R.G. Pegram, A. Rota, R. Onkelinx, D.D. Wilson, P. Bartlette, B.S. Nisbett, G. Swanston, P. Vanterpool and J.J. de Castro
Address for correspondence: CARICOM/FAO/IICA, Caribbean Amblyomma
Program, PO Box 631-c, Bridgetown, Barbados.
Authors: R.G. Pegram, Programme Manager; A. Rota, Animal Production Officer; R. Onkelinx,
Public Information and Communications; c/o FAO, PO Box 631-c, Bridgetown, Barbados. D.D.
Wilson, Director, Agricultural Health, Inter-American Institute for Cooperation on
Agriculture (IICA), San Jos�, Costa Rica. P. Bartlette, Veterinary Officer, Department of
Agriculture, Nevis. B.S. Nisbett, Chief Veterinary Officer, Department of Agriculture, St
Kitts. G. Swanston, Chief Veterinary Officer, Department of Agriculture, Monserrat. P.
Vanterpool, Veterinary Officer, Department of Agriculture, Anguilla. J.J. de Castro,
Animal Health Officer, FAO, Rome.
La tique tropicale Amblyomma variegatum, esp�ce indig�ne
d'Afrique, a �t� introduite dans les Cara�bes aux alentours de 1828 lorsque des bovins
infest�s ont �t� import�s du S�n�gal en Guadeloupe. Vu le r�le que cette tique joue
dans la transmission de la p�ricardite exsudative infectieuse (heartwater) et dans
la propagation de la dermatophilose, sa pr�sence a eu une incidence extr�mement
n�gative sur la production animale et le d�veloppement de l'�levage dans la r�gion. Le
parasite gagne en outre du terrain, en particulier par suite des d�placements du b�tail
et de la migration des h�rons garde-bœufs. Cette situation constitue une menace s�rieuse
pour les zones de production animale situ�es sur le continent am�ricain tout proche, o�
l'introduction de la tique pourrait entra�ner des pertes de plusieurs millions de
dollars.
Pour parer � cette menace, la FAO, l'Institut interam�ricain de coop�ration pour
l'agriculture (IICA) et la Communaut� des Cara�bes (CARICOM) ont mis en place un
programme d'�radication de la tique tropicale dans les Cara�bes. Le pr�sent article
d�crit les strat�gies, les activit�s et les progr�s de ce programme.
La garrapata Amblyomma variegatum, aut�ctona de Africa, se
introdujo por primera vez en el Caribe alrededor del a�o 1828, con la importaci�n de
vacunos infestados del Senegal a Guadalupe. Debido a su intervenci�n en la trasmisi�n de
la enfermedad llamada cowdriosis y la propagaci�n de la dermatofilosis, la presencia de
la garrapata tiene efectos negativos graves sobre la producci�n pecuaria y el desarrollo
de la regi�n. La distribuci�n del par�sito en el Caribe va en aumento, facilitada por
el transporte del ganado y la migraci�n de las garcetas. Esto representa una seria
amenaza para las zonas de producci�n pecuaria del cercano continente americano, donde su
introducci�n puede ocasionar p�rdidas de muchos millones de d�lares en la industria
pecuaria.
Para contrarrestar esta amenaza, la FAO, el Instituto Interamericano de Cooperaci�n para
la Agricultura (IICA) y la Comunidad del Caribe (CARICOM) han iniciado un programa para la
erradicaci�n de esta garrapata de la regi�n del Caribe. En el presente art�culo se
describen las estrategias, las actividades y los progresos de este programa.
The adult tropical bont tick, Amblyomma variegatum, rimarily
infests domestic animals. Its preferred host is cattle but it also parasitizes sheep,
goats, horses, dogs and some larger wild mammals. Immature ticks feed on cattle, sheep and
goats as well as on smaller mammals, reptiles and birds, including the cattle egret
(Walker, 1987).
The genus Amblyomma is distributed worldwide, but the tropical bont tick is of
African origin. A. variegatum was first introduced into the Caribbean in about 1828
when infested cattle were imported into Guadeloupe from Senegal. It spread to the island
of Marie Galante in 1830 and to Antigua in 1895. During the twentieth century, the tick
spread to many other Caribbean islands and, up to 1990, it was still spreading (Barre,
Garris and Camus, 1995), thus threatening the mainland countries of North, Central and
South America, and other islands in the Caribbean. Similarly, it has also become
established on the Arabian Peninsula and in Mauritius.
