''Heartland bandavirus'', sometimes called Heartland virus (HRTV), is a tick-borne ''

phlebovirus ''Phlebovirus'' is a genus of viruses in the family '' Phenuiviridae'' in the order '' Hareavirales''. The genus contains 67 species. It derives its name from Phlebotominae, the vectors of member species Sandfly fever Naples virus, which is sa ...

'' of the '' Bhanja virus'' serocomplex discovered in 2009. The lone star tick transmits the virus to people when feeding on blood. As of 2017, only five states in the

Central United States The Central United States is sometimes conceived as between the Eastern United States, Eastern and Western United States, Western as part of a three-region model, roughly coincident with the United States Census Bureau, U.S. Census Bureau's d ...

have reported 20 human infections, namely Arkansas, Indiana, Missouri, Oklahoma, and Tennessee; symptoms resemble those of two other tick-borne infections ehrlichiosis and

anaplasmosis Anaplasmosis is a tick-borne disease affecting ruminants, dogs, and horses, and is caused by ''Anaplasma'' bacteria. Anaplasmosis is an infectious but not contagious disease. Anaplasmosis can be transmitted through mechanical and biological vector ...

. The reservoir host is unknown, but deer, raccoon, coyotes, and moose in 13 different states have

antibody titer Titer (American English) or titre (British English) is a way of expressing concentration. Titer testing employs serial dilution to obtain approximate quantitative information from an analytical procedure that inherently only evaluates as positi ...

s against the virus. By 2023 over 50 human infections were reported in at least eleven states.Ed Car
(24 Feb 2023) U.S. Man's Death Suggests Deadly Tick Virus Is Spreading to New Regions
Sichen Liu, et. al
(May 2023) Fatal Case of Heartland Virus Disease Acquired in the Mid-Atlantic Region, United States

History

The ''Heartland virus'' (HRTV) was discovered in 2009 in northwestern

Missouri Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...

by Dr. Scott Folk of Heartland Regional Medical Center in

St. Joseph, Missouri St. Joseph is a city in and county seat of Buchanan County, Missouri, Buchanan County, Missouri, United States. A small portion of the city extends north into Andrew County, Missouri, Andrew County. Located on the Missouri River, it is the princ ...

. The virus was first proven to infect humans in June 2009 when two farmers, living apart, presented with fever, fatigue, diarrhea,

thrombocytopenia In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coag ...

, and

leukopenia Leukopenia () is a decrease in the number of white blood cells (leukocytes). It places individuals at increased risk of infection as white blood cells are the body's primary defense against infections. Signs and symptoms Symptoms may include: * s ...

. The Lone Star Tick transmits the virus to people when feeding on blood.

Classification

The ''Heartland virus'' is part of the ''

Bunyavirales ''Bunyaviricetes'' is a class of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. The name ''Bunyaviricetes'' derives from Bunyamwera, where the virus Bun ...

'' order of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...

which contain 3 segments of −ssRNA. The genus of the virus is '' Bandavirus'' and the species is the ''Heartland virus''.

Transmission

In 2013, researchers from the CDC and

Missouri Western State University Missouri Western State University (MWSU or MoWest) is a public university in St. Joseph, Missouri. As of 2023, it enrolled 3,815 students. History Missouri Western State University was founded in 1915 as St. Joseph Junior College and held cours ...

first isolated the ''Heartland virus'' (HRTV) from the Lone Star Tick (''

Amblyomma americanum ''Amblyomma americanum'', also known as the lone star tick, northeastern water tick, turkey tick, and cricker tick, is a type of tick indigenous to much of the eastern United States and Mexico that bites painlessly and commonly goes unnoticed, r ...

''). As of 2013 work continued to identify the reservoir host, as HRTV has not been isolated from any wild or domestic animals though many white-tailed deer and raccoon from northwestern Missouri had antibodies to HRTV, suggesting that they may be hosts. In a 2015 retrospective study using convenience samples of different wild animal sera deer, raccoon, coyotes, and moose had antibodies against HRTV. They lived in thirteen states: Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Missouri, North Carolina, Tennessee, Texas, but also New Hampshire, Maine and Vermont. The infections could have occurred as early as 2003, based on the estimated ages of affected deer. Since the Lone Star tick does not occur in northern New England it is assumed that a second type of tick can carry HRTV.

Infection

Signs and symptoms

Signs and symptoms include fever in excess of 100.4 °F (38 °C), lethargy (weakness), headaches, muscle pain (

myalgia Myalgia or muscle pain is a painful sensation evolving from muscle tissue. It is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, espec ...

), loss of appetite, nausea, diarrhea, weight loss, joint pain (

arthralgia Arthralgia () literally means ' joint pain'. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication Medication (also called medicament, medicine, pharmaceuti ...

), low white blood cell count (

) and easy bruising due to a low platelet count (

). Elevated liver transaminases may also be present.

Risk factors

All known human cases have been reported from six U.S. states: Arkansas, Indiana, Missouri, Oklahoma, North Carolina, and Tennessee. Most people infected were spending time outdoors in regions where ticks are

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

. Most infections are diagnosed between May and September. People usually report having been bitten by a tick within two weeks prior to seeking health care. https://wwwnc.cdc.gov/eid/article/30/12/24-0646_article?ACSTrackingID=USCDC_351-DM141456&ACSTrackingLabel=Vector-borne%20Infections%20Articles%20in%20the%20December%202024%20Emerging%20Infectious%20Diseases%20Journal&deliveryName=USCDC_351-DM141456

Diagnosis

Diagnosis is through the elimination of other causes of infectious diseases with related symptoms like ehrlichiosis and

or if the patient fails to respond to treatment with the antibiotic

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 ...

RT-PCR Reverse transcription polymerase chain reaction (RT-PCR) is a laboratory technique combining reverse transcription of RNA into DNA (in this context called complementary DNA or cDNA) and amplification of specific DNA targets using polymerase chain ...

may then be used to detect viral ssRNA in the blood.

Antibody titer Titer (American English) or titre (British English) is a way of expressing concentration. Titer testing employs serial dilution to obtain approximate quantitative information from an analytical procedure that inherently only evaluates as positi ...

s against the virus may also be used to indicate infection with the ''Heartland virus''.

Treatment

Treatment is non-specific. Antibiotics are not useful against viruses.

Intravenous fluid Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutr ...

administration and medications for the relief of pain are currently the best options.CDC Media relation
CDC Reports More Cases of Heartland Virus Disease
CDC press release, 27 March 2014

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.

Human cases

More than 20 human infections have been reported in the United States, but given the obscurity of the disease, the true number of cases is suspected to be substantially larger.

References

{{Taxonbar, from=Q70627232, from2=Q5692897 Phleboviruses Tick-borne diseases Unaccepted virus taxa