SPADA

Example:“Pre-event”

Use more than 1 test to increase PV+

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

Test 1: sensitivity 99%,

specificity 99%

PREV PV+

PV-

10.00% 92.80% 99.80%

1% 50% 99.99%

0.10% 9% 100.00%

Test 2: sensitivity 95%,

specificity 95%

PREV PV+

PV-

50.00% 95.00% 95.00%

10% 67% 99.00%

1.00% 16% 99.50%

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