Heartland Virus- SFTSV
Also Known As SFTS or SFTSV
(Severe Fever with Thrombocytopenia Syndrome Virus)
Heartland virus (aka SFTS), thought to be caused by a bunyavirus, was named for the Heartland Regional Medical Center in St. Joseph, MO, where it was first discovered. The two Missouri men discovered to have contracted the virus were hospitalized for nearly two weeks and it took a couple of months for them to recover. One man says he still has problems with short-term memory, fatigue and headaches three years after the initial infection.
The virus is reported to cause a fever, lymph node swelling, multi-organ dysfunction, altered consciousness, diarrhea, leucocytopenia, and a condition known as thrombocytopenia (bleeding on skin surface or internally). Patients can present with red/purple spots on their skin (petechiae) or bruises (purpura or ecchymosis). There is reported to be a high fatality rate (12%- CDC).
The virus has been discovered in lone star and other ticks in the United States and China. It can be transmitted from human to human through a patients infected blood and mucous.
General information about thrombocytopenia can be found below. Excerpts from scientific articles on the Heartland virus are as follows:
"A small tick Haemaphysalis longicornis called 'Sochamjindeugi' in Korean has bitten a week before, and an onset is characterized by fever, lymph node swelling, diarrhea, thrombocytopenia, leucocytopenia, multiorgan dysfunction, altered consciousness, and occasionally to death in extreme cases (1, 2). This emerging febrile disease, severe fever with thrombocytopenia syndrome (SFTS), was reported in 2007 by the New England Journal of Medicine (3) and Clinical Infectious Diseases (4-6). The etiology of SFTS turned out to be the SFTS virus. Yet most physicians are not familiar with this disease, and initially it is difficult to differentiate from other febrile illnesses (7-9)."
CDC- "We conclude that subclinical SFTSV infections or a relatively mild form of SFTS illness may occur in humans; however, more research is needed."
CDC- "These findings demonstrate that natural infections of SFTSV occur in several domesticated animal hosts in disease-endemic areas and that the virus has a wide host range."
CDC- "The common signs and symptoms of SFTS include high fever, gastrointestinal symptoms, thrombocytopenia, leukocytopenia, and multiorgan dysfunction with an average case-fatality rate of 10%–16%, according to the information system for disease control and prevention, Chinese Center for Disease Control and Prevention (China CDC). In severe SFTS cases, neural symptoms, hemorrhages, disseminated intravascular coagulation, and multiorgan failure can occur and may result in death (2)."
CDC- "The role of domesticated animals in the circulation and transmission of SFTSV remains unclear."
CDC- "We sampled 472 sheep, 842 cattle, 359 dogs, 839 pigs, and 527 chickens in Laizhou and Penglai counties to assess the prevalence of SFTSV RNA and antibodies. Our results showed that 3.8% (18/472) of sheep, 4.2% (35/842) of cattle, 5.3% (19/359) of dogs, 2.6% (22/839) of pigs, and 1.7% (9/527) of chickens were viral RNA-positive."
CDC- "In conclusion, we have provided evidence to show that SFTSV is circulating among several species of domesticated animals and between animals and humans in disease-endemic areas of China."
What is thrombocytopenia?
Thrombocytopenia is a condition in which the body does not have a normal number of platelets in the blood.
Blood is made up of three major cell types:
red blood cells, which carry oxygen throughout the body;
white blood cells, which help fight infection; and
platelets, which stick together at the site of a cut or wound to form a clot to stop the bleeding.
People who have thrombocytopenia don’t have enough platelets to form a blood clot, and so they may bleed excessively when they are cut.
How does thrombocytopenia occur?
Blood cells (including platelets) are made in the bone marrow, the spongy tissue inside of bones. Certain factors may interfere with the body’s ability to make platelets. Under other circumstances production is normal, but platelets are removed prematurely from the blood.
Causes of thrombocytopenia can include:
a bone marrow disease or treatment for disease. For instance, diseases such as leukemia (cancer of the bone marrow and bloodstream) and lymphoma (cancer of the lymph system) can cause dysfunction of the bone marrow.
aplastic anemia, a disease that prevents the bone marrow from making blood cells of all types
radiation and chemotherapy treatment for cancer can damage the blood stem cells that eventually become blood cells.
exposure to certain viruses, including Epstein-Barr, cytomegalovirus, hepatitis, and HIV
an autoimmune disease (the body’s immune system attacks the body), such as immune thrombocytopenic purpura or ITP)
an enlarged spleen (an organ that acts as a filter for the blood and helps the body fight infection). The enlarged spleen tends to trap platelets and prevent them from circulating in the bloodstream.
heredity (the condition is passed down from a parent)
exposure to toxic chemicals
taking certain medications, such as certain antibiotics, cardiovascular drugs, and seizure medications
drinking too much alcohol
What are the symptoms of thrombocytopenia?
