Warnell School of Forestry and Natural Resources & Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA.
Jones Center at Ichauway, Newton, GA, 39870, USA.
Sci Rep. 2019 Jul 10;9(1):9974. doi: 10.1038/s41598-019-46377-4.
Recently, a two-year study found that long-term prescribed fire significantly reduced tick abundance at sites with varying burn regimes (burned surrounded by burned areas [BB], burned surrounded by unburned areas [BUB], and unburned surrounded by burned areas [UBB]). In the current study, these ticks were tested for pathogens to more directly investigate the impacts of long-term prescribed burning on human disease risk. A total of 5,103 ticks (4,607 Amblyomma americanum, 76 Amblyomma maculatum, 383 Ixodes scapularis, two Ixodes brunneus, and 35 Dermacentor variabilis) were tested for Borrelia spp., Rickettsia spp., Ehrlichia spp., and Anaplasma phagocytophilum. Long-term prescribed fire did not significantly impact pathogen prevalence except that A. americanum from burned habitats had significantly lower prevalence of Rickettsia (8.7% and 4.6% for BUB and UBB sites, respectively) compared to ticks from control sites (unburned, surrounded by unburned [UBUB])(14.6%). However, during the warm season (spring/summer), encounter rates with ticks infected with pathogenic bacteria was significantly lower (98%) at burned sites than at UBUB sites. Thus, despite there being no differences in pathogen prevalence between burned and UBUB sites, risk of pathogen transmission is lower at sites subjected to long-term burning due to lower encounter rates with infected ticks.
最近，一项为期两年的研究发现，长期规定性火烧显著降低了不同火烧制度（火烧周围环绕火烧区[BB]、火烧周围环绕未烧区[BUB]和未烧区环绕火烧区[UBB]）地区的蜱虫数量。在当前的研究中，对这些蜱虫进行了病原体检测，以更直接地调查长期规定性火烧对人类疾病风险的影响。共检测了 5103 只蜱虫（4607 只美洲钝眼蜱、76 只肩突硬蜱、383 只肩突革蜱、2 只扁虱和 35 只变色革蜱），以检测伯氏疏螺旋体、立克次体、埃立克体和嗜吞噬细胞无形体。长期规定性火烧除了发现火烧生境中的美洲钝眼蜱的立克次体（BUB 和 UBB 地点分别为 8.7%和 4.6%）的流行率显著低于对照点（未烧，未烧环绕[UBUB]）（14.6%）外，对病原体的流行率没有显著影响。然而，在温暖季节（春季/夏季），与感染致病性细菌的蜱虫的接触率在火烧点显著降低（98%），而在 UBUB 点则较高。因此，尽管火烧点和 UBUB 点之间的病原体流行率没有差异，但由于与感染蜱虫的接触率较低，长期火烧的地点的病原体传播风险较低。
