Other DNA viruses !
- Viruses
DNA viruses that are not herpesviruses: hepadna-, papilloma-, polyoma-, parvo-, adeno- and poxviruses.
Updated 2026-11-01
What they are
This group gathers very different DNA virus families: hepatitis B virus (a hepadnavirus), HPV, JC polyomavirus, parvovirus B19, adenoviruses and the poxviruses (mpox, molluscum contagiosum and smallpox). They share rules that exams love: nearly all copy their DNA in the nucleus, and the exceptions are the classic questions.
What they share
- Nearly all are double-stranded; parvovirus B19 is the main single-stranded DNA virus that causes human disease
- Nearly all replicate in the nucleus; poxviruses replicate in the cytoplasm with their own polymerase
- Naked (no envelope): HPV, polyomaviruses, parvovirus and adenovirus (resistant to disinfectants)
- Enveloped: hepadnaviruses and poxviruses
- HBV uses a reverse transcriptase although it is a DNA virus
Microorganisms in this group
- Hepatitis B virusA virus that infects the liver; it may clear or become chronic and lead to cirrhosis and liver cancer. A vaccine is given from birth.Exam priority: high
- Human papillomavirusA very common sexually spread virus; some types cause warts and others, when they persist, cause cervical cancer.Exam priority: high
- JC polyomavirusA virus most people carry without symptoms; in the immunocompromised it destroys brain myelin (PML).Exam priority: medium
- Parvovirus B19A tiny virus that causes fifth disease (red cheeks) in children and can cause severe anemia and harm a fetus.Exam priority: medium
- AdenovirusA non-enveloped virus behind colds, sore throat, conjunctivitis and diarrhea; it resists many disinfectants and causes outbreaks.Exam priority: medium
- Mpox virusA poxvirus that causes skin and mucosal lesions with swollen lymph nodes; it caused worldwide outbreaks in 2022 and 2024.Exam priority: medium
- Molluscum contagiosum virusA poxvirus that causes small pearly bumps with a central dimple, mostly in children; it usually clears on its own.For completeness
- Variola virusThe poxvirus of smallpox, a disease eradicated in 1980 thanks to vaccination; it now exists only in authorized laboratories.For completeness
Test yourself
Think of the answer, then tap the question to see it.
Which is the only DNA virus family that replicates in the cytoplasm?
The poxviruses (smallpox, mpox, molluscum contagiosum), which carry their own DNA-dependent DNA polymerase.
Which DNA virus has a single-stranded genome?
Parvovirus B19, which is also the smallest DNA virus and has no envelope.
Which DNA virus uses reverse transcriptase?
Hepatitis B virus: it copies its DNA from a pregenomic RNA inside the capsid.
Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Hepatitis B (WHO, 2025); Human papillomavirus and cancer (WHO, 2024); Clinical Overview of Adenovirus (CDC, 2024); Mpox (WHO, 2025).
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Representative model, for educational purposes only.