The main symptom of thrombocytopenia is bleeding, either on the surface of the skin or inside the body. (In mild cases of thrombocytopenia, there may not be any symptoms.)
Symptoms of thrombocytopenia include the following:
bleeding on various parts of the skin. You may have small red or purple spots called petechiae on your lower legs, or bruising that is purple, red, or brown (known as purpura).
bleeding that doesn’t stop on its own, such as a nosebleed or bleeding from your gums when you brush your teeth
heavier bleeding during menstrual periods
internal bleeding, such as blood in the urine or stool or bleeding from the rectum
How is thrombocytopenia treated?
If your doctor feels that the thrombocytopenia is not a serious threat to your health, he or she may choose not to treat it.
Your doctor may decide to treat the thrombocytopenia by treating the disease or condition that is causing it. For instance, if you are taking a medication that is causing thrombocytopenia, your doctor may switch you to another medication. If the thrombocytopenia is caused by problems with your immune system, your doctor may prescribe steroids, immunoglobulin, or other medications.
A platelet transfusion may be needed if your platelet count is extremely low. In some cases, the patient may have his or her spleen removed in order to keep it from destroying platelets. Because the spleen helps the body fight infection, removing it may place the person at higher risk for certain types of infections. Several vaccinations are given before splenectomy to help prevent infection.
J Virol. 2013 Mar;87(6):3187-95. doi: 10.1128/JVI.02719-12. Epub 2013 Jan 2.
Characterization of the Uukuniemi virus group (Phlebovirus: Bunyaviridae): evidence for seven distinct species.
Palacios G, Savji N, Travassos da Rosa A, Guzman H, Yu X, Desai A, Rosen GE, Hutchison S, Lipkin WI, Tesh R.
United States Army Medical Research Institute for Infectious Diseases, Frederick, MD, USA. email@example.com
Evolutionary insights into the phleboviruses are limited because of an imprecise classification scheme based on partial nucleotide sequences and scattered antigenic relationships. In this report, the serologic and phylogenetic relationships of the Uukuniemi group viruses and their relationships with other recently characterized tick-borne phleboviruses are described using full-length genome sequences. We propose that the viruses currently included in the Uukuniemi virus group be assigned to five different species as follows:
Uukuniemi virus, EgAn 1825-61virus, Fin V707 virus, Chizé virus, and Zaliv Terpenia virus would be classified into the Uukuniemi species; Murrevirus, RML-105-105355 virus, and Sunday Canyon virus would be classified into a Murre virus species; and Grand Arbaud virus, Precarious Point virus, and Manawa virus would each be given individual species status.
Although limited sequence similarity was detected between current members of the Uukuniemi group and Severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus, a clear serological reaction was observed between some of them, indicating that SFTSV and Heartland virus should be considered part of the Uukuniemi virus group.
Moreover, based on the genomic diversity of the phleboviruses and given the low correlation observed between complement fixation titers and genetic distance, we propose a system for classification of the Bunyaviridae based on genetic as well as serological data. Finally, the recent descriptions of SFTSV and Heartland virus also indicate that the public health importance of the Uukuniemi group viruses must be reevaluated.
J Virol. 2013 Apr;87(7):3719-28. doi: 10.1128/JVI.02845-12. Epub 2013 Jan 16.
Characterization of the Bhanja serogroup viruses (Bunyaviridae): a novel species of the genus Phlebovirus and its relationship with other emerging tick-borne phleboviruses.
Matsuno K, Weisend C, Travassos da Rosa AP, Anzick SL, Dahlstrom E, Porcella SF, Dorward DW, Yu XJ, Tesh RB,Ebihara H.
Laboratory of Virology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, USA.
Bhanja virus (BHAV) and its antigenically close relatives Forecariah virus (FORV), Kismayo virus (KISV), and Palma virus (PALV) are thought to be members of the family Bunyaviridae, but they have not been assigned to a genus or species. Despite their broad geographical distribution and reports that BHAV causes sporadic cases of febrile illness and encephalitis in humans, the public health importance of the Bhanja serogroup viruses remains unclear, due in part to the lack of sequence and biochemical information for the virus proteins.
In order to better define the molecular characteristics of this group, we determined the full-length sequences of the L, M, and S genome segments of multiple isolates of BHAV as well as FORV and PALV. The genome structures of these Bhanja viruses are similar to those of viruses belonging to the genus Phlebovirus. Functional domains and amino acid motifs in the viral proteins that are conserved among other known phleboviruses were also identified in proteins of the BHAV group.
