Jeanette LeBlanc, 55, was on a trip to Louisiana with her wife, Vicki Bergquist, when she shucked and ate the raw shellfish she'd picked up at a local market.
'About 36 hours later she started having extreme respiratory distress, had a rash on her legs and everything,' Ms Bergquist told KLFY-TV.
Initially thinking it was an allergic reaction, Ms LeBlanc's condition rapidly deteriorated after 48 hour and she was rushed to hospital.
Doctors informed the Texas woman that she had contracted vibriosis - a bacterial infection.
While she battled bravely for 21 days to beat the virus, she never recovered and passed away on October 15, 2017.
Now her wife is speaking out to ensure others don't meet the same fate.
'If we had known that the risk was so high, I think she would've stopped eating oysters,' Bergquist said.
According to the US Centers for Disease Control and Prevention, people can become infected with vibrio after eating raw or under-cooked shellfish or by exposing open wounds to brackish water.
Just a few months earlier, in August 2017, another US woman, Jane Cunningham, 55, died after eating oysters.
Cunningham, who was already battling leukemia, ate the oysters while holidaying with her husband to celebrate her birthday. The oysters contained the bacteria vibrio, which gave her a severe infection.
Jane was rushed to hospital where doctors amputated both legs and one her arms in the hope of stopping the infection, but she passed away soon after.