Pediatric Respiratory Tract Infections and Circulating Influenza A Virus Subtypes
A Winter Study in Erbil, Iraq
DOI:
https://doi.org/10.14500/aro.12373Keywords:
Acute respiratory tract infection, Children, H1N1pdm09, Influenza A virusAbstract
Influenza and other viral respiratory infections are among the top three leading causes of morbidity and mortality in young children. This study aimed to investigate demographic and clinical characteristics of acute respiratory tract infection (ARTI) and to determine the incidence of influenza A virus subtypes among children in winter in Erbil, Iraq. A cross-sectional study was implemented to investigate the criteria of ARTI in pediatric patients aged ≤5 years who visited Raparin Teaching Hospital for Children from December 1, 2024, to February 28, 2025. A detailed history was collected, and multiplex reverse transcription quantitative polymerase chain reaction was employed for influenza A detection and subtyping. Out of 200 patients, the virus was detected in 14%, with H1N1pdm09 being the predominant subtype (10.5%). Most cases (55%) were hospitalized with severe acute respiratory infection, with ages ≤6 months showing higher susceptibility. Clinically, bronchiolitis was the main clinical diagnosis (66.5%), with hypoxia observed in 36% of cases. Infection among family members was a significant risk factor for pediatric ARTI (p = 0.045). Influenza A showed no significant correlation with hospitalization or age (p = 0.512 and p = 0.987, respectively) but demonstrated strong seasonal variation, peaking in December (p < 0.001). In conclusion, influenza A virus contributed notably, though not predominantly, to pediatric ARTI in Erbil City, with H1N1pdm09 as the predominant subtype and a peak in December. Most cases involved lower respiratory tract disease and hypoxia. Younger age and household infection increase susceptibility, highlighting the need for routine surveillance and preventive measures.
Downloads
References
Aufi, I.M., Khudhair, A.M., Al-Saadi, G.L., Almoneem, A.M.A., and Shukur M.F.M., 2021. Epidemiology and molecular characterization of seasonal influenza viruses in Iraq. Archives of Razi Institute, 76(4), pp.67-79.
Basnet, S., Adhikari, R.K., and Gurung, C.K., 2006. Hypoxemia in children with pneumonia and its clinical predictors. The Indian Journal of Pediatrics, 73(9), pp.777-781.
Beletew, B., Bimerew, M., Mengesha, A., Wudu, M., and Azmeraw, M., 2020. Prevalence of pneumonia and its associated factors among under-five children in East Africa: A systematic review and meta-analysis. BMC pediatrics, 20(1), p.254.
Centers for Disease Control and Prevention, 2024. About CDC’s Global Influenza Program- Global Influenza. Available from: https://www.cdc.gov/flu-global/ about/index.html [Last accessed on 2025 Jun 07].
Centers for Disease Control and Prevention, 2025. Interim Guidelines for Collecting and Handling of Clinical Specimens for COVID-19 Testing, COVID-19. Available from: https://www.cdc.gov/covid/hcp/clinical-care/ clinical-specimen-guidelines.html [Last accessed on 2025 Nov 15].
Certest Biotec., (2023). VIASURE Flu Typing II Real Time PCR Detection Kit: Instructions for Use. Available from: https://www.certest.es/products/flu-typingii [Last accessed on 2025 Jun 07].
Falagas, M.E., Mourtzoukou, E.G., and Vardakas, K.Z., 2007. Sex differences in the incidence and severity of respiratory tract infections. Respiratory Medicine, 101(9), pp.1845-1863.
Grohskopf, L.A., Ferdinands, J.M., Blanton, L.H., Broder, K.R., and Loehr, J., 2024. Prevention and control of seasonal influenza with vaccines: Recommendations of the advisory committee on immunization practices-United States, 2024-25 influenza season. MMWR Recommendations and Reports, 73(5), pp.1-17.
Han, S.B., Rhim, J.W., Kang, J.H., and Lee, K.Y., 2021. Clinical features and outcomes of influenza by virus type/subtype/lineage in pediatric patients. Translational Pediatrics, 10(1), pp.54-63. Iuliano, A.D., Roguski, K.M., Chang, H.H., Muscatello, D.J., Palekar, R., Tempia, S., Cohen, C., Gran, J.M., Schanzer, D., Cowling, B.J., Wu, P., Kyncl, J., Ang, L.W., Park, M., Redlberger-Fritz, M., Yu, H., Espenhain, L., Krishnan, A., Emukule, G., van Asten, L., da Silva, S.P., Aungkulanon, S., Buchholz, U., Widdowson, M.A., and Bresee, J.S., 2018, Estimates of global seasonal influenza-associated respiratory mortality: A modelling study. Lancet (London), 391(10127), pp.1285-1300.
Kirolos, A., Blacow, R.M., Parajuli, A., Welton, N.J., Khanna, A., Allen, S.J., McAllister, D.A., Campbell, H., and Nair, H., 2021. The impact of childhood malnutrition on mortality from pneumonia: A systematic review and network meta-analysis. BMJ Global Health, 6(11), p.e007411.
