Environmental Factors Associated with Cryptosporidium and Giardia

Abstract

Environmental factors significantly influence the transmission of intestinal protozoan diseases. Cryptosporidiosis and giardiasis are important zoonotic diseases characterized by diarrhea, and are mainly water or foodborne diseases caused by fecal-borne oocysts. The One Health approach effectively addresses environmentally influenced zoonotic diseases. However, the impact of environmental factors on the survival of Cryptosporidium/Giardia (oo)cysts or disease transmission is mostly uncharacterized. Associations between cryptosporidiosis and giardiasis incidence and environmental variables (e.g., climatic conditions, soil characteristics, and water characteristics) have been reported; however, the identified relationships are not consistently reported. Whether these are country-specific or global observations is unclear. Herein, we review the evidence for the influence of environmental factors on Cryptosporidium/Giardia and corresponding diseases from three perspectives: climatic, soil, and water characteristics. The (oo)cyst concentration or survival of Cryptosporidium/Giardia and the incidence of corresponding diseases are related to environmental variables. The associations identified varied among studies and have different levels of importance and lag times in different locations. This review summarizes the influence of relevant environmental factors on Cryptosporidium/Giardia from the One Health perspective and provides recommendations for future research, monitoring, and response.

Cryptosporidiosis threat under climate change in China: prediction and validation of habitat suitability and outbreak risk for human-derived Cryptosporidium based on ecological niche models

“…For example, in areas with mild climate, the density of Cryptosporidium oocysts and the incidence of cryptosporidiosis may be positively correlated with temperature; specifically, the temperature may be the highest monthly temperature, the average temperature in the wet season, or even the average temperature in the previous 1–3 months. In other regions (such as North America), the study found that the survival rate and infectivity of oocysts in the environment were negatively correlated with temperature, because higher temperatures increased the mortality of Cryptosporidium oocysts [ 27 , 28 ]. In Australia, there is a correlation between temperature and cryptosporidiosis incidence in rural areas, but not in urban areas.…”

“…Extreme weather can increase the concentration of oocysts, and heavy rainfall may cause the outbreak of cryptosporidiosis. In temperate regions, precipitation may dilute the concentration of cryptosporidium oocysts through surface water flows, resulting in a negative correlation between incidence rate and rainfall [ 27 , 28 ]. Jagai et al reported that in humid tropical climates, precipitation is a key driver of seasonal cryptosporidiosis, and the incidence of cryptosporidiosis in temperate climates peaks at high temperatures [ 29 ].…”

Investigating the relationship between extreme weather and cryptosporidiosis and giardiasis in Colorado: a multi-decade study using distributed-lag nonlinear models

“…For instance, a meta-analysis conducted by Jagai and colleagues (2009) demonstrated that while temperature was more strongly associated with cryptosporidiosis in temperate climates, precipitation was a stronger predictor in tropical climates, though notably, neither temperature nor precipitation was significantly associated with cryptosporidiosis in arid or semi-arid climates (Jagai, Castronovo et al 2009). In the case of temperature and cryptosporidiosis, more studies have reported a positive relationship between cryptosporidiosis and temperature (Hu, Tong et al 2007, Hu, Tong et al 2007, Naumova, Jagai et al 2007, Lake, Pearce et al 2008, Jagai, Castronovo et al 2009, Ajjampur, Liakath et al 2010, Hu, Mengersen et al 2010, Hu, Mengersen et al 2010, Kent, McPherson et al 2015, Ikiroma and Pollock 2021, Ma, Destouni et al 2021, Wang, Wang et al 2023) than a negative one (Britton, Hales et al 2010, Kent, McPherson et al 2015). In the case of giardiasis, the reported relationship with temperature has been less consistent (Wang, Wang et al 2023), with some studies suggesting a positive association (Naumova, Jagai et al 2007, Britton, Hales et al 2010), others reporting a negative one (Wilkes, Edge et al 2011, Li, Chase et al 2019, Masina, Shirley et al 2019), and at least one suggesting no association (Lal, Ikeda et al 2013).…”

“…In the case of temperature and cryptosporidiosis, more studies have reported a positive relationship between cryptosporidiosis and temperature (Hu, Tong et al 2007, Hu, Tong et al 2007, Naumova, Jagai et al 2007, Lake, Pearce et al 2008, Jagai, Castronovo et al 2009, Ajjampur, Liakath et al 2010, Hu, Mengersen et al 2010, Hu, Mengersen et al 2010, Kent, McPherson et al 2015, Ikiroma and Pollock 2021, Ma, Destouni et al 2021, Wang, Wang et al 2023) than a negative one (Britton, Hales et al 2010, Kent, McPherson et al 2015). In the case of giardiasis, the reported relationship with temperature has been less consistent (Wang, Wang et al 2023), with some studies suggesting a positive association (Naumova, Jagai et al 2007, Britton, Hales et al 2010), others reporting a negative one (Wilkes, Edge et al 2011, Li, Chase et al 2019, Masina, Shirley et al 2019), and at least one suggesting no association (Lal, Ikeda et al 2013). Likewise, studies assessing the relationship between precipitation and cryptosporidiosis and giardiasis have had similarly mixed results (Miller, Lewis et al 2007, Naumova, Jagai et al 2007, Keeley and Faulkner 2008, Mons, Dumètre et al 2009, Britton, Hales et al 2010, Gonzalez-Moreno, Hernandez-Aguilar et al 2013, Lal, Baker et al 2013, Daniels, Smith et al 2016, Liu, Gong et al 2020, Wang, Wang et al 2023).…”

“…In the case of giardiasis, the reported relationship with temperature has been less consistent (Wang, Wang et al 2023), with some studies suggesting a positive association (Naumova, Jagai et al 2007, Britton, Hales et al 2010), others reporting a negative one (Wilkes, Edge et al 2011, Li, Chase et al 2019, Masina, Shirley et al 2019), and at least one suggesting no association (Lal, Ikeda et al 2013). Likewise, studies assessing the relationship between precipitation and cryptosporidiosis and giardiasis have had similarly mixed results (Miller, Lewis et al 2007, Naumova, Jagai et al 2007, Keeley and Faulkner 2008, Mons, Dumètre et al 2009, Britton, Hales et al 2010, Gonzalez-Moreno, Hernandez-Aguilar et al 2013, Lal, Baker et al 2013, Daniels, Smith et al 2016, Liu, Gong et al 2020, Wang, Wang et al 2023).…”