Heartland virus

Heartland virus
Virus classification
Group: Group V ((-)ssRNA)
Order: Unassigned
Family: Bunyaviridae
Genus: Phlebovirus
Species: Heartland virus

The Heartland virus (HRTV) is a tick-borne phlebovirus of the Bhanja virus serocomplex discovered in northwestern Missouri by Dr. Scott Folk of Heartland Regional Medical Center in St. Joseph, Missouri.[1] The virus was first proven to infect humans in June 2009[2] when two farmers, living 60 miles (97 km) apart, presented with fever, fatigue, diarrhea, thrombocytopenia, and leukopenia. The Lone Star Tick transmits the virus to people when feeding on blood.

Classification

The Heartland virus is part of the Bunyaviridae family of viruses which contain 3 segments of -ssRNA. The genus of the virus is Phlebovirus and the species is the Heartland virus.[3] The SFTS virus from China, discovered in 2011, is a related species causing a similar disease.

Transmission

The Heartland virus(HRTV) has been isolated from the Lone Star Tick (Amblyomma americanum) by researchers from the CDC and Missouri Western State University.[4][5] Work continues as of 2013 to identify the reservoir host.[4] The reservoir host is unknown, as HRTV has not been isolated from any wild or domestic animals. Many white-tailed deer and raccoon from northwestern Missouri had antibodies to HRTV, suggesting that these animals may be hosts. In a retrospective study using convenience samples of different animal sera only deer, raccoon, coyotes, and moose had antibodies against HRTV. They lived in thirteen states: Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Maine, Missouri, New Hampshire, North Carolina, Tennessee, Texas, and Vermont. The infections could have occurred as early as 2003, based on the estimated ages of affected deer.[6]

Symptoms and signs

The following symptoms and signs have been reported: fever in excess of 100.4 °F (38 °C), lethargy (weakness), headaches, muscle pain (myalgia ), loss of appetite, nausea, diarrhea, weight loss, joint pain(arthralgia), low white blood cell count (leukopenia) and easy bruising from low platelet count(thrombocytopenia). Elevated liver transaminases may also be present.[7]

Risk factors

All known 10 human cases have been reported from three U.S. states: Missouri, Tennessee, and Oklahoma. All currently known cases occurred between May and September and people spent a fair amount of time outdoors in regions where ticks were endemic; In all known cases people reported being bitten by ticks in the previous 14 days.

Diagnosis

Diagnosis is currently through the elimination of other causes of infectious diseases with related symptoms like ehrlichiosis and anaplasmosis or if the patient fails to respond to treatment with the antibiotic doxycycline. RT-PCR may then be used to detect viral ssRNA in the blood. Antibody titers against the virus may also be used to indicate infection with the Heartland virus.[8]

Treatment

Treatment is non-specific. Antibiotics are not useful against viruses. Intravenous fluid administration and medications for the relief of pain are currently the best options.[9]

Prevention

When planning to spend time outdoors in areas where the virus is known or suspected to be harbored by ticks, it is recommended that one cover the body completely with long sleeves and pants, and to avoid bushy and wooded areas. Although ticks are not consistently repelled by DEET-containing repellents, insect repellents should still be applied to one's body and gear. It is recommended that one perform thorough tick checks after being outside, and to remove any tick immediately. If a tick is found, one should remove the tick by the head, preferably with a pair of fine-tipped tweezers. Squeezing the abdomen of a tick while it is attached can force viruses and bacteria into the wound, increasing the chance of infection. Crushing an unattached tick will also release bacteria and viruses from its abdomen, which may then be able to enter a wound or burrow through the skin.

Cases

Heartland virus cases
Year Location Deaths Cases
2009 Northwestern Missouri 0 2
2012–2013[8] Missouri, Tennessee[10] 1 6
2014 Missouri,[11] Oklahoma[12] 1 2

References

  1. ↑ Knox, Richard. "Mysterious New 'Heartland Virus' Discovered in Missouri". Shots: NPR's Health Blog. NPR. Retrieved 2012-08-30.
  2. ↑ Grady, Denise (2012-09-03). "New Virus Tied to Ticks Poses Puzzle for Doctors". New York Times. Retrieved 2012-09-07.
  3. ↑ Savage HM, Godsey MS, Lambert A, et al. First Detection of Heartland Virus (Bunyaviridae: Phlebovirus) from Field Collected Arthropods. The American Journal of Tropical Medicine and Hygiene. 2013;89(3):445–452. doi:10.4269/ajtmh.13-0209
  4. 1 2 Schnirring, Lisa (2013-07-22). "Researchers trace novel Heartland virus to Missouri ticks". CIDRAP. Retrieved 2013-07-23.
  5. ↑ Harry M. Savage, Marvin S. Godsey Jr., Amy Lambert, Nickolas A. Panella, Kristen L. Burkhalter, Jessica R. Harmon, R. Ryan Lash, David C. Ashley and William L. Nicholson (22 July 2013). "First Detection of Heartland Virus (Bunyaviridae: Phlebovirus) from Field Collected Arthropods". Am J Trop Med Hyg 89 (3): 445–452. doi:10.4269/ajtmh.13-0209. PMC 3771279. PMID 23878186.
  6. ↑ Riemersma KK, Komar N. Heartland Virus Neutralizing Antibodies in Vertebrate Wildlife, United States, 2009–2014. Emerg Infect Dis. 2015 Oct;21(10):1830–3. doi:10.3201/eid2110.150380
  7. ↑ Laura K. McMullan, Scott M. Folk, Aubree J. Kelly, Adam MacNeil, Cynthia S. Goldsmith, Maureen G. Metcalfe, Brigid C. Batten, César G. Albariño, Sherif R. Zaki, Pierre E. Rollin, William L. Nicholson, and Stuart T. Nichol (2012-08-30). "A New Phlebovirus Associated with Severe Febrile Illness in Missouri". New England Journal of Medicine 367 (9): 834–841. doi:10.1056/NEJMoa1203378. PMID 22931317. Retrieved 2012-08-30.
  8. 1 2 Pastula DM, Turabelidze G, Yates KF, Jones TF, Lambert AJ, Panella AJ, Kosoy OI, Velez JO, Fisher M, Staples E; Centers for Disease Control and Prevention (CDC).Notes from the field: Heartland virus disease - United States, 2012–2013. MMWR Morb Mortal Wkly Rep. 2014 Mar 28;63(12):270–1.PMID:24670929
  9. ↑ CDC Media relations CDC Reports More Cases of Heartland Virus Disease CDC press release, 27 March 2014
  10. ↑ Muehlenbachs A, Fata CR, Lambert AJ, Paddock CD, Velez JO, Blau DM, Staples JE, Karlekar MB, Bhatnagar J, Nasci RS, Zaki SR.Heartland Virus–Associated Death in Tennessee Clin Infect Dis. 2014 Sep 15;59(6):845–50. doi:10.1093/cid/ciu434
  11. ↑ TEDDYE SNELL Taking up arms against Heartland disease, Tahlequah Daily Press, June 18, 2014
  12. ↑ Associated Press Rare Heartland virus kills man in Oklahoma CBS News, May 28, 2014
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