Rate Of Nucleic Acid Detection Research Articles

Analysis of respiratory syncytial virus detection outcomes of 973 cases with severe respiratory infection during 2016-2019, Yuhang district of Hangzhou

This study collected nasopharyngeal swab specimens from severe respiratory infection cases in First People's Hospital of Yuhang District during 2016-2019. Real-time PCR was used to detect respiratory syncytial virus (RSV). Rate of RSV positive detection were analysised in different age groups and different months. A total of 973 nasopharyngeal swab specimens of severe respiratory infection cases were collected, and the total positive rate of nucleic acid test of RSV was 6.47%; The detection rate of nucleic acid in male is higher than that in female, with no statistical differences (P=0.023). The positive rate of nucleic acid test was negatively correlated with age. The positive rate was 15.2% in the group aged 0-1 years and 12% in the group aged 1-2 years. There are obvious seasonal differences in the prevalence of RSV, human are easier to infect RSV in spring and winter.

Diagnostic value of combined nucleic acid and antibody detection in suspected COVID-19 cases

ObjectivesNucleic acid testing is the gold standard method for the diagnosis of coronavirus disease 2019 (COVID-19); however, large numbers of false-negative results have been reported. In this study, nucleic acid detection and antibody detection (IgG and IgM) were combined to improve the testing accuracy of patients with suspected COVID-19. Study designThe positive rate of nucleic acid detection and antibody detection (IgG and IgM) were compared in suspected COVID-19 patients. MethodsA total of 71 patients with suspected COVID-19 were selected to participate in this study, which included a retrospective analysis of clinical features, imaging examination, laboratory biochemical examination and nucleic acid detection and specific antibody (IgM and IgG) detection. ResultsThe majority of participants with suspected COVID-19 presented with fever (67.61%) and cough (54.93%), and the imaging results showed multiple small patches and ground-glass opacity in both lungs, with less common infiltration and consolidation opacity (23.94%). Routine blood tests were mostly normal (69.01%), although only a few patients had lymphopenia (4.23%) or leucopenia (12.68%). There was no statistical difference in the double-positive rate between nucleic acid detection (46.48%) and specific antibody (IgG and IgM) detection (42.25%) (P = 0.612), both of which were also poorly consistent with each other (kappa = 0.231). The positive rate of combined nucleic acid detection and antibody detection (63.38%) was significantly increased, compared with that of nucleic acid detection (46.48%) and that of specific antibody (IgG and IgM) detection (42.25%), and the differences were statistically significant (P = 0.043 and P = 0.012, respectively). ConclusionsNucleic acid detection and specific antibody (IgG and IgM) detection had similar positive rates, and their combination could improve the positive rate of COVID-19 detection, which is of great significance for diagnosis and epidemic control.

Laboratory data analysis of novel coronavirus (COVID-19) screening in 2510 patients

BackgroundNovel coronavirus (COVID-19) is highly infectious and requires early detection, isolation, and treatment. We tried to find some useful information by analyzing the covid-19 screening data, so as to provide help for clinical practice. MethodWe collected nucleic acid and hematology data from 2510 patients for COVID-19 infection for retrospective analysis. ResultCOVID-19 and influenza A and B infection rates were 1.3%, 3%, and 3%, respectively. COVID-19 nucleic acid was detected in stool but not in tear samples from 8 positive patients. Among the 32 patients with COVID-19, 15 (47%) and 16 (50%) patients showed decreased lymphocyte count and lymphocyte ratio, 21(66%) and 24(75%) patients showed decreased eosinophil count and eosinophil ratio, and 18 (56%) patients showed increased C-reactive protein. Ten hematological indicators significantly differed in the blood of patients with COVID-19 and those with influenza A and B (P < 0.05). Eighteen hematological indicators significantly differed between patients with COVID-19 and negative patients (P < 0.05). ConclusionThe positive rate of influenza A and B infection was higher than that of COVID-19. When pharyngeal swab collection may cause infection, fecal samples can be examined. Evaluation of pharyngeal swab and fecal samples can improve the positive rate of nucleic acid detection. The COVID-19 can cause some hematological indices changes.