The bites of the tropical bont tick are severe. They may result in septic wounds and
abscesses, inflammation of the teats of cows and considerable damage to hides and skins.
The tick is the main vector of the rickettsia, Cowdria ruminantium, which causes
heartwater disease. It is also associated with an increase in the prevalence of acute
dermatophylosis, a skin disease of cattle caused by the bacteria Dermatophilus
congolensis (Jongejan and Uilenberg, 1994). In the Caribbean, acute dermatophylosis is
the major cause of economic loss resulting from the tick.
An increase in the movement of livestock between the Caribbean islands has played an
important part in the spread of the tick. However, there is considerable evidence that
migratory birds, especially cattle egrets, which carry larvae and nymphs of the tropical
bont tick, also spread the parasite. The link between the movement of the cattle egret and
the incidence of the tick in the Caribbean has been reviewed by Barre, Garris and Camus
(1995).
Cattle egrets from Antigua and Guadeloupe that are infested with the tick are known to
have migrated to other islands. During 1990-1991, cattle egrets in Guadeloupe were marked
on the wings with a dye. Some 26 marked egrets were observed, covering a radius of almost
2 000 km and extending as far as Florida (Corn et al., 1993).
Current distribution of Amblyomma variegatum in the eastern
Caribbean (as reported August 1996)
Distribution actuelle de Amblyomma variegatum dans l'est des Cara�bes (ao�t 1996)
Situaci�n actual de la distribuci�n de Amblyomma variegatum en el Caribe oriental
(agosto de 1996)
Microclimates and the environment play an important role in causing the
tropical bont tick to spread. If the potentially favourable areas predicted by Sutherst
and Maywald (1985) are correct, then the risk of further spread would appear to be very
high. These areas include Florida, Gulf of Mexico, Central America and the Caribbean and
the Atlantic coast of South America as far south as Uruguay.
There is concern that, if heartwater is introduced to livestock in North, Central or South
America, it might rapidly, and possibly irrevocably, become established. The potential for
this is enhanced by the presence of two indigenous ticks which have been shown
experimentally to transmit heartwater (Barre et al., 1987): Amblyomma maculatum,
the Gulf Coast tick, which is widely distributed in the southern United States and Central
America, and Amblyomma cajennense, the Cayenne tick, which occurs in the Caribbean,
Central and South America and in southern Texas.
The first report on attempts to eradicate the tropical bont tick from St Croix was by
Hourrigan et al. (1969). Since then, the tick has been eliminated from Culebra,
Vieques, Puerto Rico and St Croix in the United States Virgin Islands. However, St Croix
became reinfested in 1987 and Puerto Rico in 1992 (Bokma and Shaw, 1993). It was
eradicated again from these islands a year later which demonstrates that, although
eradication is possible, it must be done on a regional basis to ensure that those islands
freed of the tick are not reinfested.
An animal infested with dermatophylosis, a skin disease aggravated
by the Amblyomma ticks and responsible for serious livestock losses in St Kitts and
Nevis
Animal atteint d'une dermatophilose, maladie de peau aggrav�e par la pr�sence de tiques
du genre Amblyomma et qui a entra�n� la mort de nombreux animaux �
Saint-Kitts-et-Nevis
Animal infectado con dermatofilosis, enfermedad cut�nea agravada por las garrapatas Amblyomma,
que ocasiona importantes p�rdidas de ganado en Saint Kitts y Nevis
Photo/Foto: CAP
An example of the Caribbean Amblyomma Program's continuing public
information campaign
Exemple d'activit�s entreprises dans le cadre de la campagne d'information permanente du
public financ�e et mise en œuvre par les responsables du programme d'�radication
Ejemplo de la campa�a de informaci�n del p�blico llevada a cabo por el programa
Photo/Foto: CAP
The migration of the cattle egret, feeding among cattle, is
responsible for the movement of the tick between countries in the Caribbean region
La migration des h�rons garde-bœufs, qui s'alimentent parmi les bovins, est � l'origine
de la progression des tiques dans les pays des
La migraci�n de la garceta, que se alimenta entre el ganado vacuno, es la causa de la
trasmisi�n de la garrapata de un pa�s a otro en la regi�n del Caribe
Photo/Foto: de Castro
Amblyomma variegatum feeding on cattle
Amblyomma variegatum parasitant un bovin
Amblyomma variegatum aliment�ndose en un vacuno
Photo/Foto: CAP
School children involved in play-learning activities as part of the Amblyomma
eradication programme
Ecoliers participant � des activit�s ludo-�ducatives au titre du Programme
d'�radication
Ni�os de una escuela que aprenden jugando como parte del programa de erradicaci�n de Amblyomma
Photo/Foto: CAP
The application of Flumethin "pour on" every two weeks for
