Effects of a zoonotic pathogen, Borrelia burgdorferi, on the behavior of a key reservoir host. Issue 8 (26th March 2018)

• Record Type: Journal Article
• Authors: Ostfeld, Richard S.; Brisson, Dustin; Oggenfuss, Kelly; Devine, Jill; Levy, Michael Z.; Keesing, Felicia
• Is Part Of: Ecology and evolution. Volume 8:Issue 8(2018)
• Page Start: 4074
• Page End: 4083
• Publication Date: 2018-03-26
• Subjects: Lyme disease -- reservoir host -- tick‐borne disease -- vaccination -- wildlife reservoir -- zoonosis -- zoonotic disease; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.3961
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Most emerging infectious diseases of humans are transmitted to humans from other animals. The transmission of these "zoonotic" pathogens is affected by the abundance and behavior of their wildlife hosts. However, the effects of infection with zoonotic pathogens on behavior of wildlife hosts, particularly those that might propagate through ecological communities, are not well understood. Borrelia burgdorferi is a bacterium that causes Lyme disease, the most common vector‐borne disease in the USA and Europe. In its North American range, the pathogen is most frequently transmitted among hosts through the bite of infected blacklegged ticks ( Ixodes scapularis ). Using sham and true vaccines, we experimentally manipulated infection load with this zoonotic pathogen in its most competent wildlife reservoir host, the white‐footed mouse, Peromyscus leucopus, and quantified the effects of infection on mouse foraging behavior, as well as levels of mouse infestation with ticks. Mice treated with the true vaccine had 20% fewer larval blacklegged ticks infesting them compared to mice treated with the sham vaccine, a significant difference. We observed a nonsignificant trend for mice treated with the true vaccine to be more likely to visit experimental foraging trays (20%–30% effect size) and to prey on gypsy moth pupae (5%–20% effect size) compared to mice treated with the sham vaccine. We observed no difference between mice on true‐ versus sham‐vaccinated grids in risk‐averse foraging. Infection with this zoonotic pathogen appears to elicit behavioral changes that might reduce self‐grooming, but other behaviors were affected subtly or not at all. High titers of B. burgdorferi in mice could elicit a self‐reinforcing feedback loop in which reduced grooming increases tick burdens and hence exposure to tick‐borne pathogens. Abstract : Vaccination of field populations of white‐footed mice, which reduced titers of the Lyme disease bacterium in individual mice, reduced tick burdens by 20% compared to sham‐vaccinated mice, apparently by facilitating increased grooming behavior. This and other behavioral alterations of mice with experimentally reduced pathogen loads might affect the dynamics of forest communities of which mice are important components.