The oysters native to the coast of Georgia are usually found in clusters and consumed at oyster roasts, but if you eat raw oysters, you may have heard to avoid them in the summer, or another rules of thumb, “during months not ending in R.”
Most people know that the reason behind those rules or folk sayings is to keep from getting sick, but it is less well known how extreme the risks are.
There is a naturally occurring bacteria in the ocean called Vibrio vulnificus, and it is a particular danger if you eat raw Gulf coast oysters during the summer-time months.
It is a serious (if rare) health risk, with about 700 people becoming seriously ill from the bacteria since 1989. Almost half of that number died, and many of the surviving victims lost arms, legs, and suffered permanent scarring.
This is a danger that we could fix through stricter regulations, like California did in 2003 (requiring treating raw oysters from Florida and other Gulf states to remove the bacteria from April until November prior to sale), but other states have decided not to go that route.
In Georgia, we do close state waters to any oyster harvesting from June 1 until October 1: https://coastalgadnr.org/georgia-closes-oyster-harvest-state-waters
Why don’t we fix the problem so that other unsuspecting people aren’t maimed or killed? Unfortunately, in most places, the industry, and policy makers, state legislatures, and members of Congress would rather blame the victims, some of whom have serious underlying medical problems like diabetes or cancer. And it is true that those kinds of health problems can make it more likely you will have a bad, dangerous reaction to Vibrio vulnificus.
On the other hand, many people have serious health problems that go undiagnosed for years, and they can’t really suspect the risks that they are running when they go out to a restaurant with friends and family to enjoy a culinary delight of oysters on the half shell with lemon, shallots and vinegar, tabasco, or just straight-up.
Unfortunately, you cannot tell a bad oyster from a good one when you are eating it; there is no tip off like smell, taste or texture that will help avoid the danger.
The best advice that you can follow if you have food poisoning symptoms (including fever/chills, skin rash, vomiting, gastrointestinal distress, including pain, nausea or diarrhea) within a day or two of eating raw oysters is that you should go to the emergency room right away for aggressive antibiotic or other appropriate medical treatment.