Colorado tick fever virus

WordNet

1. make a sound like a clock or a timer; "the clocks were ticking"; "the grandfather clock beat midnight" (同)ticktock, ticktack, beat
2. a light mattress
3. any of two families of small parasitic arachnids with barbed proboscis; feed on blood of warm-blooded animals
4. a metallic tapping sound; "he counted the ticks of the clock" (同)ticking
5. sew; "tick a mattress" (同)retick
6. a state in west central United States in the Rocky Mountains (同)Centennial State, CO
7. a river in Texas; flows southeast into the Gulf of Mexico (同)Colorado River
8. an important river in the southwestern United States; rises in the Rocky Mountains of northern Colorado and flows southwest through Utah into Arizona (where it flows through the Grand Canyon) and then southward through the southern tip of Nevada, then for (同)Colorado River
9. a harmful or corrupting agency; "bigotry is a virus that must not be allowed to spread"; "the virus of jealousy is latent in everyone"
10. (virology) ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein
11. a software program capable of reproducing itself and usually capable of causing great harm to files or other programs on the same computer; "a true virus cannot spread to another computer without human assistance" (同)computer virus
12. a rise in the temperature of the body; frequently a symptom of infection (同)febrility, febricity, pyrexia, feverishness
13. intense nervous anticipation; "in a fever of resentment"
14. shrub with terminal tufts of elongated leaves used locally for thatching and clothing; thick sweet roots are used as food; tropical southeastern Asia, Australia and Hawaii (同)Cordyline terminalis
15. the syllable naming the seventh (subtonic) note of any musical scale in solmization (同)te, si

PrepTutorEJDIC

1. (時計まどの)カチカチ[という音] / 《英語》瞬間 / 照合(点検)済みの印,チェック / 〈時計などが〉カチカチ音がする《+away》 / 〈時が〉過ぎる,経過する∥+by(away)》 / 《話》〈人が〉行動する,〈機械などが〉動く
2. 〈C〉(ふとん・まくらなどの)表布
3. ダニ
4. コロラド州(米国西部の州,州都はDenver;《略》『Col.,Colo.,CO』) / 《the ~》コロラド川(カリフォルニア湾に注ぐ;Grand Canyonを流れるので有名)
5. ビールス,ろ過性病原体
6. 〈U〉《しばしばa fever》(身体の異常な)『熱』,発熱 / 〈U〉『熱病』 / 〈U〉〈C〉(…に対する)『興奮』,熱狂《+『for』+『名』》
7. シ(全音階の第7音)

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/08/06 20:05:17」(JST)

wiki en

[Wiki en表示]

Colorado tick fever virus
Virus classification
Group:	Group III (dsRNA)
Order:	Unassigned
Family:	Reoviridae
Subfamily:	Spinareovirinae
Genus:	Coltivirus
Species:	Colorado tick fever virus

Colorado tick fever
Classification and external resources
ICD-10	A93.2
ICD-9	066.1
DiseasesDB	31134
MedlinePlus	000675
eMedicine	emerg/586
MeSH	D003121

Colorado tick fever (CTF) (also called Mountain tick fever, American tick fever, and "American mountain tick fever") is a viral infection (Coltivirus) transmitted from the bite of an infected Rocky Mountain wood tick (Dermacentor andersoni). It should not be confused with the bacterial tick-borne infection, Rocky Mountain spotted fever.

The type species of the genus Coltivirus, Colorado tick fever virus (CTFV) infects haemopoietic cells, particularly erythrocytes, which explains how the virus is transmitted by ticks and also accounts for the incidence of transmission via blood transfusion.

Epidemiology

The disease develops from March to September, with the highest infections occurring in June. The disease is found almost exclusively in the western United States and Canada, mostly in high mountain areas such as Colorado and Idaho. The CTFV was first isolated from human blood in 1944.

Virology

The virus particle, like other Coltiviruses, is ~80 nm in diameter and is generally nonenveloped. The double-stranded RNA viral genome is ~20,000bp long and is divided into 12 segments, which are termed Seg-1 to Seg-12. Viral replication in infected cells is associated with characteristic cytoplasmic granular matrices. Evidence suggests viral presence in mature erythrocytes is a result of replication of the virus in hematopoitic erythrocyte precursor cells and simultaneous maturation of the infected immature cells rather than of direct entry and replication of CTFV in mature erythrocytes.

Tick

The Rocky Mountain Wood Tick is usually found attached to a host, but when it is without a host it hides in cracks and crevices, as well as soil. If for some reason the tick is not able to find a host before the winter months, it will stay under groundcover until spring, when it can resume its search. The wood tick does not typically seek hosts in the hottest summer months. Adult ticks tend to climb to the tops of grasses or low shrubs, attaching themselves to a host wandering by. They secure the attachment by secreting a cement-like substance from their mouths, inserting it into the host.

Transmission and symptoms

Colorado tick fever is acquired by tick bite. There is no evidence of natural person-to-person transmission. However, rare cases of transmission from blood transfusions have been reported. The virus which causes Colorado tick fever may stay in the blood for as long as four months after onset of the illness.

First signs or symptoms can occur about three to six days after the initial tick bite, although it can have incubation periods of up to 20 days. Patients usually experience a two-staged fever and illness which can continue for three days, diminish, and then return for another episode of one to three days. The virus has the ability to live in the blood stream for up to 120 days; therefore coming in contact without proper precautions and the donation of blood are prohibited.

