Micro & Immunology · single question
Which pathogen spreads via a BLOOD-BORNE route?
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Correct answer: A. Hepatitis B Virus (HBV)
Hepatitis B Virus (A) is a blood-borne pathogen. HBV is transmitted through: blood (needlesticks, sharing needles), sexual contact, mother-to-child (perinatal). It is a major occupational hazard in dentistry.
Blood-borne pathogens of dental relevance (OSHA standards): HBV, HCV, HIV.
• Measles (B): Airborne + direct contact with respiratory secretions.
• Mumps (C): Respiratory droplets and direct contact with saliva.
• Clinical pearl: HBV is the MOST infectious blood-borne pathogen — it can survive on dry surfaces for 7 days and is 100× more infectious than HIV per needlestick. The HBV vaccine is required for dental HCWs under OSHA standards.
Blood-borne pathogens of dental relevance (OSHA standards): HBV, HCV, HIV.
• Measles (B): Airborne + direct contact with respiratory secretions.
• Mumps (C): Respiratory droplets and direct contact with saliva.
• Clinical pearl: HBV is the MOST infectious blood-borne pathogen — it can survive on dry surfaces for 7 days and is 100× more infectious than HIV per needlestick. The HBV vaccine is required for dental HCWs under OSHA standards.
- A. HBV is a classic bloodborne pathogen, transmitted through blood, blood products, sexual contact, and vertical transmission. It is NOT airborne. The other options are respiratory viruses.
- B. Mumps is transmitted via respiratory droplets and direct contact with infected saliva — NOT via blood.
- C. Measles is transmitted via AIRBORNE route — it is NOT a bloodborne pathogen.
- D. Varicella (VZV) spreads via airborne route and direct contact with vesicle fluid — not through blood exposure.
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