Napoleon Bonaparte and Franz Schubert died from arsenic and mercury poisoning, because in the 19th century these toxins were used to treat syphilis.

In the 20th century, Al Capone succumbed to the same sexually transmitted infection.

STIs caused by viruses include hepatitis B, herpes, HIV and the human papilloma virus. Bacterial STIs are chlamydia, gonorrhea and syphilis. A parasite causes trichomoniasis.

Fortunately, antibiotics can treat bacterial and parasitic infections (although some strains are becoming antibiotic resistant).

Viral STIs are difficult to cure; you usually just manage symptoms.

Left unchecked, STIs can cause infertility, cancer, immune system damage or organ failure.

The smart move is to avoid getting one. But, if you do, treat it immediately.

Prevention: Abstinence works; Latex condoms help block out HIV and other infections but don’t protect against herpes or HPV.

The HPV vaccine prevents that infection. Yearly pelvic exams (for women) can identify infections.