Viruses are named using specific rules and conventions established by international organizations like the International Committee on Taxonomy of Viruses (ICTV) and the World Health Organization (WHO). The process of naming a virus is systematic and based on several factors, including its genetic makeup, structure, host, and disease it causes.
There are several criteria which are used to name viruses. The naming criteria include;
- Virus morphology
- corona= crown-like
- rabdo= rod-like
- arena= sand-like
- toga= cloak
- rota= wheel
- pico= small (greek)
- parvo= small (latin)
- orbi= ring
- calici= cup-like
- toro= donut shaped
3. Location of the virus in the host’s body
- Adeno= gland
- Entero= alimentary
- Rhino= upper respiratory tract
- myxo= mucous
- pneumo= air
3. Type of lesion or disease (WHO’s Role)
While ICTV focuses on the virus itself, the World Health Organization (WHO) often names viruses based on the disease they cause. This is particularly important for public health communication and helps differentiate viruses from the conditions they lead to.
- For instance, COVID-19 stands for “Coronavirus Disease 2019.” It is the disease caused by the virus SARS-CoV-2. The virus and the disease have separate names, making it easier for both scientific research and public health communication.
- pox= smallpox
- flavi= yellow fever
- morbilli= disease
- herpes= creeping
- aphtho= vesicle
- Human immunodeficiency virus (HIV): Named based on its effects on the immune system and its role in causing AIDS.
4. Virus enzymes
- retro= reverse transcriptase
5. Abbreviations
- papova= papilloma polyoma vacuolating
- reo= respiratory enteric orphan
6. Geographic Origin or Discovery
In the past, some viruses were named based on where they were first identified. However, this practice is discouraged now to avoid stigmatizing regions or communities.
- Zika virus: Named after the Zika forest in Uganda, where the virus was discovered.
- Ebola virus: Named after the Ebola River in Africa, where the virus was first identified.
- bunya= bunyamwera in Uganda
- Sendai virus, Coxsackie virus
7. How they were originally thought to be contracted
- dengue virus (“evil spirit”), influenza virus (the “influence” of bad air)
8. Molecular Features:
Viruses can also be named based on their genetic or structural characteristics:
- H1N1 influenza virus: Named based on the specific proteins (hemagglutinin [H] and neuraminidase [N]) found on its surface.
9. Naming based on how they evolve (Variants and Strains)
When viruses mutate and evolve, they can give rise to new variants or strains. Variants are typically named using a combination of numbers and letters or geographic origin, but the WHO now encourages using a simpler naming system.
For example, variants of SARS-CoV-2 have been named:
- Alpha (B.1.1.7) variant first identified in the UK.
- Delta (B.1.617.2) variant first identified in India. This helps avoid geographic stigmatization and simplifies communication.
ICTV Naming Process
The ICTV follows a formal process for naming new viruses:
- Proposals for new names are submitted by virologists, often based on a virus’s genome sequence, structure, or host.
- The proposals are reviewed by ICTV committees to ensure they meet established guidelines.
- Once approved, the virus name becomes official and is included in the ICTV database.
Main rules for the correct spelling of names of viruses and related agents:
The name of the order always ends in the suffix –virales and is written in italics and the first letter is capitalized.
The name of the family always ends in the suffix –viridae and is written in italics and the first letter is capitalized.
The name of the subfamily always ends in the suffix –virinae and is written in italics and the first letter is capitalized.
The name of the genus always ends in the suffix –virus and is written in italics and the first letter is capitalized.
For instance:
– Order Mononegavirales
– Family Paramyxoviridae
– Subfamily Paramyxovirinae
– Genus Morbillivirus
This nomenclature corresponds to the guidelines proposed by the International Committee on Taxonomy of Viruses (ICTV).
For many viruses, the family is the maximum taxonomic level reached.
Subviral Agents
The same rules also apply to the classification of viroids. The formal way to write the name
of a viroid is as follows:
– The word viroide for the species.
– The suffix viroid for the genus.
– The suffix viroinae for the subfamilies and
– The suffix viroidae for the families.