Role of bird migration in the long-distance dispersal of Ixodes dammini, the vector of Lyme disease.
To evaluate the role of migratory birds in the long-distance dispersal of Ixodes dammini ticks and in the spread of Lyme disease, a 6-year study of migrating birds to an offshore New England island was conducted during 1989-1994. I. dammini are not endemic on this island, therefore allowing assessment of long-distance tick dispersal rather than local infestation. Of 11,324 spring migrants examined, 1.2% were infested with I. dammini. Of 8607 fall migrants examined, 0.2% were infested. Of nymphal ticks examined, 20% were infected with Borrelia burgdorferi. OspB DNA sequencing of 6 B. burgdorferi isolates was identical to sequences of 2 strains common in coastal Maine. It is evident that bird migration allows for long-distance dispersal of I. dammini from areas where they are endemic to areas where they are not and that a few bird species account for the majority of tick dispersal. The likelihood of establishment of enzootic Lyme disease by this mechanism is discussed.
Smith
R P
RP
Maine Medical Center Research Institute, South Portland 04106-3295, USA.
Rand
P W
PW
Lacombe
E H
EH
Morris
S R
SR
Holmes
D W
DW
Caporale
D A
DA
D000818:Animals; D001717:Birds; D005426:Flight, Animal; D018884:Ixodes; D008193:Lyme Disease / Q000209:etiology*; D008281:Maine; D012621:Seasons