Omithodoros soft ticks
have a characteristic full oval body shape.
Relapsing fever is a worldwide disease caused by several species of spirochetes (genus Borrelia) that are carried by soft ticks
of the genus Ornithodoros.
Although it is known that soft ticks
are the only vector for TBRF, no soft ticks
were found or trapped.
Within this phylum, three families of ticks are currently recognized in the world: 1) Ixodidae (hard ticks), 2) Argasidae (soft ticks
), and 3) Nuttalliellidae (a small, curious, little-known group with some characteristics of both hard and soft ticks
The first, Argasidae, is commonly known as "soft ticks
" while the second family, Ixodidae, represents the "hard ticks."
They are classified as hard ticks and soft ticks
, depending on the consistency of their covering cuticles.
Ticks are then singled out under the superfamily Ixodoidea and then divided into two distinct subfamilies, Argasidae (soft ticks
) and Ixodidae (hard ticks).
"But it's a leap of faith at this point to extrapolate from soft ticks
to the deer [Lyme disease] tick," cautions Richard Endris of Merck Sharp & Dohme in Rahway, N.J., who served as an entomological consultant on the study.
These soft ticks
typically live in the nests of rodents such as ground squirrels, tree squirrels, and chipmunks in coniferous forests at elevations between 1,500 and 8,000 feet (457 and 2,438 meters) (5).
Tick paralysis (TP) is only transmitted by blood-feeding gravid adult female ticks by an incompletely characterized neurotoxin produced by the tick's salivary glands.11 Ticks are classified into three families: (1) the Ixodidae, or hard ticks; (2) the Argasidae, or soft ticks
; and (3) the Nuttalliellidae, a much lesser known family, with characteristics of both hard and soft ticks
As examples, Chapter 1 lists information on arthropods in this order, "soft ticks
It has been found in various other hard ticks, including species of Amblyomma, Ixodes, Haemaphysalis, and in soft ticks
, including species of Argas and Ornithodoros (4-12).