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Resumen Se ofrece una perspectiva de las epidemias y pandemias en México en tres periodos: fines del siglo XVIII y siglos XX y XXI, con el fin de analizar cómo las autoridades sanitarias y gubernamentales abordaron estos problemas, así como los desafíos que han representado. Se consultaron fuentes históricas documentales y, en los casos actuales, la participación en ellos. Se combinó metodología epidemiológica e histórica social. La presencia de las epidemias en México es una constante, lo cual evidencia la necesidad de actualizar el sistema de vigilancia epidemiológica, de estar preparados para enfrentar una epidemia y de elaborar un plan de contingencia.
Abstract A perspective of epidemics and pandemics in Mexico is offered, focusing on three time periods, namely, end of the 18th century, the 20th century, and the 21st century, in order to analyze how they were approached by health and government authorities, as well as the challenges they have represented. Historical documentary sources were consulted and, in current cases, participation in them was analyzed. Epidemiological and social historical methodologies were combined. The presence of epidemics in Mexico is a constant on its evolution, which highlights the need for the epidemiological surveillance system to be updated, the importance of being prepared to face an epidemic and to develop a contingency plan.
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Abstract: Objective: To compare the perceptions and experiences between the A(H1N1) and Covid-19 pandemics in a university population. Materials and methods: Online surveys were administered during the influenza A(H1N1) -originated in Mexico in 2009- and Covid-19 epidemics. Measures: sociodemographic characteristics, knowledge, information and communication, perception of risk, physical and mental health, effects on daily life, and preventive behaviors. Results: This study included 24 998 respondents, 51.36% from the A(H1N1) group and 48.63% from the Covid-19 group. Differences were observed in the perception of severity. During the influenza A(H1N1) pandemic worry was the feeling reported most frequently, while for Covid-19 it was anxiety. Covid-19 had greater impact on students' family economy and caused a higher uncertainty. Conclusions: The perceptions and experiences of the two pandemics were similar but the impact has been much greater for Covid-19, especially in terms of the severity, family economy, preventive behaviors, and uncertainty.
Resumen: Objetivo: Comparar las experiencias y percepciones de riesgo entre las pandemias de A(H1N1) y Covid-19 en universitarios. Material y métodos: Encuestas en línea comparables de las epidemias de influenza A(H1N1) -originada en México en 2009- y Covid-19. Evaluaciones: características sociodemográficas, conocimientos, información y comunicación, percepción de riesgo, salud física y mental, efectos en la vida cotidiana, conductas preventivas. Resultados: Participaron 24 998 sujetos; 51.36% de grupo de A(H1N1) y 48.63% del grupo de Covid-19. Se observaron diferencias en la percepción de las epidemias. En influenza A(H1N1) la preocupación fue el sentimiento más frecuente y para Covid-19, la ansiedad. En Covid-19 hubo mayor impacto en la economía familiar y mayor incertidumbre para el regreso a clases. Conclusión: Las percepciones y experiencias de las dos pandemias fueron similares, pero el impacto ha sido mucho mayor para Covid-19 especialmente en la gravedad, economía familiar, conductas preventivas y en la incertidumbre.
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BACKGROUND Influenza viral load (VL) can be a decisive factor in determining the antiviral efficacy in viral clearance. OBJECTIVE This study aimed to evaluate the rate of infection and the role of influenza VL on the clinical spectrum of illnesses among different patient groups attended at a tertiary hospital in Brazil. METHODS Samples were collected from patients presenting acute respiratory infection from 2009 to 2013. Overall, 2262 samples were analysed and distributed into three groups: (i) asymptomatic (AS); (ii) symptomatic outpatients (OP); and (iii) hospitalised patients (HP). VL (expressed in Log10 RNA copies/mL) was calculated through a quantitative real-time one-step reverse transcription-polymerase chain reaction (RT-PCR) assay aimed at the M gene, with human RNAseP target as internal control and normalising gene of threshold cycle values. FINDINGS A total of 162 (7.16%) H1N1pdm09 positive samples were analysed. Patients aged from 0.08 to 77 years old [median ± standard deviation (SD): 12.5 ± 20.54]. Children with 5 to 11 years old presented the highest detection (p < 0.0001). AS patients had the lowest VL, with a significant difference when compared with symptomatic patients (p = 0.0003). A higher VL was observed within two days of disease onset. Ten patients (HP group) received antiviral treatment and were followed up and presented a mean initial VL of 6.64 ± 1.82. A complete viral clearance for 50% of these patients was reached after 12 days of treatment. MAIN CONCLUSIONS It is important to evaluate AS patients as potential spreaders, as viral shedding was still present, even at lower VL. Our results suggest that patients with underlying diseases and severe clinical symptoms may be considered for prolonged viral treatment.
