Potential Impact of Climate Change on Schistosomiasis Transmission in China

Abstract

Appraisal of the present and future impact of climate change and climate variability on the transmission of infectious diseases is a complex but pressing public health issue. We developed a biology-driven model to assess the potential impact of rising temperature on the transmission of schistosomiasis in China. We found a temperature threshold of 15.4 degrees C for development of Schistosoma japonicum within the intermediate host snail (i.e., Oncomelania hupensis), and a temperature of 5.8 degrees C at which half the snail sample investigated was in hibernation. Historical data suggest that the occurrence of O. hupensis is restricted to areas where the mean January temperature is above 0 degrees C. The combination of these temperature thresholds, together with our own predicted temperature increases in China of 0.9 degrees C in 2030 and 1.6 degrees C in 2050 facilitated predictive risk mapping. We forecast an expansion of schistosomiasis transmission into currently non-endemic areas in the north, with an additional risk area of 783,883 km(2) by 2050, translating to 8.1% of the surface area of China. Our results call for rigorous monitoring and surveillance of schistosomiasis in a future warmer China.

Modelling spatial distribution of snails transmitting parasitic worms with importance to human and animal health and analysis of distributional changes in relation to climate

“…The response of survival and reproduction rate to temperature has been described in a number of studies (Appleton, 1978;Pflüger, 1981;Chandiwana, 1990a, 1990b;MasComa et al, 2005;Zhou et al, 2008) and temperature is therefore an obvious candidate. The analysis of model variable contribution in this study showed temperature to be the variable with the highest explanatory power in four models out of six (Table 3).…”

“…This might be an artefact but could also be due to specific snail biology. For example, studies have shown that the minimum temperature can be a limiting factor as shown with reference to the "freezing line" proposed by Zhou et al (2008). Elevated night-time minimum temperatures, such as experienced in Zimbabwe early in the 1988-2012 period, and also possibly later (Unganai, 1996), may open up new areas of suitable habitats in regions where low temperature is the current limiting factor.…”

“…Extensive research in snail ecology and results from numerous modelling studies, describe which candidate variables to use (Kristensen et al, 2001;Malone et al, 2001;Stensgaard et al, 2006Stensgaard et al, , 2013Zhou et al, 2008;Stensgaard, 2011). For the purpose of comparing two different time periods, attention was paid to identifying and compiling environmental datasets with a quality that justifies temporal comparison.…”

Remote sensing of environmental change over China: A review

“…The most significant impact of environmental change is public health. However, except for avian influenza, schistosomiasis and malaria [80][81][82][83] there are few studies involving remote sensing over China [84,85]. Atmospheric pollution cause health damages not only to urban residents but also to rural citizens [86].…”

Infectious Disease Research—What Role Is There for Hydrologists?

“…In [75] [80] [81]. [82] estimates that global warming may increase the presence of trematodes and [83] predict that schistosomiasis will spread into currently nonendemic areas in the north of China. In regions with low temperature level or current lack of vector habitats climatic changes may in general trigger epidemics [84].…”