Performance evaluation and clinical application of three antibody test kits for novel coronavirus (SARS-CoV-2)

Objective To evaluate the performance of three antibody kits for novel coronavirus (SARS-CoV-2) and to investigate the feasibility and advantages of them in clinical application. Methods A total of 104 patients who were admitted to Guangzhou Eighth People's Hospital with COVID-19 from January to February 2020 were selected as research group. Fifty-one healthy subjects were selected during the same period as negative control group. Serum antibodies (IgM/IgG) against SARS-CoV-2 were detected using two kinds of colloidal gold kits (A and B kits) and one chemiluminescence kit (C kit). The positive rates of SARS-CoV-2 nucleic acid in different samples from patients with COVID-19 were retrospectively analyzed. Results The clinical sensitivity of A kit to detect SARS-CoV-2-specific IgM and IgG was 77.88% (81/104) and 65.38% (68/104), respectively, and the clinical specificity was 70.59% (36/51) and 100.00% (51/51). However, the false positive rate in IgM detection was as high as 29.41% (15/51). The sensitivity of B kit to test total antibodies to SARS-CoV-2 was 63.46% (66/104), and the clinical specificity was 94.12% (48/51). The clinical sensitivity of C kit to detect SARS-CoV-2-specific IgM and IgG were respectively 31.73% (33/104) and 64.42% (67/104), and the clinical specificity were both 98.04% (50/51). There was a moderate correlation between the detection results of two colloidal gold kits and the chemiluminescence kit with the Kappa values of 0.462 and 0.587 (Z=6.157, P<0.01; Z=7.345, P<0.01). C kit had the highest positive detection rate for IgG, and would be more reliable to be used for IgG detection in COVID-19 patients 14 d after onset. The total positive detection rate of nucleic acid in all types of samples was 63.46% (66/104). The highest positive detection rate was in throat swabs or sputum samples, followed by those in blood samples and anal swabs. No viral nucleic acid was detected in urine samples for the time being. Conclusions SARS-CoV-2-specific antibodies could be detected in the early or late stage of COVID-19. The method of antibody detection has the advantages of shorter detection time, simple operation and high biological safety, indicating that it could be used as a supplementary or auxiliary detection for the diagnosis of suspected COVID-19 cases with negative nucleic acid test results. The chemiluminescence kit has good sensitivity and specificity, and is well recommended for clinical laboratories. Key words: SARS-CoV-2; Chemiluminescence immunoassay; Colloidal gold immunoaasay; Nucleic acid detection; Performance evaluation; Clinical application

Clinical application effect of modified nasopharyngeal swab sampling for 2019 novel coronavirus nucleic acid detection