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Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Aged , Young Adult , Respiratory Tract Infections/virology , Influenza, Human/virology , Influenza A Virus, H1N1 Subtype/genetics , RNA, Viral/genetics , Acute Disease , Viral Load , Influenza A Virus, H1N1 Subtype/classification , Influenza A Virus, H1N1 Subtype/pathogenicity , Real-Time Polymerase Chain Reaction , Middle AgedABSTRACT
Resumen: La miocarditis es una enfermedad inflamatoria del miocardio secundaria a enfermedades autoinmunes, tóxicas e infecciosas. Dentro de éstas últimas, las virales son las más frecuentes. Sin embargo, el virus de influenza A H1N1 sigue siendo una etiología poco reportada. La prevalencia de miocarditis fulminante debido a gripe estacional ha sido establecida entre 1 y 11% según los criterios diagnósticos utilizados, y la prevalencia de miocarditis causada por H1N1 se estima en 13%. Presentamos un caso clínico, de una paciente joven, donde se realiza diagnóstico retrospectivo de Miocarditis por Influenza A H1N1 con presentación de miocarditis fulminante, con alteraciones electrocardiográficas sugestivas, troponinas cardiacas positivas, caída de la función ventricular con posterior recuperación, y aislamiento microbiológico de agente causal.
Abstract: Myocarditis is an inflammatory myocardial disease secondary to autoimmune, toxic, and infectious diseases. Among the latter, virals are the most frequent. However, influenza A H1N1 virus remains a poorly reported etiology. The prevalence of fulminant myocarditis due to seasonal influenza has been established between 1 and 11% according to the diagnostic criteria used, and the prevalence of myocarditis caused by H1N1 is estimated at 13%. We report a clinical case, of a young patient, where a retrospective diagnosis of H1N1 Influenza A myocarditis was made with a presentation of fulminant myocarditis, with suggestive electrocardiographic abnormalities, positive cardiac troponins, loss of ventricular function with subsequent recovery, and microbiological isolation of the causal agent.
Resumo: A miocardite é uma doença inflamatória do miocárdio secundária a doenças autoimunes, tóxicas e infecciosas. Entre os últimos, os virais são os mais frequentes. No entanto, o vírus influenza A H1N1 permanece uma etiologia pouco relatada. A prevalência de miocardite fulminante por influenza sazonal foi estabelecida entre 1 e 11%, de acordo com os critérios diagnósticos utilizados, e a prevalência de miocardite causada pelo H1N1 é estimada em 13%. Apresentamos um caso clínico, de um paciente jovem, em que foi feito um diagnóstico retrospectivo de miocardite por influenza A H1N1, com apresentação de miocardite fulminante, com alterações eletrocardiográficas sugestivas, troponinas cardíacas positivas, perda de função ventricular com recuperação subsequente e isolamento microbiológico do agente causal.
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Influenza A(H1N1)pdm09 caused a deadly pandemic in 2009, replaced the seasonal influenza A(H1N1) virus that circulated prior to 2009, and still causes a serious infectious disease among children and adults [1]. In addition, Respiratory syncytial virus (RSV) infection remains a clinical burden on young children even though palivizumab has been effectively used for high-risk infants [2]. To compare the clinical impact of RSV infection with that of influenza in children, we retrospectively studied 2,375 children who presented to a hospital outpatient clinic between 2008 and 2010 with fever and/or symptoms of respiratory tract infection. The clinical aspects of RSV infection were compared with those of A(H1N1)pdm09 infection. After the influenza A(H1N1)pdm09 pandemic, 591 patients were diagnosed with influenza (Group 1), whereas 54 patients were diagnosed with RSV infection (Group 2). Before the pandemic, 203 patients were diagnosed with seasonal influenza (Group 3). All infections were diagnosed by using the rapid immunochromatography test, in which, prior to the pandemic, a positive test indicated seasonal influenza A(H1N1) exposure. However, during and after the pandemic, a positive test result suggested A(H1N1)pdm09 infection, which was confirmed by RT-PCR analysis of the sample and local etiological studies. In group 1, 31 children (average age 7.7 years, 5% of outpatients) required hospitalized for complications of the respiratory system (52%), central nervous system (16%), gastroenterological system (10%), and not specified (22%). In group 2, 33 children (average age 2.2 years, 60% of outpatients) were hospitalized, 27% of whom were administrated oxygen and 12% intravenous steroids. In group 3, 33 children (average age 6.8 years, 3% of outpatients) were hospitalized.
