The Carribean Amblyomma variegatum Eradication Programme: Success or Failure?

The tropical bont tick Amblyomma variegatum F. was introduced into Guadeloupe in the mid 1700s and into Antigua about 100 years later. It was mainly restricted to these islands until the mid 1970s, when the tick spread rapidly, coincident with the introduction and expansion of the cattle egret (Bubulcus ibis L.) population. Thereafter, the tick became established on 18 islands. In late 1994, an eradication programme, the Caribbean Amblyomma Programme (CAP), was initiated using a strategy based on applications every two weeks of the pour-on acaricide, flumethrin (Bayticol®), for a minimum period of 24 to 30 months. Farmers were made responsible for regular treatment of their livestock. The strategy was reinforced through intensive public information programmes. A tropical bont tick surveillance programme was carried out and data entered into a customised database "TickINFO". Progress was slower than originally foreseen, but St. Kitts and St. Lucia (November 2001), Anguilla and Montserrat (February 2002), and Barbados and Dominica (February 2003) were certified provisionally tropical bont tick-free following defined periods of surveillance. Unfortunately, St. Kitts, St. Lucia and Dominica have all had reinfestations or recrudescences of the tick since being certified. In 2004, with the increase in spread of the tick, St Kitts was decertified. St Vincent qualifies for certification, as ticks have not been seen for two years. Three CAP islands remain infested: Antigua, Nevis and St. Maarten/St. Martin. The four islands in the French West Indies programme also remain infested. Three of the four islands under the jurisdiction of the USA remain tropical bont tick-free. St Croix, however, became reinfested again in 2000 and remains so up to 2005. The major conclusions drawn from the programme are discussed in the context of successes and failures, and include administrative and financial management issues, the technical design and methodology and the future of the programme. Notably, if additional funding is not available within a few months to continue and conclude eradication activities, then it is recommended that a tick management strategy is adopted, with full cost recovery.

KEYWORDS tropical bont tick, Amblyomma variegatum, eradication, Caribbean, flumethrin, cattle egrets