Models for regional heartwater epidemiology in a variable environment.

Models for heartwater epidemiology: practical implications and suggestions for future research.

We present a simple model of the dynamics of heartwater that we use to explore and better understand various aspects of this disease. We adapted the Ross-Macdonald model for malaria epidemiology so that we could consider both host and vector populations, and evaluate the interactions between the two. We then use two more biologically detailed models to examine heartwater epidemiology. The first...

Heartwater--Ehrlichia ruminantium infection.

Summary Heartwater is a notifiable disease that is listed by the World Organisation for Animal Health. It is caused by Ehrlichia ruminantium, an obligately intracellular Gram-negative bacterium in the order Rickettsiales and the family Anaplasmataceae. The disease is borne byticks in the genus Amblyomma and causes heartwater, or cowdriosis, in wild and domestic ruminants, primarily in Africa, b...

Veterinary extension on sampling techniques related to heartwater research.

Heartwater, a tick-borne disease caused by Ehrlichia ruminantium, is considered to be a significant cause of mortality amongst domestic and wild ruminants in South Africa. The main vector is Amblyomma hebraeum and although previous epidemiological studies have outlined endemic areas based on mortalities, these have been limited by diagnostic methods which relied mainly on positive brain smears....

The non-specific resistance of cattle to heartwater.

A distinction is drawn between the non-specific resistance to heartwater of very young calves and that of cattle older than a year. The suckling-calf resistance is at its greatest during the first few weeks after birth and then gradually declines during the next 6-8 months. Aspects of its possible mechanism and significance are discussed. The role played by conglutinin in the natural resistance...

A contribution to the epidemiology of Ehrlichia Ruminantium infection (Heartwater) in small ruminants in The Gambia