Thrush can be caused by antibiotic use, which can disrupt the function of other bacteria in the body. Yeast typically lives in the body. However, antibiotics can cause yeast to develop into an infection. You should continue to take antibiotics as prescribed if you develop thrush. However, you should inform your GP.
Thrush is not a sexually transmitted infection; however, it can be passed during sexual activity. Avoid any sexual contact during an outbreak of thrush until it has cleared.