Deer tick virus (DTV) is a
virus
A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...
in the genus ''
Flavivirus'' spread via
ticks that causes
encephalitis.
Taxonomy
DTV closely resembles
Powassan virus (to which it has 84%
nucleotide sequence identity and 94%
amino acid sequence identity).
Due to their close similarities, DTV is also called Powassan virus lineage II.
The DTV lineage is presumed to be maintained between ''
Ixodes scapularis'', or deer ticks, and the white-footed mouse (''
Peromyscus leucopus'').
Epidemiology
DTV has a strong prevalence in the northeastern and north central part of the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, although little to no human infections have been reported. Only about 1 to 3% of ''I. scapularis'' ticks in the northern United States are possibly infected with DTV.
This infers that the virus is not seriously
pathogenic or it does not easily infect humans. Human incidence might be severely underestimated.
History
In 1997, it was isolated from ''I. scapularis'' ticks collected in
Massachusetts
Massachusetts ( ; ), officially the Commonwealth of Massachusetts, is a U.S. state, state in the New England region of the Northeastern United States. It borders the Atlantic Ocean and the Gulf of Maine to its east, Connecticut and Rhode ...
and
Connecticut
Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...
.
A fatal case of DTV encephalitis occurred at a
New York hospital when a 62-year-old man with a meningoencephalitis syndrome,
fever
Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...
, weaknesses in the right arm and leg, and
maculopapular rash died from the virus. After an autopsy, his tissues were found to have DTV on a PCR assay. The patient had no history of travel in the days before his admission to the hospital, which implies that the virus might be active in the New York area. He spent times outdoors in woodland areas and had frequent contacts with
horses.
Lyme disease was commonly reported in the patient's area of residence, showing that tick activity was prevalent in the patient's area (at the time of admission).
In 2017, another fatal case of DTV was documented when a 72-year-old woman was admitted to a hospital in
Maine
Maine ( ) is a U.S. state, state in the New England region of the United States, and the northeasternmost state in the Contiguous United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and ...
with a fever,
low blood pressure, and
urination problems. A month before her admission, an ''I. scapularis'' tick was removed from her left breast. Another embedded ''I. scapularis'' tick was removed from her left scapula only three weeks after the first tick had been removed. She later developed
muscle aches,
chills, and
a rash that is often seen in the early stages of Lyme disease in the same area the tick was removed from. She developed several other concerning symptoms towards the end of her admission at the hospital, which ranged from
joint pains to
thrombocytopenia. She was given doses of
doxycycline
Doxycycline is a Broad-spectrum antibiotic, broad-spectrum antibiotic of the Tetracycline antibiotics, tetracycline class used in the treatment of infections caused by bacteria and certain parasites. It is used to treat pneumonia, bacterial p ...
and antibiotics (
vancomycin
Vancomycin is a glycopeptide antibiotic medication used to treat certain bacterial infections. It is administered intravenously ( injection into a vein) to treat complicated skin infections, bloodstream infections, endocarditis, bone an ...
and
meropenem), which provided no relief to her illness. She later died and a limited autopsy was performed. A severe loss of
anterior horn cells within the spinal cord and
meningoencephalitis of the brain were discovered. A considerable loss of
Purkinje cells was evident in the patient.
See also
*
Alkhurma virus
*
Louping ill
*
Lyme disease
Footnotes
{{DEFAULTSORT:Deer Tick Virus
Flaviviruses
Viral encephalitis
Infraspecific virus taxa