Browsing by Author "Eisen, Rebecca J."
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- Heartland Virus Epidemiology, Vector Association, and Disease PotentialBrault, Aaron C.; Savage, Harry M.; Duggal, Nisha K.; Eisen, Rebecca J.; Staples, J. Erin (MDPI, 2018-09-14)First identified in two Missouri farmers exhibiting low white-blood-cell and platelet counts in 2009, Heartland virus (HRTV) is genetically closely related to severe fever with thrombocytopenia syndrome virus (SFTSV), a tick-borne phlebovirus producing similar symptoms in China, Korea, and Japan. Field isolations of HRTV from several life stages of unfed, host-seeking Amblyomma americanum, the lone star tick, implicated it as a putative vector capable of transstadial transmission. Laboratory vector competence assessments confirmed transstadial transmission of HRTV, demonstrated vertical infection, and showed co-feeding infection between A. americanum. A vertical infection rate of 33% from adult females to larvae in the laboratory was observed, while only one of 386 pools of molted nymphs (1930) reared from co-feeding larvae was positive for HRTV (maximum-likelihood estimate of infection rate = 0.52/1000). Over 35 human HRTV cases, all within the distribution range of A. americanum, have been documented. Serological testing of wildlife in areas near the index human cases, as well as in widely separated regions of the eastern United States where A. americanum occur, indicated many potential hosts such as raccoons and white-tailed deer. Attempts, however, to experimentally infect mice, rabbits, hamsters, chickens, raccoons, goats, and deer failed to produce detectable viremia. Immune-compromised mice and hamsters are the only susceptible models. Vertical infection augmented by co-feeding transmission could play a role in maintaining the virus in nature. A more complete assessment of the natural transmission cycle of HRTV coupled with serosurveys and enhanced HRTV disease surveillance are needed to better understand transmission dynamics and human health risks.
- Multistate Infestation with the Exotic Disease-Vector Tick Haemaphysalis longicornis - United States, August 2017-September 2018Ben Beard, C.; Occi, James; Bonilla, Denise L.; Egizi, Andrea M.; Fonseca, Dina M.; Mertins, James W.; Backenson, Bryon P.; Bajwa, Waheed I.; Barbarin, Alexis M.; Bertone, Matthew A.; Brown, Justin; Connally, Neeta P.; Connell, Nancy D.; Eisen, Rebecca J.; Falco, Richard C.; James, Angela M.; Krell, Rayda K.; Lahmers, Kevin K.; Lewis, Nicole; Little, Susan E.; Neault, Michael; de Leon, Adalberto A. Perez; Randall, Adam R.; Ruder, Mark G.; Saleh, Meriam N.; Schappach, Brittany L.; Schroeder, Betsy A.; Seraphin, Leslie L.; Wehtje, Morgan; Wormser, Gary P.; Yabsley, Michael J.; Halperin, William (Centers for Disease Control and Prevention, 2018-11-30)Haemaphysalis longicornis is a tick indigenous to eastern Asia and an important vector of human and animal disease agents, resulting in such outcomes as human hemorrhagic fever and reduction of production in dairy cattle by 25%. H. longicornis was discovered on a sheep in New Jersey in August 2017 (1). This was the first detection in the United States outside of quarantine. In the spring of 2018, the tick was again detected at the index site, and later, in other counties in New Jersey, in seven other states in the eastern United States, and in Arkansas. The hosts included six species of domestic animals, six species of wildlife, and humans. To forestall adverse consequences in humans, pets, livestock, and wildlife, several critical actions are indicated, including expanded surveillance to determine the evolving distribution of H. longicornis, detection of pathogens that H. longicornis currently harbors, determination of the capacity of H. longicornis to serve as a vector for a range of potential pathogens, and evaluation of effective agents and methods for the control of H. longicornis.