OBJECTIVETo compare the epidemiological and clinical features of lower respiratory tract infection (LRTI) caused by influenza virus A (IVA) and influenza virus B (IVB) in children.

METHODSThe clinical data of 366 children with LRTI caused by influenza virus (IV), who were hospitalized in Yuying Children′s Hospital of Wenzhou Medical University between 2010 and 2014, were analyzed retrospectively, and there were 272 cases caused by IVA and 94 cases caused by IVB.

RESULTSIV was mainly prevalent from December to March of the next year, with the predominance of IVA. There were small peaks of IVA prevalence in July or September every other year, and IVB was prevalent from December to March of the next year every other year. The children with LRTI caused by IVA alone had a significantly higher white blood cell (WBC) count and significantly higher percentages of children with increased WBC, abnormal serum sodium, and abnormal serum potassium than those caused by IVB alone (P<0.05). However, there were no significant differences in age, sex, underlying diseases, clinical manifestations, and co-infection rate with bacteria or atypical pathogens between the two groups (P>0.05). The rate of co-infection with respiratory syncytial virus (RSV) was significantly higher in the IVB group than in the IVA group (P<0.01).

CONCLUSIONSIVA is prevalent in winter and spring every year and has small peaks in summer every other year, while IVB is prevalent in winter and spring every other year. Compared with IVB, IVA causes more cases of increased WBC and electrolyte disturbance. The children infected with IVB are more likely to be co-infected with RSV. The children with LRTI caused by IVA and IVB have similar clinical manifestations.

Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Infant, Newborn ; Influenza A virus ; genetics ; isolation & purification ; physiology ; Influenza B virus ; genetics ; isolation & purification ; physiology ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Male ; Respiratory Tract Infections ; diagnosis ; epidemiology ; virology ; Retrospective Studies ; Seasons

No abstract available.
Antigens, Viral/*analysis ; Biological Markers/analysis ; DNA, Viral/analysis ; *Fluorescent Antibody Technique ; Humans ; Influenza A Virus, H1N1 Subtype/genetics/*immunology ; Influenza, Human/*diagnosis/epidemiology/immunology/virology ; *Pandemics ; Predictive Value of Tests ; Republic of Korea/epidemiology ; *Seasons

OBJECTIVETo understand the clinical and epidemiological aspects of avian influenza A (H7N9) virus infection in children.

METHODThe clinical data of the first confirmed pediatric case of avian influenza A(H7N9) virus infection were collected, and the epidemiological information, presenting symptoms, laboratory investigation, management and outcome were analyzed. The data of the pediatric cases were also compared with those of the adults cases.

RESULTThe case reported in this paper was a previously healthy 3.6-year-old boy residing in rural area of Shanghai. He had onset of fever and mild rhinorrhea on 31 March 2013 and he was afebrile and well since April 3. Influenza A (H7N9) virus was detected in his nasopharyngeal sample collected on 1 April through national Influenza-like Illness surveillance using real-time reverse transcriptase PCR and virus culture.His family raised domestic poultry with no apparent disease and there was no virological evidence of H7N9 infection. Monitoring and testing of 16 contacts had not found any secondary infection.

CONCLUSIONThe clinical course of H7N9 avian influenza virus infection in children was relatively mild as compared to adult cases. The source of infection and detail of exposure for children have not been known yet. Continued surveillance studies of mild and severe respiratory disease and subclinical infection are essential to further characterize the epidemiology and clinical spectrum of this emerging H7N9 virus infection in children.

