Download CHARLES H. CALISHER AND BRIAN WJ MAHY

Am. J. Trop. Med. Hyg., 68(5), 2003, pp. 505–506
Copyright © 2003 by The American Society of Tropical Medicine and Hygiene
EDITORIAL
TAXONOMY: GET IT RIGHT OR LEAVE IT ALONE
CHARLES H. CALISHER AND BRIAN W. J. MAHY
Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, College of
Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado; National Center for Infectious
Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
37 isolates of Dengue virus type 2 (family Flaviviridae, genus
Flavivirus, species Dengue virus),” and thereafter all the authors need do is write “Dengue virus type 2” or “DENV-2,”
the ICTV-approved abbreviation for that virus. Note that the
abbreviation for this virus is “DENV-2,” not “DEN 2 virus.”
When writing about West Nile virus (WNV), one could say,
“We used polymerase chain reaction assays to detect RNA of
West Nile virus (family Flaviviridae, genus Flavivirus, species
West Nile virus),” and thereafter use the ICTV-approved abbreviation “WNV,” or the words “West Nile virus.” Note that
the abbreviation for this virus is “WNV,” not “WN virus.”
West Nile is the name of a district in Uganda and no longer
has anything to do with the name of this virus.
Italicization of a virus name is incorrect. Italicization is used
by taxonomists to denote names of taxa. Given that names of
viruses are not names of taxa, one would be incorrect to say,
“We isolated West Nile virus.” Species (italicized) names are
not the names of viruses, they are the names of species, ideal
taxonomic representatives of taxa below the genus level.9
What is more, given that certain virus species are comprised
of many viruses, an overly enthusiastic or conniving bureaucrat might make use of the Federal Register itself 10 to make
life for virologists more complicated than it need be.
One cannot titrate, aliquot, ship, or be vaccinated against
infection with a virus species. Virus species exist only in the
minds of those who think about them. Therefore, whereas
virologists should know where particular viruses have been
placed in the scheme of things, there is no reason for them to
italicize the names of these viruses.
It is clear that viruses, which have been considered “Mistletoe on the Tree of Life” (McGeoch D, personal communication, 1995), have had very different origins than have eukaryotic or prokaryotic organisms. Eukaryotes have in common
the principal characteristics of cellular organization, biochemistry, and molecular biology and have been classified on the
basis of these traits. What viruses have in common is that they
are small, intracellular parasites that do not fit neatly into
universal taxonomic systems, mainly because of their replication mechanisms, not to speak of the fact that they replicate,
rather than multiply by binary fission.
Microbiologists (and some others) are successful only if
they are neat, perhaps a bit compulsive. Even decades ago it
was unacceptable to virologists to find themselves with a mere
list of the viruses recognized to that time. The question of
whether viruses should or should not be classified was ignored
for the greater good of the collective sanity, and viruses were
classified according to what they did, i.e., encephalitis viruses,
hepatitis viruses, gastroenteritis viruses, arboviruses, plant viruses, bacteriophages, etc. As additional viruses were recognized, nucleic acid content (DNA, RNA, or both) considered,
shape, size, and other physical characteristics measured, and
sophisticated molecular genetic techniques introduced, attempts were made to formulate a more reasonable, but generally acceptable, taxonomic scheme.
The International Committee on Taxonomy of Viruses
(ICTV; a section of the International Union of Microbiological Societies) has been attempting to “introduce some order
into the bewildering variety of viruses.”1 Relying on the expertise of members of the various study groups, the ICTV
continually supplements, revises, establishes, and reorganizes
virus taxa.2 The results have been both confusing and controversial.3,4 Not only do authors and journals make taxonomic
errors, so does the ICTV. The latest edition of Virus Taxonomy2 contains many errors, but these surely will be corrected, as we all become accustomed to the system. Indeed,
many attempts have been made to clarify that which seems to
be so confusing.5–8
Virus taxonomy itself is extremely complex and may be
best left to the compulsive types who devise it. Unfortunately,
all of us have to use taxonomy, so it is in all our best interests
to have at least a working understanding of taxonomy. Mammalogists are accustomed to mentioning the common name of
the mammal and then, parenthetically, the taxonomic designation of that mammal (order, family, genus, and species).
Parasitologists, entomologists, herpetologists, bacteriologists,
botanists, and essentially all other specialists do the same with
their favorite entities. Virologists should do the same. That is,
name the virus, then parenthetically cite the family, genus,
and species names.
For example, in a manuscript about Dengue virus type 2,
one might say, “We compared sequences of the prM genes of
Authors’ addresses: Charles H. Calisher, Arthropod-Borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523,
Telephone: 970-491-2987, E-mail: [email protected]. Brian W. J.
Mahy, National Center for Infectious Diseases, Centers for Disease
Control and Prevention, Atlanta, GA 30333, Telephone: 404-6392915, E-mail: [email protected]
REFERENCES
1. van Regenmortel MHV, 2000. Preface. van Regenmortel MHV,
Fauquet CM, Bishop DHL, Carstens EB, Estes MK, Lemon
SM, Maniloff J, Mayo MA, McGeoch DJ, Pringle CR, Wickner
RB, eds. Virus Taxonomy. Seventh Report of the International
Committee on Taxonomy of Viruses. San Diego, CA: Academic Press, xi–xii.
2. van Regenmortel MHV, Fauquet CM, Bishop DHL, Carstens
EB, Estes MK, Lemon SM, Maniloff J, Mayo MA, McGeoch
DJ, Pringle CR, Wickner RB, eds, 2000. Virus Taxonomy. Seventh Report of the International Committee on Taxonomy of
Viruses. San Diego, CA: Academic Press.
3. Gibbs AJ, 2000. Virus nomenclature descending into chaos. Arch
Virol 145: 1505–1507.
4. Bos L, 1999. The naming of viruses: an urgent call to order. Arch
Virol 144: 631–636.
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5. van Regenmortel MH, Mayo MA, Fauquet CM, Maniloff J, 2000.
Virus nomenclature: consensus versus chaos. Arch Virol 145:
2227–2232.
6. van Regenmortel MH, Fauquet CM, 2002. Only italicised species
names of viruses have a taxonomic meaning. Arch Virol 147:
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7. van Regenmortel MHV, 1999. How to write the names of virus
species. Arch Virol 144: 1041–1042.
8. Drebot MA, Henchal E, Hjelle B, LeDuc JW, Repik JT, Roehrig
PM, Schmaljohn CS, Shope RE, Tesh RB, Weaver SC, Calisher CH, 2002. Improved clarity of meaning from the use of
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9. van Regenmortel MH, Maniloff J, Calisher CH, 1991. The concept of virus species. Arch Virol 120: 313–314.
10. Centers for Disease Control and Prevention, 2002. Interstate
shipment of etiologic agents; select agents. Fed Reg 67: 54605–
54607.