As supplies of sodium thiopental dried up, states that still administered the death penalty began using less reliable combinations of sedatives and paralytics from compounding pharmacies.
Thus, contact VAPP cases include all paralytic infections from OPV and OPV-related viruses, but not from fully-reverted VDPV, which the model classifies as cVDPV or iVDPV outbreak cases, depending on the source of the virus.
Following polio eradication, paralytic poliomyelitis from poliovirus will only occur as a result of the continued use of the live oral poliovirus vaccine (OPV).
Global expansion of polio immunization resulted in a reduction of paralytic disease from an estimated annual prevaccine level of at least 600,000 cases to fewer than 1,000 cases in 2000.
Figure 1a shows the expected paralytic cases from serotype 2 polioviruses (PV2) for 2016-2019 with (solid blue curve) and without (red dashed curve) tOPV intensification prior to OPV2 cessation.
Figure 1b shows the expected paralytic cases from serotype 1 polioviruses (PV1) following OPV13 cessation for different options of SIA frequencies between January 1, 2017 and OPV13 cessation (Table 2).
Specifically, the model described in the next section considers a probability of detecting and confirming any individual paralytic case from AFP surveillance and a probability of detecting and confirming the presence of poliovirus in sewage from environmental surveillance for each population including that type of surveillance.
Previous simple models based on hypothetical populations assumed perfect detection of symptomatic cases and suggested the need to observe no paralytic cases from wild polioviruses (WPVs) for approximately 3-4 years to achieve 95% confidence about eradication, but the complexities in real populations and the imperfect nature of surveillance require consideration.
The questionnaire was developed from interviews of parents of children with paralytic poliomyelitis and from previous studies on knowledge, attitudes and beliefs [ 11- 13].
Between 25% and 50% of individuals who have recovered from paralytic polio in childhood can develop additional symptoms decades after recovering from the acute infection, notably new muscle weakness and extreme fatigue.
