Amblyomma variegatum in cattle in Marie Galante, French Antilles: prevalence, control measures, and infection by Ehrlichia ruminantium.

We report Marie Galante as one of the Caribbean islands most heavily infested by the tropical bont tick (TBT) Amblyomma variegatum which is associated with two major diseases of ruminants: heartwater and dermatophilosis. In 2005, a survey was undertaken to assess the prevalence of TBT infestation in cattle, the prevalence of Ehrlichia ruminantium infection in TBTs, and the tick control measures implemented by livestock owners. A random sample of 195 cattle herds out of 1885 recorded on the island was investigated by thoroughly counting adult ticks on each animal and filling a questionnaire. A randomly collected sample of 136 TBTs was tested for infection by E. ruminantium by pCS20 nested PCR. Cattle herd prevalence (hp) was 73.8% for infestation by at least one TBT, 17.9% for infestation by at least one engorged female TBT, and 8.2% for clinical dermatophilosis. Cattle individual prevalence was 42.3% for infestation by at least one TBT, 6.6% for infestation by at least one engorged female TBT, and 2.2% for clinical dermatophilosis. The minimum, maximum and average numbers of TBTs per infested animal were, respectively 1, 108 and 11.5. Prevalence of TBT infection by E. ruminantium was 19.1%. No significant difference in herd prevalence was found among parishes or among ecological zones. For cattle owners treating against ticks (97.9% of all owners), all used aspersion of amitraz and herd prevalence was significantly different among those treating every 1-2-week (hp=69.6%, n=148), and less often than every 2-week (hp=88.6%, n=35) (P=0.031). Of the 42 herd subunits treated less than 4 days before the survey, 27 (64%) were infested with at least one TBT, and 6 (14%) with at least one engorged female TBT. These results indicate a high level of TBT infestation in Marie Galante, the inefficacy of tick treatments currently performed, and the need for an improved tick control strategy. Persisting high levels of infestation in Marie Galante threaten the success of on-going TBT eradication programs in the Caribbean because TBT can spread through migrating birds and trade of animals or of animal hides to other islands and potentially the American continent.

The Caribbean animal health network: new tools for harmonization and reinforcement of animal disease surveillance.

The Caribbean Animal Health Network (CaribVET) is a collaboration of veterinary services, diagnostic laboratories, research institutes, universities, and regional/international organizations to improve animal health in the Caribbean. New tools were used by the network to develop regional animal health activities: (1) A steering committee, a coordination unit, and working groups on specific diseases or activities were established. The working group on avian influenza used a collaborative Web site to develop a regionally harmonized avian influenza surveillance protocol and performance indicators. (2) A specific network was implemented on West Nile virus (WNV) to describe the WNV status of the Caribbean countries, to perform a technology transfer of WNV diagnostics, and to establish a surveillance system. (3) The CaribVET Web site (http://www.caribvet.net) encompasses information on surveillance systems, diagnostic laboratories, conferences, bibliography, and diseases of major concern in the region. It is a participatory Web site allowing registered users to add or edit information, pages, or data. An online notification system of sanitary information was set up for Guadeloupe to improve knowledge on animal diseases and facilitate early alert.

West Nile virus surveillance, Guadeloupe, 2003-2004.

We conducted extensive surveillance for West Nile virus infection in equines and chickens in Guadeloupe in 2003-2004. We showed a high seroprevalence in equines in 2003 related to biome, followed by a major decrease in virus circulation in 2004. No human or equine cases were reported during the study.

West Nile virus, Guadeloupe.

To determine whether West Nile virus (WNV) had reached the archipelago of Guadeloupe, a serologic study in horses and birds was conducted in 2002. Immunoglobulin (Ig) G, IgM, enzyme-linked immunosorbent assay, and seroneutralization tests identified WNV infection in horses and chickens. Six months later, a high rate of seroconversion was observed in horses.