ticks with “black legs” and the discovery of ixodes … pressentations/18 ticks...ticks with...
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Ticks with “black legs” and the Ticks with “black legs” and the d fd f d ffd ffdiscovery of discovery of Ixodes affinis Ixodes affinis in in
North CarolinaNorth CarolinaNorth CarolinaNorth Carolina
Bruce A. Harrison PhDBruce A. Harrison PhDPublic Health Pest ManagementPublic Health Pest Management
WinstonWinston‐‐Salem, NCSalem, NC
Acknowledgments Walker Rayburn Jr., Perquimans CountyWalker Rayburn Jr., Perquimans County PHPM (Marcee Toliver, Barry Engber, Parker Whitt, NolanPHPM (Marcee Toliver, Barry Engber, Parker Whitt, Nolan PHPM (Marcee Toliver, Barry Engber, Parker Whitt, Nolan PHPM (Marcee Toliver, Barry Engber, Parker Whitt, Nolan
Newton)Newton) Gene Powell, RaleighGene Powell, Raleigh Lance Durden, Georgia Southern University, StatesboroLance Durden, Georgia Southern University, Statesboro Richard Robins, Armed Forces Pest Management Board, Richard Robins, Armed Forces Pest Management Board,
Washington DCWashington DCWashington, DCWashington, DC Brian Prendergast, U.S. Navy, Camp LejeuneBrian Prendergast, U.S. Navy, Camp Lejeune Rick Hickman, Brunswick CountyRick Hickman, Brunswick County Rick Hickman, Brunswick CountyRick Hickman, Brunswick County Jeff Brown, Brunswick CountyJeff Brown, Brunswick County Ricardo Maggi, NCSU Vet. School, RaleighRicardo Maggi, NCSU Vet. School, Raleigh Joe Piesman, CDC, Fort Collins, COJoe Piesman, CDC, Fort Collins, CO
The “Blacklegged tick” (previously called the “Deer tick”) or Ixodes scapularis, is the tick species confirmed as the
vector of Lyme disease spirochetes to humans in the eastern United States.eastern United States.
Lone Star tick nymphLone Star tick nymphBlacklegged tick nymphBlacklegged tick nymph
Lone Star tick nymphLone Star tick nymph
Not this one!This one!This one!
H th t l tH th t l t th i fth i fHowever, there are at least However, there are at least sevenseven other species of other species of IxodesIxodes in NC that havein NC that have “black legs” and most “black legs” and most of these do not transmit the spirochete thatof these do not transmit the spirochete thatof these do not transmit the spirochete that of these do not transmit the spirochete that causes Lyme disease in humans.causes Lyme disease in humans.
Also, there are Also, there are twotwo additional species of additional species of IxodesIxodesthat have light brown legs or banded legs.that have light brown legs or banded legs.
You cannot identify these ticks to species based on You cannot identify these ticks to species based on “black legs” Other more obscure“black legs” Other more obscureblack legs . Other more obscure black legs . Other more obscure morphological structures must be used that are morphological structures must be used that are difficult to see.difficult to see.difficult to see. difficult to see.
Ticks in NC with “black legs” and their Ticks in NC with “black legs” and their known hostsknown hostsow os sow os s
Ix. affinis Ix. affinis –– 15 mammals and 1 bird species15 mammals and 1 bird species
Ix. Ix. angustusangustus –– rodents and their predators (rodents and their predators (humanshumans))
Ix. dentatusIx. dentatus –– rabbits, their predators and birds (rabbits, their predators and birds (humanshumans)) Ix. dentatus Ix. dentatus rabbits, their predators and birds (rabbits, their predators and birds (humanshumans))
Ix. Ix. marximarxi –– squirrels, chipmunks, and their predators squirrels, chipmunks, and their predators
Ix. muris Ix. muris –– mice, rats, and birds (mice, rats, and birds (humans?humans?))
