Virus – Baltimore classification
drsuryabrata@gmail.comThis is a classification of viruses based on how they produce their mRNA. It was created in 1971 by virologist David Baltimore.
mRNA, which is required to synthesise protein, is central to this classification. By convention, mRNA is considered positive sense. Hence DNA strand (or RNA) which is similar to this, are also called +ve sense. On the other hand, the complementary strand of the DNA is -ve sense.
Group I: Double-stranded DNA virus (DS-DNA)
- Polyomavirus – BK, JC, KI, WU, Merkel cell polyoma virus.
- Papillomavirus – HPV.
- Adenovirus
- Herpes virus – HSV, VZV, EBV, CMV, HHV6, HHV7, HHV8.
- Poxvirus – Variola, vaccinia, Molluscum contagiosum, Tanapox, Yaba monkey tumour virus.
Group II: Single-stranded DNA virus (SS-DNA)
Parvoviruses – Parvovirus B19, Human Parvovirus 4, Human Bocavirus, Adeno-associated virus 2,3,5
Circovirus
Anellovirus
Most ssDNA viruses have (+) sense DNA, except family Anelloviridae.
Group III: Double-Stranded RNA virus (DS-RNA)
- Birnavirus (animal virus)
- Reovirus – Reovirus, Rotavirus
Group IV: Single-stranded positive-sense RNA virus (+ssRNA)
- Picornaviridae – Enterovirus (Enterovirus, Coxsackievirus, Echovirus, Poliovirus), Rhinovirus, Parechovirus, Hepatitis A virus.
- Caliciviridae – Norovirus, Norwalk virus, Sapovirus.
- Astroviridae – Human astrovirus
- Hepeviridae – Hepatitis E virus
- Flaviviridae – Yellow fever, Dengue, West Nile, JE, St. Louis encephalitis virus, KFD, Tick-borne encephalitis virus, Hepatitis C virus, Hepatitis G virus.
- Togaviridae – Semliki forest, Chikungunya virus, O’nyong-nyong virus, Ross River virus, Rubella virus.
- Arteriviridae (animal virus)
- Coronaviridae – Human coronavirus(HCoV) 299E, HCoV NL63, HCoV OC43, HCoV HKU1, SARS CoV, SARS CoV-2, MERS CoV.
Group V: Single-stranded negative-sense RNA virus (-ssRNA)
Non-segmented RNA:
- Rhabdovirus – Lyssavirus (Rabies)
- Bornavirus (animal virus)
- Paramyxovirus – Human parainfluenzavirus, Mumps, Measle, Hendra, Nipah, RSV, human metapneumovirus.
- Filovirus – Ebola, Marburgvirus
Segmented RNA:
- Arenavirus – LCMV, Lassa, Lujo, Junin, Machupo, Guanarito, Chapare, Tacaribe, Sabia.
- Bunyavirus – Sandfly fever virus, Rift Valley fever virus, California encephalitis virus, Crimean–Congo haemorrhagic fever, hantaan virus, Sin Nombre virus.
- Orthomyxovirus – Influenza virus
Category VI: Positive sense single-stranded RNA virus replicating through a DNA intermediate – reverse transcriptase (+ssRNA-RT)
- Retrovirus
Category VII: Double-stranded DNA virus replicating through an ssRNA intermediate – reverse transcriptase (dsDNA-RT)
- Hepadnavirus
