The Caribbean Amblyomma Program: some ecologic factors affecting its success.

The Caribbean Amblyomma Program has been operational for 8 years. However, owing to funding availability, some islands did not commence eradication activities until late 1997. During the past 2 years, 6 of the 9 islands (St. Kitts, St. Lucia, Anguilla, Montserrat, Barbados, and Dominica) under the program have attained the status of provisional freedom from the tropical bont tick (TBT). There are several administrative and technical reasons why the attainment of the program goals took longer than originally anticipated. This paper examines some of the ecologic factors that necessitated the prolongation of the treatment period and the recrudescence of TBT infestation in some islands. The introduction and subsequent spread of the cattle egret, Bulbucus ibis, in the 1960s and 1970s was most likely closely associated with the dissemination of the TBT in the region. At the national or island level, variations in land use are believed to have had a major impact on the eradication efforts in the different islands. Two islands, Antigua and Nevis, both opted out of sugar production several decades ago for economic reasons. Unfortunately, however, land from former sugar estates was not developed for other agricultural purposes and it became "unimproved free-grazing" areas for livestock. Thus, in both Antigua and Nevis, large numbers of livestock tend to become feral or free-ranging, making compliance with the mandatory treatment schedules impossible. In contrast, St. Lucia has large tracts of land allocated to banana plantations and St. Kitts to sugar plantations. Thus, feral or free-ranging livestock were rarely a problem in these islands. These differences in land use management are compared and discussed in relation to their perceived profound impact on TBT eradication efforts in the region.