two years by the farmers is the backbone of the Caribbean Amblyomma Program. This method
of acaricide application is probably the least environmentally damaging of all the ones
available today
L'application de flum�thine (un acaricide qu'il suffit de verser sur l'animal) tous les
15 jours pendant deux ans constitue la part essentielle du Programme. De toutes les
m�thodes actuellement utilisables, celle-ci est probablement la moins dommageable pour
l'environnement
El elemento fundamental del programa es la aplicaci�n de flumetina por parte de los
agricultores, que la vierten cada dos semanas durante dos a�os. Este m�todo de
aplicaci�n de acaricidas es probablemente el menos perjudicial para el medio ambiente
entre todos los disponibles en la actualidad
Photo/Foto: CAP
A feasibility study carried out in 1986 led to the development of a programme for the eradication of the tropical bont tick from the Caribbean and, in the following year, a report was presented at a technical workshop, organized by the Caribbean Community (CARICOM). A programme proposal was formulated but funding was not obtained until 1994. The feasibility appraisal was supported by several scientific studies: on the probability of the spread of Amblyomma variegatum in the Caribbean (Alderink and McCauley, 1988); on biological and ecological aspects and their implications for eradication (FAO, 1989; Barre and Garris, 1990); and, finally, on the most suitable acaricides for eradication (Barre, Garris and Aprelon, 1993).
On the basis of the distribution of the tropical bont tick and the risks of infestation, the islands and surrounding mainland areas of the Caribbean region have been classified into three main risk areas (CARICOM/FAO/IICA, 1995).
The Caribbean Amblyomma Program (CAP) was established in 1994 with the
aim of eradicating the tropical bont tick from the Caribbean. It is jointly implemented by
FAO and IICA. A similar and complementary eradication programme is operating on the
islands of the French West Indies.
Because of the very high costs involved in the delivery, through government services, of
intensive tick control activities required for eradication, the responsibility for
compulsory treatment of animals with selected acaricides was delegated to the farmers.
Government inspection teams were then mandated to ensure that farmers complied with the
treatment schedules. Legislation was revised, making it illegal for farmers to be in
possession of tick-infested animals. This reliance on the active participation of farmers
has been successfully reinforced through intensive public information and sensitization
programmes.
Communications officers in the Ministries of Agriculture are largely responsible for the
distribution of information to government information services and to regional and local
public media (newspapers, radio and television). Additional promotional material produced
by CAP is distributed to livestock farmers, animal owners and the community, chiefly
through animal health officers (see Box 2, Communications and public awareness multimedia
packages).
The participation expected from the community can be divided into two categories:
Collaborative efforts have been established between the CAP and the
ongoing programme in the French Caribbean Territories. In addition to the exchange of
communication materials, close collaboration in the production of some items has been
established to avoid duplication. Language barriers and the different treatment methods do
not affect the objective of tick eradication which is common to both programmes.
The acceptance of the farmers' responsibility for the Flumethrin "pour on"
pesticide treatments has been outstanding, with over 80 percent compliance. Moreover,
there has been a rapid increase in gaining the confidence of the livestock industry and
numerous farmers have reverted to cattle raising, particularly on the island of Nevis.
The implementation strategies of the programme are classed on the degree of risk, depending on the distribution and prevalence of the tropical bont tick.
Low and medium risk areas. The following activities are planned or in progress:
High risk areas. In the high risk priority areas, the main activities are:
The field activities undertaken for the registration and census of livestock and the specific themes addressed by information materials are summarized in Boxes 1 and 2, respectively.
BOX 1
|
BOX 2
|
Caribbean Amblyomma Program
|
HOST |
CATEGORY |
Weight |
Bayticol |
Cattle |
Adults (Large) |
400 |
40 |
Adults (Small) |
300 |
30 |
|
Yearlings/Youngstock |
200 |
20 |
|
Calves |
100 |
10 |
|
Sheep & Goats |
Adults/Full Grown |
30-50 |
5 |
Kids and Lambs |
10-25 |
2.5 |
The eradication is based on the use of the pesticide Flumethrin,
formulated for topical or "pour on" application and applied to livestock at
14-day intervals over a period of two to three years (see the Treatment instructions on
the next page).