Animals ; Child, Preschool ; China ; epidemiology ; Communicable Diseases, Emerging ; Humans ; Influenza A Virus, H7N9 Subtype ; genetics ; isolation & purification ; Influenza in Birds ; Influenza, Human ; diagnosis ; drug therapy ; virology ; Male ; Oseltamivir ; therapeutic use ; Poultry ; Real-Time Polymerase Chain Reaction ; Retrospective Studies ; Reverse Transcriptase Polymerase Chain Reaction

influenza virus can infect humans and cause disease. The clinical presentation of human infection is usually mild, but the infection caused by A(H5N1) avian influenza virus occurring initially in Hongkong in 1997 or the A(H7N9) virus isolated first at the beginning of this year in China is severe and characterized by high mortality. The mortality rate of adolescents and children caused by H5N1 avian influenza is lower than that of adults and the younger the child the lower the mortality rate. A few pediatric H7N9 avian influenza cases recovered soon after treatment. A child was determined to be a H7N9 avian influenza virus carrier. These findings suggested that the pediatric H7N9 avian influenza infection was mild. It is very important to start anti-virus treatment with oseltamivir as early as possible in cases of avian influenza infection is considered. Combined therapy, including respiratory and circulatory support and inhibiting immunological reaction, is emphasized in the treatment of severe cases.
Animals ; Birds ; virology ; China ; epidemiology ; Disease Outbreaks ; Humans ; Influenza A Virus, H5N1 Subtype ; Influenza in Birds ; virology ; Influenza, Human ; diagnosis ; drug therapy ; epidemiology ; virology ; Time Factors

Since the first report of a swine influenza virus (SIV) infection in humans in 1958, cases have occurred continuously and increased significantly after the 2009 H1N1 pandemic. Although exposure to swine is thought to be a risk factor for human SIVs infections, approximately half of the reported cases had no known exposure to pigs. Besides, epidemiological investigation showed that several cases had limited human-to-human transmission. Based on the analyses of data on swine influenza virus infection in humans in this review, both the improved SIVs surveillance in humans and swine population and wider vaccination coverage among occupational workers are critical strategies in pandemic preparedness and response.
Animals ; Humans ; Influenza A virus ; genetics ; isolation & purification ; physiology ; Influenza, Human ; diagnosis ; epidemiology ; transmission ; virology ; Orthomyxoviridae Infections ; diagnosis ; epidemiology ; veterinary ; virology ; Swine ; Swine Diseases ; diagnosis ; epidemiology ; transmission ; virology ; Zoonoses ; diagnosis ; epidemiology ; transmission ; virology

OBJECTIVESymptomatic predictors of influenza could assess risks and improve decisions about isolation and outpatient treatment. To develop such predictors, we undertook a prospective analysis of pandemic (H1N1) 2009 and seasonal influenza (H3N2) in patients attending fever clinics.

METHODSFrom 1 May 2009 to 1 January 2010, all adult patients admitted to fever clinics for suspected influenza, confirmed by real time RT-PCR, were enrolled. Predictors of influenza virus infection were selected with logistic regression models. Measures of sensitivity, specificity, positive and negative likelihood ratios (LRs) were calculated to identify the best predictors.

RESULTSThe clinical features and routine blood test results of influenza (H1N1) 2009 and seasonal influenza were similar. The positive and negative LRs of current US CDC influenza-like illness (ILI) criteria were modest in predicting influenza infection. Our modified clinic predictors improved the ability of the positive and negative LRs to recognize pandemic (H1N1) 2009 and seasonal influenza. The revised criteria are: fever >38 °C accompanied by at least one of the following-cough, arthralgia or relative lymphopenia.

CONCLUSIONPatients with symptoms and signs that meet the new criteria are likely to have influenza and timely antiviral therapy may be appropriate. In addition, physicians should ascertain if influenza is circulating within the community or if there is a contact history of influenza and combine this information with the newly developed criteria to clinically diagnose influenza.

