Objective:To establish and evaluate a rapid nucleic acid detection method for SARS-CoV-2 based on COYOTE ? Flash20 real-time fluorescent quantitative PCR instrument. Methods:A rapid reaction system was constructed by using specific primer and probe sets targeting ORF1ab and N gene of SARS-CoV-2, and the sensitivity and specificity of the system were verified. At the same time, 108 clinical samples of COVID-19 were used to evaluate the application of this method.Results:The detection method did not require nucleic acid extraction, and the manual operation time was only one minute. After the sample was sent to the system, the test could be completed in 30 minutes. The detection limit of this method was 4×10 2 copies/ml. It had no cross-reactivity with other human coronaviruses (including HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, SARS-CoV and MERS-CoV) and other respiratory viruses. The evaluation of clinical sample application showed that the total coincidence rate with the conventional RT-qPCR which required nucleic acid extraction was 98.15%. Conclusions:Through the application evaluation of the rapid fluorescent quantitative PCR method of SARS-CoV-2, it was found that the method was simple, fast, specific and sensitive, and it was suitable for real-time and rapid detection needs in varieties of situations.

Objective: To identify the etiology and source of infection in a diarrhea outbreak in Yunnan in May 2017 and to provide the evidence for formulating prevention and control measures. Methods: Epidemiological investigation was carried out on the epidemic situation of diarrhea in the village of Lvchun County in Yunnan Province, the field sampling, laboratory testing and data analysis were also performed. Results: Among the 44 patients, 11 of the 13 samples were positive for rotavirus nucleic acid in group A, and the positive rate was 84.62%. The survey showed that the water supply pipe was damaged and polluted by human and livestock manure and domestic sewage. The trend of the damaged water pipe was basically the same as the case distribution, and the rainfall was significantly related to the number of the disease. Conclusions This event was an outbreak of diarrhea caused by group A rotavirus. The direct pollution of drinking water caused by rainfall may be the risk factor of this outbreak. The health management of rural drinking water should be strengthened and the health knowledge and education of preventing intestinal infectious diseases should be promoted.