Opinions on the relative importance of localized, residual tick foci and the potential for
the reintroduction of ticks by carriage on egrets and livestock are varied and need to be
assessed early in the project. The problems relating to the treatment of feral hosts and
loose livestock will also require attention. Applied and appropriate research will
therefore be carried out to resolve such specific problems.
Actions at the national level. National tick control and eradication projects have been planned for the eight infested CARICOM islands (Anguilla, Antigua, Barbados, Dominica, Montserrat, Nevis, St Lucia and St Kitts). On the five French islands of Guadeloupe, La D�sirade, Marie Galante, St Martin and Martinique, a complementary eradication programme was initiated in 1995. The United States Department of Agriculture continues to monitor the situation in Puerto Rico and associated islands as well as on the United States Virgin Islands.
Regional coordination. A regional coordination unit supports the CARICOM national projects through the bulk purchase of acaricide and other equipment and supplies; advice on legislation; preparation and distribution of extension materials; technical backstopping of national projects, including veterinary support and train-ing; routine surveillance; and a database to record the progress of eradication.
Amblyomma Program Council. As a forerunner to the present
eradication campaign, the Amblyomma Program Council (APC) was established in 1987 to:
develop policies and guidelines for the overall eradication programme; propose independent
technical adviser and consultants needed to prepare technical reviews and evaluate
progress; review and recommend budgetary requirements and identify sources of funds; and
review, monitor and evaluate the status of the tropical bont tick in the Caribbean and
surrounding areas. Its membership is made up of national representatives, international
organizations and donor agencies.
The APC is supported administratively by the regional coordination unit and an ad hoc
working group of the APC which consists of CARICOM, FAO, IICA and government staff. Its
mandate is to meet the immediate and periodic needs of the programme and to review and
endorse work plans.
The national eradication projects in the CARICOM region (for an estimated value of US$15.6
million) are supported by donor inputs ($4.5 million), government contributions ($2.9
million) and inputs in kind by farmers to the value of $8.2 million. The regional
coordinating unit is responsible for training and the production of promotional materials
for use in the national projects as well as for travel (estimated cost, $4.4 million).
In comparison, the cost of the French West Indies programme is estimated to be about $17
million.
A recent review of the technical status in the CARICOM and associated
islands has shown that the distribution of A. variegatum and its related diseases
has remained fairly static over the past ten years. In Dominica and Montserrat, the tick
population is generally well under control, but periodic new foci do occur and are
believed to be connected to the movement of egrets. Since the rapid spread of the tick in
the 1970s and early 1980s, when the number of islands infested increased from four to 16,
governments have maintained fairly rigorous control programmes which have largely
contributed to arresting the spread of the tick both within and between the islands. In
Barbados, however, the tropical bont tick has spread to seven parishes out of ten since
its introduction in 1990.
To date, the most intensive efforts have been made on Anguilla, St Kitts, Nevis and
Montserrat which have a livestock population of approximately 5 000, 11 000,
27 000 and 19 000, respectively. The most successful field operations have been
on St Kitts and Nevis, where about 90 percent of sheep, goats and cattle are being treated
regularly by the livestock owners themselves.
Recent annual reports indicate that very few ticks and only four cases of dermatophylosis
have been identified on these islands. Preparatory activities are now being planned to
expand the eradication programme to Antigua, Dominica, St Lucia and Barbados.
The funds currently available are insufficient to cover the entire programme. Without
adequate funds the tick will not be eradicated, which in turn will increase the risk of
further spread, possibly as far as mainland South, Central and North America. Equally at
risk is the $17 million invested in the French West Indies programme.
The worst consequences of failure, associated with either financial or
epidemiological risks, have been assessed. Gersabeck (1994) estimated a potential loss of
US$762 million annually if the tick and associated diseases became established in the
mainland countries.
Apart from preventing the spread of the tropical bont tick into the Americas, its
eradication will greatly benefit Caribbean livestock producers. In 1993, livestock farmers
in tick-infested Caribbean countries only produced 11 000 tonnes of fresh beef,
mutton and goat meat, with an estimated value of $26 million. During the same period,
however, the value of imported beef, mutton and goat meat was $54.5 million out of a total
of $237 million spent overall on meat importation. With the exception of Barbados, milk
production is insignificant in the region. In 1992, it amounted to about $50 000,
compared with the importation of milk estimated at $60 million over the same period.
