A surveillance form that asks what you ate and where you swam

The Cholera and Other Vibrio Illness Surveillance (COVIS) system is how US
cases of Vibrio infection — cholera and vibriosis — are reported. The
CDC started it in 1989, with the Food and Drug Administration and four Gulf
Coast states: Alabama, Florida, Louisiana and Texas.

What the form asks

Health officials report cases on the COVIS case report form, which captures:

• A description of the illness and any underlying health conditions
• Recent seafood consumption
• Recent exposure to:
• • Bodies of water
  • Raw or live seafood, or their drippings
  • Marine life
• The source or sources of the implicated seafood

That list is unusually specific for a surveillance form, and each item earns
its place. Vibrio lives in warm coastal water, so a person can acquire it by
eating shellfish or by getting seawater into a wound. "Drippings" is there
because handling raw seafood — not eating it — is a real route. "Marine life"
covers the fisherman cut by a fin.

A form that only asked "did you eat oysters" would miss a substantial share of
cases and misattribute the rest.

What it is for

The information **helps the CDC track infections and determine patient, food
and environmental risk factors** — and the three-way split matters. Some
Vibrio risk is about the person (underlying liver disease raises the danger
sharply), some is about the food (which harvest area the oysters came from),
and some is about the environment (water temperature in a given season).

Asking about all three on one form is what lets them be told apart.

Source: Centers for Disease Control and Prevention.