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Background & objectives: Influenza virological surveillance is an essential tool for the early detection of novel genetic variants of epidemiologic and clinical significance. This study was aimed to genetically characterize A(H1N1)pdm09 virus circulating in 2017 and to compare it with the global data. Methods: The regional/State Viral Research and Diagnostic Laboratories (VRDLs) provided influenza diagnosis for referred clinical samples and shared influenza A(H1N1)pdm09 positives with the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, India, for hemagglutinin (HA) gene phylogenetic analysis. Sites at Manipal, Jaipur and Dibrugarh performed the sequencing and shared the sequence data for analysis. The antiviral susceptibility of influenza viruses was assessed for known molecular marker H275Y at the ICMR-NIV, Pune. Results: All the eight VRDLs had well-established influenza diagnostic facilities and showed increased activity of influenza A(H1N1)pdm09 during 2017. Phylogenetic analysis showed that the viruses from the different regions of the country were similar to A/Michigan/45/2015 strain which was the 2017-2018 recommended vaccine strain and were clustered with the globally circulating clade 6B.1 with signature mutations S84N, S162N and I216T. The clade 6B.1 showed further subgrouping with additional mutations S74R, S164T and I295V; however, there was no significant association between the presence of these mutations and severity of disease due to influenza. All the study viruses were sensitive to oseltamivir. Interpretation & conclusions: During the study period, all the study sites reported globally circulating A/Michigan/45/2015 vaccine strain of influenza A(H1N1)pdm09 viruses and remained sensitive to oseltamivir. Further genetic and antigenic characterization of influenza viruses is recommended to address public health concerns.
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Background: Mortality profile is an analytical tool used to identify the various factors responsible for poor outcome of disease and it can also use to evaluate quality and efficiency of healthcare providers. The aim of this study is to summarise the clinical and epidemiological factors as well as to identify the risk factors associated with mortality among swine flu cases.Methods: It is a cross-sectional, descriptive, hospital-based study conducted on 62 deceased patients due to swine flu reported at Maharana Bhupal Government Hospital, Udaipur, Rajasthan during the outbreak of influenza A H1N1 in the year 2015. A standardized pre-structured questionnaire with consent was filled by help of bed head tickets and by interview of attendants of deceased patients.Results: Deaths were higher among age group of 31-45 years (35.48%). Case fatality rate for male patients (13.88%) was higher. Mortality was highest in females of rural background 27(43.55%). Majority of deceased patients (70.97%) had delay of 4-7 days in admission after onset of symptoms. Diabetes, cardiovascular diseases and pregnancy was the major risk factors for poor outcome.Conclusions: Delay in diagnosis and admission may be the reason for higher mortality rate. The most common co morbid illness was Diabetes mellitus, cardiovascular diseases (Ischemic heart disease, Rheumatic heart disease, Hypertension) and pregnancy.
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Background: Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses). Swine flu cases resurfaced in month of January 2015 in Southern region of India which are continuation of pandemic 2009. Aim of this study is to summaries the clinical and epidemiological factors associated with swine flu as well as to estimate the burden of Influenza A H1N1 (Swine Flu) cases.Methods: A complete data of all the patients visiting swine flu OPDs, swine flu wards and ICU were maintained for year 2015. Each patient visiting either the swine flu OPD or the swine flu ward, who was suspected clinically to be H1N1 positive were tested for real time PCR.Results: Out of 1247 samples tested for rt-PCR 491 (39.37%) cases were identified as positive for H1N1. Maximum swine positivity was seen in the age group of 16-30 year i.e. 147 (29.94%). Overall swine positivity was significantly (<0.001) higher in females than male and extremely statistically significant (p<0.0001) higher in rural areas than urban. Cough was the most common clinical symptoms affecting 469(95.52%) patients followed by fever (92.26%) and breathlessness 402(81.87%).Conclusions: Our study will help epidemiologist and clinician to identify epidemiological factors and clinical picture of swine flu.
