How infectious is HIV compared to Hep B?

• A. HIV is more infectious than Hep B
• B. Hep B is 50-100% more infectious than HIV
• C. They have equal infectiousness
• D. HIV is twice as infectious as Hep B

Answer: (B)

Infectiousness reflects how easily a virus spreads through typical exposure routes. Hepatitis B virus is extremely contagious because it can be transmitted with very small amounts of blood or body fluids and can remain viable outside the body for a long time. HIV, while also transmissible, generally has a lower per-exposure transmission rate. The established comparison is that Hep B is far more infectious than HIV—often described as tens of times more likely to be transmitted per exposure. That large difference is why the statement that Hep B is more infectious than HIV best fits the real-world data. The other options either reverse the relationship or imply equal or greater HIV infectiousness, which do not align with how these viruses transmit.