Community-based control of the brown dog tick in a region with high rates of Rocky Mountain spotted fever, 2012-2013.

Naomi A Drexler ,Kenneth Komatsu,Stephen Piontkowski,Jessica Francies,Suzanne Todd,Cye Goseyun,Timothy Shelhamer,Regina Hovet,Erica Weis,Kristen Herrick,Laura Adams,Anita Brock,Velda Williams,Justin Gerding,Carmen Eribes,F Scott Dahlgren,Patsy Sneezy,Harty Bendle,Jennifer H Mcquiston,B Hamilton ,Robert F Massung ,José Velascosoltero ,Nelva J Bryant ,Mark D Miller

doi:10.1371/journal.pone.0112368

Abstract

Rocky Mountain spotted fever (RMSF) transmitted by the brown dog tick (Rhipicephalus sanguineus sensu lato) has emerged as a significant public health risk on American Indian reservations in eastern Arizona. During 2003–2012, more than 250 RMSF cases and 19 deaths were documented among Arizona's American Indian population. The high case fatality rate makes community-level interventions aimed at rapid and sustained reduction of ticks urgent. Beginning in 2012, a two year pilot integrated tick prevention campaign called the RMSF Rodeo was launched in a ∼600-home tribal community with high rates of RMSF. During year one, long-acting tick collars were placed on all dogs in the community, environmental acaricides were applied to yards monthly, and animal care practices such as spay and neuter and proper tethering procedures were encouraged. Tick levels, indicated by visible inspection of dogs, tick traps and homeowner reports were used to monitor tick presence and evaluate the efficacy of interventions throughout the project. By the end of year one, <1% of dogs in the RMSF Rodeo community had visible tick infestations five months after the project was started, compared to 64% of dogs in Non-Rodeo communities, and environmental tick levels were reduced below detectable levels. The second year of the project focused on use of the long-acting collar alone and achieved sustained tick control with fewer than 3% of dogs in the RMSF Rodeo community with visible tick infestations by the end of the second year. Homeowner reports of tick activity in the domestic and peridomestic setting showed similar decreases in tick activity compared to the non-project communities. Expansion of this successful project to other areas with Rhipicephalus-transmitted RMSF has the potential to reduce brown dog tick infestations and save human lives.

Highlights

Rocky Mountain spotted fever (RMSF) is a severe and potentially fatal tickborne disease caused by the bacterium Rickettsia rickettsii
Thousands of cases of RMSF are reported annually to the Centers for Disease Control and Prevention (CDC) from across the United States, with the majority of cases originating from the South-Atlantic states [2]
In the United States, RMSF is most commonly transmitted by the American Dog tick (Dermacentor variabilis), which is widely distributed east of the Rocky Mountains, and on the California coastline

Summary

Introduction

Rocky Mountain spotted fever (RMSF) is a severe and potentially fatal tickborne disease caused by the bacterium Rickettsia rickettsii. This intracellular bacterium can cause widespread vasculitis resulting in organ failure and death if left untreated, even in previously healthy individuals [1]. In the United States, RMSF is most commonly transmitted by the American Dog tick (Dermacentor variabilis), which is widely distributed east of the Rocky Mountains, and on the California coastline. It is transmitted by Dermacentor andersoni (the Rocky Mountain wood tick) in the western United States. Both of these tick vectors prefer wooded areas and acquire the majority of blood meals from wildlife [4]

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Conclusion