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Introduction: Influenza A(H1N1)pdm09 virus, since its identification in April 2009, has continued to cause significant outbreaks of respiratory tract infections including pandemics in humans. In the course of its evolution, the virus has acquired many mutations with an ability to cause increased disease severity. A regular molecular surveillance of the virus is essential to mark the evolutionary changes that may cause a shift to the viral behavior. Materials and Methods: Samples of Throat/Nasal swabs were collected from a total of 3715 influenza-like illness cases and screened by Real-time Reverse Transcription-Polymerase Chain Reaction for influenza viruses. Nucleotide sequence analysis was done to identify changes in antigenicity of the virus strains. Results: The present study describes the molecular characteristics of influenza A(H1N1)pdm09 viruses detected in Assam of Northeast India during 2009�15. Influenza A viruses were detected in 11.4% (425/3715), of which influenza A(H1N1)pdm09 viruses were detected in 41.4% (176/425). The nucleotide sequencing of influenza A(H1N1)pdm09 viruses revealed a total of 17 and 22 amino acid substitutions in haemagglutinin (HA) and neuraminidase (NA) genes of the virus, respectively, compared to contemporary vaccine strain A/California/07/2009. The important mutations detected in HA genes of A/Assam(H1N1)pdm09 strains included E391K, K180Q and S202T. Mutation 'N248D' which has an ability to develop oseltamivir resistance was also detected in NA gene of A/Assam(H1N1)pdm09 strains. Conclusions: Regular molecular surveillance of influenza A(H1N1)pdm09 is important to monitor the viral behavior in terms of increase virulence, drug resistance pattern and emergence of novel strains.
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Objective@#To understand the epidemiological characteristics of influenza A(H1N1)pdm09 virus in Sichuan population during the monitoring period of 2018-2019, and to clarify the antigenic variation, the gene characteristics and the matching of current epidemic strains, vaccine strains, representative strains at home and abroad.@*Methods@#A total of 118 strains of influenza A(H1N1)pdm09 virus isolated in Sichuan region influenza network laboratory from April 2018 to March 2019 were selected. The hemagglutination inhibition (HI) assay was conducted for antigen analysis. The HA and NA genes of 16 strains with low-response strains were sequenced. Phylogenetic analysis and amino acid locus variation analysis were applied using BioEdit and MEGA5.0 software.@*Results@#The result of the antigen analysis demonstrated that more than 95% of the A(H1N1) pdm09 influenza viruses detected were similar to the WHO recommended vaccine strain A/Michigan/45/2015. The analysis of HA gene characteristics showed that some low-response strains had amino acid site variation in the Sa, Sb and Cb regions of the HA protein. A total of 15 low-response strains belonged to the 6B.1 branch. And their evolutionary relationship were close to the representative strains A/beijin-xicheng/SWL1633/2018 and A/brisbane/02/2018, which were popular at home and abroad. Compared with A/sichuan/1/2009, there are mutations involving 6, 14 and 1 amino acid sites in the antigen-determining regions (Sa, Sb, Ca and Cb), non-determined regions and receptor binding site(RBS) respectively. No amino acid site mutations related to resistance to NA gene were found.@*Conclusions@#In 2018-2019, the epidemic A(H1N1) pdm09 influenza virus in Sichuan is consistent with the global epidemic characteristics, which also matched with vaccine strains recommended by WHO in the northern hemisphere. Compared with A/sichuan/1/2009 which was the first isolated in China in 2009, there were amino acid sites mutations in antigen-determining region and receptor binding site of the HA protein, and the transmembrane region of the NA protein, drug and antibody binding sites.
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Objective@#To evaluate the effect of vaccine and provide scientific evidence for prevention and control of influenza virus, this study aims to analyze the characteristics of genomic variation of influenza A (H1N1) pdm09 viruses in Inner Mongolia.@*Methods@#The 16 viral strains were selected randomly according to the influenza A (H1N1) pdm09 viruses isolated from network laboratories in Inner Mongolia, 2013-2017. The hemagglutinin(HA) and neuraminidase(NA) genomic sequences were obtained by using RT-PCR and sequencing, and genomic characteristics were analyzed via bioinformatics.@*Results@#Compared to the A/California/07/2009 vaccine strain, the relatively obvious variation of antigen of influenza A (H1N1) pdm09 viruses in Inner Mongolia since 2014, and the vaccine provided a poor protection to influenza A (H1N1) pdm09 virus infection, while the A/Michigan/45/2015 vaccine strain recommended by WHO recently has a satisfactory protective effects. Several viral isolates from Inner Mongolia increased the binding force of virus in human upper respiratory tract because of D222N and D222G substitution within HA. E119K and H275Y substitution within NA gene of viral strains, suggesting that the viruses were resistant to NA inhibitors.@*Conclusions@#The influenza A (H1N1) pdm09 viruses had gradual variations as time went on, and the WHO recommended vaccine was relatively lagging. Virulent strains and drug-resistant strains appeared in the population, and the genetic characteristics of influenza virus surveillance should be strengthened to find the new mutants of virus in time, which provide evidence for the prevention and control of influenza.
