Please look for these two articles, I think it can help you:
1. Experimental infection of capybaras Hydrochoerus hydrochaeris by Rickettsia rickettsii and evaluation of the transmission of the infection to ticks Amblyomma cajennense.
Vet Parasitol. 2009 Apr 6;161(1-2):116-21. Epub 2008 Dec 13.
2. MIRANDA, J. ; CONTRERAS, V. ; NEGRETE, Y. ; LABRUNA, M. B. ; MATTAR, S. . Vigilancia de la infección por Rickettsia sp. en capibaras (Hydrochoerus hydrochaeris) un modelo potencial de alerta epidemiológica en zonas endémicas. Biomédica (Bogotá), v. 31, p. 216-221, 2011.