JOURNAL OF THE LOUISIANA STATE MEDICAL SOCIETY
diseases worldwide include travel to and prolonged outdoor exposures in regionally endemic areas; male gender; age over 40-50 years; and a compromised immune system from cancer chemotherapy, organ transplant rejection therapy, or advanced human immunodeficiency virus infection .1
The tickborne viral infections are caused primarily by flaviviruses (Family Flaviviridae) and may be divided into two separate clinical presentations, each with preferred tick vectors and zoonotic reservoirs: (1) the viral encephalitides (Table 1) and (2) the viral hemorrhagic fevers (Table 2). With very few exceptions, most tickborne viral infections are transmitted by ixodid or hard ticks (Family Ixodidae) (Figure 1).
TABLE 1
ZOONOTIC RESERVOIRS
VIRUS NAME
FAMILY TAXONOMY
GEOGRAPHIC DISTRIBUTION Europe, except Iberian Peninsula
TICK VECTORS
Central European tickborne encephalitis (TBEV-Eu)
Flaviviridae
Ixodid ticks, especially Dermacentor marginatus, Ixodes persulcatus, and I. ricinus
Mammals - especially rodents, including hedgehogs, wood mice, and voles; deer and other ungulates, birds, domestic livestock, especially goats
Deer tick virus
Flaviviridae
New England state - U.S. (Connecticut, Massachucetts, New York) Eastern Russia, China to Far Eastern Japan
Deer
Ixodes scapularis
Far Eastern TBE (TBEV-FE)
Flaviviridae
Mammals - rodents, including hedgehogs, wood mice, voles; also birds, deer, other ungulates, domestic livestock, especially goats
I. persulcatus
Langat
Flaviviridae
Malaysia
Ixodid ticks
Mammals - monkeys, rodents
Louping III
Flaviviridae
United States, Scotland
Ixodid ticks
Sheep
Powassan encephalitis
Flaviviridae
Canada, U.S. Northeast, Far Eastern Russia
Ixodes spp., I. persulcatus, I. ricinus Ixodes spp., particularly I. scapularis, I. cookei, Dermacentor andersoni
Mammals - rodents including hedgehogs, wood mice, voles; also birds, deer, other ungulates, domestic livestock, especially goats Mammals - rodents, skunks, other medium-sized mammals, especially woodchucks
Siberian (Russian) spring-summer encephalitis (TBEV-Sib)
Flaviviridae
Russia
Turkish sheep encephalitis Bhanja virus
Flaviviridae
Turkey
Ixodid ticks
Sheep
Bunyaviridae
Eastern Europe, Russia, Central andWest Africa
Cattle, sheep, goats, hedgehogs
Dermacentor spp. Haemaphysalis intermedia
Crimean - Congo hemorrhagic fever (HF)
Bunyaviridae
Asia, Eastern Europe, Africa, Middle East
Mammals - many domestic animals (buffalo, camels, cattle, goats, sheep), rabbits, rodents (hedgehogs), birds
Hyalomma marginatum, Hyalomma anatolicum
Table 1: The Tickborne Encephalitis Viruses
J La State Med Soc VOL 170 MARCH/APRIL 2018 47
Made with FlippingBook Digital Publishing Software