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Objective: To evaluate the effect of Chuankezhi injection on mouse model of pneumonia induced by influenza A (H1N1) FM1 strain. Method: ICR mice were randomly divided into normal group, model group, tamiflu control group (27.5 mg·kg-1·d-1) and Chuankezhi injection group (1.5 mL·kg-1·d-1). In the death protection experiment, mice were infected with 2×half lethal dose (LD50) of influenza virus FM1.The Chuankezhi injection was given once a day for 4 days. The number of death animal within 14 days was counted. The mortality and the death protection rate were calculated. In the treatment experiment, mice were infected with 0.8×LD50 of influenza virus, and the Chuankezhi injection was given once a day for 4 days. On the 5th day after the infection, the levels of interleukin-8 (IL-8) in lung, prostaglandin E2 (PGE2) and vasopressin (AVP) in brain were tested by enzyme-linked immunosorbent assay (ELISA). The viral load of influenza virus in lung was tested by Real-time PCR. In the pre-treatment experiment, mice were given Chuankezhi injection once a day for 5 days. 1 hour after the last treatment, mice were infected with 0.8×LD50 influenza virus. 4 days after the infection, the lung index, spleen index, thymus index, and viral load in lung tissue were calculated. Result: Compared with normal group, the IL-8, PGE2 content, lung index and viral load in the lung tissue of model group were significantly increased (P2, and the viral load of influenza(PPPPConclusion: Chuankezhi injection could effectively prevent the mouse model of pneumonia induced by influenza A (H1N1) virus. The mechanism might be related to the reduction of inflammation and inhibiting viral replication.
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Objective@#To investigate the clinical features, laboratory results, chest CT imaging manifestations and treatments of severe and critical influenza A (H1N1), and to analyze the relationship with the prognosis.@*Methods@#The clinical data of 54 adult patients with severe and critical H1N1 admitted to the Fourth People's Hospital of Nanning from November 2018 to February 2019 were analyzed retrospectively. Throat swab specimens of the patients were determined for nucleic acid detection of influenza A (H1N1) virus, and all of the patients were confirmed. The gender, age, course of disease, underlying diseases, symptoms, body temperature, hospital stays, chest CT findings and laboratory results were collected, and the treatments and prognosis were recorded.@*Results@#Of 54 patients, 38 patients were enrolled in severe group, and 16 in critical group. Fever, cough, sputum, shortness of breath and so on could be found in the two groups. The CD4+ T lymphocytes were less than normal reference value (410-1 590/μL) in both groups. The chest CT findings manifestations of severe group were scattered patchy shadows and ground glass appearance, all of them were cured and discharged after antiviral, antibiotics, and oxygen treatment. In critical group, the time in hospital was longer, the disease progresses varied faster, the shortness of breath was more apparent, and a large patch of fuzzy and real change shadows on both lungs could be found from CT findings. Compared with the severe group, creatine kinase (CK), lactic dehydrogenase (LDH), C-reactive protein (CRP) and procalcitonin (PCT) levels in the critical group were increased more significantly [CK (U/L): 704.50 (908.50) vs. 146.00 (220.75), LDH (U/L): 614.50 (492.25) vs. 217.00 (142.75), CRP (mg/L): 85.65 (56.13) vs. 18.80 (50.63), PCT (μg/L): 1.30 (5.00) vs. 0.10 (0.16), all P < 0.01], white blood cells count (WBC) and neutrophil ratio were also increased more significantly [WBC (×109/L): 12.37±7.63 vs. 8.29±3.32, neutrophil ratio: 0.81±0.11 vs. 0.75±0.11] without statistical differences (both P > 0.05). Nine patients in critical group were cured with cure rate of 56.25%. Seven patients died with mortality of 43.75%, including 2 patients with acquired immunodeficiency syndrome (AIDS) and uremia respectively, who had multiple organ failure (MOF) on admission and waive the mechanical ventilation treatment; 3 patients complicated with acute renal failure but abandon hemodialysis; 1 patient with nasopharyngeal carcinoma radiotherapy after operation; and 1 patient with chronic renal failure uremia period combined multiple drug-resistant bacteria infection, and died from MOF finally.@*Conclusions@#The patients with severe and critical influenza A (H1N1) show fever, cough, dyspnea, and organ dysfunction in varying degrees. Severe patients were mainly pulmonary lesions, while critical patients show MOF such as heart, lung and kidney, and the lesions progressed rapidly. The major cause of death for critical influenza A (H1N1) may be chronic underlying diseases and MOF.