Phylogenetic and serological analyses revealed that the BHAVs are most closely related to the novel emerging tick-borne phleboviruses severe fever with thrombocytopenia syndrome virus andHeartland virus, which have recently been implicated as causing severe acute febrile illnesses associated with thrombocytopenia in humans in China and the United States.
Our results indicate that the Bhanja serogroupviruses constitute a single novel species in the genus Phlebovirus. The results of this study should facilitate epidemiological surveillance for other, similar tick-borne phleboviruses that may represent unrecognized causes of febrile illness in humans.
PMID: 23325688 [PubMed - indexed for MEDLINE] PMCID: PMC3624231 [Available on 2013/10/1]
PLoS One. 2013 Apr 29;8(4):e62083. doi: 10.1371/journal.pone.0062083. Print 2013.
The genome sequence of Lone Star virus, a highly divergent bunyavirus found in the Amblyomma americanum tick.
Swei A, Russell BJ, Naccache SN, Kabre B, Veeraraghavan N, Pilgard MA, Johnson BJ, Chiu CY.
Department of Laboratory Medicine, University of California San Francisco, San Francisco, California, United States of America.
Viruses in the family Bunyaviridae infect a wide range of plant, insect, and animal hosts. Tick-borne bunyaviruses in the Phlebovirus genus, including Severe Fever with Thrombocytopenia Syndrome virus (SFTSV) in China,Heartland virus (HRTV) in the United States, and Bhanja virus in Eurasia and Africa have been associated with acute febrile illness in humans.
Here we sought to characterize the growth characteristics and genome of Lone Star virus (LSV), an unclassified bunyavirus originally isolated from the lone star tick Amblyomma americanum. LSV was able to infect both human (HeLa) and monkey (Vero) cells. Cytopathic effects were seen within 72 h in both cell lines; vacuolization was observed in infected Vero, but not HeLa, cells.
Viral culture supernatants were examined by unbiased deep sequencing and analysis using an in-house developed rapid computational pipeline for viral discovery, which definitively identified LSV as a phlebovirus. De novo assembly of the full genome revealed that LSV is highly divergent, sharing <61% overall amino acid identity with any other bunyavirus.
Despite this sequence diversity, LSV was found by phylogenetic analysis to be part of a well-supported clade that includes members of the Bhanja group viruses, which are most closely related to SFSTV/HRTV.
The genome sequencing of LSV is a critical first step in developing diagnostic tools to determine the risk of arbovirus transmission by A. americanum, a tick of growing importance given its expanding geographic range and competence as a disease vector. This study also underscores the power of deep sequencing analysis in rapidly identifying and sequencing the genomes of viruses of potential clinical and public health significance.
PMID: 23637969 [PubMed - in process] PMCID: PMC3639253 Free PMC Article
Emerg Infect Dis. 2013 Jun;19(6):864-9. doi: 10.3201/eid1906.130173.
Cell culture and electron microscopy for identifying viruses in diseases of unknown cause.
Goldsmith CS, Ksiazek TG, Rollin PE, Comer JA, Nicholson WL, Peret TC, Erdman DD, Bellini WJ, Harcourt BH, Rota PA, Bhatnagar J, Bowen MD, Erickson BR, McMullan LK, Nichol ST, Shieh WJ, Paddock CD, Zaki SR.
During outbreaks of infectious diseases or in cases of severely ill patients, it is imperative to identify the causative agent. This report describes several events in which virus isolation and identification by electron microscopy were critical to initial recognition of the etiologic agent, which was further analyzed by additional laboratory diagnostic assays.
Examples include severe acute respiratory syndrome coronavirus, and Nipah, lymphocytic choriomeningitis, West Nile, Cache Valley, and Heartland viruses. These cases illustrate the importance of the techniques of cell culture and electron microscopy in pathogen identification and recognition of emerging diseases.
Cache Valley virus, Heartland virus, Nipah virus, SARS coronavirus, Viruses, West Nile virus, cell culture, electron microscopy, emerging diseases, lymphocytic choriomeningitis virus
PMID: 23731788 [PubMed - in process] Free full text http://wwwnc.cdc.gov/eid/article/19/6/13-0173_article.htm
OTHER ARTICLES & NEWS
Tick-Borne Virus May Have Claimed Third Victim in Korea
A 69-year-old man who died this week in the southern port city of Busan may have been the third victim to fall prey to a tick-borne virus in the country in recent weeks, although the cause of death is still being investigated.
Pusan National University Yangsan Hospital, the medical center to which the man was admitted, said he suffered from a high fever and indigestion before he died of septicemia.
The hospital has reported the case to the Korea Centers for Disease Control and Prevention, saying the patient might have been infected with the tick-borne virus known as SFTS, or severe fever with thrombocytopenia syndrome.
Two people have died from the virus in Korea over the past month or so.
Arirang News / May 27, 2013 10:53 KST