Heatwaves differentially affect risk of Salmonella serotypes.
Given increasing frequency of heatwaves and growing public health concerns associated with foodborne disease, we examined the relationship between heatwaves and salmonellosis in Adelaide, Australia.



Poisson regression analysis with Generalised Estimating Equations was used to estimate the effect of heatwaves and the impact of intensity, duration and timing on salmonellosis and specific serotypes notified from 1990 to 2012. Distributed lag non-linear models were applied to assess the non-linear and delayed effects of temperature during heatwaves on Salmonella cases.



Salmonella typhimurium PT135 notifications were sensitive to the effects of heatwaves with a twofold (IRR 2.08, 95% CI 1.14-3.79) increase in cases relative to non-heatwave days. Heatwave intensity had a significant effect on daily counts of overall salmonellosis with a 34% increase in risk of infection (IRR 1.34, 95% CI 1.01-1.78) at >41 °C. The effects of temperature during heatwaves on Salmonella cases and serotypes were found at lags of up to 14 days.



This study confirms heatwaves have a significant effect on Salmonella cases, and for the first time, identifies its impact on specific serotypes and phage types. These findings will contribute to the understanding of the impact of heatwaves on salmonellosis and provide insights that could mitigate their impact.
School of Public Health, The University of Adelaide, Adelaide, 5000, South Australia, Australia. Electronic address: adriana.milazzo@adelaide.edu.au.
Adriana
A
Milazzo
School of Public Health, The University of Adelaide, Adelaide, 5000, South Australia, Australia. Electronic address: lynne.giles@adelaide.edu.au.
Lynne C
LC
Giles
School of Public Health, The University of Adelaide, Adelaide, 5000, South Australia, Australia; School of Public Health, The University of Sydney, Sydney, 2006, New South Wales, Australia. Electronic address: ying.zhang@sydney.edu.au.
Ying
Y
Zhang
Communicable Disease Control Branch, Department for Health and Ageing, Adelaide, 5000, South Australia, Australia. Electronic address: Ann.Koehler@sa.gov.au.
Ann P
AP
Koehler
School of Public Health, The University of Adelaide, Adelaide, 5000, South Australia, Australia; School of Health Sciences, Swinburne University of Technology, Melbourne, 3122, Victoria, Australia. Electronic address: jhiller@swin.edu.au.
Janet E
JE
Hiller
School of Public Health, The University of Adelaide, Adelaide, 5000, South Australia, Australia. Electronic address: peng.bi@adelaide.edu.au.
Peng
P
Bi
D001315:Australia / Q000453:epidemiology; D057231:Climate Change; D004636:Emergency Service, Hospital; D006760:Hospitalization; D006358:Hot Temperature; D006801:Humans; D017711:Nonlinear Dynamics; D012044:Regression Analysis; D012475:Salmonella / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology; D012478:Salmonella Food Poisoning / Q000453:epidemiology / Q000382:microbiology; D012480:Salmonella Infections / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology*; D012621:Seasons; D065288:Serogroup; D013696:Temperature
Climate change; Distributed lag non-linear model; Generalised estimating equations; Heatwaves; Salmonella serotypes; Salmonellosis; Temperature