The important point determining the accuracy of carrying out researches on COVID-19 is the correct intake of material for carrying out a research. At the wrong intake of material, its wrong storage or transportation, the risk of false-negative results is high that can lead to wrong diagnostics and refusal of holding anti-epidemic actions where they are shown.
As an initial research on COVID-19 the fence and assessment of a smear from the upper airways (a nasopharynx (NG)) is recommended. If the fence of an oropharyngeal smear (RG) is made, it is located in one test tube together with a smear from NG; at the same time the smear from the RG has the smaller importance, than a smear from NG.
Only patients with damp cough are subject to the procedure of a fence of a phlegm. Stimulation of formation of a phlegm is not recommended. If there are samples from the lower respiratory tracts, they are also subject to testing.
In the presence of clinical indications (i.e. if to the patient artificial ventilation of the lungs is carried out), the fence and a research of material from the lower respiratory tracts is made or the fence of bronchoalveolar allocations is made. In this case the intake of material is carried out in intensive care units and resuscitation. At the intubated patients it makes sense to carry out an intake of endotracheal aspirate or the samples received during bronchoalveolar lavage for carrying out not only analyses on COVID-19, but also other analyses: PTsR panel of atypical activators (mycoplasmas, chlamydias, legionella), panel of respiratory viruses. Also it makes sense to conduct other researches if the etiology of heavy pneumonia is not defined: antigen definition legionell in urine, an antiserum capacity to a mycoplasma, crops on tuberculosis, researches on opportunistic pathogens at patients with the weakened immunity.
It has to be collected immediately as soon as was suspicion on COVID-19 is established, regardless of when symptoms appeared. At the time of sampling the sanitary and epidemic mode has to be observed. The personnel have to be taught the technique of capture of smears.
The samples taken from the lower respiratory tracts
Bronchoalveolar lavage, tracheal aspirate
From 2 to 3 ml of a sample in a sterile, sealed container for a fence of a phlegm which twists a cover with a carving, or in a sterile dry container have to be collected.
Phlegm
The patient should rinse a mouth water and after deep cough to otkashlyanut a phlegm directly in a sterile, sealed container for a fence of a phlegm which twists a cover with a carving, or in a sterile dry container.
The samples taken from the upper airways
Smears from noso-/stomatopharynxes
For a fence the probe tampon only from synthetic fiber is used. Probes from calcium alginate or probes on a wooden core should not be used, both from which can inactivate some viruses and inhibit the polymerase chain reaction (PCR). Probes have to be immediately placed in the sterile test tubes containing 2–3 ml of the virus transport environment. As a rule, recommend to carry out sampling only from NG. When the fence is made also from the RG, it has to be placed at a fence together with a smear from NG in one test tube.
For a sample fence from NG, the probe has to be entered into a nostril parallel to the sky on depth equal to distance from a nostril to an opening of an external ear. In order that allocations were absorbed, the probe has to be left in an injection site for several seconds. Then it has to be slowly taken. At extraction of the probe the employee who is carrying out a fence has to rotate it. At a sample fence from the RG (i.e. a smear from a pharynx) a back part of a throat has to be processed by a tampon, at the same time it is necessary to avoid contact with language.
Washout/aspirate from nasopharynx / aspirate from a nasal cavity
From 2 to 3 ml of a sample in a sterile, sealed container for a fence of a phlegm which is closed by a cover which twists with the help sowed on it carvings, or in a sterile dry container have to be collected.
Storage conditions
Samples are subject to storage at a temperature from 2 to 8 °C within no more than 72 hours from the moment of a fence. In case of transferring of terms of carrying out a research or delivery of samples, samples are subject to storage at a temperature of -70 °C and below.
Delivery
Packing, delivery and transportation of samples is made according to rules of transportation of the dangerous freights developed for each concrete state. Samples are subject to storage at a temperature from 2 to 8 °C within no more than 72 hours from the moment of a fence and are brought to laboratory an isothermal container next day. The samples subjected to freezing at a temperature of -70 °C have to be placed in a container with dry ice and are brought to laboratory next day.