Assessing the association between the geographic distribution of deer ticks and seropositivity rates to various tick-transmitted disease organisms in dogs.
OBJECTIVE
To determine whether the geographic distribution of deer ticks (Ixodes scapularis) was associated with the distribution of dogs seropositive for various tick-transmitted disease organisms (ie, Borrelia burgdorferi, Rickettsia rickettsii, the human granulocytic ehrlichiosis [HGE] agent, Ehrlichia canis, and Bartonella vinsonii subsp berkhoffii).


METHODS
Serologic survey.


METHODS
Serum samples from 277 dogs in animal shelters and veterinary hospitals in Rhode Island.


RESULTS
Overall, 143 (52%) dogs were seropositive for B burgdorferi, 59 (21.3%) were seropositive for R rickettsii, 40 (14.4%) were seropositive for the HGE agent, 8 (2.9%) were seropositive for E canis, and 6 (2.2%) were seropositive for B vinsonii. Regression analysis indicated that the natural logarithm of nymphal deer tick abundance was correlated with rate of seropositivity to the HGE agent and to B burgdorferi but not to rate of seropositivity to R rickettsii, E canis, or B vinsonii. Percentages of samples seropositive for B burgdorferi, R rickettsii, the HGE agent, and E canis were significantly higher for samples from the southwestern part of the state where ticks in general and deer ticks in particular are abundant than for samples from the northern and eastern portions of the state, where ticks are relatively rare.


CONCLUSIONS
Results suggested that all 5 disease agents are in Rhode Island and pose a risk to dogs and humans. Knowledge concerning tick distributions may be useful in predicting the pattern of disease associated with particular tick species and may aid diagnostic, prevention, and control efforts.
Hinrichsen
V L
VL
Center for Vector-Borne Disease, University of Rhode Island, Kingston 02881, USA.
Whitworth
U G
UG
Breitschwerdt
E B
EB
Hegarty
B C
BC
Mather
T N
TN
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D001096:Arachnid Vectors / Q000382:microbiology / Q000502:physiology*; D001473:Bartonella / Q000276:immunology; D001474:Bartonella Infections / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D015748:Borrelia burgdorferi Group / Q000276:immunology; D003670:Deer; D004283:Dog Diseases / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D004285:Dogs; D004536:Ehrlichia / Q000276:immunology; D016873:Ehrlichiosis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods / Q000662:veterinary; D018884:Ixodes / Q000382:microbiology / Q000502:physiology*; D008193:Lyme Disease / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D012237:Rhode Island / Q000453:epidemiology; D012284:Rickettsia rickettsii / Q000276:immunology; D012373:Rocky Mountain Spotted Fever / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary; D016036:Seroepidemiologic Studies; D017282:Tick-Borne Diseases / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*
D000907:Antibodies, Bacterial