Hepatitis Risk Calculator: Screen for Hepatitis B and C from Exposure Factors
Worldwide, an estimated 296 million people live with chronic hepatitis B and 58 million with hepatitis C — most without knowing it. Both diseases progress silently for years before cirrhosis or liver cancer appear. Early detection changes the trajectory dramatically.
This guide shows how to quantify your personal hepatitis risk — based on 13 CDC- and WHO-recommended exposure factors. Anyone in the moderate or high band should pursue targeted testing.
Hepatitis B vs. hepatitis C — what's different?
Both viruses target the liver, but differ in transmission, course, and treatment:
| Feature | Hepatitis B (HBV) | Hepatitis C (HCV) |
|---|---|---|
| Transmission | Sex, perinatal, blood | Primarily blood (IV) |
| Chronicity | 5–10 % in adults | 75–85 % of all infections |
| Vaccine | Yes (3-dose, highly effective) | No |
| Treatment | Tenofovir / entecavir (suppression) | DAAs — cure in > 95 % |
| Incubation | 30–180 days | 14–180 days |
Note: Hepatitis A spreads through contaminated food (fecal-oral route) and is not part of this risk model. Travelers to endemic regions should get the HAV vaccine, which protects for 20+ years.
The 13 most important risk factors
The calculator weights 13 factors that CDC and WHO explicitly cite as a screening indication:
| Factor | Points | Why it matters |
|---|---|---|
| Injection drug use | 4 | Leading HCV transmission route worldwide |
| Transfusion before 1992 | 3 | Pre-systematic donor screening era |
| Long-term hemodialysis | 3 | Elevated nosocomial risk |
| Infected mother | 3 | Perinatal HBV transmission in 70–90 % without vaccine |
| High-prevalence country of birth | 2 | East Asia, sub-Saharan Africa, Pacific |
| Born 1945–1965 | 2 | CDC HCV birth cohort |
| HIV infection | 2 | Shared routes; co-infection is common |
| Occupational needlestick | 2 | HBV ~30 %, HCV ~1.8 % per incident |
| Elevated liver enzymes | 2 | Unexplained ALT/AST elevation needs workup |
| Hep+ household contact | 2 | Shared razors / toothbrushes possible |
| Unsterile tattoo / piercing | 1 | Done abroad or without single-use needles |
| Multiple sex partners | 1 | ≥ 4 in 6 months or unprotected |
| Long incarceration | 1 | Elevated prevalence in correctional settings |
A complete HBV vaccination subtracts 2 points from the score (never below zero) — it protects against HBV, but not HCV.
Run the hepatitis risk calculator
13 exposure factors plus vaccination status — instant result with severity grade and clinical guidance. Anonymous and no sign-up.
Calculate for free →What tests should you run?
- HBsAg: Hepatitis-B surface antigen — positive in acute or chronic infection.
- Anti-HBc: Antibody to the core antigen — marker of past or current HBV infection.
- Anti-HBs: Protective antibody from vaccine or cleared infection (titer > 10 IU/L = immune).
- Anti-HCV: Hepatitis-C antibody screen. If positive, confirm with HCV-RNA PCR.
- HCV-RNA PCR: Direct virus detection — distinguishes active from cleared infection.
- ALT/AST: Transaminases as markers of liver inflammation — usually elevated, but not specific.
Post-exposure prophylaxis (PEP)
After acute exposure — needlestick or unprotected sex with a confirmed HBV carrier — post-exposure prophylaxis should be considered within 72 hours:
- HBV PEP: Active vaccination plus hepatitis-B immune globulin (HBIG) for unvaccinated or seronegative contacts.
- HCV: No PEP available — close monitoring (HCV-RNA at 4 and 12 weeks). If infection confirmed, early DAA therapy is possible.
Treatment and cure
Hepatitis C is curable today. Direct-acting antivirals (sofosbuvir/velpatasvir, glecaprevir/pibrentasvir) achieve cure rates above 95 % in 8–12 weeks with virtually no side effects. In most countries, treatment cost is fully covered by insurance.
Hepatitis B usually cannot be eradicated, but tenofovir or entecavir suppress viral DNA below the detection limit and dramatically reduce the risk of cirrhosis and liver cancer. Acute hepatitis B in adults clears spontaneously in 90–95 % of cases.
Related calculators
Hepatitis risk overlaps with other liver and transmission risks. To estimate alcohol as an additional liver stressor, see the blood alcohol calculator or the longer-term alcohol units guide. Chronic fatigue can be an early sign of HCV — the anemia risk calculator is helpful here, since chronic liver disease often comes with anemia.
Summary
Hepatitis B and C are common but mostly silent. The key question is: are there risk factors? With our hepatitis risk calculator you can answer that in seconds. The earlier chronic hepatitis is detected, the better treatment outcomes are — and HCV is now curable in the vast majority of cases.