{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T12:47:42Z","timestamp":1785934062196,"version":"3.56.0"},"reference-count":31,"publisher":"BMJ","issue":"8","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"unspecified","delay-in-days":4,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2026,7,24]]},"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>To describe the epidemiological pattern, temporal trends of influenza and SARS-CoV-2, and determinants of severe acute respiratory infection (SARI)-confirmed positivity among patients hospitalised with SARI in Cambodia.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>A hospital-based retrospective cross-sectional surveillance data analysis using national sentinel SARI surveillance data collected from 2020 to 2024.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>Nine SARI sentinel hospitals are located across Cambodia.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>A total of 16 739 hospitalised patients who met the SARI case definition.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Measure<\/jats:title>\n                    <jats:p>SARI-confirmed positivity defines all SARI cases with laboratory-confirmed influenza or SARS-CoV-2 infections as the main outcome measure. Descriptive and bivariate analyses were performed, followed by multivariate logistic regression to identify factors associated with SARI-confirmed positivity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Among 16\u2009739 SARI cases, median age in years was 16 (IQR=59), with 54.6% being male; 13.5% were laboratory-confirmed for influenza or SARS-CoV-2. High mortality rate in 2021. A(H3N2) dominated in 2020, followed by widespread SARS-CoV-2 circulation in 2021. In 2022, SARS-CoV-2 co-circulated with A(H3N2) and influenza B (Victoria). A(H1N1)pdm became the predominant strain in 2023 as SARS-CoV-2 and A(H3N2) declined. In 2024, A(H3N2) again led circulation, with B(Victoria) and SARS-CoV-2 also detected. Sporadic A(H5N1) cases began appearing in late 2023. Multivariable analysis indicated higher odds of SARI-confirmed positivity among children aged 5\u201314 years (adjusted OR (aOR)=1.85; 95%\u2009CI 1.47 to 2.31)\u2009and adults 50\u201364 years (aOR=1.36; 95%\u2009CI 1.15 to 1.60) compared with adults 25\u201349 years, during the rainy season (aOR=2.09; 95%\u2009CI 1.89 to 2.32)\u2009and among patients in Phnom Penh compared with other regions (p&lt;0.001). Influenza detection markedly increased from 2022 to 2024 following the decline observed during the COVID-19 pandemic.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>These results indicate that there was an increase in SARI trends over the periods and the changing influenza subtypes circulating each year, along with a high mortality rate during the Delta variant COVID-19 pandemic in Cambodia. Age, region, year and season were significant factors associated with SARI-confirmed positivity. Targeted interventions and preventive measures should be prioritised for specific high-risk groups.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2025-114583","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T11:55:30Z","timestamp":1785930930000},"page":"e114583","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Epidemiology, trends and determinants of influenza and SARS-CoV-2 positivity among severe acute respiratory infection patients in Cambodia, 2020\u20132024: a hospital-based retrospective cross-sectional surveillance data analysis"],"prefix":"10.1136","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-1052-3195","authenticated-orcid":false,"given":"Khemrin","family":"Pong","sequence":"first","affiliation":[{"name":"National Reference Medical Laboratory, National Institute of Public Health, Phnom Penh, Cambodia"},{"name":"Field Epidemiology Training Program, Phnom Penh, Cambodia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hayputhik","family":"Long","sequence":"additional","affiliation":[{"name":"Field Epidemiology Training Program, Phnom Penh, Cambodia"},{"name":"Department of Communicable Disease Control, Ministry of Health, Phnom Penh, Cambodia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3279-1479","authenticated-orcid":false,"given":"Sokly","family":"Mom","sequence":"additional","affiliation":[{"name":"Field Epidemiology Training Program, Phnom Penh, Cambodia"},{"name":"Department of Communicable Disease Control, Ministry of Health, Phnom Penh, Cambodia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-4799-9311","authenticated-orcid":false,"given":"Sophanith","family":"Ung","sequence":"additional","affiliation":[{"name":"Field Epidemiology Training Program, Phnom Penh, Cambodia"},{"name":"South Asia Field Epidemiology and Technology Network, Inc. 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