Nearly 1/3 of menstrual-related TSS cases recur within six months. The risk of recurrence increases drastically if the original bacteria remain after antibiotic treatment.
Studies have shown that about 66% of women don't develop the antibodies needed to prevent infection after they've had menstrual-related TSS. Also, non-menstrual-related TSS sufferers are at increased risk of recurrence, though their risk of getting it again is more rare.