You should replace your toothbrush as soon as you start antibiotics for strep throat, or at minimum once you’ve been on antibiotics for 24 hours. Group A Streptococcus bacteria can survive on toothbrush bristles, and continued use of a contaminated brush creates a small but real risk of reintroducing those bacteria into your mouth and throat during recovery.
Why Your Toothbrush Matters During Strep
Bacteria from your mouth transfer to your toothbrush every time you brush. Once strep bacteria settle into the bristles, they can persist there for days. Research published in the European Journal of Microbiology & Immunology found that continuous re-exposure through tooth brushing can maintain persisting oral infections or lead to auto-reinfection. While the overall risk is described as minimal, reducing bacterial colonization on toothbrushes is considered an advisable, inexpensive precaution.
The concern isn’t just theoretical. Strep bacteria are hardy enough to survive on moist bristles between brushings. Each time you use a contaminated brush, you’re reintroducing those organisms to your throat, which is especially counterproductive when you’re actively trying to clear the infection with antibiotics.
The Best Time to Swap It Out
The ideal approach is to replace your toothbrush twice during a strep infection:
- Once when you start antibiotics. Your bacterial load is highest at this point, and anything you used while symptomatic is likely contaminated.
- Once after you feel better and finish treatment. This gives you a completely clean start and eliminates any bacteria that transferred to the new brush during the tail end of your infection.
If replacing it twice feels excessive, the single most important swap is right when you begin antibiotics. People become non-contagious within about 12 hours of their first antibiotic dose, according to public health guidelines. A fresh toothbrush at that point means you’re not undermining the medication’s work by reintroducing bacteria from your old brush.
Can You Disinfect Instead of Replacing?
Sanitizing a toothbrush can reduce bacteria, but the results vary widely depending on the method. A study published in Cureus tested multiple disinfection techniques and found significant differences in how well they worked:
- Hydrogen peroxide (3%): Reduced bacterial colonies by about 87%.
- UV sterilizer (7-minute exposure): Reduced bacteria by roughly 77%. Some commercial UV devices have shown reductions of 83% to 100% depending on the brand.
- Chlorhexidine mouthwash soak: Soaking a brush in 0.2% chlorhexidine for 20 minutes daily was effective in multiple studies. A longer soak of two hours in 0.12% chlorhexidine eliminated 100% of bacteria in one trial.
- Listerine soak: A 20-minute soak significantly reduced mouth bacteria on brushes in some studies, though one trial found only a 31% reduction in colony counts at lower concentrations.
These methods can help, but none of them are as reliable as simply using a new brush. A basic toothbrush costs a couple of dollars, and given that even the best sanitizing methods leave some bacteria behind, replacement is the safer and easier choice during an active infection.
Protecting the Rest of Your Household
Strep spreads easily in close quarters, and toothbrush storage is one overlooked route. If your family stores toothbrushes together in a shared cup or holder, bacteria can transfer between brushes through direct contact or water droplets. During an active strep infection, keep the sick person’s toothbrush completely separate from everyone else’s.
Research on toothbrush contamination has found that brushes stored in bathrooms, particularly near toilets, accumulate more bacteria overall. Storing brushes upright and allowing them to air dry between uses helps reduce bacterial survival, since the organisms thrive in moisture. During a strep infection, you can also store your brush in a small cup of 3% hydrogen peroxide or chlorhexidine between uses to limit bacterial buildup.
If someone else in the household develops symptoms, the same rules apply: new toothbrush when treatment starts, and keep it isolated from other brushes until the infection clears.
What About Recurring Strep Infections?
Some people, especially children, seem to get strep throat repeatedly. While contaminated toothbrushes are unlikely to be the sole cause of recurrence, they can be a contributing factor. If you or your child deals with frequent strep infections, replacing toothbrushes after every episode and storing them in a disinfecting solution between uses is a low-cost habit worth adopting.
Beyond the toothbrush, recurring strep often involves re-exposure from close contacts at school, daycare, or within the household. Someone in the home may be an asymptomatic carrier, harboring the bacteria without showing symptoms and passing it along repeatedly. If strep keeps coming back despite good hygiene practices, testing household members for carrier status is a reasonable next step.