Objective: To study the clinical application effect of modified nasopharyngeal swab sampling for 2019 novel coronavirus nucleic acid detection. Methods: This study covered the period from January 14 to March 1, 2020.The supine position method and the protective face screen were used to collect nasopharyngeal swabs from February 24 onwards, before which, the nasopharyngeal swabs were collected by sitting position method. All the patients who were diagnosed with suspected/confirmed 2019 novel coronavirus infection were admitted from February 19 with the nasopharyngeal swabs collected outside the hospital before admission. (1) Thirty-four swabbing operators meeting the inclusion criteria of the study were recruited in this retrospective cohort study. They were grouped according to the collection method of nasopharyngeal swabs. Sixteen operators of Wuhan Taikang Tongji Hospital who applied the supine position method and the protective face screen were included in supine position method+ protective face screen group (15 males and 1 female, aged 34-49 years); 18 operators (12 from the First Affiliated Hospital of Army Medical University (the Third Military Medical University), 1 from Wuhan Jiangxia Mobile Cabin Hospital, 5 from the East District of People's Hospital of Wuhan University) who applied the traditional sitting position method were included in sitting position method group (2 males and 16 females, aged 25-49 years). In supine position method+ protective face screen group, when collecting sample, the patient lay flat and wore a special protective face screen for nasopharyngeal swab sampling, with neck slightly extending and face turning to the opposite side of the operator about 10°. The self-designed questionnaire was used to investigate the cooperation, the incidence of nausea, coughing, sneezing, and struggling of patients evaluated by the operators, the operation time for a single swab sample, the fear of operation and the perceived exposure risk of operators in the two groups. (2) Sixty-five patients (22 males and 43 females, aged 25-91 years) admitted to Wuhan Taikang Tongji Hospital who successively received the sitting position method and supine position method+ protective face screen for nasopharyngeal swabs sampling and with complete nucleic acid detection results were included. The positive rates of nucleic acid detection by the two sampling methods of nasopharyngeal swabs of the patients were statistically analyzed. (3) Forty-one patients who could express their feelings accurately were selected out of those 65 patients (12 males and 29 females, aged 27-83 years). The comfort of patients in the process of sampling by the two methods was investigated. (4) Thirty-four patients (10 males and 24 females, aged 25-83 years) with two or more consecutive negative results of nucleic acid detection of nasopharyngeal swabs by sitting position method were selected from the above 65 patients. The positive rate of nucleic acid detection of nasopharyngeal swab of patients by supine position method+ protective face screen, i. e. negative to positive rate was statistically analyzed. Data were statistically analyzed with t test, Wilcoxon signed rank test, and chi-square test. Results: (1) Compared with those of sitting position method group, the cooperation score of patients evaluated by the operators in supine position method+ protective face screen group was significantly higher (Z=-4.928, P<0.01), the incidence of nausea, choking cough, sneezing, and struggling of patients evaluated by the operators, and the fear of operation score and the perceived exposure risk score of operators in supine position method+ protective face screen group were significantly lower (Z=-5.071, -5.046, -4.095, -4.397, -4.174, -5.049, P<0.01), and the operation time for a single swab sample in supine position method+ protective face screen group was significantly longer (t=223.17, P<0.01). (2) The positive rate of nucleic acid detection of nasopharyngeal swabs by supine position method+ protective face screen was 60.00% (39/65), which was obviously higher than 41.54% (27/65) by sitting position method (χ(2)=4.432, P<0.05). (3) The comfort score of the 41 patients during nasopharyngeal swabs sampling by supine position method+ protective face screen was significantly higher than that by sitting position method (Z=-5.319, P<0.01). (4) Of the 34 patients with two or more consecutive negative results of nucleic acid detection of nasopharyngeal swabs by sitting position method, the rate of negative to positive of nucleic acid detection was 26.47% (9/34) after sampling by supine position method+ protective face screen. Conclusions: Compared with the traditional sitting position method, detection of 2019 novel coronavirus nucleic acids of nasopharyngeal swabs collected by supine method combined with protective face screen is worth promoting, because of its better comfort of patients, low exposure risk for operators, in addition to reducing in the false negative result to some extent, which may help reduce false recurrence of discharged patients.

Manifestations of digestive system of hospitalized patients with coronavirus disease 2019 in Wuhan, China: a single-center descriptive study

Objective To study the manifestations of digestive system of hospitalized patients with coronavirus disease 2019 (COVID-19) in Wuhan, China, and to provide a reference for disease control and treatment. Methods The data of hospitalized patients with COVID-19 in the Sino-French Branch of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 27 to February 14, 2020 were retrospectively analyzed, which included general information, positive rate of nucleic acid test, severity of disease, incubation period, initial symptoms and manifestations of digestive system. The general information, positive rate of nucleic acid detection, and manifestations of digestive system were compared between critical patients who required non-invasive or invasive assisted ventilation (critical group) and non-critical patients without assisted ventilation (non-critical group). Continuous corrected Chi-square test and independent sample median Chi-square test were used for statistical analysis. Results Among the 305 patients, there were 146 males (47.9%) and 159 females (52.1%), and the median age was 57 years old. Nucleic acid assay of nasopharyngeal swabs or pharyngeal swabs were positive in 84.1% (228/271) patients including 46 patients (15.1%) of critical group and 259 patients (84.9%) of non-critical group. The incubation period was one to fifteen days, and the median period was six days. The initial symptoms were mainly fever (81.1%, 163/201), cough (39.3%, 79/201), fatigue (54.7%, 110/201), and loss of appetite (50.2%, 101/201). In one to ten days after the disease onset, 79.1% (159/201) of patients developed gastrointestinal symptoms including nausea (29.4%, 59/201), vomiting (15.9%, 32/201), or abdominal pain (6.0%, 12/201). 49.5% (146/295) of patients had diarrhea, with a median time of 3.3 days, (3.3±1.6) times per day, and a duration of (4.1±2.5) days. After excluding possible drug-related diarrhea, the incidence of diarrhea was still 22.2%. Only 6.9% (4/58) of patients had positive fecal leukocytes or fecal occult blood test. Alanine aminotrans ferase (ALT), aspartate aminotransferase (AST), or total bilirubin (TBil) increased in 39.1% (119/304) of patients on admission. Patients with ALT or AST ≥ 80 U/L only accounted for 7.9% (24/304) and 6.3% (19/304), respectively. About 2.0% (6/304) of patients also had increased TBil level, and the average level was (37.4±21.1) μmol/L. The median age of critical group was older than that of non-critical group (65 years vs. 56 years), the proportion of patients with abnormal liver function and slightly increased AST (40- 0.05). Conclusions The manifestation of digestive system of hospitalized COVID-19 patients in Wuhan is significant, the proportion of patients with diarrhea and abnormal aminotransferase level is high. And on admission the proportion of patients with abnormal liver function of critical group is higher than that of non-critical group, which will provide reference for the prevention and treatment of COVID-19. Key words: 2019-nCoV; COVID-19; Diarrhea; Liver function; Gastrointestinal tract

