It depends on the letter. Hepatitis B is genuinely a sexually transmitted infection — more infectious than HIV per exposure and a standard part of STI panels. Hepatitis C spreads mainly through blood, with sexual transmission possible but inefficient. Hepatitis A transmits fecally-oral, linked to oral–anal sex rather than intercourse. All three inflame the liver; all three are preventable or curable to varying degrees.
Key Takeaways
- Hepatitis B: vaccine-preventable, sexually transmissible, incurable but controllable chronically.
- Hepatitis C: blood-borne primarily; curable in >95% of cases with 8–12 weeks of pills.
- Hepatitis A: fecal-oral; vaccine exists; outbreaks tied to oral–anal sexual contact.
- Standard STD panels vary — verify hepatitis B/C are included or add them.
- One-time hep C screening is recommended for all U.S. adults born 1945–1965 and broadly for adults.
Side-by-Side Comparison
| Feature | Hepatitis A | Hepatitis B | Hepatitis C |
|---|---|---|---|
| Main sexual relevance | Oral–anal contact | Fully sexually transmissible | Low sexual efficiency |
| Vaccine? | Yes | Yes | No (as of 2026) |
| Curable? | Self-clears | No cure; managed | Yes — >95% cured |
| Chronic risk | None | ~5% adults; 90% infants | 55–85% untreated |
| Typical test | IgM antibody | Surface antigen + core Ab | Ab screen → RNA confirm |
Why Hepatitis B Belongs in STI Conversations
Per-exposure, hepatitis B virus is 50–100 times more infectious through blood than HIV and survives outside the body for about a week. It transmits efficiently via semen and vaginal fluids, which is why the CDC recommends universal infant vaccination plus catch-up for unvaccinated adults through 59, and why sexual-health visits should include HBV status review. Chronic infection raises cirrhosis/liver-cancer risk across decades — silent unless screened. Vaccination history matters: most younger Americans received the series at birth.
Hepatitis C: The Blood-Bone Exception
HCV's sexual efficiency is low (~1–4% per year in stable monogamous discordant couples), but risk concentrates in contexts like coinfection with HIV, rougher practices causing bleeding, group sex, and MSM networks. Injection drug use dominates transmission statistics. The triumph story: direct-acting antivirals cure over 95% of infections in 8–12 weeks with minimal side effects — WHO frames global elimination as achievable. Because most chronic carriers feel fine for decades, guideline bodies recommend broad adult screening at least once; our STBBI explainer situates hep C within integrated testing logic.
Adding Hepatitis Tests to Your Panel
When ordering online, look for panels listing “hepatitis B surface antigen” and “hepatitis C antibody”; add hepatitis A IgG if exposure involved rimming or you're unvaccinated during an outbreak region. Positive hep C antibody triggers automatic RNA confirmation to distinguish cleared vs active infection. Liver enzymes (ALT/AST) offer supporting context but don't diagnose. If results confuse you, our false-positive explainer clarifies why antibody screens sometimes flag resolved infections.
Frequently Asked Questions
Can I get hepatitis B from one night without a condom?
Possible — HBV is highly infectious through a single exposure. Vaccination beforehand removes most worry; testing 3–6 weeks afterward confirms status otherwise.
Is there a hepatitis C vaccine?
Not yet. Prevention relies on avoiding blood contact and curing infections rapidly to break chains — treatment-as-prevention works because DAAs are so effective.
Do I need hepatitis testing if I feel healthy?
Yes, once. Chronic hep B and C are famously silent for decades while damaging the liver. One-time adult screening catches them while cure/control is easiest.
Which hepatitis is an official 'STD'?
Hepatitis B appears in classic STI lists and CDC STI treatment guidelines; C is grouped under blood-borne/STBBI frameworks; A sits adjacent via oral–anal transmission.