Spatial and temporal variation in the association between temperature and salmonellosis in NZ

Abstract

Objective: Modelling the relationship between weather, climate and infectious diseases can help identify high‐risk periods and provide understanding of the determinants of longer‐term trends. We provide a detailed examination of the non‐linear and delayed association between temperature and salmonellosis in three New Zealand cities (Auckland, Wellington and Christchurch). Methods: Salmonella notifications were geocoded to the city of residence for the reported case. City‐specific associations between weekly maximum temperature and the onset date for reported salmonella infections (1997–2007) were modelled using non‐linear distributed lag models, while controlling for season and long‐term trends. Results: Relatively high temperatures were positively associated with infection risk in Auckland (n=3,073) and Christchurch (n=880), although the former showed evidence of a more immediate relationship with exposure to high temperatures. There was no significant association between temperature and salmonellosis risk in Wellington. Conclusions: Projected increases in temperature with climate change may have localised health impacts, suggesting that preventative measures will need to be region‐specific. This evidence contributes to the increasing concern over the public health impacts of climate change.

Variabilidad climática y sus posibles efectos sobre la salud, 1985 -2015

“…En cuanto a los agentes causales, los resultados del estudio indican que el aumento de las temperaturas medias máximas semanales y del mes en curso están relacionadas con un mayor riesgo de presentación de casos de salmonelosis (36)(37)(38)(39).…”

Climate change, extreme events, and increased risk of salmonellosis: foodborne diseases active surveillance network (FoodNet), 2004-2014

“…Several studies have observed that the prevalence of Salmonella infections is strongly influenced by changes in ambient temperature [ 12 , 18 , 22 , 33 – 38 ], with higher rates often observed during the summer [ 12 , 22 , 39 ]. Multiple studies have also provided evidence that salmonellosis rates are positively associated with increased rainfall events [ 19 , 22 , 33 , 40 ].…”

“…Multiple studies have also provided evidence that salmonellosis rates are positively associated with increased rainfall events [ 19 , 22 , 33 , 40 ]. Moreover, there is growing evidence suggesting projected changes to climate [ 23 ] will affect the incidence of foodborne illness, including Salmonella infections [ 12 , 16 , 18 , 24 , 25 , 41 ]. Our findings provide further evidence that increases in ambient temperature and precipitation levels, particularly in the form of extreme events, are associated with increases in rates of salmonellosis.…”

Climate change and infectious diseases in Australia's Torres Strait Islands

“…This research employed a desktop‐based study to identify climate‐sensitive diseases of concern in the Torres Strait; these are defined as infections that may be affected by changing climatic conditions including local weather, air temperature, precipitation and humidity, water availability and food sources. Such conditions can change the distribution and breeding conditions of vector‐borne diseases, the population density or location of the animal species reservoir, and the disease transmission pathways 11,20 …”

“…This research responds to part of this call by identifying the present and future likelihood of increased occurrence of climate‐sensitive infectious diseases. It provides more detail to previous climate‐focused health research that noted changes in “temperature, humidity and rainfall can influence the transmission dynamics of infectious diseases” 6 (p561) and that climate change will compound determinants of infectious diseases, notably “globalisation, population growth and social and demographic inequalities” 11 . (p1) In responding to this call, this research addresses climate disruption through a localised perspective of the geographically vulnerable Torres Strait Islands.…”