title: Respiratory syncytial virus activity and climate parameters during a 12-year period.
abstract: 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.
authors.affiliation: Division of Infectious Diseases, First Department of Pediatrics, University of Athens, Athens, Greece.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sirimi
authors.affiliation: Division of Infectious Diseases, First Department of Pediatrics, University of Athens, Athens, Greece.
authors.forename: Michael
authors.initials: M
authors.lastname: Miligkos
authors.affiliation: Division of Infectious Diseases, First Department of Pediatrics, University of Athens, Athens, Greece.
authors.forename: Foteini
authors.initials: F
authors.lastname: Koutouzi
authors.affiliation: Department of Microbiology, "Aghia Sophia" Children's Hospital, Athens, Greece.
authors.forename: Evi
authors.initials: E
authors.lastname: Petridou
authors.affiliation: Department of Neonatology, First Department of Pediatrics, University of Athens, Athens, Greece.
authors.forename: Tania
authors.initials: T
authors.lastname: Siahanidou
authors.affiliation: Division of Infectious Diseases, First Department of Pediatrics, University of Athens, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Michos
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002980:Climate; D058872:Epidemics / Q000706:statistics & numerical data; D005260:Female; D006115:Greece / Q000453:epidemiology; D006801:Humans; D006813:Humidity; D007167:Immunotherapy; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control / Q000628:therapy; D018113:Respiratory Syncytial Virus, Human / Q000502:physiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D012189:Retrospective Studies; D012621:Seasons; D013696:Temperature; D013997:Time Factors
keywords: climate; meteorology; relative air humidity; respiratory syncytial virus; temperature