Adult ; China ; epidemiology ; Female ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza A Virus, H3N2 Subtype ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Logistic Models ; Male ; Multivariate Analysis ; Pandemics ; Predictive Value of Tests ; Prospective Studies ; Young Adult

BACKGROUND/AIMS: Pandemic influenza A (H1N1) virus infection presents with variable severity. However, little is known about clinical predictors of disease severity. We studied the clinical predictors of severe pandemic H1N1 pneumonia and their correlation with radiological findings. METHODS: We reviewed medical and radiological records of adults with pandemic H1N1 pneumonia. After classification of patients into severe and non-severe groups, the following data were evaluated: demographic data, pneumonia severity index (PSI), CURB65, risk factors, time to first dose of antiviral medication, routine laboratory data, clinical outcome, and radiological characteristics. RESULTS: Of 37 patients with pandemic H1N1 pneumonia, 12 and 25 were assigned to the severe and non-severe groups, respectively. PSI score, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dyhydrogenase (LDH) levels were higher in the severe group than in the non-severe group (p = 0.035, 0.0003, 0.0023, and 0.0002, respectively). AST, ALT, and LDH levels were positively correlated with the radiological findings (p < 0.0001, 0.0003, and < 0.0001, respectively) and with the number of involved lobes (p = 0.663, 0.0134, and 0.0019, respectively). The most common finding on high resolution computed tomography (HRCT) scans was ground-glass attenuation with consolidation (n = 22, 60%), which had a predominantly patchy distribution (n = 31). CONCLUSIONS: We demonstrated a positive correlation between clinical findings, such as serum AST, ALT, and LDH levels, and radiological findings. A combination of clinical and HRCT indicators would be useful in predicting the clinical outcome of pandemic H1N1 pneumonia.
Adolescent ; Adult ; Aged ; Alanine Transaminase/blood ; Antiviral Agents/therapeutic use ; Aspartate Aminotransferases/blood ; Biological Markers/blood ; Chi-Square Distribution ; Clinical Enzyme Tests ; Female ; Humans ; Influenza A Virus, H1N1 Subtype/*pathogenicity ; Influenza, Human/*diagnosis/mortality/radiography/therapy/virology ; L-Lactate Dehydrogenase/blood ; Lung/*radiography/virology ; Male ; Middle Aged ; *Pandemics ; Pneumonia, Viral/*diagnosis/mortality/radiography/therapy/virology ; Predictive Value of Tests ; Prognosis ; Republic of Korea/epidemiology ; Respiration, Artificial ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Severity of Illness Index ; *Tomography, X-Ray Computed ; Young Adult

No abstract available.
Adolescent ; Child ; Child, Preschool ; Diagnosis, Differential ; Humans ; Infant ; *Influenza A Virus, H1N1 Subtype ; Influenza, Human/epidemiology/*radiography/*virology ; Predictive Value of Tests ; Radiographic Image Interpretation, Computer-Assisted ; Radiography, Thoracic ; Republic of Korea/epidemiology ; *Tomography, X-Ray Computed

OBJECTIVEThis study aimed to explore the epidemiological factors of an influenza A (H1N1) outbreak in a hospital.

METHODSGeneral data were collected via face-to-face interview and telephone survey. Total 132 individuals including medical and nursing staffs (37), in-patients (39) and patients' family members (56) who were exposed to the pediatric surgery ward during August 11 - 18, 2009, were investigated. The case group included 35 cases according to the diagnostic criteria for influenza A (H1N1). The other 97 persons were grouped as control. A case-control study was then conducted to explore the epidemic factors, and layering analysis was applied to determine the interactions among these factors.

