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Background:Influenza is one of the diseases which have the pandemic potential. Influenza surveillance as part of the pandemic preparedness activities was initiated in Sri Lanka in 2005. This study would help in evaluating, strengthening influenza surveillance system of DGH Matara, and taking targeted preventive measures and contribute to more efficient resource allocation in the future.Methods:This was a cross sectional analytical study.Results:Case definitions for ILI and SARI used were consistent with the epidemiology unit Sri Lanka prescribed definitions. Though the site collected data on cases daily and sampled weekly, sampling technique was not random. Respiratory specimen collection, packaging, storage and transport were consistent with the guidelines of epidemiology Unit, Sri Lanka. Refrigerator temperature monitoring, analyzing surveillance data on site as well as supervisory visits made by central level were not satisfactory. No clear pattern of ILI and SARI was observed among different age groups during 2014-2018. Influenza viral activity was detected except for 搖ntyped� from respiratory samples sent by DGH, Matara during 2014-2018.Pandemic preparedness by the site was not at optimal level.Conclusions:Representativeness of data obtained from respiratory specimen collection and data analyzing were not satisfactory. Temperature monitoring inside storage refrigerators of the site was not possible as no written records were available. Supervision from the central level was not satisfactory.
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Objective The influenza monitoring results in Huzhou city were analyzed to understand the characteristics of influenza pandemic and to provide a scientific basis for prevention and control of influenza. Methods The influenza-like cases(ILI)were collected from two sentinel hospitals in Huzhou according to the protocol of The National Influenza Surveillance Program. Pharynx swab samples of the ILI were taken randomly for the test of influenza virus. Results Among 5 322 788 patients who went to the sentinel hospitals in Huzhou from 2011 to 2017, 185 010 were ILI. The percentage of ILI was 3.48% and there was a slowly rising trend in ILI% of month from 2011 to 2017(trend χ2 = 2 970.93, P < 0.001). Winter /spring and summer seasons marked the peaks in influenza epidemics. Patients were mostly children under 14 years old(accounting for 89.1%). In a total of 11 490 throat swabs collected from ILI, 1 975 were tested to be positive for influenza virus(positive rate 17.19%). These included A type H3N2, 1 008; A type H1N1, 350; B type, 614(160 Victoria type, 238 Yamagata, 216 unclarified B type), and 3 mixed type. The correlation between positive rate of influenza nucleic acid test and ILI% is statistically significant(r = 0.40, P < 0.001). Conclusion The incidence peaks of influenza in Huzhou are mainly in the winter /spring and summer periods. The influenza is mainly occurs in young people under 14 years old and the main type virus is A(H3N2). The prevalence of influenza B and H1N1 occurs at intervals. There is a positive correlation between influenza activity and ILI%.
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ObjectiveTo analyze the effects of respiratory control measures before and after COVID-19 epidemic on influenza virus. MethodsThe percentage of influenza-like cases， the positive rate of influenza virus and the change of influenza outbreaks before and after the COVID-19 pandemic were compared and analyzed by selecting the data of influenza surveillance sentinel-points in Shanghai. ResultsThe percentage of influenza-like illness after the outbreak of COVID-19 in 2020 was significantly higher than that during the same period between 2017 and 2019. The positive rate of influenza virus detection in 2020 was significantly lower than the average rate of influenza virus detection from 2017 to 2019 with significant statistical difference （χ 2=2 359.07， P<0.001）. The number of outbreaks in 2020 was significantly lower than that from 2017 to 2019. ConclusionDuring the respiratory season， personal protection and reduction of human aggregation can effectively reduce the infection of influenza and the incidence of influenza in the population.
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ObjectiveTo analyze the effects of respiratory control measures before and after COVID-19 epidemic on influenza virus. MethodsThe percentage of influenza-like cases， the positive rate of influenza virus and the change of influenza outbreaks before and after the COVID-19 pandemic were compared and analyzed by selecting the data of influenza surveillance sentinel-points in Shanghai. ResultsThe percentage of influenza-like illness after the outbreak of COVID-19 in 2020 was significantly higher than that during the same period between 2017 and 2019. The positive rate of influenza virus detection in 2020 was significantly lower than the average rate of influenza virus detection from 2017 to 2019 with significant statistical difference （χ 2=2 359.07， P<0.001）. The number of outbreaks in 2020 was significantly lower than that from 2017 to 2019. ConclusionDuring the respiratory season， personal protection and reduction of human aggregation can effectively reduce the infection of influenza and the incidence of influenza in the population.
