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Background and Aim: Newcastle disease (ND) is a major viral disease of poultry worldwide. However, data on the molecular characterization of Newcastle disease virus (NDV) in Vietnam are limited. This study aimed to identify the molecular characteristics of NDV strains from the vaccinated chickens farmed in Northern Vietnam. Materials and Methods: We used reverse-transcription polymerase chain reaction (PCR), sequencing and phylogenetic analysis to characterize NDV strains from vaccinated chicken farms in Northern Vietnam. Results: Seven out of 72 (9.7%) chicken tissue samples collected from seven chicken farms in the four cities/provinces in northern Vietnam were positive for the NDV genome by PCR method. The complete sequences of the fusion (F) and hemagglutinin-neuraminidase (HN) genes of NDVs isolated in the North of Vietnam from 2021 to 2022 were further evaluated. The results indicated that all seven Vietnamese isolates obtained were reported as virulent NDV strains with the amino acid (AA) sequence of the F0 protein proteolytic cleavage site motif (112RRRKRF117). Phylogenetic analysis revealed that they were grouped with other NDV class II from subgenotype VII.2, including the two previous Vietnamese NDV (2015), the Chinese (2017), and Southern African (2013) NDV strains. In addition, some AA substitutions were observed in the neutralizing epitopes of the F and HN proteins of the current Vietnamese NDV strains. Conclusion: The present findings provide useful information for future studies of the evolution of NDVs and improve strategies for ND-controlling programs in Vietnam.
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To date, many fluorescence- and gel-based multiplex polymerase chain reaction (PCR) assays have been developed for the simultaneous detection of multiple infectious agents of respiratory disease in poultry. However, PCR assays are not available for other important emerging respiratory bacteria, such as Ornithobacterium rhinotracheale (ORT). We aimed to fill this gap by establishing a new duplex PCR method for the simultaneous detection of infectious laryngotracheitis virus (ILTV) and ORT. Multiplex primer design software was used to select the compatible multiplex primer pairs. It was determined that an annealing temperature of 65 °C and an initial concentration of 2.5 pmol/µL for each primer set were the most suitable conditions for multiplex PCR. The assay was confirmed to be specific, as it only detected the target pathogens, even in the presence of six non-target agents. The limit of detection was up to 103 copies/µL of template DNA for both ILTV and ORT. In the screening of 304 field samples, 23, 88, and 44 were positive for both ILTV and ORT, solely for ILTV, and solely ORT, respectively.
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Background: The Japanese government advised mild or asymptomatic coronavirus disease-2019 (COVID-19) cases to self-isolate at home, while more severe individuals were treated at health posts. Poor compliance with self-isolation could be a potential reason for the new outbreak. Our study aimed to find out the correlation between the rising new cases of COVID-19 and home-based patients in Japan. Methods: A secondary data analysis study was conducted with the data from COVID-19- involved databases collected from Johns Hopkins University, Japanese Ministry of Health, Labour and Welfare, and Community Mobility Reports of Google. New community cases, stringency index, number of tests, and active cases were analyzed. Using a linear regression model, an independent variable was utilized for a given date to predict the future number of community cases. Results: Research results show that outpatient cases, the stringency, and Google Mobility Trend were all significantly associated with the number of COVID-19 community cases from the sixth day to the ninth day. The model predicting community cases on the eighth day (R2=0.8906) was the most appropriate showing outpatients, residential index, grocery and pharmacy index, retail and recreation index, and workplaces index were positively related (ß1=24.2, 95% CI: 20.3- 26.3, P<0.0001; ß2=277.7, 95% CI: 171.8-408.2, P<0.0001; ß3=112.4, 95% CI: 79.8-158.3, P<0.0001; ß4=73.1, 95% CI: 53- 04.4, P<0.0001; ß5=57.2, 95% CI: 25.2-96.8, P=0.001, respectively). In contrast, inpatients, park index, and adjusted stringency index were negatively related to the number of community cases (ß6=-2.8, 95% CI: -3.9 - -1.6, P<0.0001; ß7=-33, 95% CI: -43.6 - -27, P<0.0001; ß8=-14.4, 95% CI: -20.1- -12, P<0.0001, respectively). Conclusion: Outpatient cases and indexes of Community Mobility Reports were associated with COVID-19 community cases.