There is a chance of transmitting STDs (sexually transmitted diseases) with each unprotected encounter. The risks of transmission vary with type of disease, type of intercourse as well as ongoing treatment.
To name a few:
Genital herpes - this is most infectious when lesions (red bumps, blisters) are present but patients can still be shedding the virus and pass to their partners when asymptomatic.
HIV - The chance of transmission from penile-vaginal intercourse from an infected source is 8 in 10,000 (1). Factors that may increase the risk of transmission include acute or late stage HIV infection or high viral load. Anti-retroviral treatment, Pre-exposure prophylaxis and male circumcision are factors that reduce the risk.
Therefore, the most effective way to prevent STD transmission is to avoid casual sex and patients engaging in high risk sexual behavior should use protection and get themselves regularly tested for STD
References:
- Patel P, Borkowf CB, Brooks JT. Et al. Estimating per-act HIV transmission risk: a systematic review. AIDS. 2014. doi: 10.1097/QAD.0000000000000298.
