Geospatial epidemiology of hospitalized patients with a positive influenza assay: A nationwide study in Iran, 2016–2018

Abstract

Introduction Seasonal influenza is a significant public health challenge worldwide. This study aimed to investigate the epidemiological characteristics and spatial patterns of severe hospitalized influenza cases confirmed by polymerase chain reaction (PCR) in Iran. Methods Data were obtained from Iran’s Ministry of Health and Medical Education and included all hospitalized lab-confirmed influenza cases from January 1, 2016, to December 30, 2018 (n = 9146). The Getis-Ord Gi* and Local Moran’s I statistics were used to explore the hotspot areas and spatial cluster/outlier patterns of influenza. We also built a multivariable logistic regression model to identify covariates associated with patients’ mortality. Results Cumulative incidence and mortality rate were estimated at 11.44 and 0.49 (per 100,000), respectively, and case fatality rate was estimated at 4.35%. The patients’ median age was 40 (interquartile range: 22–63), and 55.5% (n = 5073) were female. The hotspot and cluster analyses revealed high-risk areas in northern parts of Iran, especially in cold, humid, and densely populated areas. Moreover, influenza hotspots were more common during the colder months of the year, especially in high-elevated regions. Mortality was significantly associated with older age (adjusted odds ratio [aOR]: 1.01, 95% confidence interval [CI]: 1.01–1.02), infection with virus type-A (aOR: 1.64, 95% CI: 1.27–2.15), male sex (aOR: 1.77, 95% CI: 1.44–2.18), cardiovascular disease (aOR: 1.71, 95% CI: 1.33–2.20), chronic obstructive pulmonary disease (aOR: 1.82, 95% CI: 1.40–2.34), malignancy (aOR: 4.77, 95% CI: 2.87–7.62), and grade-II obesity (aOR: 2.11, 95% CI: 1.09–3.74). Conclusions We characterized the spatial and epidemiological heterogeneities of severe hospitalized influenza cases confirmed by PCR in Iran. Detecting influenza hotspot clusters could inform prioritization and geographic specificity of influenza prevention, testing, and mitigation resource management, including vaccination planning in Iran.

Estimation of seasonal influenza disease burden using sentinel site data in Pakistan 2017–2019: A cross‐sectional study

“…Although different years had variation in influenza transmission patterns, influenza viruses circulate all year round, with September in every year seeing a decline in influenza activity. Influenza virus subtypes A (H3) was the predominant strain during 2017 which was similar to findings of Iran 13 . During 2018 and 2019 seasons, influenza H1N1pdm09 was the dominant strain followed by A (H3) and influenza B; this similar pattern of subtype circulation was observed in Egypt 14 …”

“…Influenza virus subtypes A (H3) was the predominant strain during 2017 which was similar to findings of Iran. 13 During 2018 and 2019 seasons, influenza H1N1pdm09 was the dominant strain followed by A (H3) and influenza B; this similar pattern of subtype circulation was observed in Egypt. 14 The incidence rate of influenza-associated hospitalizations was highest among those 65 years and above followed by children under 5 years.…”

Evaluation of the antiviral potential of gemini surfactants against influenza virus H1N1

“…These viruses undergo antigenic changes including antigenic drift and antigenic shift, which are minor and major modifications of the virus surface antigens, respectively. The latter causes the emergence of new viral strains with no immunity against it (Blut 2009 ; Iuliano et al 2018 ; MohammadEbrahimi et al 2022 ). Therefore, despite widespread access to vaccines and antiviral remedies, influenza virus infection cannot be eradicated from human populations (MohammadEbrahimi et al 2022 ).…”

“…The latter causes the emergence of new viral strains with no immunity against it (Blut 2009 ; Iuliano et al 2018 ; MohammadEbrahimi et al 2022 ). Therefore, despite widespread access to vaccines and antiviral remedies, influenza virus infection cannot be eradicated from human populations (MohammadEbrahimi et al 2022 ). From billion cases of influenza incidence annually worldwide, almost 500,000 cases are expected to death (Iuliano et al 2018 ).…”