1, polymerase chain reaction: fluorescence quantitative PCR, which is suitable for a large number of specimens and has low cost.

2. Second-generation gene sequencing: NGS method is more accurate, which generation of nucleotides and viruses can be read out, such as the complete data of Delta virus nucleotide sequence, which are all in the database. If the detected virus is compared with the complete data, it is Delta virus.

3. There will be small variations in the process of circulation, even the first generation and the second generation are different, and small differences can be found through comparison. Therefore, we can find out who and where the first generation of patients, namely 1, came from during this local community outbreak, and NGS method is better for virus traceability.

4. Both methods have their own advantages and disadvantages, which can accurately reflect whether the nucleic acid test is positive or not, and can achieve the purpose of detection. If traceability is required, the collected virus nucleotides will be compared with virus databases in all databases, thus helping diagnosis and guiding treatment.

Collect saliva, throat swabs and other samples from patients. Genetic material is extracted from saliva or throat swab samples of patients. If the patient carries the virus, the sample will contain the viral genetic material RNA. Perform RNA reverse transcription on the extract, and reverse transcribe RNA into CDNA. PCR amplification was carried out with virus CDNA as specific primer.