Elimination of Borrelia burgdorferi and Anaplasma phagocytophilum in Rodent Reservoirs and Ixodes scapularis Ticks Using a Doxycycline Hyclate-Laden Bait

Abstract

We report a novel host-targeted approach using doxycycline hyclate-impregnated bait.14-16 After promising laboratory studies, we conducted a field trial in a Lyme disease-endemic area in central New Jersey to assess the ability of these baits to prophylactically protect small-mammal reservoirs, cure infected reservoirs, and reduce infection of immature I. scapularis ticks by both the Lyme disease spirochete, Borrelia burgdorferi , and the agent of human granulocytic anaplasmosis, Anaplasma phagocytophilum . MATERIALS AND METHODSStudy areas. The study was conducted in an area of mixed hardwood forest located in Millstone Township, Monmouth County, New Jersey, where I. scapularis and its small-mammal hosts are well-established. 12,17,18 The 10-to 15-m canopy was dominated by chestnut oak ( Quercus prinus L.), red oak ( Q. rubra L.), and white oak ( Q. alba L.), with associated species including red maple ( Acer rubrum L.), yellow poplar ( Liriodendron tulipifera L.), black gum ( Nyssa sylvatica Marsh.), and American beech ( Fagus grandifolia Ehrh.). The understory and shrub layer consisted of saplings and seedlings of canopy species, highbush blueberry ( Vaccinium corymbosum L.), lowbush blueberry ( V. angustifolium Ait.), huckleberries ( Gaylussacia spp.), sweet pepperbush ( Clethra alnifolia L.), and greenbriar ( Smilax glauca Walt.). The treatment site and one of the control sites were ~2.5-ha singlefamily residential properties located ~200 m apart. A second undeveloped control site (~3 ha) was located ~1,000 m south in nearby Assunpink Wildlife Management Area (WMA).Deployment and maintenance of bait stations. Beginning in May of 2007 and 2008, 50 Protecta LP bait stations (Bell Laboratories, Inc., Madison, WI) were fitted with ~135 g extruded, wax-based bait blocks containing 500 mg/kg doxycycline (Genesis Laboratories, Inc., Wellington, CO) and deployed at the treatment site. Bait stations were placed in forested habitat at ~20-m intervals along two concentric perimeters at distances of ~5 and 25 m from the lawn-forest interface. Whenever possible, bait stations were deployed adjacent to natural structures, including fallen trees, stumps, brush piles, woodpiles, and outbuildings, which are considered to be likely foraging or nesting sites for small mammals. Bait stations were inspected weekly to assess overall condition and bait consumption, and they were rebaited as necessary. Consumption of bait was recorded using a five-point Activity Index (1 = no bait consumption, 2 = 25% bait consumed, 3 = 50% bait consumed, 4 = 75% bait consumed, and 5 = 100% bait consumed) ( Figure 1 ). In addition, any bait station that was significantly damaged by eastern gray squirrels ( Sciurus carolinensis ) was replaced. All bait stations were withdrawn in September of both years after 19 consecutive weeks of deployment.Small-mammal trapping and tick burdens. Small mammals were collected using 7.6 × 8.9 × 30. Control and Prevention, Fort Collins, Colorado; Terry L. Schulze, PhD, Inc., Perrineville, New Jersey; Freehold Area...

Evidence for Personal Protective Measures to Reduce Human Contact With Blacklegged Ticks and for Environmentally Based Control Methods to Suppress Host-Seeking Blacklegged Ticks and Reduce Infection with Lyme Disease Spirochetes in Tick Vectors and Rodent Reservoirs

“…A single published field study has evaluated the use of a rodent-targeted antibiotic bait to suppress host-seeking B. burgdorferi -infected I. scapularis nymphs in a New Jersey woodland setting (Dolan et al 2011; Table 7). A doxycycline hyclate-laden bait delivered via rodent bait stations was shown to eliminate B. burgdorferi in rodent reservoirs and reduce infection by 92–94% in host-seeking nymphs after 1–2 yr of treatment in a woodland setting in New Jersey.…”

Infection resistance and tolerance in Peromyscus spp., natural reservoirs of microbes that are virulent for humans

“…This includes attracting the rodents with baits for application of pesticides to kill the attached ticks [61], and administering antibiotics in the field to kill bacterial pathogens the animals may be carrying [62]. There is also the controversial concept of increasing the proportion of animals that are less competent as reservoirs than P. leucopus to eventually “dilute out” B. burgdorferi in the population of ticks [63–65].…”

Efficacy of an Experimental Azithromycin Cream for Prophylaxis of Tick-Transmitted Lyme Disease Spirochete Infection in a Murine Model

“…Nymphal ticks were tested for infection with B. burgdorferi by PCR as previously described (24). Briefly, after ticks were removed from the host, DNA was extracted and tested for the presence of B. burgdorferi using a primer set directed against the fliD gene of B. burgdorferi.…”

“…3 weeks after the nymphal feeding, xenodiagnostic larval ticks from our uninfected colony were allowed to feed on these test mice, as well as on naive controls. Larval xenodiagnostic ticks were tested for the presence of spirochetes by PCR at 10 days post-larval feeding as previously described (24).…”