Virus hunters: new cases of the heartland virus

 Between 1900 and 2009, only 14 new tick-borne viruses or bacteria that could cause disease were identified [4]. Two additional novel viruses have been identified since then, the Heartland virus (HRTV), in 2009 [3], and the Bourbon virus, in 2014 [5]. Erin J. Staples, an epidemiologist with the Centers for Disease Control and Prevention, has been charged with tracking and containing HRTV, a phlebovirus, with the most commonly associated symptoms of fever, significant fatigue, weakness, and headache [1]. She has documented and is tracking 50 cases thus far [4], as cases continue to be reported [1]. 

Studies of the virus reveal that it may well have been present for more than the ten years since it was initially discovered and, after the first two cases of HRTV was confirmed, additional cases were identified [4].  Further, in northwestern Missouri, where the cases were originally confirmed in 2009, it has been found that 0.9% of blood donors were found to be seropositive for the HRTV antibody [2]. Currently there are no effective antivirals available [4]. Dr. Staples suggests that given that for patients with encephalitis, inflammation of the brain, in as many as 70% of the cases no primary diagnosis is obtained, many more viruses and bacteria are yet to be identified, potentially some that have been there, others that are merging, and some that are new [4]. 

- Claire Hillier

References:

[1] Decker MD, Morton CT, Moncayo AC. One Confirmed and Two Suspected Cases of Heartland Virus Disease. Clin Infect Dis. 2020 May 27:ciaa647. PMID: 32459327.

[2] Lindsey NP, Menitove JE, Biggerstaff BJ, et al. Seroprevalence of heartland virus antibodies in blood donors, northwestern Missouri, USA. Emerg Infect Dis 2019; 25:358-360.

[3] McMullan LK, Folk SM, Kelly AJ, et al. A new phlebovirus associated with severe febrile illness in Missouri. N Engl J Med 2012; 367:834-41.  

  

[4] Pickett M. An interview with a virus-hunter. MIT Technology Review. 21 Oct 2020. 123(6).

[5] Lambert AJ, Velez JO, Brault AC, Calvert AE, Bell-Sakyi L, Bosco-Lauth AM, Staples JE, Kosoy OI. Molecular, serological and in vitro culture-based characterization of Bourbon virus, a newly described human pathogen of the genus Thogotovirus. J Clin Virol. 2015 Dec;73:127-132. PMID: 26609638.