Ix. scapularis Ix. scapularis –– 41 41 mammal, mammal, 57 57 bird bird and and 11 reptile 11 reptile species (species (humanshumans))
Ix. Ix. texanustexanus –– raccoons, opossums, and rabbits (raccoons, opossums, and rabbits (humanshumans))te a uste a us accoo s, opossu s, a d abb ts (accoo s, opossu s, a d abb ts ( u a su a s))
Ix. Ix. woodiwoodi –– woodratswoodrats, predators, and birds (, predators, and birds (humanshumans) )
The life cycle for all of these species is basically the same but there are distinct biological differencessame, but there are distinct biological differences
Habitats Habitats usually match that of the primary host species usually match that of the primary host species tili d b th i t t d d lt Altili d b th i t t d d lt Alutilized by the immature stages and adults. Also utilized by the immature stages and adults. Also
birds can transport them to abnormal areas.birds can transport them to abnormal areas.
HostsHosts can be highly variable as some tick species are verycan be highly variable as some tick species are very Hosts Hosts can be highly variable, as some tick species are very can be highly variable, as some tick species are very specific in selecting their hosts, while others are specific in selecting their hosts, while others are generalists. generalists.
Distribution Distribution is also associated with the primary hosts, but is also associated with the primary hosts, but also determined by latitude, elevation, temperature, also determined by latitude, elevation, temperature, rainfall, humidity, vegetation type, etc.rainfall, humidity, vegetation type, etc., y, g yp ,, y, g yp ,
PhenologyPhenology (seasonality)(seasonality) of the life stages is variable. Some of the life stages is variable. Some species have the immature stages during coolspecies have the immature stages during cool--cold cold months, while others including the Blackmonths, while others including the Black--legged tick legged tick have the immatures during the warm months. have the immatures during the warm months.
Tick life cycle
Ticks collected by PHPM since Oct. 2008
31,108 total specimens
24,882 Am. americanum (Lone Star tick)
1,050 D. variabilis (American dog tick)
3,108 Ix. scapularis (Blacklegged tick)
853 Ix. affinis (no common name)
1,215 other species
The 2008 Collection of Ix. affinis in NCWhere: Gates Co.
When: April 2008When: April 2008
Who: Walker Rayburn
Explanation: This tick was not correctly identified until April 2009. Later, we found an earlier publishedan earlier published record of one specimen from a deer in Hyde County inin Hyde County in 1987
Ixodes affinis: Basic Information•• Originally a CentralOriginally a Central--South American speciesSouth American species
Fi t f d i Fl id i 1953 d t G i dFi t f d i Fl id i 1953 d t G i d•• First found in Florida in 1953, spread to Georgia and First found in Florida in 1953, spread to Georgia and South Carolina, and finally identified in NC in 2009South Carolina, and finally identified in NC in 2009
•• Easily misidentified asEasily misidentified as Ixodes scapularisIxodes scapularis, because they, because theyEasily misidentified as Easily misidentified as Ixodes scapularisIxodes scapularis, because they , because they are both collected in the same habitats in spring and fallare both collected in the same habitats in spring and fall
•• Adults active March Adults active March –– November, and easily collected November, and easily collected d i th th t f A td i th th t f A tduring the summer months, except for Augustduring the summer months, except for August
•• No published documentation that they bite humans, but No published documentation that they bite humans, but they feed on many other mammals and at least one birdthey feed on many other mammals and at least one birdthey feed on many other mammals and at least one birdthey feed on many other mammals and at least one bird
•• Common in coastal plain counties of NCCommon in coastal plain counties of NC•• Implicated as an enzootic (or maintenance) vector of Implicated as an enzootic (or maintenance) vector of
Borrelia burgdorferi s.s. Borrelia burgdorferi s.s. in small rodent hosts in South in small rodent hosts in South Carolina and GeorgiaCarolina and Georgia
Photos by Marcee Toliver
affinisfemale
scapularisfemale
Marcee Toliver Marcee Toliver
Ix. affinis female
Marcee Toliver
Ix. affinis male
= large central pores
Marcee Toliver
males(ventral views)
Ix. scapularis( e t a e s)
Ix. affinis
Marcee Toliver
Marcee Toliver
Marcee Toliver
Classic habitat for Ix. affinis is in moist shaded woods near water
NOT IN DIRECT SUNLIGHT
Marcee Toliver
Known mammal and bird hosts for Ix. affiinis in the USA
Gerrish and Ossorio (1965)
Cotton mouse
Photo by J. Parnell in Webster et al. 1985 in Webster et al.1985
Eastern wood rat
Photo by J. Parnell Photo by J. Parnell inin Webster et al. 1985Webster et al. 1985 in Webster et al.1985
Marsh rice rat
Photo by J. Parnell in Webster et al. 1985
Photo by J. Parnell in Webster et al. 1985
in Webster et al.1985
Hispid cotton rat
Inin Webster et al.1985
Hispid cotton rat
Seasonal (Phenological) Differences
Ixodes affinisIxodes affinis
Marcee Toliver
I odes scap larisc
Ixodes scapularis c
Marcee Toliver, in partM
Some of the Some of the following are following are My Opinions!My Opinions!
