Poliovirus Surveillance by Examining Sewage Water Specimens: Studies on Detection Probability Using Simulation Models

Abstract

Efficiency of environmental surveillance of poliovirus circulation was studied using simulation models. First, three transmission models were defined for describing different scenarios of poliovirus infections in a large unstructured population. Second, environmental factors, such as the total volume of the sewage network and losses of viruses, were modeled for computing the virus output at the sewage sampling site. Third, the effect of sampling and laboratory procedures was accounted for in the probability of detection, given the amount of polioviruses in a specimen. The simulation model can be used for theoretical assessments of the likely efficiency of environmental surveillance, compared with acute flaccid paralysis (AFP) surveillance. Under reasonable assumptions in a vaccinated population, the AFP surveillance can be outperformed if the poliovirus outbreak is not large. However, this depends on the assumed case-to-infection ratio and on the sampling frequency of the sewage water specimens. Increasing the latter will lead to a higher detection probability, which will further enhance the method based on environmental surveillance.

Frequent Detection of Highly Diverse Variants of Cardiovirus , Cosavirus , Bocavirus , and Circovirus in Sewage Samples Collected in the United States

“…As has been previously shown, sewage water represents a convenient material to test large populations for the presence of enteric viruses (8-10, 18, 19, 21, 22, 25, 42, 55). Modeling studies have indicated that a single poliovirus toilet "flush" could contain enough enterovirus to be detected in a city's sewage system for up to 4 days (47). Studies of untreated sewage waters collected at different times might show seasonal fluctuation and yield further insight into the epidemiology of these viruses.…”

Characterization of a Highly Evolved Vaccine-Derived Poliovirus Type 3 Isolated from Sewage in Estonia

“…Second, the virus was isolated by a trap sampling method. Theoretically, the likelihood of detecting virus excreted by a single person in a sewage system where excreta from a given person are mixed with sewage derived from half a million nonexcretors, is very small (19,32). The nonselective adsorbent immersed in the sewage is likely to be rapidly saturated with unrelated suspended materials abundant in a city's sewage.…”

Role of environmental poliovirus surveillance in global polio eradication and beyond

“…Ranta and co-workers [11] have presented a mathematical model visualizing how different factors influence the proportion of excreted PV which can be recovered at a downstream sampling site, and thus sample sensitivity or population sensitivity, respectively, in ENV (Fig. 2).…”