STIs caused by parasites (e.g. pubic lice/crabs, scabies, trichomoniasis) are usually easy to detect, treat and cure. Without treatment, they spread easily and cause uncomfortable symptoms like itchiness, rash and irritation.
STBBIs caused by bacteria (e.g. chlamydia, gonorrhea, syphilis) may not always have symptoms, but can be detected through STI testing. They can be cured with medication. Untreated bacterial STI can cause very serious health problems.
STBBIs caused by viruses (e.g. herpes, HPV, Hep B & C, HIV) may not always have symptoms. Some can be difficult to detect while others can be detected through testing. All can be treated; some cured; some can be prevented with vaccine. Some untreated viral STBBI can cause very serious health problems. HPV and herpes (HSV) are the most common STBBI.