A systematic review and meta-analysis of ambient temperature and diarrhoeal diseases

Abstract

Changes in temperature due to global climate change can and may already be affecting diarrhoeal disease incidence. The vulnerability of populations may depend, in part, on local pathogen distribution. However, evidence of publication bias and the uneven geographical distribution of studies limit the precision and generalizability of the pooled estimates.

Planning for climate change: The need for mechanistic systems-based approaches to study climate change impacts on diarrheal diseases

“…In particular, studies have shown increases in diarrhea incidence of 3–11%, per degree Celsius ambient temperature increase in Fiji (Singh et al, 2001), Bangladesh (Hashizume et al, 2007), Peru (Checkley et al, 2000; Lama et al, 2004) and Japan (Onozuka et al, 2010). These regional results are corroborated by a recent global meta-analysis indicating a 7% increase in all-cause diarrhea per degree Celsius temperature increase based on the 10 studies that met the inclusion criteria (Carlton et al, 2015). While some of this research has shown a linear relationship between temperature and diarrhea rates (Hashizume et al, 2007), these associations can be non-linear and depend on local climatic conditions and pathogens.…”

“…The aforementioned recent meta-analysis found that the relationship between temperature and all-cause diarrhea was not modified by either geographical climate category or national income group. However, for bacterial diarrhea, there was a stronger effect size between temperature and diarrhea for low and middle income countries and in tropical climates (Carlton et al, 2015). …”

“…For instance, rotavirus is positively associated with cooler and drier weather in the tropics (Levy et al, 2009a; Jagai et al, 2012), norovirus incidence peaks in the winter months in temperate climates (Ahmed et al, 2013), cryptosporidiosis is positively associated with warmer and wetter weather (Jagai et al, 2009), campylobacter incidence peaks in the springtime in temperate climates and is not correlated to rainfall (Kovats et al, 2005) and Shigella is associated with warmer weather (Gao et al, 2014). Indeed, a recent meta-analysis of the influence of temperature on diarrhea incidence found that pathogen taxa was a significant source of heterogeneity across the 26 studies they analyzed (Carlton et al, 2015). It is important to note that these pathogen-temperature associations are correlational relationships and may not be directly causally linked.…”

Untangling the Impacts of Climate Change on Waterborne Diseases: a Systematic Review of Relationships between Diarrheal Diseases and Temperature, Rainfall, Flooding, and Drought

“…Meta-analysis was conducted on a subset of studies of temperature and diarrhea that met more rigorous reporting and design criteria; this analysis has been described elsewhere. 22 For studies of heavy rainfall, flooding and drought meta-analysis was not appropriate, according to the Cochrane Collaboration Handbook, because of the disparate analytical methods and exposure definitions applied in these studies. 20 The approach used here allows us to present a semi-quantitative summary of the studies we identified, in order to allow inclusion of the widest range of studies and to avoid selection bias that would result from restricting studies to those with a single exposure and outcome definition.…”

El Niño Southern Oscillation (ENSO) and Health: An Overview for Climate and Health Researchers

“…Notwithstanding the complex pathways linking climate anomalies and diarrhoea [69] and the challenges this poses for quantifying the effects of weather and climate on water-associated diseases in general [70][71][72], diarrhoeal illness is generally sensitive to climate anomalies [73][74][75][76][77][78] with unusually warm conditions conducive to enhanced pathogen replication and survival rates, while rainfall surpluses may transport faecal matter into water courses with micro-organisms becoming concentrated in water bodies during periods of rainfall deficit. While Demisse and Mengisitie [79] noted that El Niño has an impact on diarrhoea incidence for a number of major geographic regions, many of the cited papers address temperature/rainfall-diarrhoea association as opposed to climate driven variations in diarrhoea moderated by ENSO.…”