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 novel, tick-borne Phlebovirus discovered in northwestern Missouri by Dr. Scott Folk of Heartland Regional Medical Center in St. Joseph, Missouri.[1]

The virus first appeared in humans in June 2009[2] when two farmers, living 60 miles (97 km) apart, presented with the following symptoms: fever, fatigue, diarrhea, thrombocytopenia, and leukopenia.[3]

It is a member of the Bhanja virus serocomplex; the recently discovered SFTS virus from China is a related species causing a similar disease.

The virus has been traced by researchers from the CDC and Missouri Western State University back to the Lone Star Tick, which transmits the virus to people when feeding on blood.[4][5] Work continues as of 2013 to identify the reservoir host.[4]

Characteristics

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.[6]

Transmission

The Heartland virus has been isolated from the Lone Star Tick (Amblyomma americanum). The phleboviruses, in general, can be transmitted by mosquitoes, ticks and sand flies. Patients in all known cases of the Heartland virus in the United States reported being bitten by ticks in the previous 14 days. The reservoir host has yet to be identified.

Signs and symptoms

Fever in excess of 100.4°F (38°C), lethargy (weakness), headaches, myalgia (muscle pain), loss of appetite, nausea, diarrhea, weight loss, arthralgia (joint pain), leukopenia (low white blood cells) and thrombocytopenia (low platelets). Elevated liver transaminases may also be present.

Risk factors

All known cases reported in the United States have been reported in three states: Missouri, Tennessee, and Oklahoma. Patients in all currently known cases spent a fair amount of time outdoors in regions where ticks were endemic, all patients were aged over 50. All cases occurred from May - September.

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.[7]

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.[8]

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[9] 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. ↑ 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.
  4. ↑ 4.0 4.1 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.
  6. ↑ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3771279/
  7. ↑ http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6312a4.htm
  8. ↑ http://www.cdc.gov/media/releases/2014/p0327-heartland.html
  9. ↑ http://www.medscape.com/viewarticle/822710
  10. ↑ http://cid.oxfordjournals.org/content/early/2014/06/09/cid.ciu434.abstract
  11. ↑ http://www.tahlequahdailypress.com/local/x701910561/Taking-up-arms-against-Heartland-disease
  12. ↑ http://www.cbsnews.com/news/rare-heartland-virus-kills-man-in-oklahoma/