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Objective To investigate the clinical features, laboratory results, chest CT imaging manifestations and treatments of severe and critical influenza A (H1N1), and to analyze the relationship with the prognosis. Methods The clinical data of 54 adult patients with severe and critical H1N1 admitted to the Fourth People's Hospital of Nanning from November 2018 to February 2019 were analyzed retrospectively. Throat swab specimens of the patients were determined for nucleic acid detection of influenza A (H1N1) virus, and all of the patients were confirmed. The gender, age, course of disease, underlying diseases, symptoms, body temperature, hospital stays, chest CT findings and laboratory results were collected, and the treatments and prognosis were recorded. Results Of 54 patients, 38 patients were enrolled in severe group, and 16 in critical group. Fever, cough, sputum, shortness of breath and so on could be found in the two groups. The CD4+ T lymphocytes were less than normal reference value (410-1 590/μL) in both groups. The chest CT findings manifestations of severe group were scattered patchy shadows and ground glass appearance, all of them were cured and discharged after antiviral, antibiotics, and oxygen treatment. In critical group, the time in hospital was longer, the disease progresses varied faster, the shortness of breath was more apparent, and a large patch of fuzzy and real change shadows on both lungs could be found from CT findings. Compared with the severe group, creatine kinase (CK), lactic dehydrogenase (LDH), C-reactive protein (CRP) and procalcitonin (PCT) levels in the critical group were increased more significantly [CK (U/L): 704.50 (908.50) vs. 146.00 (220.75), LDH (U/L): 614.50 (492.25) vs. 217.00 (142.75), CRP (mg/L):85.65 (56.13) vs. 18.80 (50.63), PCT (μg/L): 1.30 (5.00) vs. 0.10 (0.16), all P < 0.01], white blood cells count (WBC) and neutrophil ratio were also increased more significantly [WBC (×109/L): 12.37±7.63 vs. 8.29±3.32, neutrophil ratio:0.81±0.11 vs. 0.75±0.11] without statistical differences (both P > 0.05). Nine patients in critical group were cured with cure rate of 56.25%. Seven patients died with mortality of 43.75%, including 2 patients with acquired immunodeficiency syndrome (AIDS) and uremia respectively, who had multiple organ failure (MOF) on admission and waive the mechanical ventilation treatment; 3 patients complicated with acute renal failure but abandon hemodialysis; 1 patient with nasopharyngeal carcinoma radiotherapy after operation; and 1 patient with chronic renal failure uremia period combined multiple drug-resistant bacteria infection, and died from MOF finally. Conclusions The patients with severe and critical influenza A (H1N1) show fever, cough, dyspnea, and organ dysfunction in varying degrees. Severe patients were mainly pulmonary lesions, while critical patients show MOF such as heart, lung and kidney, and the lesions progressed rapidly. The major cause of death for critical influenza A (H1N1) may be chronic underlying diseases and MOF.
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Objective To explore the characteristics and causes of death of severe influenza cases,in order to attract the attention of pediatricians.Methods The data of 19 cases with influenza-associated deaths admitted to Shenzhen Children's Hospital from September 2009 to November 2018 were retrospectively analyzed.Results There were 11 males and 8 females,aged from 4 months to 12 years old,of whom 5 cases were over 5 years old.Five deaths occurred during the 2009 influenza A (H1N1) pandemic,followed by 1 case in 2014,6 cases in 2016,3 cases in 2017 and 4 cases in 2018.Four of the 19 deaths were due to underlying diseases.The time from onset to death was 0.5-36.0 days,and the most common clinical manifestations were high fever,convulsions,coma and dyspnea.Among them,11 cases died of influenza-associated encephalopathy,4 cases died of severe pneumonia,acute respiratory distress syndrome(ARDS) and respiratory failure,3 cases died of sepsis caused by secondary streptococcus pneumoniae infection,and 1 case died of secondary fungal pyothorax and fungal meningitis.Conclusions Children under 5 years of age,even if they were previously healthy,may still be at high risk of dying from influenza.Neurological complications were high and the leading causes of death were influenza-associated encephalopathy,severe pneumonia,ARDS and secondary severe bacterial infection.
