Climate variations and salmonellosis in northwest Russia: a time-series analysis

Abstract

<jats:title>SUMMARY</jats:title><jats:p>Associations between monthly counts of all laboratory-confirmed cases of salmonellosis in Arkhangelsk, northern Russia, from 1992 to 2008 and climatic variables with lags 0–2 were studied by three different models. We observed a linear association between the number of cases of salmonellosis and mean monthly temperature with a lag of 1 month across the whole range of temperatures. An increase of 1 °C was associated with a 2·04% [95% confidence interval (CI) 0·25–3·84], 1·84% (95% CI 0·06–3·63) and 2·32% (95% CI 0·38–4·27) increase in different models. Only one of the three models suggested an increase in the number of cases, by 0·24% (95% CI 0·02–0·46) with an increase in precipitation by 1 mm in the same month. Higher temperatures were associated with higher monthly counts of salmonellosis while the association with precipitation was less certain. The results may have implications for the future patterns of enteric infections in northern areas related to climate change.</jats:p>

The effect of temperature on differentSalmonellaserotypes during warm seasons in a Mediterranean climate city, Adelaide, Australia

“…Further to this a lag of 1 month was found in five Australian states, including SA [12]. Varying lags have been detected in other studies with temperature peaking at 1 week [20], 2 weeks [17], 1 month [11,14,15,22] and up to 2 months [13,16,18]. A lag of temperature on Salmonella spp.…”

“…We found an increase in daily counts of 1•3% on the overall number of salmonellosis cases per 1°C rise in maximum temperature, with greater observed increases ranging from 3•4% to 4•4% in cases depending on the serotype and phage type. Other studies examining the effect of temperature on salmonellosis found increases of 1-15% of cases per 1°C rise in temperature [11][12][13][14][15][16][17][18][19][20][21][22]. However, these estimates are based on Salmonella spp.…”

“…Our findings are in accordance with those from previous studies in that salmonellosis cases increase with warmer temperature. However, as addressed in the limitations of some studies [14,19], serotypes could have different sensitivity to climate variables and should be examined to account for such effects. Two studies considered the effect of temperature on S. Typhimurium [20,21], a common serotype isolated from humans and farm animals in Australia as well as in other countries [29], and S. Enteritidis, which is not commonly reported in Australia.…”

“…Previous studies have found an association between warmer ambient temperature and Salmonella spp. infection [11][12][13][14][15][16][17][18][19]. In spite of this, there is limited information on whether there is greater sensitivity to increased temperature and likelihood of causing foodborne disease among different serotypes of Salmonella spp.…”

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

“…Study findings indicate that The positive association between temperature and salmonellosis risk in Auckland and Christchurch is consistent with previous studies from NZ 6 and elsewhere. [26][27][28] Salmonellosis tends to peak in summer and decrease in winter. 10,29 Increased temperatures could provide optimal conditions to enhance pathogen survival and multiplication and therefore increase pathogen load in food 9,10 and environmental reservoirs 30 and prolong transmission seasons.…”