Article

Assessing peridomestic entomological factors as predictors for Lyme disease.

Center for Vector-Borne Disease, University of Rhode Island, 9 East Alumni Ave., Suite 7, Kingston, RI 02881, USA.
Journal of Vector Ecology (impact factor: 0.88). 01/2007; 31(2):364-70. pp.364-70
Source: PubMed

ABSTRACT The roles of entomologic risk factors, including density of nymphal blacklegged ticks (Ixodes scapularis), prevalence of nymphal infection with the etiologic agent (Borrelia burgdorferi), and density of infected nymphs, in determining the risk of human Lyme disease were assessed at residences in the endemic community of South Kingstown, RI. Nymphs were sampled between May and July from the wooded edge around 51 and 47 residential properties in 2002 and 2003, respectively. Nymphs were collected from all residences sampled. Tick densities, infection rates, and densities of infected nymphs were all significantly higher around homes reporting Lyme disease histories in 2003, while only infection rates were significantly higher in 2002. However, densities of infected nymphs did not significantly predict the probability of Lyme disease at a residence (by logistic regression) in either year. There were no significant differences in entomologic risk factors between homes with state-confirmed Lyme disease histories and homes with self-reported cases (not reported to the state health department). Therefore, although entomologic risk factors tended to be higher at residences with cases of Lyme disease, entomological indices, in the absence of human behavior measures, were not useful predictors of Lyme disease at the scale of individual residences in a tick-endemic community.

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Keywords

47 residential properties
 
Borrelia burgdorferi
 
endemic community
 
entomologic risk factors
 
entomological indices
 
etiologic agent
 
human behavior measures
 
human Lyme disease
 
individual residences
 
Ixodes scapularis
 
logistic regression
 
Lyme disease
 
Lyme disease histories
 
nymphal blacklegged ticks
 
residences sampled
 
self-reported cases
 
state health department
 
state-confirmed Lyme disease histories
 
Tick densities
 
tick-endemic community