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Objective To analyze the types and epidemiological characteristics of influenza virus in Xi'an during 2009 to 2017.Methods A total of 21 856 samples of throat swabs from patients with influenza like illness ( ILI) were collected from 5 national influenza sentinel surveillance hospitals from August 2009 to December 2017.Influenza virus nucleic acid was detected by real-time fluorescence quantitative PCR and virus types were confirmed , chick-embryo cells or Madin-Darby canine kidney (MDCK) cells were used to isolate influenza virus.SPSS 18.0 software was used for data analysis.Results The positive detection rate of influenza virus was 16.19%(3 539/21 856), the seasonal influenza A virus subtypes including H1, H3, the new type H1and H7 accounted for 62.39%(2 208/3 539), influenza B virus subtypes including Victoria , Yamagata and unclassified type B accounted for 37.50%( 1 327/3 539), and the mixed influenza virus infection accounted for 0.11%(4/3 539).The positive rate of influenza virus detected in different years was significantly different ( χ2＝357.651, P ＜0.01).During January to March the major influenza A viruses accounted for 49.07%(947/1 930), influenza B viruses accounted for 50.93%(983/1 930); during October to December , the influenza A viruses accounted for 78.07%( 1 061/1 359 ), and influenza B viruses accounted for 21.93%( 298/1 359 ); there was significant difference in composition of type A virus and type B virus between different seasons ( χ2＝ 550.06, P＜0.05).The positive detection rate of influenza virus in patients with ILI of age groups 0-3 years,＞3-7 years,＞7-13 years,＞13-18 years,＞18-24 years,＞24-60 years and ＞60 years were 12.61%, 19.41%, 19.66%, 22.98%, 14.91%, 13.50% and 12.84%, respectively ( χ2＝202.52, P＜0.05).Conclusion Influenza A virus is common in Xi'an,winter and spring are the peak seasons for influenza epidemics.It is recommended for susceptible people to take influenza vaccination .
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We investigated and analyzed the first case of human infection with avian influenza A(H9N2) virus in Yunnan Province,China,so as to provide a better basis for preventing and controlling human infections with viruses of animal origin in the future.We carried out the field epidemiological survey among the patient,close contacts and the live poultry markets,detected and analyzed the samples from patient and the outdoor environment.Results showed that the 9-month-old boy was a case of human infection with avian influenza A(H9N2) virus with the history of live poultry markets exposure and the results of nucleic acid detection and virus isolation.There was a lot of contamination of the avian influenza virus in the live poultry markets.The second generation cases have not occurred.The monitoring of pneumonia of unknown etiology and influenza like cases in medical institutions is the important means to find timely cases of human infected with avian influenza.Regular disinfection and closing-down of live poultry markets are key measures to reduce the exposure opportunity.
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Objective To understand the epidemic characteristics of influenza in Minhang District of Shanghai during 2013-2016,so as to provide scientific basis for the prevention and control of influenza.Methods Surveillance data of influenza like illness (ILI) cases from the national influenza network and data of pathogen detection during 2013-2016 in Minhang District were selected to analyze the epidemic characteristics of influenza.Results The number of influenza like illness (ILI) was 37 738 from 2013 to 2016,which accounted for 0.90％ of the outpatients in monthly average.Meanwhile,4 094 samples were collected,among which 857 samples were virus positive.The total isolation rate was 20.93％.In 2013,the dominant strain was mainly seasonal influenza A (H3N2).Dominant strains of 2014 were influenza B (Yamagata) and seasonal influenza A (H3N2).In 2015,dominant strain was seasonal influenza A (H3N2) of summer peak,but the dominant strains of winter-spring peak were new type influenza H1N1 (H1N1 pdm09) and influenza B (Victoria) from December 2015 to April 2016.The dominant strain of winter peak in 2016 was seasonal influenza A (H3N2) popular.Spearman correlation analysis showed positive rate between ILI visiting rate (ILI％) and influenza virus (rs =0.460,P＜0.05).Conclusions The epidemic peaks of of influenza were winter-spring and summer in Minhang District,advantages strains were interaction pandemic with certain regulation.The characteristics of ILI visiting rate was coincident with influenza virus activity.