Manifestations of Digestive system in hospitalized patients with novel coronavirus pneumonia in Wuhan, China: a single-center, descriptive study

Objective To study the manifestations of digestive system of hospitalized patients with novel coronavirus pneumonia (NCP) in Wuhan, China, and to provide reference for disease control and treatment. Methods The data of hospitalized patients with NCP in the Sino-French Branch of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology was retrospectively analyzed, which included general information, nucleic acid test, severity degree of disease, incubation period, initial symptoms and manifestations of digestive system. The general information, positive rate of nucleic acid detection, and manifestations of digestive system were compared between critical patients who required non-invasive or invasive assisted ventilation (critical group) and non-critical patients without assisted ventilation (non-critical group). Continuous corrected chi-square test and independent sample median test were performed for statistical analysis. Results Among the 305 patients there were 146 males (47.9%) and 159 females (52.1%), median age 57 years old. Nucleic acid assay of nasopharynx swab or pharynx swab of 84.1% (228/271) patients were positive. Forty-six patients (15.1%) were in critical group and 259 patients (84.9%) were in non-critical group. The incubation period was one to fifteen days, and the median period was six days. The initial symptoms mainly were fever (81.1%, 163/201), cough (39.3%, 79/201), fatigue (54.7%, 110/201), and loss of appetite (50.2%, 101/201). In one to ten days after the disease onset, 79.1% (159/201) of patients developed gastrointestinal symptoms including nausea (29.4%, 59/201), vomiting (15.9%, 32/201), or abdominal pain (6.0%, 12/201). 49.5% (146/295) of patients had diarrhea, median time was 3.3 days, (3.3±1.6) times per day, and a duration of (4.1±2.5) days. Excluding possible drug-related diarrhea, the incidence of diarrhea still was 22.2%. Only 6.9% (4/58) of patients were found leukocytes or fecal occult blood positive in regular stool test. ALT, AST, or bilirubin increased in 39.1% (119/304) of patients at admission. Patients with ALT or AST ≥ 80 U/L only accounted for 7.9% (24/304) and 6.3% (19/304), respectively. About 2.0% (6/304) of patients also had increased bilirubin level, average level was (37.4 ± 21.1) μmol/L. The median age of critical group was older than that of non-critical group (65.5 years vs. 56 years), at admission the rates of abnormal liver function test abnormal and slightly increased AST (40~80 U/L) of critical group were both higher than those of non-critical group (67.4% (31/46) vs. 34.1% (88/258) and 47.8% (22/46) vs. 21.7% (56/228)), and the differences were statistically significant (x2=5.885, 18.154 and 15.723;all P 0.05). Conclusions The manifestation of digestive system of hospitalized NCP patients in Wuhan is significant, the ratio of patients with diarrhea and abnormal aminotransferase level is high. And at admission the rate of patients with abnormal liver function rate of critical group is higher than that of non-critical group, which will provide reference for the prevention and treatment of NCP. Key words: 2019-nCoV; Novel coronavirus pneumonia; Corona virus disease 2019; Diarrhea; Liver function; Gastrointestinal tract; Wuhan

