Introduction - Waterborne Pathogens: Detection Methods and Applications - page 3

400,000 people were infected. 3 Additionally, it has been estimated that
10% of all the hospital patients in the United States contract diseases due to
poor water, significantly increasing morbidity, mortality and the financial
burden.
Waterborne pathogens also have a significant economic impact. One
such cost, although it is very necessary, involves the building, upgrading and
maintaining of water treatment plants to remove pathogens from the water
supply. Therefore, it has been suggested that catchment management strate-
gies, which attempt to reduce the pathogen load entering the water source,
is a more cost-effective strategy than adopting more and more advanced,
and expensive, treatment technologies. However, it has been shown that, in
some regions, investment in the provision of water treatment returns a net
economic benefit through alleviation of health-related effects. The health
impact of waterborne pathogens is considerable in terms of both health care
costs and lost productivity. This is true for both outbreaks and endemic dis-
ease. For example, the above outbreak example in Milwaukee was estimated
to cost US$96 million. 3 An Escherichia coli O157:H7 outbreak in Canada in
2000 killed seven, infected 2300 residents and cost $155 million. 4 Overall,
in the United States lost productivity due to waterborne diseases is esti-
mated at $20 million per year. 5
An overview of the most important types of microbial contamination
that pose risks to health is given in Chapter 2. Based on a List of Relevant
Pathogens published by the WHO, this chapter describes in detail the most
problematic waterborne pathogens, focusing upon those for which trans-
mission occurs via ingestion of water, e.g. via drinking water.
In order to alleviate the problems associated with waterborne patho-
gens, the WHO recommends adoption of a Water Safety Framework (WSF)
approach, tailoring the design of Water Safety Plans (WSPs), which nations
or regions design to suit the relevant environmental, social, economic and
cultural conditions. Further information on the WSF and WSPs is given in
Chapter 3, where the role of monitoring and detection of pathogens in the
delivery of a WSF is also considered.
Monitoring for pathogens is important for many reasons:
• Investigativemonitoringallowsforananalysisofthesourcewater,
which enables the selection of appropriate barriers (e.g. catchment
management or particular water treatment technologies) to remove
the identified type of pathogen from the water. Another example of
investigative monitoring is the identification of sources of an out-
break, which contributes to halting and preventing the reoccurrence