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Objective:To clarify the infection and epidemic characteristics of the human metapneumovirus (HMPV) in Chinese patients with febrile respiratory syndrome (FRS), and to provide important baseline data for clinical diagnosis, treatment, prevention and control of HMPV-induced respiratory tract diseases in China.Methods:FRS cases from January 2009 to June 2021 in 9 provinces in China, including Beijing, Hebei, Jilin, Shandong, Shaanxi, Xinjiang, Anhui, Guangdong, Hunan were retrospectively analyzed for their respiratory samples, clinical and epidemic data.The respiratory samples were detected for HMPV by quantitative real-time PCR.Results:A total of 11 660 cases were tested for HMPV, involving 296 (2.54%) HMPV-positive cases.Among 296 HMPV-positive cases, 218 were single HMPV infection, and 78/296 (26.35%) were co-infected with one or more respiratory viruses.HMPV mainly affected children under 5 years of age (3.10%), and in this population, the proportion of pneumonia in HMPV co-infection cases was significantly higher than that of single HMPV infection.HMPV could be detected all year round, which was more popular in winter and spring, with the peak of HMPV epidemic in March.Conclusions:HMPV is one of the important pathogens causing acute respiratory infection in children, showing a clear seasonal epidemic.HMPV can be infected alone or in combination with other respiratory viruses, which may increase the risk of pneumonia in children.
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Objective@#To establish a real-time fluorescence recombinase acid amplification (RAA) method for the detection of adenovirus type 3(HAdV-3)without extraction nucleic acid.@*Methods@#According to the conserved sequence of adenovirus type 3 gene, a pair of primers and a probe were designed, and a real-time fluorescence RAA without extracting nucleic acid was established and optimizing the condition of DNA-free extraction. The sensitivity of the method was analyzed by a series of dilution and the specificity of the method was evaluated by detecting the original samples of other respiratory viruses. The clinical samples of HAdV-3 were detected and compared with the traditional real-time fluorescence quantitative PCR method for nucleic acid extraction.@*Results@#The sensitivity of the real-time fluorescence RAA method was as high as that of qPCR in the detection of 10 series diluted HAdV-3 strains. The highest corresponding CT value of qPCR was 36.87. The sensitivity of the real-time fluorescence RAA method was similar to that of the real-time fluorescence quantitative PCR method . There was no cross-reaction to other common types of respiratory viruses. The two method were used to detect 56 clinical samples at the same time, and the result were completely consistent.@*Conclusions@#We provide the first report of the real-time fluorescent RAA assays for the detection of HAdV-3 without extracting nucleic acid and it has high sensitivity and specificity. Is suitable for rapid detection of HAdV-3 in clinical laboratories and on-site unite.
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Objective@#To better understand the evolution and epidemiology of human adenovirus-55 (HAdV-55) and provide a scientific basis for the prevention and control of the epidemic of HAdV-55 in China.@*Methods@#HAdV-55 isolates from 5 provinces in China included Beijing, Hebei, Shandong, Hunan and Yunnan were collected during 2011-2014. The hexon, fiber and penton base gene were sequenced, and compared with other strains of HAdV-55 sequences downloaded from GenBank for homology and evolution analysis.@*Results@#During the past decade, HAdV-55 was found in 15 provinces throughout China. Genetic and phylogenetic analysis showed that the HAdV-55 virus is highly conservative in evolution due to aggregation in a branch in the evolutionary tree. However, bayesian phylogenetic tree shows a certain time evolution trend. The evolution rate of hexon and fiber gene of HAdV-55 are 5.228×10-5 and 1.238×10-4 substitutions/site/year respectively, and the latest coevolutionary ancestor tMRCA of hexon gene can be traced back to 1963.@*Conclusions@#HAdV-55 has been widely spread and continued circulating in China. Establishing effective monitoring system and conducting vaccine related research is very important for its control and prevention.