The reservoir status of goats recovered from heartwater

Experiments were conducted with Creole goats and Amblyomma variegatum ticks in Guadeloupe to investigate whether it is possible to transmit Cowdria ruminantium to susceptible hosts with nymphs fed in the larval stage on recovered goats. Of 88 batches of larvae fed after the return of the goats' temperature to normal, or after challenge or immunosuppression, only the 9 batches of larvae fed during the febrile reaction, 2 batches applied 2 and 3 days respectively after recovery, and a single batch applied 5 days after challenge, became infective. On average, blood appears to be infective for A. variegatum larvae for only an 8-day period associated with the temperature reaction following a primary infection. Recovered goats are not reservoirs of Cowdria, even if--with one exception in our experiment--they are reinfected after recovery.