Potential impact of wildlife on the tropical bont tick eradication program in the Caribbean

Wildlife are hosts for A. variegatum throughout its range in Africa, and have been demonstrated to serve as hosts for larvae and nymphs on several islands in the Caribbean. Studies conducted in the Caribbean have indicated that most larvae and nymphs and all adults of the tick feed on livestock; therefore, eradication can be approached through the treatment of livestock. However, since small numbers of animals such as the mongoose are infested with larvae and nymphs, these animals may represent a short-term alternative host system. Such infestations potentially could result in a presence of small numbers of ticks for up to 46 months after the onset of a treatment program and could serve as a source to reinfest livestock during the eradication process. Wildlife surveys have been conducted in St. Croix, Puerto Rico, Guadeloupe, and Antigua; but the host status of species present on other islands such as the white-tailed deer on St. Kitts has not been evaluated. As part of the eradication program, the species of wildlife present on each island and the association of these species with infested pastures should be determined. Surveys of wildlife can be used during the eradication to determine if wildlife are serving as an alternative host system. Cattle egrets may serve to disseminate the tick among islands in the region, and to areas outside the region. Cattle egrets have been shown to serve as hosts for the tick, and to move throughout the eastern Caribbean and to North America. The potential for interisland dissemination of ticks by cattle egrets, as well as by other means, substantiates the need for a region-wide eradication program.