SPADA

Example:“Pre-event” Use more than 1 test to increase PV+

Individual with clinical scenario with fever, followed by centifugal rash:

PREV PV+ PV- 10.00% 92.80% 99.80% 1% 50% 99.99% 0.10% 9% 100.00% PV- 50.00% 95.00% 95.00% 10% 67% 99.00% 1.00% 16% 99.50% PREV PV+

Test 1: sensitivity 99%,

specificity 99%

Test 2: sensitivity 95%, specificity 95%

Pre event: prevalence of smallpox is zero Peri event: prevalence of smallpox is low • Clinical scenario should be consistent – Use febrile rash algorithm; validate algorithm • Wide availability of other key diagnostic tests especially rapid VZV testing to rule in VZV • Limit the number of laboratories performing Variola virus testing

– Establish confirmatory testing protocols