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

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

OBJECTIVETo summarize characteristics and outcomes of critically ill children with 2009 influenza A (H1N1).

METHODA prospective observational study of 14 critically ill children with 2009 influenza A (H1N1) in pediatric intensive care unit (PICU) in Suzhou between Oct. 1(st) 2009 and Dec. 25(th) 2009. The primary outcome measures included frequency and duration of mechanical ventilation and duration of ICU stay.

RESULTCritical illness occurred in 14 patients with confirmed (n = 14), community-acquired 2009 influenza A virus (H1N1) infection. The mean (SD) age of the 14 patients with confirmed 2009 influenza A (H1N1) was (4.91 ± 4.14) years, 7 were female (50.0%). The median duration from symptom onset to hospital admission was (3.09 ± 1.30) days and from hospitalization to ICU admission was (0.95 ± 0.96) day. All the patients were severely hypoxemic [mean (SD) ratio of PaO2/FiO2 was (191.27 ± 80.58) mm Hg] at ICU admission. ARDS occurred in 11 cases (78.6%). Mechanical ventilation was applied for 10 patients (71.4%). The median duration of ventilation was (12.51 ± 10.03) days and ICU stay was (12.58 ± 10.65) days. The median length of time during which the real-time RT-PCR test results were positive was (17.27 ± 5.57) days; Comorbidities such as iron deficiency anemia, cerebral palsy and congenital heart disease were found in 8 cases (57.1%). The longer length of mechanical ventilation and ICU stay were found in cases with higher admission PRISM III Score and lower Pediatrics Critical Illness Score.

CONCLUSIONCritical illness due to 2009 influenza A (H1N1) in Suzhou occurred rapidly after hospital admission and was associated with severe hypoxemia, ARDS, a condition that required prolonged mechanical ventilation. There were myocardial damages in critically ill children with severe 2009 influenza A (H1N1).

Child ; Child, Preschool ; Critical Illness ; Female ; Humans ; Infant ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Male ; Prognosis ; Risk Assessment

OBJECTIVEAnalyze the clinical characteristics of the mild cases of pandemic influenza H1N1 virus infection, as well as the relationship of clinical characteristics and patient genders.

METHODSA total of 245 influenza A (H1N1) patients confirmed by viral nucleic acid detection were included in the study. The patients' personal information, signs and symptoms, lab and iconography data, disease course, negative seroconversion duration of new influenza A (H1N1) viral nucleic acid after antiviral treatment and hospitalization stay were analyzed. Measurement data were analyzed using one-way analysis of variance (ANOVA) by software SPSS 11.5. P < 0.05 was defined as statistically significant.

RESULTS(1) Among the 245 patients, 130 were males and 115 were females, yielding a sex ratio of 1.13:1. Almost 52.0% (127/245) of the patients came from Australia, and 64.5% (158/245) were between 18 and 40 years old. (2) Clinical manifestations included fever (98.4%, 241/245), cough (80.8%, 198/245) and throat congestion (95.9%, 235/245), and lab findings were characterized by elevated C-reaction protein (CRP, 71.0%, 174/245) and neutrophil (52.2%, 128/245). (3) Female patients had significantly lower serum Prealbumin (pre-A) levels than male patients [(245.04 ± 75.3) vs (273.34 ± 92.18) mg/L, F = 5.55, P = 0.019]. (4) The patients' serum CRF levels significantly decreased after the treatment [(4.06 ± 3.47) vs (14.54 ± 14.68) mg/L, F = 6.18, P = 0.016], while the levels of CD3, CD4 and CD8 were significantly increased after treatment [(1451.23 ± 443.97) vs (819.97 ± 375.75) cell/µl, F = 32.61, P = 0.000; (771.33 ± 251.92) vs (435.36 ± 215.35) cell/µl, F = 44.43, P = 0.000; (593.16 ± 237.19) vs (342.47 ± 180.12) cell/µl, F = 28.518, P = 0.000, respectively]. (5) Approximately 30.6% (75/245) of the patients had abnormal signs on chest CT iconography, and 22.0% (54/245) had obvious signs indicating pneumonia. The average disease course was (3.9 ± 1.2) days, the average hospitalization stay was (5.0 ± 1.4) days, and the negative seroconversion duration of the mRNA after antiviral treatment was (3.8 ± 1.4) days.

CONCLUSIONThe influenza A (H1N1) virus was characterized by fever, cough and throat congestion, with elevated CRP and neutrophil being the most significant lab findings. The influenza A (H1N1) strain was able to affect multiple organs, including being able to affect hepatic synthesis of pre-A as well as immune functioning. The influenza A (H1N1) influenza virus strain was mild clinically, with short disease course and good prognosis.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Male ; Middle Aged ; Pregnancy ; Prognosis ; Young Adult

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

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

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

OBJECTIVETo explore the value of different types of samples, including throat swabs, stools, bloods in pandemic A (H1N1) influenza diagnosis and virus shedding patterns.

METHODSFrom May to June in 2009, 135 samples were collected from 23 confirmed cases of pandemic influenza A (H1N1) infection, including 99 throat swabs, 14 stools, 11 bloods, 1 respiratory tract washing from 13 confirmed cases and 10 blood samples from other confirmed cases. The virus was detected by real-time RT-PCR, the antibody was detected by haemagglutination inhibition assay.

RESULTSFor 99 throat swabs of 13 patients, the median time of the first positive real-time RT-PCR was 1 day (ranged from 0 to 7 days) after the onset of the symptoms of illness; the median length of time duration of positive real-time RT-PCR results from throat swabs was 3 days (ranged from 1 to 15 days). Four cases intermittently released virus. One respiratory tract washing sample was positive. In 14 stools, 8 stools were real-time RT-PCR positive, the positive rate was 57.14%. The median time of the positive real-time RT-PCR was 3 days (ranged from 1 to 4 days) after the onset of the symptoms of illness. In 21 blood samples collected at 2 to 9 days of onset, 1 blood sample was real-time RT-PCR positive, the positive rate was 4.76%. All these 21 blood samples were antibody negative.

CONCLUSIONThroat swabs and stools samples can be used as A (H1N1) influenza early diagnosis. The length of time duration of positive real-time RT-PCR in throat swabs was longer than stool samples and intermittently releasing of virus were found in throat swabs. Influenza A H1N1 cases showed the presence of small amount of viremia and antibody was negative in early blood samples (< 9 days).

Adolescent ; Adult ; Antibodies, Viral ; analysis ; Child ; China ; epidemiology ; Female ; Hemagglutination Inhibition Tests ; Humans ; Influenza A Virus, H1N1 Subtype ; immunology ; Influenza, Human ; diagnosis ; epidemiology ; virology ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; Virus Shedding ; Young Adult

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