Acceptable microbial risk: Cost–benefit analysis of a boil water order for Cryptosporidium

Abstract

Ryan et al | http://dx.Casman, E.A.; Fischhoff, B.; Palmgren, C; Small, M.J.; & Wu, F., 2000. An Integrated Risk Model of a Drinking-Water-Borne Cryptosporidiosis Outbreak. Risk Analysis, 20:4:495. Castro-Hermida, J.A.; Garcia-Presedo. I.; Almeida, A.; Gonzalez-Warleta, M.; Da Costa, J.M.; & Mezo, M., 2009. Detection of Cryptosporidium spp. and Giardia duodenalis in Surface Water: A Health Risk for Humans and Animals. Water Research, 43:17:4133. http://dx.doi.org/10.1016/j.watres.2009.06.020. Castro-Hermida, J.A.; Garcia-Presedo, I.; Almeida, A.; Gonzalez-Warleta, M.; Da Costa, J.M.; & Mezo, M., 2008. Presence of Cryptosporidium spp. and Giardia

Microbiological Risk Assessment – Guidelines for food

“…The authors developed a simple decision tree (Figure 11) for Boil Water Order (BWO), including the effectiveness of the BWO and illness and death as possible outcomes (Ryan et al, 2013a(Ryan et al, , 2013b. For each branch in the decision tree the authors assigned the relevant probabilities, including the probability of illness, probability of death, and probability of the boiling process being ineffective.…”

“…[…] many water supplies that exceed this concentration may already be applying additional treatment, given that a concentration of 46 oocysts/L would require treatment beyond the 3-log removal required by the Long Term Enhanced Surface Water Treatment Rule. (Ryan et al, 2013a) Part 1 D e t a i l e d considerations It should be emphasized that the attributes of good risk assessment, as described in Chapter 3, apply equally to qualitative as they do to quantitative risk assessment. Appropriate data must be collected, documented and fully referenced and synthesized in a logical and transparent manner, whichever method is employed.…”

“…Schematic representation of the model framework for a productionto-consumption risk assessment of V. parahaemolyticus in Bloody clam (Figure II-6 in FAO and WHO, 2011a) Figure 11. Decision tree for Boil Water Orders for Cryptosporidium showing the probabilities and estimated costs for illness and death outcomes (Ryan et al, 2013a). ( Reproduced with permission from John Wiley and Sons)…”

“…FIGURE 11. Decision tree for Boil Water Orders for Cryptosporidium showing the probabilities and estimated costs for illness and death outcomes(Ryan et al, 2013a). (Reproduced with permission from John Wiley and Sons)…”