title: Influenza and other respiratory viruses detected by influenza-like illness surveillance in Leyte Island, the Philippines, 2010-2013.
abstract: This study aimed to determine the role of influenza-like illness (ILI) surveillance conducted on Leyte Island, the Philippines, including involvement of other respiratory viruses, from 2010 to 2013. ILI surveillance was conducted from January 2010 to March 2013 with 3 sentinel sites located in Tacloban city, Palo and Tanauan of Leyte Island. ILI was defined as fever ≥38°C or feverish feeling and either cough or running nose in a patient of any age. Influenza virus and other 5 respiratory viruses were searched. A total of 5,550 ILI cases visited the 3 sites and specimens were collected from 2,031 (36.6%) cases. Among the cases sampled, 1,637 (75.6%) were children aged <5 years. 874 (43.0%) cases were positive for at least one of the respiratory viruses tested. Influenza virus and respiratory syncytial virus (RSV) were predominantly detected (both were 25.7%) followed by human rhinovirus (HRV) (17.5%). The age distributions were significantly different between those who were positive for influenza, HRV, and RSV. ILI cases were reported throughout the year and influenza virus was co-detected with those viruses on approximately half of the weeks of study period (RSV in 60.5% and HRV 47.4%). In terms of clinical manifestations, only the rates of headache and sore throat were significantly higher in influenza positive cases than cases positive to other viruses. In conclusion, syndromic ILI surveillance in this area is difficult to detect the start of influenza epidemic without laboratory confirmation which requires huge resources. Age was an important factor that affected positive rates of influenza and other respiratory viruses. Involvement of older age children may be useful to detect influenza more effectively.
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Hirono
authors.initials: H
authors.lastname: Otomaru
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Kamigaki
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Raita
authors.initials: R
authors.lastname: Tamaki
authors.affiliation: Tacloban City Health Office, Tacloban City, the Philippines.
authors.forename: Jamie
authors.initials: J
authors.lastname: Opinion
authors.affiliation: Tanauan Rural Health Unit, Tanauan, the Philippines.
authors.forename: Arlene
authors.initials: A
authors.lastname: Santo
authors.affiliation: Leyte Provincial Health Office, Palo, the Philippines.
authors.forename: Edgard
authors.initials: E
authors.lastname: Daya
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Michiko
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan; Tohoku-RITM Research Center for Emerging and Reemerging Infections, Muntinlupa City, the Philippines.
authors.forename: Mariko
authors.initials: M
authors.lastname: Saito
authors.affiliation: Research Institute for Tropical Medicine, Muntinlupa City, the Philippines.
authors.forename: Veronica
authors.initials: V
authors.lastname: Tallo
authors.affiliation: Research Institute for Tropical Medicine, Muntinlupa City, the Philippines.
authors.forename: Soccoro
authors.initials: S
authors.lastname: Lupisan
authors.affiliation: Virus Research Center, Clinical Research Division, Sendai Medical Center, Sendai, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Suzuki
authors.affiliation: Department of Virology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Oshitani
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003710:Demography; D005260:Female; D005843:Geography; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000453:epidemiology* / Q000821:virology*; D062312:Islands / Q000453:epidemiology*; D008297:Male; D009975:Orthomyxoviridae / Q000502:physiology*; D010679:Philippines / Q000453:epidemiology; D018111:Pneumovirus / Q000502:physiology*; D011159:Population Surveillance; D055815:Young Adult