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Not yet recruitingNCT07767019Updated Aug 17, 2026

Climate Change Trends and Their Impact on the Seasonal Upper Respiratory Tract Disease Burden

An observational study in Upper Resp Tract Infection, sponsored by Barzilai Medical Center. Not yet recruiting at 1 site in Israel. Per ClinicalTrials.gov, last updated 2026-08-17.

Sponsored by Barzilai Medical Center · Observational

Study type
Observational
Model
Case-only
Time perspective
Retrospective
Enrollment
5,000
Sex
All
01

Study summary

Investigators assume that global climate changes can influence upper respiratory tract infection peak prevalence, which may have significant clinical implication, for example, by adjusting seasonal Influenzas' vaccine timing. Therefore, the investigators will collect data from electronic medical database about patients tested positive for winter seasonal respiratory tract viruses from 2022 and compare the incidence to the meteorological profile of that season.

Read the detailed description

The seasonal cycle of respiratory viral diseases has been widely recognized for thousands of years, as annual epidemics of the common cold and influenza hit the human population like clockwork in temperate regions during winter. Many explanations for this phenomenon appear in the literature. Huang et al. reported in 2017 a decrease in Influenza incidence while average temperatures increased in Queensland, Australia. Weather variability appears to be more influential on seasonal influenza transmission among younger age groups (0-14). Not only is the temperature relevant, but all meteorological parameters also vary. For example, Qi et al. found that both low and high absolute humidity might increase influenza risk in China, and the relationship varies geographically.

The meteorological service in Israel reports a marked increase in temperature when comparing 2006-2020 to 1964-1979 and 1995-2009 across all seasons. The average warming rate from 1964-1979 to 2006-2020 is approximately 1.5°C, highlighting a notable temperature difference.

The investigators assume that global climate changes can influence Influenza peak prevalence, which may have significant clinical implication by adjusting seasonal Influenzas' vaccine timing.

The study will include identification of all patients who tested positive for URT infection with seasonal virus (Influenza, RSV, Rhinovirus, Human MetaPneumoVirus, ParaInflunza) via respiratory PCR since 2022, whether in the emergency department or during hospitalization. This will be followed by a review of medical records to extract baseline data: age, sex, weight, underlying medical conditions, and the need for hospitalization, intensive care admission, mechanical ventilation, vasopressors, or renal replacement therapy.

02

Conditions studied

  • Upper Resp Tract Infection

Keywords

  • URTI
  • Influenza
  • RSV
  • Climate change
03

Who can participate

Ages eligible
Child (0–17), Adult (18–64), Older adult (65+)
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

All patients with a positive nasopharyngeal swab for a respiratory virus - Influenza, RSV, Para-Influenza, Human MetaPneumoVirus, Rhinovirus.

Inclusion criteria

  • All patient with a positive nasopharyngeal swab for a respiratory virus

Exclusion criteria

Exclusion Criteria:

  • No medical record available
04

Study design

Observational model
Case-only
Time perspective
Retrospective
Enrollment
5,000 participants (estimated)
Patient registry
No

Groups and cohorts

  • URTI infection

    Patients with a positive RV7 sample

    Other: No Intervention: Observational Cohort

Interventions

  • OtherNo Intervention: Observational Cohort

    No intervention, observational retrospective study.

05

What researchers measure

Primary outcomes

  1. Incidence

    Examining the incidence of severe upper respiratory tract illness (requiring hospital visits) in relation to weather changes over the last four seasons.

    Time frame: 4 winter seasons, from 2022 to 2026.

Secondary outcomes

  1. Morbidity

    Analysis of winter morbidity trends among patients presenting to the hospital with Influenza. Including severity of illness (need for ICU admission, mechanical ventilation and/or inotropes assistance).

    Time frame: 4 winter seasons, 2022 to 2026.

  2. Mortality

    Analysis of winter mortality trends among patients presenting to the hospital with Influenza. Including mortality during hospitalization or within 30 days.

    Time frame: 4 winter seasons 2022-2026

  3. recurrence

    Analysis of upper respiratory tract infection recurrence trends among patients presenting to the hospital with Influenza. Including recurrent admission within 30 days.