Krammer, F., Smith, G.J.D., Fouchier, R.A.M., Peiris, M., Kedzierska, K., Doherty, P.C., Palese, P., Shaw, M.L., Treanor, J., Webster, R.G., and GarcíaSastre, A., 2018. Influenza. Nature Reviews, 4(1), p.3.
Moore, M., Chan, E., Lurie, N., Schaefer, A.G., Varda, D.M., and Zambrano, J.A., 2008. Strategies to improve global influenza surveillance: A decision tool for policymakers. BMC Public Health, 8, p.186.
Nair, H., Brooks, W.A., Katz, M., Roca, A., Berkley, J.A., Madhi, S.A., Simmerman, J.M., Gordon, A., Sato, M., Howie, S., Krishnan, A., Ope, M., Lindblade, K.A., Carosone-Link, P., Lucero, M., Ochieng, W., Kamimoto, L., Dueger, E., Bhat, N., Vong, S., Theodoratou, E., Chittaganpitch, M., Chimah, O., Balmaseda, A., Buchy, P., Harris, E., Evans, V., Katayose, M., Gaur, B., O’Callaghan-Gordo, C., Goswami, D., Arvelo, W., Venter, M., Briese, T., Tokarz, R., Widdowson, M-A., Mounts, A.W., Breiman, R.F., Feikin, D.R., Klugman, K.P., Olsen, S.J., Gessner, B.D., Wright, P.F., Rudan, I., Broor, S., Simões, E.A., and Campbell, H., 2011. Global burden of respiratory infections due to seasonal influenza in young children: A systematic review and metaanalysis. The Lancet, 378(9807), pp.1917-1930.
Petrova, V.N., and Russell, C.A., 2018. The evolution of seasonal influenza viruses. Nature Reviews Microbiology, 16(1), pp.47-60.
Radhi, A.H., Ibrahim, Z.H., and Alhilifi, R., 2023. The epidemiological pattern of seasonal influenza in four sentinel sites in Iraq. Influenza and Other Respiratory Viruses, 17(4), p.e13134.
Rafeek, R.A.M., Divarathna, M.V.M., Morel, A.J., and Noordeen, F., 2022. Clinical and epidemiological characteristics of influenza virus infection in hospitalized children with acute respiratory infections in Sri Lanka. PLoS One, 17(9), p.e0272415.
Rhedin, S., Hamrin, J., Naucler, P., Bennet, R., Rotzén-Östlund, M., Färnert, A., and Eriksson, M., 2012. Respiratory viruses in hospitalized children with influenza-like illness during the H1n1 2009 pandemic in Sweden. PLoS One, 7(12), p.e51491.
Rudan, I., Biloglav, Z., Boschi-Pinto, C., Mulholland, K., and Campbell, H., 2008. Epidemiology and etiology of childhood pneumonia. Bulletin of the World Health Organization, 86(5), pp.408-416.
Simonsen, L., Clarke, M.J., Williamson, G.D., Stroup, D.F., Arden, N.H., and Schonberger, L.B., 1997. The impact of influenza epidemics on mortality: Introducing a severity index. American Journal of Public Health, 87(12), pp.1944-1950.
Tian, J., Wang, X.Y., Zhang, L.L., Liu, M.J., Ai, J.H., Feng, G.S., Zeng, Y.P., Wang, R., and Xie, Z.D., 2023. Clinical epidemiology and disease burden of bronchiolitis in hospitalized children in China: A national cross-sectional study. World Journal of Pediatrics, 19(9), pp.851-863.
Tong, S., Li, Y., Rivailler, P., Conrardy, C., Castillo, D.A.A., Chen, L-M., Recuenco, S., Ellison, J.A., Davis, C.T., York, I.A., Turmelle, A.S., Moran, D., Rogers, S., Shi, M., Tao, Y., Weil, M.R., Tang, K., Rowe, L.A., Sammons, S., Xu, X., Frace, M., Lindblade, K.A., Cox, N.J., Anderson, L.J., Rupprecht, C.E., and Donis, R.O., 2012. A distinct lineage of influenza A virus from bats. Proceedings of the National Academy of Sciences of the United States of America, 109(11), pp.4269-4274.