(Not everyone in PHPM( ymay agree with me!)
In northeastern U.S.A. the immatures of Ixodes scapularis feed on the
White- footed mouse
pwhite-footed mouse and the adults feed on deer. What is happening along our coast where this mouse does not occur? We still have Lyme cases reported in that area of the
Photo by J. Parnell in Webster et al. 1985cases reported in that area of the state.
IxodesIxodesscapularis
In Webster et al. 1985
?Marcee Toliver
Apperson et al. (1993) established that the primary hosts for Ixodes scapularis larvae and nymphs along the coast in North Carolina are
reptiles. Whether this holds in the piedmont is another question.
Southeastern five-lined skink
Eastern glass lizard
Slender glass lizard
Eastern glass lizard
Photos/maps by Jack Dermid in Beane et al. (2010), Amphibians and Reptiles of the Carolinas and Virginia
Broad-headed skink
What about What about Ixodes affinis Ixodes affinis and Lyme and Lyme diseasedisease inin Virginia?Virginia?gg
You have You have Ixodes affinis Ixodes affinis in southeastern Virginia (Ft. Eustis) and a in southeastern Virginia (Ft. Eustis) and a large concentration of humans in the Norfolk area.large concentration of humans in the Norfolk area.
What do theWhat do the Ix. scapularisIx. scapularis nymphs and larvae in southeastern VAnymphs and larvae in southeastern VA What do the What do the Ix. scapularis Ix. scapularis nymphs and larvae in southeastern VA nymphs and larvae in southeastern VA feed on? Do they feed on reptiles as they do in NE North Carolina?feed on? Do they feed on reptiles as they do in NE North Carolina?
Do you have a second enzootic cycle of Do you have a second enzootic cycle of Borrelia burgdorferi s. sBorrelia burgdorferi s. s. in . in southeastern VA based on the cotton mouse or other rodents beside southeastern VA based on the cotton mouse or other rodents beside the whitethe white--footed mouse?footed mouse?
What are the human case rates for What are the human case rates for B. burgdorferi s. sB. burgdorferi s. s. in . in southeastern VA compared to the rest of the state?southeastern VA compared to the rest of the state?
in Webster et al. 1985 in Webster et al. 1985 in Webster et al. 1985
B.
All Testing Combined: I. scapularisB.
All Testing Combined: I. scapularisooooooooooooooo (383 specimens) B. burgdorferi sl, 0, 0%
B
IGSP Pos, 1, 0%
B. burgdorferi sl, 0, 0%
B
IGSP Pos, 1, 0%
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
Borrelia miyamotoi 0.0% (1/383)
B. bissettii, 0, 0%
B. burgdorferi ss, 3, 1%
B. bissettii, 0, 0%
B. burgdorferi ss, 3, 1%
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
Borrelia burgdorferi s.s.< 1% (3/383)
Mix, 0, 0%Mix, 0, 0%oo
Neg, 379, 99%
Neg, 379, 99%
M. Toliver, in part
(186 specimens)
B. burgdorferi s.l.1% (2/186)
oooooooooooooooooooooooooooooooB. burgdorferi s.s.
oooooooooooo
31% (58/186)
oBorrelia mixed oooooooooooo
ooooooooooooo
Borrelia mixed3% (6/186)
Marcee Toliver, in part