OBJECTIVETo investigate clinical and epidemiological characteristics of hospitalized severe acute respiratory illnesses (SARI) patients under 15 years old registered by sentinel hospitals at 10 cities and risk factors analysis of severe illness.

METHODSThe objects of this study were 2 937 SARI patients under 15 years old registered by sentinel surveillance in internal wards, pediatrics wards and intensive care units (ICU) of 10 sentinel hospitals in 10 cities during the period from December 2009 to June 2014. We also collected case report form (CRF) of them and their throat swabs for influenza testing. The inclusion criteria was hospitalized patients who were admitted by surveillance departments, registered by SARI surveillance system, under 15 years old, meeting SARI case definition and with complete CRF. Rank-sum test was used to compare the difference of age, the duration including from onset to admission, hospital stay and from onset to discharging/death between mild illness and severe illness. Chi-square test was used to compare the difference of demographic characteristics, influenza psoitive rate, vaccination rate of influenza, chronic medical conditions and clinical characteristics between mild illness and severe illness. Logistic regression was used to analysis risk factors associated with severe illness by two stratifications from SARI surveillance protocol (< 2 years old and ≥ 2 years old).

RESULTSAmong 2 937 SARI patients under 15 years old, 97.7% (2 872/2 937) was mild illnesses, and 2.3% (65/2 937) was severe illnesses. 78.8% (2 315/2 937) was under 5 years old. The median ages of severe illness and mild illness were 0.4 and 2.0 years old (U = -6.23, P < 0.001). The proportions of severe illness and mild illness with at least one chronic medical condition were 32.3% (21/65) and 8.4% (240/2 872) (χ² = 45.03, P < 0.001). The positive rate of influenza virus was 6.5% (190/2 937), which was 6.5% (186/2 858) for mild illness and 6.2% (4/65) for severe illness (χ² = 0.08, P = 0.961). The proportion of seasonal influenza vaccination was 1.5% (42/2 853), which was 1.5% (42/2 788) for mild illness and higher than that for severe illness (0) (χ² = 6.09, P = 0.048). For under 2 years old patients, age < 11 months and with at least one chronic medical condition were risk factors for severe SARI illness, and the risk for SARI patients who was 12-23 months and without medical condition was 14.71 (5.35-40.44) and 5.61 (2.96-10.63). For ≥ 2 years old patients, age, with at least one chronic medical condition and seasonal influenza vaccination history have no association with severe illness, OR (95% CI) was 0.92 (0.80-1.05), 0.67 (0.09-5.05) and 0.85 (0.31-2.35), respectively.

CONCLUSIONMost of SARI patients registered by 10 urban sentinel hospitals were patients under 5 years old. Age < 11 months and with at least chronic medical conditions were possible risk factors of severe illness of SARI patients.

Adolescent ; Child ; Child, Preschool ; China ; Chronic Disease ; Cities ; Hospitalization ; Hospitals ; Humans ; Infant ; Influenza, Human ; Orthomyxoviridae ; Respiratory Tract Diseases ; Risk Factors ; Sentinel Surveillance ; Vaccination

Most common causative agents for hand, foot and mouth disease (HFMD) are enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16). The symptomatic and asymptomatic cases could transmit the disease in population. Many sero-epidemiological surveys were launched to estimate the sero-incidence of EV-A71 and CV-A16 enterovirus, the susceptibility of different sub-population, and to observe the dynamics of neutralizing antibody. A literature search of sero-epidemiological study focused on EV-A71 or CV-A16 was conducted via PubMed and China Hospital Knowledge Database. Based on the 20 selected studies, the different age groups' antibody level, the susceptibility, the dynamics of antibody and sero-incidence of EV-A71 or CV-A16 were analyzed. From our results, the antibody level against EV-A71 or CV-A16 in neonates was associated with their mothers, which was similar with that of adults. The antibody level against EV-A71 or CV-A16 in neonates dropped to lowest level at one years-old, and started to dramatically increase until four years-old, and reached a plateau at five years-old. In conclusion, the infants aged 6-12 months were the priority group to receive vaccination when the EV-A71 vaccine is licensed in the future.
Adaptive Immunity ; Adult ; Age Factors ; Antibodies, Neutralizing ; Child ; China ; Enterovirus ; Enterovirus A, Human ; Humans ; Immunity, Maternally-Acquired ; Infant ; Infant, Newborn ; Mothers ; Seroepidemiologic Studies ; Vaccination

OBJECTIVETo estimate the rates due to influenza-associated-excess-hospitalization in children aged 0-14 years in Wuxi city,Jiangsu province in 2005-2010.

METHODSWe collected data on hospitalization due to influenza, pneumonia and other respiratory diseases from fourteen 2nd level or above hospitals in Wuxi, as well as data on influenza virological surveillance in southern China to fit the negative binomial regression models, to estimate the rate on influenza-associated-excess hospitalization.