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Objective To understand the epidemic characteristics of influenza in Minhang District of Shanghai during 2013-2016,so as to provide scientific basis for the prevention and control of influenza.Methods Surveillance data of influenza like illness (ILI) cases from the national influenza network and data of pathogen detection during 2013-2016 in Minhang District were selected to analyze the epidemic characteristics of influenza.Results The number of influenza like illness (ILI) was 37 738 from 2013 to 2016,which accounted for 0.90％ of the outpatients in monthly average.Meanwhile,4 094 samples were collected,among which 857 samples were virus positive.The total isolation rate was 20.93％.In 2013,the dominant strain was mainly seasonal influenza A (H3N2).Dominant strains of 2014 were influenza B (Yamagata) and seasonal influenza A (H3N2).In 2015,dominant strain was seasonal influenza A (H3N2) of summer peak,but the dominant strains of winter-spring peak were new type influenza H1N1 (H1N1 pdm09) and influenza B (Victoria) from December 2015 to April 2016.The dominant strain of winter peak in 2016 was seasonal influenza A (H3N2) popular.Spearman correlation analysis showed positive rate between ILI visiting rate (ILI％) and influenza virus (rs =0.460,P＜0.05).Conclusions The epidemic peaks of of influenza were winter-spring and summer in Minhang District,advantages strains were interaction pandemic with certain regulation.The characteristics of ILI visiting rate was coincident with influenza virus activity.
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The World Health Organization’s Regional Office for the Western Pacific has developed an interactive online influenza platform linking data from National Influenza Centres and Influenza Surveillance in the Western Pacific Region. This platform for regional monitoring of influenza enhances the accessibility of data and information for international and national authorities.
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Background: Recent studies on antiviral susceptibiliy from South-East Asia, Europe and the United States have shown sporadic neuraminidase inhibitor (NAI) resistance in A(H1N1)pdm09 viruses. We undertook a study to evaluate NAI resistance in these viruses isolated in India. Methods: Pandemic influenza viruses, isolated from 2009 to 2013, along with clincal samples were genetically analysed for known resistance markers in the neuraminidase (NA) gene. Clinical samples (n=1524) were tested for H275Y (N1 numbering; H274Y in N2 numbering) mutation by real time reverse transcriptase PCR (rRT-PCR). One hundred and ten randomly selected resistant and sensitive viruses were analysed by phenotypic assay. Results: All but one of the 2013 A(H1N1)pdm09 isolates were sensitive to oseltamivir. Genetic analysis of this isolate as well as the original clinical material showed that the presence of H275Y mutation was responsible for reduced susceptibility to oseltamivir in the patient. This was confirmed by phenotypic assay. Conclusion: The emergence of a pandemic influenza strain resistant to oseltamivir emphasizes the need for monitoring antiviral resistance as part of the National Influenza Programme in India.
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Objective To observe epidemic status and the types of the influenza virus, to analyse influenza epidemic trends in Tianshui City, and to provide basis for influenza prevention and control. Methods Throat swab specimens of influenza cases in pilot hospitals and area of influenza-like a typical outbreak in Nov. 2005-Oct. 2008 was tested by chicken embryo and MDCK cells.The identifi cation of the isolates was carried out by hemagglutination and hemagglutination inhibition test. The separation of strains were sent to the National Influenza Center to conduct a review appraisal. Results 1819 throat swab specimens of influenza-like were collected and 247 were isolated. Isolation rate was 13.58%. There were 36 strains (14.57%) of A (H1N1) subtype, 75 strains (30.36%) of A (H3N2) subtype and 136 (Victoria department 121, Yamagata department 15) strain (55.06%) of B subtype. Conclusion There were three epidemic types of influenza virus types-A (H1N1), A (H3N2) and B in Tianshui. Virus were epidemic at the same time or alternating at different intensity in different years. Outbreaks of influenza have occurred in rural primary and secondary schools, and B subtype was dominating.