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To study the effect and underlying mechanism of Mahuang Tang against influenza A virus ， the influenza virus-infected Madin-Darby canine kidney(MDCK) cells were used as the carrier in this study to detect the median tissue culture-infective dose(TCID₅₀) of influenza A virus strains(A/PR8/34) on MDCK cells with cytopathic effect(CPE) assay. Blocking influenza virus invading host cells and anti-influenza virus biosynthesis were used as two different administration methods， and then the methyl thiazolyl tetrazolium(MTT) assay was utilized to determine the antiviral effective rate(ER)， median efficacious concentration(EC₅₀) and therapeutic index(TI) of Mahuang Tang. The quantitative Real-time polymerase chain reaction(RT-PCR) was used to measure virus load and the mRNA expression levels of TLR4， TLR7， MyD88 and TRAF6 in MDCK cells at 24， 48 h after the treatment. The experiment results indicated that TCID₅₀ of A/PR8/34 for MDCK cells was 1×10-4.32/mL. The EC₅₀ values of two different treatment methods were 4.92，1.59 g·L⁻¹ respectively， the TI values were 12.53， 38.78 respectively， and when the concentration of Mahuang Tang was 5.00 g·L⁻¹， ER values were 50.21%， 98.41% respectively， showing that Mahuang Tang can block influenza virus into the host cells and significantly inhibit their biosynthesis. Meanwhile， as compared with the virus group， the virus load was significantly inhibited in Mahuang Tang groups， and Mahuang Tang high and middle doses had the significant effect on decreasing the mRNA expression of TLR4， TLR7，MyD88 and TRAF6 at 24， 48 h after the treatment. It can be demonstrated that the mechanisms of Mahuang Tang against influenza A virus are related to the inhibition of influenza virus replication and the mRNA expression of correlative genes in TLR4 and TLR7 signaling pathways.
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Animals , Dogs , Antiviral Agents , Pharmacology , Drugs, Chinese Herbal , Pharmacology , Influenza A Virus, H1N1 Subtype , Physiology , Madin Darby Canine Kidney Cells , Orthomyxoviridae Infections , Toll-Like Receptor 4 , Metabolism , Toll-Like Receptor 7 , Metabolism , Virus ReplicationABSTRACT
Objective To screen the pneumonia-related abnormal metabolites in lung tissue of mice infected by Influenza A/H1N1, and to monitor the regulation effect of Pudilan Xiaoyan Oral Liquid and to explore potential anti-pneumonia mechanism. Methods ICR mice were randomly divided into four groups with ten mice in each group: normal group, model group, Pudilan group, and Ribavirin group. The mice were infected with H1N1 virus intranasally and gavage once every-day for six consecutive days. 2 h after the last dose, the mice were sacrificed and lungs were collected. Metabolomics based on GC-MS was applied to analyze the changes of metabolites in the lung tissue of each group. The potential biomarkers of H1N1-induced pneumonia were screened by three conditions: P 1.0, and Fold Change > 1.5. Metabolic pathways related to the treatment mechanism of Pudilan Xiaoyan Oral Liquid were analyzed. Results The infection of H1N1 virus leads to infiltration of inflammatory cells in the lungs of mice and various degrees of pneumonitis and metabolic disorders. Pudilan Xiaoyan Oral Liquid and ribavirin can both ameliorate the symptoms of pneumonia and play role in callback of various metabolites. Conclusion The treatment effect of Pudilan Xiaoyan Oral Liquid on H1N1-induced pneumonia is related to the regulation effects on 14 potential biomarkers and 12 associated metabolic pathways.
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Objective@#To analyze the clinical manifestations and results of etiological examinations of 17 elderly patients with influenza A (H1N1) viral pneumonia, and to understand the clinical features of pneumonia and molecular characteristics of influenza A (H1N1) virus infection in the elderly.@*Methods@#The elderly patients with pneumonia who were hospitalized in the Department of Respiratory Diseases of Nanjing First Hospital from January 2018 to March were enrolled. The cases were confirmed by nucleic acid examination for influenza virus and the clinical data were collected. After the amplification of the whole genome of influenza virus, the high throughput sequencing and bioinformatics analysis were performed.@*Results@#The mean age of the 17 enrolled patients was 73.8±10.8. All of them had at least 1 underlying disease, and 7 cases had co-infection. Respiratory symptoms and fever were the most prominent clinical manifestations. Lesions in both lungs were found in 76.5% of the patients. The result of high throughput sequencing showed that all the viruses were highly homologous to the vaccine strain, and the HA gene belonged to the 6B.1 subgroup. Furthermore, three variations of antigenic locus (H138Y, S74R and S164T in HA) and a drug-resistant variation (H275Y in NA) were detected in the circulating strains.@*Conclusions@#Elderly patients with influenza A (H1N1) virus pneumonia often have underlying diseases and are prone to have co-infection. The molecular characteristics of the virus and the variation of key amino acid loci should be closely monitored in order to provide evidence for epidemic prevention and clinical antiviral treatment.