RESULTSDuring 2005-2010, an average annual hospitalization rate appeared as 91.6‰ (79.2‰ -99.3‰). Among the total hospitalization eases, respiratory diseases accounted for 54.2%, while both influenza and pneumonia accounted for 38.1%. The average annual influenza- associated-excess-hospitalization rates due to influenza and pneumonia appeared as 1.28‰ (95% CI:0.29‰ -4.84‰), while 2.18‰ (95% CI:0.61‰ -6.79‰) due to respiratory diseases. In 2009, A (H1N1) pdm induced influenza pandemic caused 993 excess hospitalizations due to influenza/pneumonia and 1 042 excess hospitalizations due to respiratory diseases, with rates as 1.14‰ and 1.20‰ respectively.

CONCLUSIONBoth seasonal and pandemic A(H1N1)pdm influenza caused considerable burden on hospitalization in children aged 0-14 years inWuxi.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Hospitalization ; statistics & numerical data ; Humans ; Infant ; Infant, Newborn ; Influenza, Human ; epidemiology ; Male

China ; Humans ; Influenza Vaccines ; administration & dosage ; Influenza, Human ; prevention & control

OBJECTIVETo estimate the hospitalization rate of severe acute respiratory infection (SARI) cases attributable to influenza in Jingzhou city, Hubei province from 2010 to 2012.

METHODSSARI surveillance was conducted at four hospitals in Jingzhou city, Hubei province from 2010 to 2012. Inpatients meeting the SARI case definition and with informed consent were enrolled to collect their demographic information, clinical features, treatment, and disease outcomes, with their respiratory tract specimens collected for PCR test of influenza virus.

RESULTSFrom April, 2010 to September, 2012, 19 679 SARI cases enrolled were residents of Jingzhou, and nasopharyngeal swab was collected from 18 412 (93.6%) cases of them to test influenza virus and 13.3% were positive for influenza. During the three consecutive 2010-2012 flu seasons, laboratory-confirmed influenza was associated with 102 per 100 000, 132 per 100 000 and 244 per 100 000, respectively. As for the hospitalization rate attributable to specific type/subtype of influenza virus, 48 per 100 000, 30 per 100 000 and 24 per 100 000 were attributable to A (H3N2), A (H1N1) pdm2009, and influenza B, respectively in 2010-2011 season; 42 per 100 000 [A (H3N2)] and 90 per 100 000 (influenza B) in 2011-2012 season; 90 per 100 000 [A (H3N2)] and one per 100 000 [influenza B] from April, 2010 to September, 2012. SARI hospitalization caused by influenza A or B occurred both mainly among children younger than five years old, with the peak in children aged 0.5 year old.

CONCLUSIONInfluenza could cause a substantial number of hospitalizations and different viral type/subtype result in different hospitalizations over influenza seasons in Jingzhou city, Hubei province. Children less than five years old should be prioritized for influenza vaccination in China.

Child ; Child, Preschool ; China ; epidemiology ; Demography ; Hospitalization ; Hospitals ; Humans ; Infant ; Influenza A Virus, H1N1 Subtype ; Influenza A Virus, H3N2 Subtype ; Influenza, Human ; epidemiology ; Inpatients ; Laboratories ; Orthomyxoviridae ; Polymerase Chain Reaction ; Respiratory Tract Infections ; Seasons ; Vaccination

OBJECTIVETo identify clinical characteristics of hospitalized laboratory-confirmed influenza cases of children under 15 years old, and their risk factors of influenza infection.

METHODSAnalyzing the reports of hospitalized laboratory-confirmed influenza cases of children under 15 years old who were detected by the sentinel surveillance systems in 10 provinces from December 2009 to June 2014. Such data as their demographic, medical history, clinical symptoms and signs, treatment and outcome were collected using questionnaires, with their clinical characteristics and their risk factors of influenza infection described.

RESULTSOf the 2 937 severe acute respiratory infection inpatients, 190 (6.5%) were laboratory-confirmed influenza cases. 123 (64.7%) of such confirmed cases were male, and 139 (73.2%) were children under 5 years old, with age median of 3.0 years (IQR: 1.0-5.0 years). 20 (10.5%) of them had at least one chronic medical condition, mostly chronic cardiovascular disease (3.2%), immunosuppressive disease (3.2%), and cancer/tumor (2.6%). Most common clinical symptoms of the cases were fever (92.6%) and cough (88.8%), of which abnormal pulmonary auscultation (51.1%) and abnormal chest X-ray performance (36.1%) were the most common clinical signs. 29 cases (15.8%) had complications, of which pneumonia (15.3%) was most common. 16 cases (8.6%) used antiviral drugs, and 4 cases (2.2%) were admitted into ICU. Risk factor analysis suggested that age < 6 months (OR = 0.406, 95% CI: 0.203-0.815) was a protective factor against influenza infection; and age 5-9 years old (OR = 2.535, 95% CI: 1.059-6.066) was a risk factor for influenza infection.

CONCLUSIONHospitalized laboratory-confirmed influenza cases were found mostly in children under 5 years old. Risk exposure for influenza infection varied among age groups.

Acute Disease ; Adolescent ; Antiviral Agents ; Child ; Child, Preschool ; China ; epidemiology ; Cough ; Female ; Fever ; Hospitalization ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; epidemiology ; pathology ; Inpatients ; Laboratories ; Male ; Protective Factors ; Risk Assessment ; Risk Factors ; Sentinel Surveillance ; Surveys and Questionnaires