Evidence map›Paper›PMID 42556831›Full record

ArticleBMJ open2026

Epidemiology, trends and determinants of influenza and SARS-CoV-2 positivity among severe acute respiratory infection patients in Cambodia, 2020-2024: a hospital-based retrospective cross-sectional surveillance data analysis.

Khemrin Pong, Hayputhik Long, Sokly Mom, Sophanith Ung, Darapheak Chau, Sengdoeurn Yi, Piseth Keam, Heng Seng, Ly Sovann

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Article in BMJ open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

Authors and funding

9 authors.

Khemrin PongNational Reference Medical Laboratory, National Institute of Public Health, Phnom Penh, Cambodia khemrinpong@gmail.com.ORCID 0009-0004-1052-3195
Hayputhik LongField Epidemiology Training Program, Phnom Penh, Cambodia.
Sokly MomField Epidemiology Training Program, Phnom Penh, Cambodia.ORCID 0000-0003-3279-1479
Sophanith UngField Epidemiology Training Program, Phnom Penh, Cambodia.ORCID 0009-0005-4799-9311
Darapheak ChauNational Reference Medical Laboratory, National Institute of Public Health, Phnom Penh, Cambodia.
Sengdoeurn YiField Epidemiology Training Program, Phnom Penh, Cambodia.
Piseth KeamKandal Provincial Health Department, Ministry of Health, Takhmao, Cambodia.
Heng SengDepartment of Communicable Disease Control, Ministry of Health, Phnom Penh, Cambodia.
Ly SovannDepartment of Communicable Disease Control, Ministry of Health, Phnom Penh, Cambodia.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveTo 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.

designA hospital-based retrospective cross-sectional surveillance data analysis using national sentinel SARI surveillance data collected from 2020 to 2024.

settingNine SARI sentinel hospitals are located across Cambodia.

participantsA total of 16 739 hospitalised patients who met the SARI case definition. MEASURE: 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.

resultsAmong 16 739 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 5-14 years (adjusted OR (aOR)=1.85; 95% CI 1.47 to 2.31) and adults 50-64 years (aOR=1.36; 95% CI 1.15 to 1.60) compared with adults 25-49 years, during the rainy season (aOR=2.09; 95% CI 1.89 to 2.32) and among patients in Phnom Penh compared with other regions (p<0.001). Influenza detection markedly increased from 2022 to 2024 following the decline observed during the COVID-19 pandemic.

conclusionThese 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.

Indexed as

COVID-19Influenza, HumanAdolescentAdultAgedCambodiaChildChild, PreschoolCross-Sectional StudiesFemaleHospitalizationHumansInfantInfluenza A Virus, H3N2 SubtypeMaleMiddle AgedCOVID-19EPIDEMIOLOGYPublic health

Identifiers

PMID42556831
PMCPMC13448632

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