    Time frame: 4 winter seasons, 2022-2026

06

Study locations

1 site
  • Barzilai Medical Center
    Ashkelon, Israel
07

References and documents

Publications

  • Roussel M, Pontier D, Cohen JM, Lina B, Fouchet D. Quantifying the role of weather on seasonal influenza. BMC Public Health. 2016 May 26;16:441. doi: 10.1186/s12889-016-3114-x. PubMed 27230111 ↗
  • Sloan C, Moore ML, Hartert T. Impact of pollution, climate, and sociodemographic factors on spatiotemporal dynamics of seasonal respiratory viruses. Clin Transl Sci. 2011 Feb;4(1):48-54. doi: 10.1111/j.1752-8062.2010.00257.x. PubMed 21348956 ↗
  • Zhang S, Chen C, Wang R, Liu L, Wang X, Zhang X. Influence and lagged effects of weather and air pollution on pediatric RSV-ALRI in Shenyang, NE China. Respir Med. 2026 Apr;254:108711. doi: 10.1016/j.rmed.2026.108711. Epub 2026 Feb 13. PubMed 41690416 ↗
  • Yan ZL, Liu WH, Long YX, Ming BW, Yang Z, Qin PZ, Ou CQ, Li L. Effects of meteorological factors on influenza transmissibility by virus type/subtype. BMC Public Health. 2024 Feb 16;24(1):494. doi: 10.1186/s12889-024-17961-9. PubMed 38365650 ↗
  • Qi L, Liu T, Gao Y, Li Q, Tang W, Tian D, Su K, Xiong Y, Yang J, Feng L, Liu Q. Effect of absolute humidity on influenza activity across different climate regions in China. Environ Sci Pollut Res Int. 2022 Jul;29(32):49373-49384. doi: 10.1007/s11356-022-19279-8. Epub 2022 Feb 26. PubMed 35218485 ↗
  • Singh DE, Marinescu MC, Carretero J, Delgado-Sanz C, Gomez-Barroso D, Larrauri A. Evaluating the impact of the weather conditions on the influenza propagation. BMC Infect Dis. 2020 Apr 5;20(1):265. doi: 10.1186/s12879-020-04977-w. PubMed 32248792 ↗
  • Moriyama M, Hugentobler WJ, Iwasaki A. Seasonality of Respiratory Viral Infections. Annu Rev Virol. 2020 Sep 29;7(1):83-101. doi: 10.1146/annurev-virology-012420-022445. Epub 2020 Mar 20. PubMed 32196426 ↗
  • Huang X, Mengersen K, Milinovich G, Hu W. Effect of Weather Variability on Seasonal Influenza Among Different Age Groups in Queensland, Australia: A Bayesian Spatiotemporal Analysis. J Infect Dis. 2017 Jun 1;215(11):1695-1701. doi: 10.1093/infdis/jix181. PubMed 28407143 ↗
  • Saino N, Ambrosini R, Rubolini D, von Hardenberg J, Provenzale A, Huppop K, Huppop O, Lehikoinen A, Lehikoinen E, Rainio K, Romano M, Sokolov L. Climate warming, ecological mismatch at arrival and population decline in migratory birds. Proc Biol Sci. 2011 Mar 22;278(1707):835-42. doi: 10.1098/rspb.2010.1778. Epub 2010 Sep 22. PubMed 20861045 ↗
  • Kilpatrick AM, Chmura AA, Gibbons DW, Fleischer RC, Marra PP, Daszak P. Predicting the global spread of H5N1 avian influenza. Proc Natl Acad Sci U S A. 2006 Dec 19;103(51):19368-73. doi: 10.1073/pnas.0609227103. Epub 2006 Dec 7. PubMed 17158217 ↗

Individual participant data

Plan to share: No — There is not a plan to make IPD available.

08

Registry details

Key details

Study ID
NCT07767019
Lead sponsor
Barzilai Medical Center
Responsible party
Dr. Daniel Leshin Carmel (Head of Infection Control and Prevention Unit, Barzilai Medical Center) — Principal investigator
First posted
Aug 17, 2026
Start date
Aug 15, 2026 (estimated)
Primary completion
Jan 1, 2027 (estimated)
Completion
Jan 31, 2027 (estimated)
Last update
Aug 17, 2026

Study contacts

Daniel leshin Carmel Head of Infection Control and Prevention, MD
Contact
danielles@bmc.gov.il
+972525253037
Pnina Nir Study Coordinator
Contact
pninan@bmc.gov.il
Daniel Leshin Carmel, MD
principal investigator · Barzilai Medical Center

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.

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