The Amblyomma variegatum Fabricius also called the tropical bont tick, is a three-host tick that is native to Africa. It has spread to several countries, including the Caribbean islands. It is known as the Antigua gold tick and the Senegalese tick. The Bubulcus ibis or cattle egret is invasive in some Caribbean countries and a known spreader of tickborne diseases.
The bite from the bont tick causes skin lesions on the afflicted animal can lead to acute dermatophilosis, triggered by the bacteria Dermatophilus congolensis. This bacterium is the main vector for Cowdria ruminantium, a type of micro-organism that causes heartwater disease in domestic animals like cattle. However, the disease is not actually transmitted by the tick, but by the wounds affected by the immunosuppression and large mouthparts that occur secondary to feeding. The feeding predisposes entry of the bacteria into the skin.
Heartwater disease can be prevented by vaccination, blocking methods, and regular dripping at set intervals. After diagnosis, treatment should follow immediately with an antibiotic containing oxytetracycline. Another prevention method is to isolate infected animals and treat them with Terralon LA in the event of an outbreak.[CA1] Learn more about these treatment methods for Heartwater disease in livestock here.
Dermatophilus congolensis and heartwater diseases are the only diseases to be detected in the Caribbean, as hosts have demonstrated clinical symptoms.
Heartwater disease can result in economic losses such as poor quality and often unusable hides, loss of milk production, weight loss, and sometimes death. There are other diseases that the tropical bont tick is a vector, which are yellow fever virus, African tick bite fever (Rickettsia africae), Jos virus, Dugbe virus and Crimean-Congo hemorrhagic fever virus. Read more about the tropical bont tick and other invasive species in our Policy Brief titled ‘Invasive Species Threaten Livelihood and Valuable Biodiversity in the Caribbean’.
Read more from our sources below!
Policy Brief – Invasive Species Threaten Livelihoods and Valuable Biodiversity in the Caribbean
CABI – Amblyomma variegatum (tropical bont tick)
Entnemdept – Tropical bont tick
Virbac – Heartwater Disease in Livestock