If there is no -70°C storage condition, it will be temporarily stored at -20°C. Avoid repeated freezing and thawing of specimens. Set up a special library or counter to preserve specimens, and manage with double locks.
5. The transfer container is removed. Después de su uso, the inner and outer walls of the two-layer container were wiped and disinfected with 75% ethanol, and then removed from the biological safety cabinet.
Specimen Testing and Quality Control
Follow the relevant requirements of the “COVID-19 Nucleic Acid Detection Work Manual for Medical Institutions (Trial Second Edition)”.
Test Result Processing
The COVID-19 nucleic acid qualitative test report should include test results (detected/positive, undetected/negative), methodology, detection limit, etc..
1. Judgment of results. According to the instructions of the amplification reagent used, the test result is judged as undetected/negative or detected/positive.
2. Review of positive results.
(1) If the mixed collection test result is positive, gray area or single target positive, notify the relevant department to temporarily isolate the 20 subjects in the mixed collection tube, and re-collect a single-tube swab for review.
(2) If the single-tube nucleic acid test is negative, it will be reported as a negative result. Temporary isolation personnel are released from isolation; if the test results are positive, they will be reported according to procedures.
Post-Test Sample Processing
Specimen processing after testing shall be carried out in accordance with the relevant requirements of the “Guidelines for the Implementation of COVID-19 Nucleic Acid Testing Organizations for All Staff (Second Edition)”.
Technicians Basic Requirements
Sampling personnel and testing personnel should meet the requirements of the “Medical Institutions Novel Coronavirus Nucleic Acid Detection Work Manual (Versión de prueba 2)”.
Biosafety Protection
The protection of specimen collection and transportation personnel and laboratory staff shall be carried out in accordance with the relevant requirements of the “COVID-19 Pneumonia Prevention and Control Plan (Eighth Edition)”.
Fuente: National Health Commission
