Related Experiment Video
Updated: Oct 23, 2026
Glass Wool Filters for Concentrating Waterborne Viruses and Agricultural Zoonotic Pathogens
Published on: March 3, 2012
Problems with the interpretation of epidemiological data in heartwater: a study on 23 farms
1Veterinary Research Institute, Onderstepoort.
Insights
Cattle seropositivity for heartwater (Cowdria ruminantium) is primarily linked to tick load, not the infection rate within ticks. Tick control methods did not significantly impact cattle immunity or disease prevalence in endemic areas.
Area of Science:
- Veterinary Epidemiology
- Infectious Diseases
- Parasitology
Background:
- Heartwater, caused by Cowdria ruminantium, is endemic in many regions.
- Understanding factors influencing cattle immunity is crucial for disease management.
Purpose of the Study:
- To investigate the relationship between tick burden, Cowdria ruminantium infection rates, and cattle seropositivity.
- To assess the impact of different tick control strategies on heartwater prevalence and cattle immunity.
Main Methods:
- Epidemiological study on 23 endemic farms.
- Quantified antibodies to Cowdria ruminantium in cattle.
- Assessed Amblyomma hebraeum tick loads and infection rates.
Main Results:
- 64.3% of cattle showed antibodies to Cowdria ruminantium.
- Average of 6 adult Amblyomma hebraeum ticks per animal; 7.0% of ticks infected.
- Cattle seropositivity correlated strongly with tick load, less so with tick infection rate.
- No clear link between farm-level heartwater prevalence and animal immune status.
- Higher tick counts observed on farms with strategic tick control compared to total control programs.
Conclusions:
- Tick load is the dominant factor in determining cattle seropositivity for heartwater.
- Current tick control methods did not demonstrably influence cattle immunity, tick infection rates, or heartwater prevalence.
- Further research into effective tick control strategies impacting host immunity is warranted.
Abstract:
In an epidemiological study undertaken on 23 farms where heartwater occurs endemically, it was found that on an overall average, antibodies to Cowdria ruminantium were detected in 64.3% of the cattle, 6 adult Amblyomma hebraeum ticks were counted per animal and 7.0% of ticks were infected with the heartwater agent. It was found that the seropositivity of the animals was determined largely by the tick loads to which they were subjected and that the influence of the tick C. ruminantium infection rate was less evident. There was no parallel between the prevalence of heartwater on the farms and the immune status of the animals. In general, higher tick counts were recorded in herds where strategic tick control is practised than on farms with a total tick control programme. The method of tick control did not, however, appear to influence the immune status of the cattle, the tick infection rate, or the prevalence of heartwater.
More Related Videos
09:58Environmental Screening of Aeromonas hydrophila, Mycobacterium spp., and Pseudocapillaria tomentosa in Zebrafish Systems
Published on: December 8, 2017
09:44Characterization of a Pathogenic Escherichia coli Strain Derived from Oreochromis spp. Farms Using Whole-Genome Sequencing
Published on: December 23, 2022
Related Concept Videos
01:26Introduction to Epidemiology
01:22Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies
01:28Toxoplasmosis