China ; Disease Outbreaks ; Humans ; Influenza B virus ; Influenza, Human ; epidemiology

No abstract available.
Humans ; Influenza B virus* ; Influenza, Human* ; Magnetic Resonance Imaging

China ; epidemiology ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza B virus ; genetics ; Influenza, Human ; epidemiology ; genetics

Influenza B virus infections appear to be more common extra-respiratory tract symptoms, compared to influenza A virus infections. Benign acute childhood myositis (BACM) is a benign disease that is caused mainly by many viruses like influenza A or B virus infection. Usually BACM is fully cured with only supportive treatment without unnecessary investigation or invasive procedure. This report describes an eight-year-old boy with acute bilateral calf pain and walking difficulty who diagnosed with BACM after influenza B virus infection.
Child ; Herpesvirus 1, Cercopithecine ; Humans ; Influenza A virus ; Influenza B virus ; Influenza, Human ; Male ; Myositis ; Walking

Animals ; Cytokines ; physiology ; Humans ; Influenza A virus ; immunology ; Influenza B virus ; immunology ; Influenza Vaccines ; Influenza, Human ; immunology ; prevention & control ; Vaccines, DNA

To understand the genetic characteristics of hemagglutinin (HA) and neuraminidase (NA) of type B influenza viruses in Guangzhou in 2006, three virus strains from etiology surveillance and seven strains from outbreaks were investigated. Genome RNAs of type B influenza viruses were extracted and reverse-transcripted into cDNAs using random primers. The whole-length DNA of HA and NA were amplified by polymerase chain reaction (PCR), cloned into T-A plasmid and sequenced, and analyzed phylogenetically by DNAstar software. The results showed that the HA of type B influenza viruses were similar and the homology were more than 99%. The type B influenza viruses belong to Victoria lineage. The NA of the type B influenza viruses were similar and the homology were more than 98%. Phylogenetic trees of HA and NA showed that the isolates from etiology surveillance formed a cluster, and the isolates from outbreaks were separated from the cluster. The homology of the type B influenza viruses with B/Shanghai/361/2002, which is the WHO recommended influenza vaccine strain in 2005-2006, were 88.9%-89.7%. It suggested the protective effect of influenza vaccine against type B influenza viruses used in 2005-2006 in Guangzhou may not be afforded.
China ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Influenza B virus ; genetics ; Neuraminidase ; genetics ; Phylogeny ; Time Factors

<b>OBJECTIVEb>To investigate the prevalence and subtypes of influenza viruses in Liaoning regions from November 1999 to March 2005.

<b>METHODSb>Influenza virus was isolated by embryonated eggs together with cell culture and subtypes, identified by HI test.

<b>RESULTSb>During the study in 1999 - 2005, a total number of 2713 swab specimens were collected in different cities in Liaoning regions in which 188 strains were identified for influenza viruses with an average rate as 7.0%. A total number of 1466 swab specimens were collected by both Centers for Disease Control and Prevention in Dalian city and Liaoning province, and 167 strains were identified positive with an average rate of 11.4%. Influenza A3, A1 and B/Yamagata all appeared before March 2002 which were predominant strains. However, since then Influenza A1 has never appeared again in Liaoning regions and B showed some changes, from Yamagata to Victoria, the characteristics on the prevalence of influenza appeared only in the period of November to February.

<b>CONCLUSIONb>It was meaningful to analyze the surveillance data of influenza in different years in Liaoning regions in order to better understand the characteristics of influenza and the shifting of subtype.

China ; epidemiology ; Humans ; Influenza A virus ; classification ; isolation & purification ; Influenza B virus ; classification ; isolation & purification ; Influenza, Human ; epidemiology ; Population Surveillance ; Seasons

BACKGROUND: Influenza virus is a cause of annual outbreaks of acute respiratory disease and is responsible for considerable mortality and morbidity in all age groups. To achieve maximum efficacy antiinfluenza drugs must be started within 48 h of the development of influenza symptoms. Improvements in rapid diagnosis methods are needed to identify influenza infections. The aim of this study was to compare a quick rapid antigen test with viral culture assays. METHODS: A total of 87 nasopharyngeal swab specimens were collected from symptomatic paediatric patients during March, 2004. The performance of the Quick S-Influ A/B rapid test for influenza virus detection was compared to that of the viral culture. RESULTS: The overall rate of detection for viral culture was 23.4% for influenza A virus and 13.4% for influenza B virus. The Quick S-Influ A/B assay identified 17 of 18 influenza A viruses (sensitivity, 94.4%; specificity, 96.8%; PPV, 89.5%; NPV, 98.4%), and identified 7 of 9 influenza B viruses (sensitivity, 77.8%; specificity, 98.4%; PPV, 87.5%; NPV, 96.8%). CONCLUSIONS: The Quick S-Influ A/B assay was easy to perform and showed comparable sensitivities and specificities. This rapid test kit can be an alternative tool for interventions in disease management.
Diagnosis ; Disease Management ; Disease Outbreaks ; Humans ; Influenza A virus ; Influenza B virus ; Influenza, Human* ; Mortality ; Orthomyxoviridae* ; Sensitivity and Specificity

Influenza is a disease known to continue to afflict a large number f people and cause many deaths throughout the world. Influenza A and B are the two types of influenza that cause epidemic human disease. The influenza illness is characterized by the abrupt onset of fever, myalgia, headache, and sore throat. Amantadine and rimantadine have been used to treatment and prophylaxis of influenza, but these agents can only reduce symptomatic illness due to influenza A virus and are ineffective against influenza B virus. Inhibitors of influenza neuraminidase constitute a new class of anti-influenza agents that reduce replication of influenza A and influenza B. Vaccination against influenza virus is the primary strategy to reduce the morbidity and mortality associated with influenza.
Amantadine ; Fever ; Headache ; Humans ; Influenza A virus ; Influenza B virus ; Influenza, Human* ; Mortality ; Myalgia ; Neuraminidase ; Orthomyxoviridae ; Pharyngitis ; Rimantadine ; Vaccination

BACKGROUND: Rapid antigen test and real-time reverse transcription PCR (rRT-PCR) are widely used for the detection of influenza A virus. In this study, we evaluated and compared the effectiveness of a rapid antigen test, currently used for detecting influenza B virus, with the effectiveness of using rRT-PCR for the same purpose. METHODS: Samples obtained from 92 patients during an outbreak of influenza B were assessed using the rapid antigen test (SD BIOLINE Influenza Ag; SD, Korea) and rRT-PCR (Anyplex FluA/B Real-time Detection; Seegene, Korea). RESULTS: The sensitivity and specificity of the rapid antigen test were 69% and 100%, respectively, in detecting influenza B when compared to rRT-PCR. Twenty-nine patients (31.5%) were positive for both rapid antigen test and rRT-PCR, while 50 (54.3%) were negative for both rapid antigen test and rRT-PCR. The overall concordance rate between rapid antigen test and rRT-PCR was 85.9%. Thirteen patients (14.1%) were positive only for rRT-PCR. CONCLUSIONS: The rapid antigen test showed high specificity and good correlation with rRT-PCR and is likely to be as useful in the detection of influenza B viruses.
Humans ; Influenza A virus ; Influenza B virus ; Influenza, Human ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Reverse Transcription ; Sensitivity and Specificity