Close Contacts among Student Contributing to an Influenza Outbreak in a Semi-boarding Sports School, Chiang Mai Province, Thailand, 2022
DOI:
https://doi.org/10.59096/osir.v16i4.262111Keywords:
influenza A, influenza-like illnesses, ILI, school, outbreak investigation, ThailandAbstract
On 11 Sep 2022, the Department of Disease Control was notified of a cluster of influenza-like illnesses (ILI) in a semi-boarding sports school in Sanpatong District, Chiang Mai Province, Thailand. The investigation objectives were to confirm the outbreak, describe its epidemiological characteristics, determine risk factors, and recommend control measures. A descriptive study followed by a retrospective cohort study was conducted. A case was defined as a person presenting at the school from 22 Aug to 20 Sep 2022 and having at least two symptoms compatible with ILI. We observed dormitory conditions and students’ activities and collected throat and nasopharyngeal swab specimens. We identified 113 cases, resulting in an attack rate of 26.5% among the screened population and 18.9% among the total population. Almost all cases were students and none developed serious illness. Of 11 specimens tested, nine were positive for influenza A (H3N2). Key risk factors included attending a sports program with adjusted odds ratio (AOR) 2.9, 95% confidence interval (CI) 1.2–6.8, and being in close contact with other cases (AOR 2.3, 95% CI 1.4–3.7). Dormitory overcrowding and close contact during football practice were observed. We recommended regular ILI screening, especially for sports students, and adjusting the dormitory environment to maintain physical distancing.
References
Centers for Disease Control and Prevention. How flu spreads [Internet]. Atlanta: Centers for Disease Control and Prevention (US); [updated 2022 Sep 20; cited 2023 Mar 27]. <https://www.cdc.gov/flu/about/disease/spread.htm>
Centers for Disease Control and Prevention. Key facts about influenza (Flu) [Internet]. Atlanta: Centers for Disease Control (US); [updated 2022 Oct 24; cited 2023 Mar 27]. <https://www.cdc.gov/flu/about/keyfacts.htm>
World Health Organization. Influenza [Internet]. Geneva: World Health Organization; [cited 2023 Mar 27]. <https://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/vaccines-quality/influenza>
Division of Epidemiology, Department of Disease Control (TH). Influenza-like illness surveillance system [Internet]. Nonthaburi: Division of Epidemiology; c2009 [cited 2023 Mar 29]. <http://164.115.25.123/ili/index.php?page=about&p=manual5>. Thai.
Yasopa A. Thailand influenza report in 2022, week 52: 35–31 December 2022 [Internet]. Nonthaburi: Department of Disease Control; 2022 [cited 2023 Mar 28]. <https://ddc.moph.go.th/uploads/ckeditor2//files/DOE_flu_52.2565.pdf>. Thai.
Division of Epidemiology, Department of Disease Control, Ministry of Public Health (TH). National disease surveillance (report 506): influenza [Internet]. Nonthaburi: Division of Epidemiology; [cited 2023 Mar 28]. <http://doe.moph.go.th/surdata/disease.php?ds=15>
Nishiura H, Castillo-Chavez C, Safan M, Chowell G. Transmission potential of the new influenza A(H1N1) virus and its age-specificity in Japan. Euro Surveill. 2009 Jun 4;14(22):19227. doi:10.2807/ese.14.22.19227-en.
Lessler J, Reich NG, Cummings DA. Outbreak of 2009 pandemic influenza A (H1N1) at a New York City School [Internet]. N Engl J Med. 2009 Dec 31 [cited 2023 Dec 9];36(1):26288–36. <https://www.nejm.org/doi/pdf/10.1056/NEJMoa0906089?articleTools=true>
Biggerstaff M, Cauchemez S, Reed C, Gambhir M, Finelli L. Estimates of the reproduction number for seasonal, pandemic, and zoonotic influenza: a systematic review of the literature. BMC Infect Dis. 2014 Sep 4 [cited 2023 May 27];14:480. doi:10.1186/1471-2334-14-480.
Khan SR, Billah MM, Monalisa, Billah SMB, Shirin T, Rahman M. Risk factors of an influenza A(H1N1)pdm09 outbreak in a nursing institute, Noagaon, Bangladesh, 2015. OSIR [Internet]. 2021 Dec 30 [cited 2023 Mar 27];14(4).144–8. <https://doi.org/10.59096/osir.v14i4.262519>
Rosner B. Fundamentals of Biostatistics. 5th ed. Pacific Grove: Duxbury Press; 1999 Dec 17. 816 p.
Fleiss JL, Levin B, Paik MC. Statistical methods for rates and proportions. 3rd ed. New Jersey: Wiley-Interscience; 2003 Oct. 800 p.
Ngamjarus C. n4Studies: sample size calculation for an epidemiological study on a smart device. Siriraj Med J [Internet]. 2016 Jun 9 [cited 2023 Mar 27];68(3):160–70. <https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/58342>
Randolph HE, Barreiro LB. Herd Immunity: understanding COVID-19. Immunity [Internet]. 2020 May 19 [cited 2023 May 28];52(5):737–41. <https://doi.org/10.1016/j.immuni.2020.04.012>
Donaldson AL, Harris JP, Vivancos R, O’Brien SJ. Risk factors associated with outbreaks of seasonal infectious disease in school settings, England, UK. Epidemiol Infect [Internet]. 2020 Nov 18 [cited 2023 Mar 27];148:e287. doi:10.1017/S0950268820002824.
