This study aimed to understand the differences in clinical, epidemiological, and laboratory features between the new coronavirus disease 2019 (COVID-2019) and influenza A in children. Data of 23 hospitalized children with COVID-19 (9 boys, 5.7 ± 3.8 years old) were compared with age- and sex-matched 69 hospitalized and 69 outpatient children with influenza A from a hospital in China. The participants' epidemiological history, family cluster, clinical manifestations, and blood test results were assessed. Compared with either inpatients or outpatients with influenza A, children with COVID-19 showed significantly more frequent family infections and higher ratio of low fever (< 37.3 °C), but shorter cough and fever duration, lower body temperature, and lower rates of cough, fever, high fever (> 39 °C), nasal congestion, rhinorrhea, sore throat, vomiting, myalgia or arthralgia, and febrile seizures. They also showed higher counts of lymphocytes, T lymphocyte CD8, and platelets and levels of cholinesterase, aspartate aminotransferase, lactate dehydrogenase, and lactic acid, but lower serum amyloid, C-reactive protein, and fibrinogen levels and erythrocyte sedimentation rate, and shorter prothrombin time. The level of alanine aminotransferase in children with COVID-19 is lower than that in inpatients but higher than that in outpatients with influenza A. Pediatric COVID-19 is associated with more frequent family infection, milder symptoms, and milder immune responses relative to pediatric influenza A.
Betacoronavirus ; physiology ; Case-Control Studies ; Child ; Coronavirus Infections ; blood ; epidemiology ; immunology ; virology ; Female ; Humans ; Influenza, Human ; blood ; epidemiology ; immunology ; Male ; Pandemics ; Pneumonia, Viral ; blood ; epidemiology ; immunology ; virology

The recent human infection with avian influenza virus revealed that H9N2 influenza virus is the gene donor for H7N9 and H10N8 viruses infecting humans. The crucial role of H9N2 viruses at the animal-human interface might be due to the wide host range, adaptation in both poultry and mammalian, and extensive gene reassortment. As the most prevalent subtype of influenza viruses in chickens in China, H9N2 also causes a great economic loss for the poultry industry, even under the long-term vaccination programs. The history, epidemiology, biological characteristics, and molecular determinants of H9N2 influenza virus are reviewed in this paper. The contribution of H9N2 genes, especially RNP genes, to the infection of humans needs to be investigated in the future.
Animals ; Chickens ; virology ; China ; epidemiology ; Humans ; Influenza A Virus, H7N9 Subtype ; genetics ; Influenza A Virus, H9N2 Subtype ; genetics ; immunology ; physiology ; Influenza in Birds ; epidemiology ; transmission ; virology ; Influenza, Human ; epidemiology ; transmission ; virology ; Vaccination ; Viral Proteins ; classification ; metabolism

Since March 2009, pandemic A/H1N1/2009 influenza virus has been spreading throughout many countries including China. The emerged virus caused great harm to human health and social economy. Hemagglutinin (HA) is the most important viral surface glycoprotein, mainly possessing three kinds of functions: (1) binding to host cell receptor, (2) triggering the fusion between viral envelop and target cell membrane, (3) stimulating the body to generate the neutralizing antibody. Advances in the structure, primary function, evolution and antigenicity of pandemic A/H1N1/2009 influenza virus HA protein are reviewed in this paper.
Animals ; Evolution, Molecular ; Hemagglutinin Glycoproteins, Influenza Virus ; chemistry ; genetics ; immunology ; metabolism ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; pathogenicity ; physiology ; Influenza, Human ; epidemiology ; virology ; Pandemics

OBJECTIVETo understand the distribution of influenza A H9N2 virus in chickens and men in Shenzhen area.

METHODSVirus isolation was performed in embryonated hen s eggs with routine method. The antibody to H9N2 virus was detected with micro-hemagglutination inhibition (HI) test, then the results were checked by using the neutralization assay in MDCK cells.

RESULTSTotally 27 strains of influenza A H9N2 virus were isolated from chickens in farm markets in Shenzhen, whereas no H9N2 virus was isolated from men. Approximately 26% of human sera with the HI titers > or =20 to H9N2 virus were detected. However only 7% of chicken sera with the HI titers > or =20 to H9N2 virus were detected. Meanwhile the HI titer and (MGT) of antibody to H9N2 virus in human sera increased with age. It was also found that there was a close relationship between HI antibody titer to H9N2 virus in human sera and occupation.

CONCLUSIONSThe distribution of influenza A H9N2 virus in chicken and men in Shenzhen was rather wide. The human H9N2 virus infection probably derived from chicken H9N2 virus.

Animals ; Antibodies, Viral ; blood ; Chickens ; China ; epidemiology ; Hemagglutination Inhibition Tests ; Humans ; Influenza A Virus, H9N2 Subtype ; Influenza A virus ; classification ; immunology ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Seroepidemiologic Studies

Animals ; History, 20th Century ; Humans ; Influenza A Virus, H1N1 Subtype ; genetics ; immunology ; isolation & purification ; Influenza, Human ; epidemiology ; history ; immunology ; virology ; Russia ; epidemiology

Abattoirs ; manpower ; Adult ; Antibodies, Viral ; blood ; China ; Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza A Virus, H3N2 Subtype ; immunology ; Influenza A Virus, H3N8 Subtype ; immunology ; Influenza A Virus, H5N1 Subtype ; immunology ; Influenza A Virus, H9N2 Subtype ; immunology ; Influenza A virus ; classification ; immunology ; Influenza, Human ; epidemiology ; prevention & control ; virology ; Middle Aged ; Population Surveillance ; methods ; Seroepidemiologic Studies ; Young Adult

Adolescent ; Adult ; Aged ; Antibodies, Viral ; blood ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Influenza A virus ; immunology ; Influenza B virus ; immunology ; Influenza, Human ; epidemiology ; virology ; Male ; Middle Aged ; Seroepidemiologic Studies

OBJECTIVETo identify variations in hemagglutinin genes from influenza viruses (H3N2) isolated from infants and young children with acute respiratory infection (ARI) between March, 2004 and April 2005.

