A preliminary investigation on the use of imidocarb dipropionate in the prophylaxis of anaplasmosis and babesiosis [abstract]

The prophylactic effect of imidocarb dipropionate on anaplasmosis and babesiosis was studied using twenty-seven heifers at the university field station. Fifteen animals were administered imidocarb dipropionate intramuscularly at a dose of 2mg-kg 1 while twelve were left as controls. All animals were subsequently turned out to pasture from a feedlot environment which was tick-free. Over a period of seven months, the heifers were monitored for tick infestation, weight gain, body temperature, haematological para-meters such as packed cell volume, haemoglobin, white blood cell count, total plasma protein, the differences in other parameters between treated and untreated control heifers were not significantly different. It is concluded that the administration of imidocarb dipropionate for the purpose of prophylaxis of babesiosis and/or anaplasmosis in this situation was of no significant value. (AU)

Vector situation of tick-borne diseases in the Caribbean islands

The most important ticks transmitting diseases to ruminants in the Caribbean islands are: Amblyomma variegatum, vector of cowdriosis and associated with acute dermatophilosis: Amblyomma cajennense, potential vector of cowdriosis; Boophilus microplus, vector of babesiosis and anaplasmosis. At the present time, Amblyomma variegatum is widespread in the Lesser Antilles from Barbados to Puerto Rico. The inensity of the tick control program varies in the different islands and the tick infestation in each island ranges from limited foci to widespread infestations. The vector situation appeared stable since 1988 in the Lesser Antilles but the outbreak in 1992 in Puerto Rico emphasized the risk of spread to other islands and to the American mainland, particularly with cattle egrets. Cowdriosis remains apparently limited to Guadeloupe and Antigua. Amblyomma cajennense, experimental vector of cowdriosis, is present in Cuba, Jamaica and Trinidad but also in most American countries. Boophilus microplus is widespread throughout the Caribbean. Its presence and importance are often indirectly estimated by the clinical and serological diagnosis of babesiosis and anaplasmosis. There is no correlation between the intensity of Amblyomma variegatum control in each island of the Lesser Antilles and the effect on the Boophilus microplus population measured by the seroprevalence to babesiosis and anaplasmosis, but within the island of Martinique a regular Amblyomma variegatum control decreases the seroprevalences to babesiosis and anaplasmosis (AU)

Bovine anaplasmosis and babesiosis in the Lesser Antilles: risk assessment of an unstable epidemiologic situation

A seroepidemiological survey on tick-borne diseases of ruminants was carried out on 11 islands of the Lesser Antilles from Grenada to St Martin. A total of 1,795 cattle were randomly sampled and sera tested for antibodies to anaplasmosis (Anaplasma marginale) and babesiosis (Babesia bovis and B bigemina) using a dot-ELISA test. Except of anaplasmosis, which was virtually absent from Guadeloupe, the seroprevalence of the 3 tick-borne diseases ranged from 18 to 71 percent. The epidemiologic situation was considered to be unstable in all of the study sites. The risk of clinical outbreaks was high in all the islands except for B bigemina in Montsterrat and St Lucia and B bovis in St Lucia. The practical consequences in terms of tick eradication, tick control, and vaccination are discussed (Summary)

Epidemiology of bovine anaplasmosis and babesiosis in Latin America and the Caribbean

The various parameters which interact in the epizootiology of babesiosis and anaplasmosis and which it is necessary to obtain in a survey are analysed and the two diseases compared. Where no data are available from Latin America and the Caribbean, the references from Australia and the United States of America are discussed. The two principal objectives of a study on the epidemiology of babesiosis and anaplasmosis are: to determine the risk of occurrence to understand the relevant factors leading to outbreaks. The first objective is relatively simple to achieve for both diseases by calculating the animal inoculation rate (h) at a determined age and the critical value of h for enzootic stability. The second objective requires exhaustive and complex studies. For babesiosis epidemiology, studies of the tick infection rate, cattle infestation rate, genetic composition of cattle, acaricides, stocking rate, climatic data and other factors are necessary. Anaplasmosis epidemiology cannot be satisfactorily explained by considering it purely as a tick-borne disease. Difficulties to be overcome include the great diversity of haematophagous Diptera in Latin America, and the scarcity of data on the capacity of these insects as anaplasmosis vectors and their feed preferences on cattle. (AU)

The history of the outbreak of paralytic rabies in Trinidad transmitted by bats to human beings and the lower animals from 1925

In 1925 animals began to die from a disease which was erroneously diagnosed by the veterinary surgeons and the government bacteriologist, Dr. J. L. Pawan, as Botulism or Bulbar Paralysis. In 1929 Dr. J. A. Waterman diagnosed a case of "Acute Ascending Myelitis" and stated that it was probably a new disease. Twelve other cases were discovered during the year, but the diagnosis was changed from Acute Ascending Myelitis to Anterior Poliomyelitis by the senior officers of the department. The government pathologist and bacteriologist confirmed the diagnosis of Anterior Poliomyelitis. In 1931 Dr. Hurst, bacteriologist, Lister Institute discovered Negri bodies in the brain tissue forwarded to him by Dr. K. S. Wise. He suggested that the transmitting agent may be the bat. In 1931 Dr. H. Metivier, Veterinary Surgeon, inoculated a calf, a guinea pig, and a rabbit with the brain tissue of three rabid bats, all of which developed typical symptoms of the disease. To Dr. Metivier must go all the credit for establishing beyond doubt the connection between the bites of bats and the fatal disease, paralytic rabies. In July 1931, Dr. Wise, then Surgeon General, read a paper in which he stated that both diseases were due to the virus of rabies. In September 1931, Negri bodies were demonstrated by Dr. Pawan, Government Bacteriologist, in the brain of a bat with unusual habits. (Summary)