| Abstrakt: |
Similar to other states in the southeastern United States, human cases of tick-borne diseases in Alabama have risen steadily over the last 2 decades. Nevertheless, limited data have been published on ticks or tick-borne pathogen (TBP) distributions since the 1990s. To better understand the risk of tick and TBP exposure in eastern central Alabama, ticks were sampled repeatedly across 8 sites associated with recreational use during May and June of 2015 to characterize tick density and diversity. Although habitats were similar across sites, tick density varied among locations. Seven species were collected, but 97.7% of 1,310 samples were the lone star tick, Amblyomma americanum(L.), the primary vector of ehrlichial agents and the tick species most commonly linked to alpha-gal syndrome and southern tick-associated rash illness. To investigate pathogen prevalence among sites, we tested A. americanumby a multiplex qPCR assay for 5 bacterial species, including 3 Ehrlichiaspp. and 2 Rickettsiaspp. None of the specimens tested positive for Panola Mountain Ehrlichiaor Rickettsia parkeri. However, causative agents of human ehrlichiosis, Ehrlichia chaffeensisand Ehrlichia ewingii, occurred at half of the locations with, respectively, 0.27% and 0.45% of A. americanuminfected on average. In contrast, Rickettsia amblyommatis, a tick endosymbiont suspected to be nonpathogenic, was found in 54.5% of the 1119 A. americanumtested. Despite low infection rates of Ehrlichiaspp. in A. americanum, high encounter rates with this species in recreational deciduous woodlands suggest a moderate risk of tick bite and a low-to-moderate risk of TBP exposure in late spring. |