Troeger, C., Blacker, B., Khalil, I.A., Rao, P.C., Cao, J., Zimsen, S.R.M., Albertson, S.B., Deshpande, A., Farag, T., Abebe, Z., Adetifa, I.M.O., Adhikari, T.B., Akibu, M., A.l., Lami, F.H., Al-Eyadhy, A., Alvis-Guzman, N., Amare, A.T., Amoako, Y.A., Antonio, C.A.T., Aremu, O., Asfaw, E.T., Asgedom, S.W., Atey, T.M., Attia, E.F., Avokpaho, E.F.G.A., Ayele, H.T., Ayuk, T.B., Balakrishnan, K., Barac, A., Bassat, Q., Bhaumik, S., Bhutta, Z.A., Bijani, A., Brauer, M., Brown, A., Camargos, P.A.M., Castañeda-Orjuela, C.A., Colombara, D., Conti, S., Dadi, A.F., Dandona, L., Dandona, R., Do, H.P., Dubljanin, E., Edessa, D., Elkout, H., Endries, A.Y., Fijabi, D.O., Foreman, K.J., Forouzanfar, M.H., Fullman, N., Garcia-Basteiro, A.L., Gessner, B.D., Gething, P.W., Gupta, R., Gupta, T., Hailu, G.B., Hassen, H.Y., Hedayati, M.T., Heidari, M., Hibstu, D.T., Horita, N., Ilesanmi, O.S., Jakovljevic, M.B., Jamal, A.A., Kahsay, A., Kasaeian, A., Kassa, D.H., Khader, Y.S., Khan, E.A., Khan, M.N., Khang, Y-H., Kim, Y.J., Kissoon, N., Knibbs, L.D., Kochhar, S., Koul, P.A., Kumar, G.A., Lodha, R., Magdy Abd El Razek, H., Malta, D.C., Mathew, J.L., Mengistu, D.T., Mezgebe, H.B., Mohammad, K.A., Mohammed, M.A., Momeniha, F., Murthy, S., Nguyen, C.T., Nielsen, K.R., Ningrum, D.N.A., Nirayo, Y.L., Oren, E., Ortiz, J.R., Pa, M., Postma, M.J., Qorbani, M., Quansah, R., Rai, R.K., Rana, S.M., Ranabhat, C.L., Ray, S.E., Rezai, M.S., Ruhago, G.M., Safiri, S., Salomon, J.A., Sartorius, B., Savic, M., Sawhney, M., She, J., Sheikh, A., Shiferaw, M.S., Shigematsu, M., Singh, J.A., Somayaji, R., Stanaway, J.D., Sufiyan, M.B., Taffere, G.R., Temsah, M-H., Thompson, M.J., Tobe-Gai, R., Topor-Madry, R., Tran, B.X., Tran, T.T., Tuem, K.B., Ukwaja, K.N., Vollset, S.E., Walson, J.L., Weldegebreal, F., Werdecker, A., West, T.E., Yonemoto, N., Zaki, M.E.S., Zhou, L., Zodpey, S., Vos, T., Naghavi, M., Lim, S.S., Mokdad, A.H., Murray, C.J.L., Hay, S.I., and Reiner, R.C., 2018. Estimates of the global, regional, and national morbidity, mortality, and aetiologies of lower respiratory infections in 195 countries, 1990–2016: A systematic analysis for the Global Burden of Disease Study 2016. The Lancet Infectious Diseases, 18(11), pp.1191-1210.
United Nations, 2025. Sustainable Development Goal 3: Ensure Healthy Lives and Promote Well-Being for all at all Ages. United Nations Department of Economic and Social Affairs. Available from: https://sdgs.un.org/goals/goal3 [Last accessed on 2025 Nov 06].
World Health Organization, 2014. Revised WHO Classification and Treatment of Pneumonia in Children at Health Facilities: Evidence Summaries, World Health Organization, Geneva. Available from: https://iris.who.int/handle/10665/137319 [Last accessed on 2025 Jun 16].
World Health Organization, 2018a. Surveillance Case Definitions for ILI and SARI. World Health Organization - Regional Office for the Eastern Mediterranean. Available from: https://www.who.int/teams/global-influenzaprogramme/surveillance-and-monitoring/case-definitions-for-ili-and-sari [Last accessed on 2025 Jun 01].
World Health Organization, 2018b. Influenza Monthly Update. World Health Organization-Regional Office for the Eastern Mediterranean Retrieved. Available from: https://cdn.who.int/media/docs/default-source/influenza/influenzaupdates/2023/2023_10_30_surveillance_update_457.pdf?sfvrsn=d94c8c1_3& download=true [Last accessed on 2025 Jun 15].
World Health Organization, 2025. Influenza (Seasonal). World Health Organization, Geneva. Available from: https://www.who.int/news-room/factsheets/detail/influenza-(seasonal) [Last accessed on 2025 Jun 15].
Ygberg, S., and Nilsson, A., 2012. The developing immune system-from foetus to toddler. Acta Paediatrica, 101(2), pp.120-127.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Sazan M. Abdulaziz
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Authors who choose to publish their work with Aro agree to the following terms:
-
Authors retain the copyright to their work and grant the journal the right of first publication. The work is simultaneously licensed under a Creative Commons Attribution License [CC BY-NC-SA 4.0]. This license allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
-
Authors have the freedom to enter into separate agreements for the non-exclusive distribution of the journal's published version of the work. This includes options such as posting it to an institutional repository or publishing it in a book, as long as proper acknowledgement is given to its initial publication in this journal.
-
Authors are encouraged to share and post their work online, including in institutional repositories or on their personal websites, both prior to and during the submission process. This practice can lead to productive exchanges and increase the visibility and citation of the published work.
By agreeing to these terms, authors acknowledge the importance of open access and the benefits it brings to the scholarly community.
Accepted 2025-11-19
Published 2026-01-29
ARO Journal is a scientific, peer-reviewed, periodical, and diamond OAJ that has no APC or ASC.