University of Maryland Biotechnology Institute, College Park, MD 20740, USA.
J Appl Microbiol. 1998 Dec;85 Suppl 1:134S-137S. doi: 10.1111/j.1365-2672.1998.tb05292.x.
An environmental source of cholera was hypothesized as early as the late nineteenth century by Robert Koch, but not proven because of the ability of Vibrio cholera, the causative agent of cholera, to enter a dormant phase between epidemics. Standard bacteriological procedures for isolation of the vibrios from the environmental samples, including water, between epidemics generally were unsuccessful. Vibrio cholera, a marine vibrio requiring salt for growth, enters into a dormant 'viable but non-culturable' stage when conditions are unfavourable for growth and reproduction. The association of V. cholera with plankton, notably copepods, provides evidence for the environmental origin of cholera, as well as an explanation for the sporadic and erratic nature of cholera epidemics. Thus, the association of V. cholera with plankton was established only recently, allowing analysis of epidemic patterns of cholera, especially in those countries where cholera is endemic. The sporadic and erratic nature of cholera epidemics can now be related to climate and climate events, such as El Niño. Since zooplankton have been shown to harbour the bacterium and zooplankton blooms follow phytoplankton blooms, remote sensing can be employed to determine the relationship of cases of cholera with chlorophyll, as well as sea surface temperature (SST), ocean height, and turbidity. Cholera occurs seasonally in Bangladesh with two annual peaks in the number of cases occurring each year. From the data obtained and analysed to date, when the height of the ocean is high and sea surface temperature is also elevated, cholera cases are numerous. When the height is low and sea surface temperature is also low, little or no cholera is recorded. From the examination of data for the 1992-1993 cholera epidemic in India, preliminary comparisons of cholera data for Calcutta show a similar relationship between cholera cases, ocean height and SST. In conclusion, from results of studies of SST, phytoplankton and zooplankton, and their relationships to incidence of cholera, correlation of selected climatological factors and incidence of V. cholera appears to be significant, bringing the potential of predicting conditions conducive to cholera outbreaks closer to reality.
早在 19 世纪后期，罗伯特·科赫就假设了霍乱的环境来源，但由于霍乱弧菌（霍乱的病原体）在流行间歇期能够进入休眠状态，因此这一假设并未得到证实。在流行间歇期，从环境样本（包括水）中分离弧菌的标准细菌学程序通常都不成功。霍乱弧菌是一种需要盐分才能生长的海洋弧菌，当生长和繁殖条件不利时，它会进入休眠的“有生命力但不可培养”状态。霍乱弧菌与浮游生物（尤其是桡足类动物）的关联为霍乱的环境来源提供了证据，也为霍乱流行的零星和不稳定性质提供了解释。因此，霍乱弧菌与浮游生物的关联直到最近才被确定，从而可以分析霍乱的流行模式，特别是在那些霍乱流行的国家。霍乱流行的零星和不稳定性质现在可以与气候和气候事件（如厄尔尼诺现象）相关联。由于已经证明桡足类动物携带这种细菌，并且桡足类动物的爆发紧随浮游植物的爆发之后，因此可以使用遥感来确定霍乱病例与叶绿素以及海面温度（SST）、海洋高度和浊度的关系。孟加拉国的霍乱季节性发生，每年有两个发病高峰期。根据迄今为止获得和分析的数据，当海洋高度较高且海面温度也升高时，霍乱病例较多。当高度较低且海面温度也较低时，记录到的霍乱病例很少或没有。从对印度 1992-1993 年霍乱流行的数据进行的检查中，对加尔各答的霍乱数据进行了初步比较，结果表明霍乱病例、海洋高度和 SST 之间存在类似的关系。总之，从对 SST、浮游植物和浮游动物及其与霍乱发病率的关系的研究结果来看，选择的气候因素与霍乱弧菌发病率之间的相关性似乎很重要，使预测有利于霍乱爆发的条件更接近现实。