Application of combined nucleic acid test with serologic test in blood screening for voluntary blood donors in Weifang City of Shandong Province

Objective To explore the combined application of nucleic acid test and serologic test in blood screening for voluntary blood donors in Weifang City of Shandong Province. Methods From June to December 2016, a total of 55 852 voluntary blood donors in Weifang Blood Centre were selected as study subjects. Enzyme-linked immunosorbent assay (ELISA) was used to perform serologic tests on plasma specimens from all voluntary blood donors. ELISA tests included HBsAg, anti-hepatitis C virus (HCV), anti-human immunodeficiency virus (HIV), anti-Treponema pallidum (TP) and alanine aminotransferases (ALT). For the plasma specimens with negative results of ELISA test, the nucleic acid amplification technology (NAT) was used to detect the viral nucleic acid by viral nucleic acid detection system of Kehua Bio-engineering Co., Ltd of Shanghai and viral nucleic acid detection system of Novartis Diagnostics of Switzerland. NAT tests included HBV DNA, HCV RNA and HIV RNA. For the plasma specimens with HBsAg negative of ELISA test and HBV DNA positive of NAT split test and identification test, the five viral markers test of hepatitis B virus (HBV) were performed, which included HBsAg, HBsAb, HBeAg, HBeAb and HBcAb test. And according to the results of five viral markers of HBV, the HBV infection of voluntary blood donors were presumed. χ2 test was used to compare positive detection rates of nucleic acid in plasma specimens of Kehua viral nucleic acid detection system and Novartis viral nucleic acid detection system. The continuous correction χ2 test was used to compare the effective split rate of Kehua viral nucleic acid detection system and the positive detection rate of identification test for HBV DNA, HCV RNA and HIV RNA in plasma specimens of Novartisc viral nucleic acid detection system. Results ① In 55 852 plasma specimens from voluntary blood donors, 1 962 plasma specimens were positive for ELISA test. In 53 890 plasma specimens with negative ELISA results, 19 (0.035%, 19/53 890) plasma specimens were positive for NAT test. ② There were 53 890 plasma specimens were performed NAT test in this study. Among them, the positive detection rate of nucleic acid in plasma specimens of Kehua viral nucleic acid detection system was 0.014% (4/28 199), the positive detection rate of nucleic acid in plasma specimens of Novartis viral nucleic acid detection system was 0.058% (15/25 691). There was a statistically difference between the positive detection rate of Kehua viral nucleic acid detection system and that of Novartis viral nucleic acid detection system (χ2=7.50, P<0.05). ③ The effective split rate of Kehua viral nucleic acid detection system was 44.4% (4/9). The positive detection rate of identification test for HBV DNA, HCV RNA and HIV RNA in plasma specimens of Novartisc viral nucleic acid detection system was 50.0% (15/30). There was a statistically difference between the effective split rate and identification test positive detection rate (χ2=0.03, P=0.87). ④ There were 18 voluntary blood donors who were negative for HBsAg of ELISA test and positive for HBV DNA of NAT test. There were 5 serologic infection patterns in these 18 voluntary blood donors, including occult HBV infection accounted for 88.9% (16/18), and suspectedwindow periodHBV infection accounted for 11.1% (2/18). Conclusions There is a certain risk of missed detection of ELISA serologic tests in blood screening for voluntary blood donors. NAT test is an effective supplement to ELISA. The mixed sample test reduces the positive detection rate of the viral nucleic acid, by reducing the sensitivity of NAT test. The risk of transmitting HBV through blood transfusion needs to be highly vigilant for the blood collection and supply institution in Weifang City. Nucleic acid test as a supplemental method for serological test can further reduce the risk of transmitting HBV through blood transfusion, and ensures blood safety. Key words: Blood safety; Nucleic acid amplification techniques; Serologic tests; Enzyme-linked immunosorbent assay; Blood donors; Blood screening