Smallpox
Outbreak Control Activities and Strategies
Surveillance
and Containment (Ring Vaccination) (22:V1:51)
Description
Surveillance
and containment is the central strategy for containing an outbreak
of smallpox. It is sometimes called ring vaccination too, although
that term leaves out the infection control measures that also need
to be implemented. The principle behind this strategy is to identify
cases of smallpox, vaccinate their household and other close contacts,
then also vaccinate close contacts of the primary household and
close contacts to the case. Then, if the primary contacts developed
smallpox despite vaccination, their close contacts would already
be protected and the chain of transmission would have been broken.
 
Steps for Surveillance
and Containment:
- Search for
cases.
- Provide a
ring of immunity around each case. This includes vaccinating
close contacts and close contacts of contacts.
- In order
to control disease the most efficient use of vaccine is required
as is minimizing adverse reactions.
Surveillance (22:V1:52)
Surveillance
is important both before a smallpox outbreak and after a smallpox
outbreak. In the pre-event situation, we might just be able to
look for the typical, ordinary type smallpox cases. We will need
to confirm the initial case by laboratory testing. A positive laboratory
result will lead to the surveillance and containment strategy with
vaccination. In the post-event setting, we will refine our ability
to clinically diagnose cases, so we will attempt to find all cases,
both typical and atypical. Since the smallpox activities are already
underway and we will know that smallpox virus is again circulating,
a clinical diagnosis of smallpox is enough to being vaccination
of the contacts. In this setting, we will need active surveillance,
with contact being made daily with hospitals in order to track
the progression of the outbreak.
Pre-Event Surveillance
Steps include:
- Identifing
cases with typical presentation.
- Rapid laboratory
confirmation.
- Confirmation
initiates contact vaccination.
- Passive with
more specificity.
Post-Event Surveillance
Steps include:
- Identify
all potential cases (typical/atypical).
- Clinical
diagnosis can initiate contact vaccination.
- Active with
increased sensitivity.
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