Dates of onset of canine babesiosis within a hyperendemic focus in France (Rhone Valley, south of Jura and north of the Alps) were compared to the seasonal population level of the adult stage of Dermacentor reticulatus over a 12-month period (December 1982-November 1983). Cases of babesiosis occurred in spring and fall when adult D. reticulatus were active. The fluctuations of the vector tick population and the onsets of canine babesiosis were also correlated with climatic changes: no tick activity or clinical cases of disease were detected in winter (low temperature) or in summer. The slight disparities observed between both distributions might be explained by various factors such as the development of immunity against the parasites, the intervals between tick bites and appearance of symptoms of the disease, or the asynchrony between different biotopes.
Animals Arachnid Vectors