Estimating the national burden of hospitalizations for influenza-associated severe acute respiratory infection in the Lao People’s Democratic Republic, 2016
Objective: Estimates of the burden of influenza are needed to inform prevention and control activities for seasonal influenza, including to support the development of appropriate vaccination policies. We used sentinel surveillance data on severe acute respiratory infection (SARI) to estimate the burden of influenza-associated hospitalizations in the Lao People’s Democratic Republic.
Methods: Using methods developed by the World Health Organization, we combined data from hospital logbook reviews with epidemiological and virological data from influenza surveillance from 1 January to 31 December 2016 in defined catchment areas for two sentinel sites (Champasack and Luang Prabang provincial hospitals) to derive population-based estimates of influenza-associated SARI hospitalization rates. Hospitalization rates by age group were then applied to national age-specific population estimates using 2015 census data.
Results: We estimated the overall influenza-associated SARI hospitalization rate to be 48/100 000 population (95% confidence interval [CI]: 44–51) or 3097 admissions (95% CI: 2881–3313). SARI hospitalization rates were estimated to be as low as 40/100 000 population (95% CI: 37–43) and as high as 92/100 000 population (95% CI: 87–98) after accounting for SARI patient underascertainment in hospital logbooks. Influenza-associated SARI hospitalization rates were highest in children aged <5 years (219; 95% CI: 198–241) and persons aged >=65 years (106; 95% CI: 91–121).
Discussion: Our findings have identified age groups at higher risk for influenza-associated SARI hospitalization, which will support policy decisions for influenza prevention and control strategies, including for vaccination. Further work is needed to estimate the burdens of outpatient influenza and influenza in specific high-risk subpopulations.
GBD 2017 Influenza Collaborators. Mortality, morbidity, and hospitalisations due to influenza lower respiratory tract infections, 2017: an analysis for the Global Burden of Disease Study 2017. Lancet Respir Med.2019 Jan;7(1):69-89. doi: 10.1016/S2213-2600(18)30496-X.
Iuliano, AD, Roguski, KM, Chang, HH et al. Estimates of global seasonal influenza-associated respiratory mortality: a modelling study. Lancet. 2017; (published online Dec 13.)
Lee VJ. Ho JZM, Goh EH, et. al. Advances in measuring influenza burden of disease. Influenza Other Respi Viruses. 2018;12:3–9.
Khamphaphongphane B, Ketmayoon P, Lewis H, Phonekeo D, Sisouk T, Xayadeth S, et al. Epidemiological and virological characteristics of seasonal and pandemic influenza in Lao PDR, 2008–2010. Influenza Other Respi Viruses. 2013;7(3):304–11.
Phengxay M, Mirza S, Reyburn R, Xeuatvongsa A, Winter C, Lewis H, et al. Introducing seasonal influenza vaccine in low‐income countries: an adverse events following immunization survey in the Lao People’s Democratic Republic. Influenza Other Respi Viruses. 2015;9(2):94–8.
World Health Organization. A manual for estimating disease burden associated with seasonal influenza [Internet]. Geneva; 2015. Available from: http://apps.who.int/iris/bitstream/10665/178801/1/9789241549301_eng.pdf
WHO Global Technical Consultation: global standards and tools for influenza surveillance. Geneva: World Health Organization; 2011. Available from: http://apps.who.int/iris/bitstream/10665/70724/1/WHO_HSE_GIP_2011.1_ eng.pdf [cited June 30 2019].
Results of Population and Housing Census 2015. Available at: https://www.lsb.gov.la/pdf/PHC-ENG-FNAL-WEB.pdf [cited on 2 February 2018]
Lafond K, Nair H, Rasooly M, Valente F, Booy R, Rahman M, et al. Global Role and Burden of Influenza in Pediatric Respiratory Hospitalizations, 1982-2012: A Systematic Analysis. PLoS Med / Public Libr Sci. 2016;13(3):e1001977.
Ieng, V., Tolosa, M.X., Tek, B., Sar, B., Sim, K., Seng, H., Thyl, M., Dara, C., Moniborin, M., Stewart, R.J. and Bell, L.C., 2018. National burden of influenza-associated hospitalizations in Cambodia, 2015 and 2016. Western Pacific Surveillance and Reponse, 2018; 9.
Yoshida L, Suzuki M, Yamamoto T, Nguyen H, Nguyen C, Nguyen A, et al. Viral pathogens associated with acute respiratory infections in central vietnamese children. Pediatr Infect Dis J. 2010;29(1):75–7.
Bresee, J.S., Lafond, K.E., McCarron, M., Azziz-Baumgartner, E., Chu, S.Y., Ebama, M., Hinman, A.R., Xeuatvongsa, A., Bino, S., Richardson, D. and Porter, R.M., 2019. The partnership for influenza vaccine introduction (PIVI): Supporting influenza vaccine program development in low and middle-income countries through public-private partnerships. Vaccine, 37(35), pp.5089-5095.
Xeuatvongsa A, Mott JA, Khanthamaly V, Patthammavong C, Phounphenghak K, McKinlay M, Mirza S, Lafond KE, McCarron M, Corwin A, Moen A, Olsen SJ. and Bresee JS. Progress toward sustainable influenza vaccination in the Lao Peoples' Democratic Republic, 2012–2018. Vaccine. 2019;37:3002-3005
Marcone, D.N., Durand, L.O., Azziz-Baumgartner, E., Vidaurreta, S., Ekstrom, J., Carballal, G. and Echavarria, M., 2015. Incidence of viral respiratory infections in a prospective cohort of outpatient and hospitalized children aged≤ 5 years and its associated cost in Buenos Aires, Argentina. BMC infectious diseases, 15(1), p.447.
Hirve S, Chadha M, Lele P, et al. Performance of case definitions used for influenza surveillance among hospitalized patients in a rural area of India. Bulletin of the World Health Organization 2012; 90(11): 804-12.
Gordon, A. and Reingold, A., 2018. The burden of influenza: a complex problem. Current epidemiology reports, 5(1), pp.1-9.
Bochaton A, Xayaseng V, Noy C. Health Seeking Behaviour ( HSB ) in Thailand : the case of the patients living in Vientiane. 2007. Available from: https://www.researchgate.net/publication/301892443_Health_Seeking_Behaviour_HSB_in_Thailand_the_case_of_the_patients_living_in_Vientiane [cited 4 April 2018].
Charoenmukayananya S, Sriratanaban J, Hengpraprom S, Trarathep C. Factors influencing decisions of Laotian patients to use health care services in Thailand. Asian Biomed. 2014;8(5):665–71.