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Objective@#To analyze the genetic characteristics of the hemagglutinin(HA) and neuraminidase(NA) genes of the influenza A/H1N1(09pdm) viruses isolated in the city of Yancheng in 2014-2017.@*Methods@#The throat swab specimens of patients with influenza-like illness (ILI) from sentinel surveillance hospitals and outbreak sites were detected using the method of real time RT-PCR. The influenza A/H1N1(09pdm) viruses were isolated using MDCK cell culture method in 2014-2017. The strains in 2014-2017 were selected randomly and their sequences of the HA1 and NA genes were amplified through one step RT -PCR method and the PCR products were sequenced. The mutations of genes and acid locus were analyzed and the evolutional trees were generated using bioinformatics software.@*Results@#The clustering relationships of the respective branches of HA1 and NA genes of seventeen A/H1N1(09pdm) strains isolated in Yancheng area were basically the same and the phylogenetic trees of HA1 and NA genes were respectively clustered into four evolutionary branches. Compared with the vaccine strain A/California/07/2009(H1N1pdm)in the Northern Hemisphere, a total of three antigen epitopes (Ca, Sa, Sb) in HA1 genes of strains in Yancheng area were involved in six antigenic sites (K154R, S162N, K163Q, S185T, L191I, S203T); there were three mutations (D222G/N, G223R, E224K) in the 220 ring and one locus (L191I) in the 190 helix of the receptor binding sites; the two strains (A/Jiangsu-YC/SWL1540/2017, A/Jiangsu-YC/SWL1545/2017) isolated in 2017 increased the 162NQS glycosylation site. Because the strains of the antigen epitopes, receptor binding sites and glycosylation sites in the HA1 genes had a certain degree of variations in Yancheng area in 2014-2017, the protective effects of vaccine strain A/California/07/2009 (H1N1pdm) was limited at the gene level. The two strains (A/Jiangsu-YC/SWL1540/2017 and A/Jiangsu-YC/SWL1545/2017) isolated in 2017 were clustered with vaccine strain A/Michigan/45/2015(H1N1pdm) and had better protective effects. Seventeen A/H1N1(09pdm) strains had no mutations in catalytic residues and drug resistant sites of NA genes, but a part of strains had a certain degree of variations in glycosylation sites of NA genes.@*Conclusions@#These results indicated the HA1 and NA genes of influenza A/H1N1(09pdm) viruses circulated in Yancheng area in 2014-2017 changed gradually. The accumulation of these mutations would result in antigenic drift of influenza A/H1N1(09pdm) viruses.
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Objective To study the antiviral effect of Jin Qiao Tablets on influenza A H1N1 virus in vivo. Methods The mouse pneumonia model was established by nasal inhalation of 15 LD50 of influenza virus. After prophylactic or therapeutic medication for 5 d,mouse lung tissue was taken out and weighed. Viral load in lung tissue was measured by polymerse chain reaction(PCR),and the level of γ-interferon(γ-IFN)in rat serum and lung was detected by double antibody sandwich enzyme-linked immunosorbent assay (ELISA)for evaluating the effect of Jin Qiao Tablets on lung index, viral load and γ-IFN in rats. After prophylactic or therapeutic medication for 7 d,morbidity and mortality within 14 d of mice with pneumonia induced by nasal inhalation of 3 LD50 were observed to evaluate the action of Jin Qiao Tablets for protecting against death and prolonging life span. Results Jin Qiao Tablets markedly decreased the increased lung index,promoted the death-protection rate and life-prolongation rate, decreased viral load, raised the level of γ-IFN in mice (P < 0.05 or P < 0.01). Experimental results in vivo showed that Jin Qiao Tablets had better anti-influenza virus activity than Yinqiao Jiedu Tablets and Lianhua Qingwen Capsules, and the effect of Jin Qiao Tablets was equivalent to that of Tamiflu. The prophylactic effect of Jin Qiao Tablets was stronger than the therapeutic effect, but there was no significant difference between them. Conclusion Jin Qiao Tablets have obvious effect against influenza A H1N1 virus in vivo.