Microbial agents in drinking-water
Rolling revision of the WHO Guidelines for Drinking-water Quality
Microbial agents are included in the plan of work of the rolling revision of the WHO Guidelines for Drinking-water Quality.
The GDWQ FTF meeting (Geneva, 2003) recommended that risk assessments be prepared on E. coli O157, Cryptosporidium, Campylobacter and enteric viruses with varying levels of priority depending on the availability of sufficient data. Drafts had previously been prepared on Cryptosporidium and enteric viruses. Both were incomplete, and there was concern about the lack of data regarding enteric viruses. The Microbial Aspects WG was informed about ongoing projects that will undertake risk assessments of norovirus infection.
- Quantitative microbial risk assessment (QMRA) on Cryptosporidium to be combined with the text on Cryptosporidium currently published as part of the microbiological addendum to the Second Edition to become a free-standing report;
- Stand-alone document on Campylobacter;
- Revised fact sheet on Cryptosporidium for Fourth Edition.
Progress to date
A draft document on Cryptosporidium was initiated. The GDWQ WG meeting (Geneva, 2004) agreed that further risk assessments would not be undertaken at this time due to a lack of data. The GDWQ WG meeting (Geneva, 2005) determined that additional documents were needed and agreed to a plan of work. The GDWQ WG meeting (Geneva, 2006) endorsed publication of the draft document on Cryptosporidium, subject to satisfactory incorporation of review comments. The GDWQ WG meeting (Berlin, 2007) noted that the document could be published following review, revision to incorporate comments and approval by the Microbial Aspects WG via e-mail. The GDWQ WG meeting (Singapore, 2008) was advised that the Cryptosporidium document had been approved for publication and that work on stand-alone documents on Campylobacter and enteroviruses was progressing.