Initial symptoms include fever, chills, headaches, pain behind the eyes, light sensitivity, muscle pain, generalized malaise, abdominal pain, hepatosplenomegaly, nausea, and vomiting, as well as a flat or pimply rash. During the second phase of the virus, a high fever can return with an increase in symptoms. CTF can be very severe in cases involving children and have even required hospitalization. Complications with this disease have included aseptic meningitis, encephalitis, and hemorrhagic fever, but these are rare.

CTF is seasonal, mostly occurring in the Rocky Mountain region of the United States and usually in altitudes from 4,000 to 10,000 feet. Patients with CTF are mostly campers and young males, who most likely have been bitten because of their occupational activities.

Diagnosis

A combination of clinical signs, symptoms and laboratory tests can confirm the likelihood of having CTF. Some tests include complement fixation to Colorado tick virus, immunofluoresence for Colorado tick fever, and some other common laboratory findings suggestive of CTF, including leucopenia, thrombocytopenia, and mildly elevated liver enzyme levels.

Detection of viral antibodies on RBCs is possible.

Treatment

No specific treatment for CTF is yet available. The first thing to do is make sure the tick is fully removed from the skin, then acetaminophen and analgesics can be used to help relieve the fever and pain. Aspirin is not recommended for children, as it has been linked to Reye’s syndrome in some viral illnesses. Salicylates should not be used because of thrombocytopenia, and the rare occurrence of bleeding disorders. People who suspect they have been bitten by a tick or are starting to show signs of CTF should contact their physicians immediately.

Proper tick removal

Ticks should be removed promptly and carefully with tweezers and by applying gentle, steady traction. The tick's body should not be crushed when it is removed and the tweezers should be placed as close to the skin as possible to avoid leaving tick mouthparts in the skin; mouthparts left in the skin can allow secondary infections. Ticks should not be removed with bare hands. Hands should be protected by gloves and/or tissues and thoroughly washed with soap and water after the removal process.

A match or flame should not be used to remove a tick. This method, once thought safe, can cause the tick to regurgitate, expelling any disease it may be carrying into the bite wound.

Prevention

To avoid tick bites and infection, experts advise:

• Avoid tick-infested areas, especially during the warmer months.
• Wear light-colored clothing so ticks can be easily seen. Wear a long sleeved shirt, hat, long pants, and tuck pant legs into socks.
• Walk in the center of trails to avoid overhanging grass and brush.
• Clothing and body parts should be checked every few hours for ticks when spending time outdoors in tick-infested areas. Ticks are most often found on the thigh, arms, underarms and legs. Ticks can be very small (no bigger than a pinhead). Look carefully for new "freckles".
• The use of insect repellents containing DEET on skin or permethrin on clothing can be effective. Follow the directions on the container and wash off repellents when going indoors.
• Remove attached ticks immediately.

Contracting the CTF virus is thought to provide long-lasting immunity against reinfection. However, it is always wise to be on the safe side and try to prevent tick bites.

References

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 節足動物媒介性脳炎 arthropod borne encephalitides
• 2. 回帰熱の臨床的特徴およびマネージメント clinical features diagnosis and management of relapsing fever
• 3. 好中球減少症における感染の原因 infectious causes of neutropenia
• 4. 小児および思春期における急性ウイルス性脳炎：臨床症状および診断 acute viral encephalitis in children and adolescents clinical manifestations and diagnosis
• 5. ヒトエーリキア症およびアナプラズマ症 human ehrlichiosis and anaplasmosis

English Journal

• Noncoding subgenomic flavivirus RNA: multiple functions in West Nile virus pathogenesis and modulation of host responses.

• Roby JA1, Pijlman GP2, Wilusz J3, Khromykh AA4.
• Viruses.Viruses.2014 Jan 27;6(2):404-27. doi: 10.3390/v6020404.
• Flaviviruses are a large group of positive strand RNA viruses transmitted by arthropods that include many human pathogens such as West Nile virus (WNV), Japanese encephalitis virus (JEV), yellow fever virus, dengue virus, and tick-borne encephalitis virus. All members in this genus tested so far are
• PMID 24473339

• Aedes (Stegomyia) aegypti in the continental United States: a vector at the cool margin of its geographic range.

• Eisen L1, Moore CG.
• Journal of medical entomology.J Med Entomol.2013 May;50(3):467-78.
• After more than a half century without recognized local dengue outbreaks in the continental United States, there were recent outbreaks of autochthonous dengue in the southern parts of Texas (2004-2005) and Florida (2009-2011). This dengue reemergence has provoked interest in the extent of the future
• PMID 23802440

Japanese Journal

• Electron Microscopic Studies on the Replication of Ibaraki Virus

• Japanese Journal of Microbiology 16(3), 215-222, 1972
• NAID 130004237208

Related Links

• Colorado tick fever virus | definition of Colorado tick fever virus ...

Col·o·ra·do tick fe·ver vi·rus a virus of the genus Coltivirus, from the family Reoviridae, found in the Rocky Mountain region of the U.S. and transmitted by the tick, Dermacentor andersoni; it causes Colorado tick fever. Colorado tick ...

• Colorado Tick Fever

Colorado tick fever (CTF) is a disease caused by an RNA virus, Colorado tick fever virus (CTFV). Symptoms, which are oftern non-specific, begin 3 to 5 days after the bite with an abrupt onset of fever and any of these: headaches, chills, malaise, photophobia, myalgias, nausea, vomiting, diarrhea and ...

Related Pictures

---

★リンクテーブル★

リンク元	「コロラドダニ熱ウイルス」
関連記事	「tick」「virus」

「コロラドダニ熱ウイルス」

　　[★]

英

Colorado tick fever virus

関

コロラドダニ熱

「tick」

　　[★] ダニ 　 　 　 　 　 　 　 　

「virus」

　　[★] ウイルス