2. Environmental poliovirus surveillance (ENV) means monitoring of poliovirus (PV) transmission in human populations by examining environmental specimens supposedly contaminated by human faeces
3. It is estimated that systematic ES would detect 1 individual excreting wild poliovirus among 10,000 inhabitants
3a. Deficiencies in AFP surveillance are suspected
3b. Persistent virus circulation is suspected
3c. Frequent virus re-introduction is perceived
3d. Low polio vaccination coverage
3e. There is risk of poliovirus importation
4a. In several countries, wild polioviruses have been detected in the environment in the absence of reported polio cases.
5. ES is also a potential tool for monitoring circulating vaccine-derived poliovirus (cVDPV)
6. Sampling frequency should, preferably, be twice a month, but at least once a month
7. Sampling sites are inlets to sewage treatment plants or other major collector sewers.
8a. One or two should be responsible for collecting the samples at each sampling site
8b. Should be organized by the local authorities or in collaboration with MoH/WHO
8c. Training and written instructions should be provided to persons collecting the samples
9a.Trap samples are collected by hanging a bag of non-specifically absorbing material in the sewage stream
9b. Grab method an amount (one liter) of raw sewage is collected at a selected sampling site,
10b. peak morning hours of household sewage
