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