Tick-borne diseases, particularly dermatophylosis and heartwater, are significant
constraints to livestock production in several Caribbean countries. In St Kitts and Nevis,
the former caused a dramatic decline of animal populations owing to mortality and the
premature selling of diseased animals for slaughter by owners who were afraid of losing
their complete herd. As an alternative to eradication, continuous and intensive tick
control in the infested areas would cost about $6 million a year (R.G. Pegram, unpublished
data).
It is important to note that the eradication programme also includes several activities
that will provide secondary and immediate benefit to animal production. Recording of
animal production data and epidemiological parameters has never been undertaken in the
region. Now, for the first time in the history of Caribbean agriculture, livestock
identification and registration are providing an accurate estimate of animal populations.
Moreover, the livestock sector is being recognized by several governments in the region as
an area with substantial, albeit somewhat neglected, agricultural potential. Tick
eradication will contribute significantly to national self-sufficiency in food production
and thereby reduce dependency on importation. The consequent savings in important foreign
exchange could be directed to improving livestock development within more sustainable and
productive mixed farming.
Financial support for CARICOM's Caribbean Amblyomma Program has been provided by the Governments of Belgium, Germany, Italy, the United Kingdom and the United States and by both FAO and the Inter-American Institute for Cooperation on Agriculture (IICA). Technical support from the staff of the Departments of Agriculture and the national media services in Anguilla, Montserrat and St Kitts and Nevis are gratefully acknowledged.
Alderink, F.J. & McCauley, E.H. 1988. The probability of the
spread of Amblyomma variegatum in the Caribbean. Prev. Vet. Med., 6:
285-298.
Barre, N. & Garris, G.I. 1990. Biology and ecology of Amblyomma variegatum
(Acari: Ixodidae) in the Caribbean: Implications for a regional eradication programme. J.
Agric. Entomol., 7: 1-9.
Barre, N., Garris, G. & Aprelon, R. 1993. Acaricides for eradication of the
tick Amblyomma variegatum in the Caribbean. Rev. �lev. m�d. v�t. pays trop.,
46: 349-354.
Barre, N., Garris, G. & Camus, E. 1995. Propagation of the tick Amblyomma
variegatum in the Caribbean. Rev. sci. tech. Off. int. �piz., 14: 841-855.
Barre, N., Uilenberg, G., Morel, P.C. & Camus, E. 1987. Danger of introducing
heartwater onto the American main-land. Onderstepoort J. Vet. Res., 54:
405-417.
Bokma, B.H. & Shaw, J.L. 1993. Eradication of a new focus of Amblyomma
variegatum in Puerto Rico. Rev. �lev. m�d. v�t. pays trop., 46: 355-358.
CARICOM/FAO/IICA. 1995. Eradicating the tropical bont tick from the Caribbean.
Oxford, UK, Words and Publications. 7 pp.
Corn, J., Barre, N., Theibot, B., Creekmore, R., Garris, G.I. & Nettles, V.F.
1993. The potential role of cattle egrets, Bubulcus ibis (Ciconiformes: Ardeie), in
the dissemination of Amblyomma variegatum (Acari: Ixodidae) in the eastern
Caribbean. J. Med. Entomol., 6: 1029-1037.
FAO. 1989. Biology and ecology of Amblyomma variegatum in Guadeloupe and its
importance in eradication strategy. Barre & Garris in The eradication of ticks,
p. 230-245. FAO Animal Production and Health Paper No. 75.
Gersabeck, E.F. 1994. The tropical bont tick in the Western Hemisphere. In Comprehensive
reports on technical items presented to the International Committee, p. 121-132.
Paris, OIE.
Hourrigan, J.L., Strickland, R.K., Kelsey, O.L., Knisely, B.E., Crago, C.C., Whittaker,
S. & Gilhooly, D.J. 1969. Eradication efforts against tropical bont tick, Amblyomma
variegatum, in the Virgin Islands. J. Am. Vet. Med. Assoc., 154: 540-545.
Jongejan, F. & Uilenberg, G. 1994. Ticks and control methods. In
Ectoparasites of animals and control methods. Rev. sci. tech. Off. int. �piz., 13:
1201-1226.
Sutherst, R.W. & Maywald, G.F. 1985. A computerized system for matching
climates in ecology. Agric., Ecosyst. Environ., 13: 281-299.
Walker, J.B. 1987. The tick vectors of Cowdria ruminantium (Ixodoidaea,
Ixodidae, genus Amblyomma) and their distribution. Onderstepoort J. Vet. Res.,
54: 353-379.