Uyeki TM, Hui DS, Zambon M, Wentworth DE, Monto AS. Influenza. Lancet [Internet]. 2022 Aug 27 [cited 2023 Mar 28];400(10353):693–706. <http://www.thelancet.com/article/S0140673622009825/fulltext>
Ridgway JP, Bartlett AH, Garcia-Houchins S, Cariño S, Enriquez A, Marrs R, et al. Influenza among afebrile and vaccinated healthcare workers. Clinical Infectious Diseases [Internet]. 2015 Jun 1 [cited 2023 Mar 28];60(11):1591–5. doi:10.1093/cid/civ163.
Monto AS, Gravenstein S, Elliott M, Colopy M, Schweinle J. Clinical signs and symptoms predicting influenza infection. Arch Intern Med [Internet]. 2000 Nov 27 [cited 2023 Mar 28];160(21):3243–7. doi:10.1001/archinte.160.21.3243.
Babcock HM, Merz LR, Fraser VJ. Is Influenza an influenza-like illness? Clinical presentation of influenza in hospitalized patients. Infect Control Hosp Epidemiol [Internet]. 2006 Mar [cited 2023 Mar 28];27(3):266–70. doi:10.1086/501539.
Niramitsantipong A, Iamsirithaworn S, Jungtiyanon K, Tantiwaithayapan S, Kitpati R, Jittakarnpitch M. An outbreak of influenza B in a prison, Sukhothai Province, Thailand, October–November 2007. Weekly Epidemiological Surveillance Report [Internet]. 2010;41(18):273–8. <https://apps-doe.moph.go.th/boeeng/annual/Annual/aesr2553/wesr_2553/wk53_18.pdf>. Thai.
Tanprasert S. Outbreak investigation of influenza-like illness in a primary school, Lampang Province, Thailand, 2016. Lampang Medical Journal [Internet]. 2016 Dec 30 [cited 2023 Mar 28];37(2):57–66. <https://he01.tci-thaijo.org/index.php/LMJ/article/view/185871>
Wonghirundecha T, Darasawang W, Tankasikit T, Sukprasan T, Baramee P, Boonrat P, et al. Approaches to prevent influenza transmission among new conscripts in a battalion during high seasonality. OSIR [Internet]. 2018 Dec 27 [cited 2023 Mar 28];11(4):14–22. <https://doi.org/10.59096/osir.v11i4.263050>
Wongsanuphat S, Wonghirundecha T, Boonwisat P, Kerdsalung K, Ploddi K, Sawangjaeng I, et al. Behavioral and environmental factors associated with an influenza outbreak in a prison of Thailand. OSIR [Internet]. 2019 Dec 27 [cited 2023 Mar 27];12(4):116–25. <https://doi.org/10.59096/osir.v12i4.262919>
Sirirungreung A, Yimchoho N, Monpungteim K, Pinthadis W, Jirapongsa C. The 2009 pandemic influenza a virus in an outbreak during 2014 in Samut Prakan Province, Thailand. OSIR [Internet]. 2016 Nov 17 [cited 2023 May 28];8(3):1–7. <https://doi.org/10.59096/osir.v8i3.263232>
Prasertwachirakul P, Sae-aui P, Hatta C, Samayo S, Abdulhanung U, Arrong S, Wonghirundecha T. An outbreak investigation of influenza B in a government primary school, Muang District, Pattani Province, Thailand, 25th January–4th February 2019. Weekly Epidemiological Surveillance Report. 2021;52(2):17–25. Thai.
Sonthichai C, Iamsirithaworn S, Cummings D, Shokekird P, Niramitsantipong A, Khumket S, et al. Effectiveness of non-pharmaceutical interventions in controlling an influenza A outbreak in a school, Thailand, November 2007. OSIR [Internet]. 2016 Nov 18 [cited 2023 Mar 28];4(2):6–11. <https://doi.org/10.59096/osir.v4i2.263354>
King JC, Stoddard JJ, Gaglani MJ, Moore KA, Magder L, McClure E, et al. Effectiveness of school-based influenza vaccination. N Engl J Med [Internet]. 2006 [cited 2023 May 28];355:2523–32. doi:10.1056/NEJMoa055414.
National Center for Immunization and Respiratory Diseases. Flu shots for children [Internet]. Atlanta: Centers for Disease Control and Prevention (US); [updated 2019 Aug 2; cited 2023 Mar 27]. <https://www.cdc.gov/vaccines/parents/diseases/flu.html>
Nichol KL, Wuorenma J, Von Sternberg T. Benefits of influenza vaccination for low-, intermediate-, and high-risk senior citizens. Arch Intern Med [Internet]. 1998 Sep 14 [cited 2023 May 28];158(16):1769–76. doi:10.1001/archinte.158.16.1769.
Setapura P, Pornsopin A, Tantirat P, Soma R, Deeoum C, Jiraphongsa C, et al. An outbreak investigation of influenza in a university, Nakhon Ratchasima Province, Thailand, 8–17 August 2018. Weekly Epidemiological Surveillance Report. 2020;51(6):81–8.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 Outbreak, Surveillance, Investigation & Response (OSIR) Journal
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