RESULTSThe overall incidence in this study was 26.5% (35/132), which included 12 confirmed and 23 suspected cases, and there was no severe case. The first case was a child with the influenza-like symptoms before admission on August 11. The onsets of these cases were during August 7 - 17. The cases were distributed in 9 of 13 rooms, and there was no room aggregation in the cases distribution (χ(2) = 0.00, P > 0.05). Twelve of 25 oropharyngeal swabs were influenza A (H1N1) nucleic acid positive. The case-control study showed that exposure to the enema room accounted for 93.10% (27/29) in cases and 72.73% (48/66) in control; OR = 5.06, 95%CI = 1.01 - 34.23), long time exposure to ward was 71.43% (25/35) in cases and 44.33% (43/97) in control; OR = 3.14, 95%CI = 1.27 - 7.90), and short distance contact with the nurse LIU (76.46% (26/34) in cases and 50.52% (49/97) in control; OR = 3.18, 95%CI = 1.22 - 8.54) were the risk factors. However, keeping the window open (27.59% (8/29) in cases and 68.18% (45/66) in control; OR = 0.14, 95%CI = 0.05 - 0.39) and hand washing (25.71% (9/35) in cases and 76.29% (74/97) in control; OR = 0.11, 95%CI = 0.04 - 0.28) were the protective factors. The longer time exposure to ward had the higher risk (ratios of cases to control were 4:20 (0 - 1 day), 6:34 (2 - 4 days) and 25:43 (≥ 5 days); χ(2)(trend) = 5.737, P < 0.05). In contrast, hand washing with more frequencies (ratios of cases to control were 26:23 (0 - 1 time one day), 7:9 (2 - 3 times one day) and 2:65 (≥ 4 times one day); χ(2)(trend) = 37.136, P < 0.01) and the longer time window opening (ratios of cases to control were 21:21 (no), 4:13 (a few) and 4:32 (often); χ(2)(trend) = 13.830, P < 0.01) had the lower risk. Nevertheless, layering analysis excluded long time exposure to ward from the risk factors (for individuals with more frequent hand washing, 6.90% (2/29) exposed in cases, 7.14% (1/14) exposed in control, OR = 0.97, 95%CI = 0.06 - 29.51; for individuals keeping window open, 21.21% (7/33) exposed in cases, 8.33% (1/12) exposed in control, OR = 2.55, 95%CI = 0.26 - 60.87), indicating the main risk factors in this outbreak were exposure to the enema room and short distance contagion with the infected nurse.

CONCLUSIONThe influenza A (H1N1) outbreak in this hospital was induced by an inpatient infected with influenza A (H1N1) virus before admission. Infected medical staffs keeping on work and exposure to the same place, e.g.the enema room in this study might spread the influenza A (H1N1) virus, and frequent hand washing and keeping the window open are the most effective and economic methods to prevent influenza A (H1N1) infection.

Adult ; Case-Control Studies ; Child ; Cross Infection ; epidemiology ; virology ; Disease Outbreaks ; statistics & numerical data ; Female ; Hospitals ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Male ; Occupational Exposure ; Risk Factors

PURPOSE: Pandemic influenza A (H1N1) virus has spread rapidly and prompt diagnosis is needed for successful treatment and prevention of transmission. We investigated clinical predictors, validated the use of previous criteria with laboratory tests, and evaluated the clinical criteria for H1N1 infection in the Korean population. MATERIALS AND METHODS: We analyzed clinical and laboratory evaluation data from outpatient clinics at Severance Hospital in Seoul, Korea between November 11 and December 5, 2009. RESULTS: This analysis included a total of 828 patients. Of these, 372 (44.9%) patients were confirmed with H1N1 infection by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The most common and predictive symptom was cough (90.3%, OR 8.87, 95% CI 5.89-13.38) and about 40% of H1N1-positive patients were afebrile. The best predictive model of H1N1 infection was cough plus fever or myalgia. The sensitivities, specificities, positive predictive values, and negative predictive values of our suggested criteria were 73.9%, 69.5%, 66.4%, and 76.6%, respectively. CONCLUSION: Cough was the most common independent symptom in patients with laboratory-confirmed H1N1 infection, and while not perfect, the combination of cough plus fever or myalgia is suggested as clinical diagnostic criteria. Health care providers in Korea should suspect a cough without fever to be an early symptom of H1N1 infection.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Influenza A Virus, H1N1 Subtype/*metabolism ; Influenza, Human/*diagnosis/*epidemiology/virology ; Male ; Middle Aged ; Pandemics ; Predictive Value of Tests ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Sensitivity and Specificity