Temporal characteristics of respiratory syncytial virus infection in children and its correlation with climatic factors at a public pediatric hospital in Suzhou.

Respiratory syncytial virus (RSV) is the most important viral pathogen in infants and children. It is important to analyze RSV epidemic patterns and related relevant factors in order to prevent further infections and related complications. To explore the relationship between RSV infection rate in hospitalized children from Suzhou area and climatic factors. 42,664 nasopharyngeal specimens from hospitalized children with acute respiratory infections were screened for RSV antigens using direct immunofluorescence. 472 RSV positive samples were randomly selected and performed real-time PCR to identify RSV subtype. Monthly meteorological data in Suzhou area was collected (average temperature, relative humidity, precipitation, total sunshine, and average wind speed) from 2001 to 2011. The relation between RSV infections and climatic factors was evaluated using correlation and stepwise regression analyses. The annual RSV infection rate in hospitalized children in Suzhou from 2001 to 2011 varied between 11.85% and 27.30%. The highest monthly infection rates occurred from November to April. The time interval from November to April was considered the infection season. Seasonal RSV infection rates from 2001 to 2010 were 40.75%, 22.72%, 39.93%, 27.37%, 42.71%, 21.28%, 38.57%, 19.86%, and 29.73%. The infection rate of any season was statistically different from the next season. There was no significant difference in RSV infection rates in the 2010-2011 and 2009-2010 epidemic seasons. Among the 472 randomly selected RSV positive samples, 412 were found to be RSV subtype A (RSV-A), while 60 subtype B (RSV-B). The monthly RSV infection rate was negatively correlated with monthly average temperature (r=-0.84), total sunshine (r=-0.47), precipitation (r=-0.31), relative humidity (r=-0.20), and average wind speed (r=-0.20), (P<0.05). Stepwise regression analysis showed monthly average temperature fit into a linear model (R(2)=0.64, P<0.01) with a regression coefficient of -1.52 (t=15.21, P<0.01). RSV infection in Suzhou occurred most frequently between November and April. The number of infections peaked every other year. Abnormally high infection rate in non-epidemic season only caused by RSV-A. Ambient temperature played an important role in the development of RSV infection.

Zhang XL ，Shao XJ ，Wang J ，Guo WL ... -  《-》

[Characteristics and the prevalence of respiratory viruses and the correlation with climatic factors of hospitalized children in Suzhou children's hospital].

Ji W ，Chen ZR ，Guo HB ，Wang MJ ，Yan YD ，Zhang XL ，Ding YF ... -  《-》

[Prevalence of respiratory syncytial virus infection in hospitalized children at a children's hospital and effects of climate change on the prevalence in Suzhou, China].

Geng J ，Guo WL ，Zhang XL 《-》

[Characteristics of human metapneumovirus respiratory tract infection in children and the relationship between the infection and meteorological conditions].

Wang YQ ，Ji W ，Chen ZR ，Yan YD ，Guo HB ，Chu C ，Liu J ，Ding YF ，Shao XJ ，Xu J ... -  《-》

Respiratory syncytial virus activity and climate parameters during a 12-year period.

The epidemic pattern of respiratory syncytial virus (RSV) infection during long periods and the factors that determine seasonality are not well studied. In order to correlate the RSV epidemic activity with climate parameters, we conducted a retrospective study of children (0-14 year) who were hospitalized because of respiratory tract infection and had an RSV test performed in the major tertiary pediatric hospital of Greece during a 12-year period (2002-2013). Daily data regarding temperature and humidity were obtained from the Hellenic National Meteorological Service. A total of 2030/7516 (27%) children were tested positive for RSV infection. Among RSV positive children 1945/2030 (95.8%) were infants <1 year. A peak of RSV activity was measured in years 2002, 2003, and 2006 (>35% positive). The RSV season in our area spanned from December to April, with higher incidence during January through March. The peak monthly RSV incidence was observed during February with mean temperature 10.34 °C and mean relative humidity 69.16%. Regarding climate conditions, a statistically significant positive correlation was found between monthly RSV activity and mean monthly relative humidity (rho = 0.66, P-value = 0.02), whereas a negative correlation was found with mean monthly temperature (rho = -0.81, P-value = 0.002). However, in the multivariable analysis, only the effect of mean monthly temperature remained statistically significant (IRR = 0.72, 95% CI: 0.68, 0.80). Further understanding of RSV seasonality in different geographic areas would be important in order to timely implement preventing strategies with immunoprophylaxis or future RSV vaccines.

Sirimi N ，Miligkos M ，Koutouzi F ，Petridou E ，Siahanidou T ，Michos A ... -  《-》