Leptospirosis in Colombia: isolation of Leptospira spp. from the kidneys of brown rats (Rattus norvegicus) trapped on infected piggeries.

Leptospira interrogans serotypes pomona and icterohaemorrhagiae were isolated from the kidneys of Rattus norvegicus trapped on pomona infected piggeries. The isolation of pomona from one of 111 cultured kidneys, although of interest, strongly suggests that this rat does not play an important part in the epidemiology of infection by this serotype. Kidney tubular degeneration, focal mononuclear infiltrations and fibroplasia are morphological traces which remain after an attack of leptospirosis. The high percentage (48.6) of these lesions found in the rat kidneys examined does not seem to be related to serotype pomona but to icterohaemorrhagiae. The importance of this last serotype in swine in the Cauca Valley has yet to be assessed.