Relationships between historic pandemic events and climate : a regional case study of the 1st-6th cholera pandemic events in the 19th century to early 20th century

Abstract

Human civilization has been constantly combating with communicable diseases throughout courses of history, and is expected to be entangled with evolved diseases, together with the changing environmental conditions (e.g. Climate Change), in the foreseeable future. Cholera is an exemplified disease which caused major Pandemic Events in different parts of the world since early 19th Century. Although later studies have confirmed the contagious school of thoughts as the major mechanism for transmitting Cholera since the discovery of the bacteria V. Cholera in mid-19th Century, the conventional Climate school of thoughts has long been argued as one of the major causes of the diseases and hence epidemic events. This can be viewed from the initial acts and mentality of the British Indian Government towards the epidemics and the contemporary findings from the recent Cholera modelling studies and remote sensing studies. Series of quantitative studies have been conducted for detecting possible signals of climate trend and climate change during early 19th Century to early 20th Century in this study, through cross-correlation between climatological measurements (on STA, SST and PPT) and proxies (TRW, TSI, Sunspot), trend and change point detections through Mann-Kendall Test and Sequential Mann-Kendall Test. Meanwhile, cross-correlation has also been conducted, for detecting possible causality between Cholera-related Crude Mortality Rate and various climatological measurements (i.e. STA, SST and PPT). Though results of quantitative analysis in this study may have been greatly affected by the temporal resolution and availability of data, and hence limited signals can be detected in these quantitative tests (as compared with other more recent studies), qualitative analysis have suggested the complexity between epidemic outbreaks and environment, governmental approaches, medicines, etc.. In spite of the technological breakthroughs and medical advancements, Cholera is still a major public threat to the Third World. In light of the imminent impacts of Climate Change, Cholera is likely to be evolved together with the change environmental conditions. Thereby, studies in understanding the mechanisms of climate-driven Cholera outbreaks may be essential, and one way of achieving such aim is through historic epidemiology.