Experts say the patient contracted a drug-resistant strain of HIV. This new strain doesn’t match his partner’s – so he must have contracted the virus during sex with another person, according to researchers.
PrEP, or pre-exposure prophylaxis, is a medication for HIV-negative people who are engaging in sex with a person who is HIV-positive. Studies show that daily PrEP use can lower the chance of contracting HIV by more than 90 percent, according to the Centers for Disease Control.
Though the pill is a highly effective prevention method, experts say it is even more effective when used with condoms and other safety measures. People on Truvada should get tested for HIV every three months and talk to their physician regularly about how the medication is treating the body.