Table 2:

Expected detected-event free period (DEFP) required for 95% and 99% confidence about no circulation (CNCx%) and time of undetected circulation between the last paralytic case and die-out (TUCx%) in Borno and Yobe assuming perfect and imperfect surveillance (based on 1,000 iterations) for WPV1^* (two scenarios) and WPV3.

Virus	WPV1 (PIR = 1/200)				WPV3 (PIR = 1/1000)
POE	100%				100%
Metric	CNCx%		TUCx%		CNCx%		TUCx%
x%	95%	99%	95%	99%	95%	99%	95%	99%
	DEFP values assuming perfect AFP surveillance
Scenario 1	1.33	1.83	0.97	1.38	1.75	2.50	1.41	1.76
Scenario 2	1.58	1.92	0.98	1.34
	DEFP values assuming less than perfect AFP surveillance, lower bound
Scenario 1	3.00	3.75	2.75	3.69	3.08	6.50	2.21	6.49
Scenario 2	3.42	3.75	3.35	3.72
	DEFP values assuming less than perfect AFP surveillance, accessibility factor
Scenario 1	1.92	2.25	1.14	1.58	2.42	4.42	1.52	3.99
Scenario 2	2.08	2.50	1.11	1.69
	DEFP values assuming less than perfect AFP surveillance, upper bound
Scenario 1	1.75	2.08	1.07	1.58	2.25	3.42	1.48	3.18
Scenario 2	2.00	2.33	1.05	1.46

^*Scenario 1 assumes sufficient indirect vaccination introductions into the isolated subpopulations to eliminate undetected WPV1 transmission after the outbreak detected in 2016; Scenario 2 assumes insufficient indirect vaccination introductions into isolated subpopulations to eliminate undetected WPV1 transmission through the end of 2019.

Abbreviations: AFP, acute flaccid paralysis; CNCx%, DEFP at which the confidence about no circulation exceeds x%; DEFP, detected-event-free period; PIR, paralysis-to-infection ratio; POE, probability of eradication; TUCx%, the x^th percentile of the distribution of the times of undetected circulation after the last detected-event (for those iterations in which extinction occurs); WPV(1,3), wild poliovirus (serotypes 1,3).