METHODSRNAs from influenza A virus strains (subtype H3) isolated from specimens collected from ARI children were extracted followed by amplification for HA1 fragments from hemagglutinin (HA) genes by RT-PCR. The sequences of the fragments were defined by direct sequencing for the PCR products or the target inserts after the PCR fragments were cloned into the TA-cloning vector pBS-T and analyzed by bioinformatic software.

RESULTSFragments of 987 bps of HA1 (encoding 329 amino acids) from a total of 32 strains of influenza A virus (subtype H3) isolated from the 2004 season and 1 from the 2003 season were amplified and the sequences were compared with vaccine reference strains recommended by WHO which were used in recent years. There were several consistent amino acid variations which involved in both antigenic epitopes A and B and receptor binding site (RBS) for isolated strains in the 2004 influenza season compared with the vaccine strains used during the recent years and the virus strains isolated in March 2004, indicated the antigenic drift of the viruses isolated in 2004 influenza season may lead to variant viruses.

CONCLUSIONThe variations of the HA genes from influenza virus (subtype H3) strains in the 2004-2005 influenza season were confirmed by sequence analysis for the HA1 regions of the hemagglutinin genes, which indicate that the antigenic drift would have been caused by the diversification of the genes and the efficacy of the recently used vaccines should be kept under close watch.

Antigenic Variation ; Child ; China ; epidemiology ; Evolution, Molecular ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza A Virus, H3N2 Subtype ; genetics ; immunology ; isolation & purification ; Influenza, Human ; epidemiology ; immunology ; virology ; RNA, Viral ; genetics ; Sequence Analysis, RNA

OBJECTIVETo explore the trend of influenza epidemics, predominate strains of the virus in Tianjin city and to analyze the economic impact of vaccine-based interventions for the prevention and control of influenza.

METHODSData on epidemiological studies and on virus surveillance was gathered. Monte Carlo mathematical simulation modelwas used for data analyses.

RESULTSFrom 29, December, 2003 to 2, January, 2005, the proportion of influenza-like infection cases was accounted for 8.93% of the total number of patients from the outpatient departments of 4 general hospitals in Tianjin. The proportion reached its peak from November to February and it was accounted for 9.39% in epidemic period, which was significantly different from that in the non-epidemic period (u = 15.53, P< 0.05). There was 56 strains of influenza virus isolated in which 45 were indentified as A(H3N2) and 11 as B with a total positive rate as 13.21%. Predominant strain was found bing type A(H3N2). The positive rate was 15.41% in the epidemic period, which was significantly different from that in the non-epidemic period (u = 2.519, P < 0.05). The cost per visit ranged from 475.93 to 581.69 Yuan (RMB) with an average cost of 528.81 Yuan. When the attack rate increased to 30 percent, the positive mean net returns would have been 24 million Yuan among the 0-19 age group.

CONCLUSIONInfluenza did not seem to be prevalent in Tianjin from 29, December, 2003 to 2, January, 2005. The main type of influenza was type A(H3N2). It is necessary to pay attention to the all-year round surveillance program due to the transformation of influenza type A and the slight increase of incidence in summer.

Adolescent ; Adult ; Child ; Child, Preschool ; China ; epidemiology ; Health Care Costs ; statistics & numerical data ; Humans ; Infant ; Infant, Newborn ; Influenza A Virus, H3N2 Subtype ; physiology ; Influenza B virus ; physiology ; Influenza, Human ; economics ; epidemiology ; immunology ; virology ; Middle Aged ; Population Surveillance ; Seasons ; Viral Vaccines ; immunology

Avian influenza has emerged as one of the primary public health concern of the 21st century. Influenza strain H5N1 is capable of incidentally infecting humans and other mammals. Since their reemergence in 2003, highly pathogenic avian influenza A (H5N1) viruses have been transmitted from poultry to humans (by direct or indirect contact with infected birds) in several provinces of Mainland China, which has resulted in 22 cases of human infection and has created repercussions for the Chinese economy. People have been concerned whether a new pandemic will occur in the future. The eradication of pathogenic avian influenza viruses appears to be the most effective way to prevent an influenza pandemic. This paper will examine the features of H5N1, including incidence, infection, immunity, clinical management, prevention and control, and therapy in Mainland China.
Adolescent ; Adult ; Animals ; Birds ; Child ; China/epidemiology ; Disease Outbreaks/prevention & control ; Female ; Humans ; Incidence ; *Influenza A Virus, H5N1 Subtype ; Influenza in Birds/prevention & control ; Influenza, Human/*epidemiology/immunology/therapy ; Male ; Zoonoses/epidemiology/transmission/virology