Survey of seroprevalence of Q fever in dogs in the southeast of France, French Guyana, Martinique, Senegal and the Ivory Coast.

A serological survey was carried out on 429 dogs belonging to the French military in France, French Guyana, Martinique, Senegal and the Ivory Coast. Serology against phase I and II antigens of Coxiella burnetii, the intracellular zoonotic bacterium was performed using indirect immunofluorescence techniques. Specific antibodies were found in dogs from France (9.8%), Senegal (11.6%), Ivory Coast (8.3%), French Guyana (5.2%) but not in those from Martinique. The seroprevalence among 77 dogs who had contact with sheep compared with 352 dogs who had had no contact, demonstrated a significantly higher seroprevalence in the former. Our results indicate that dogs, living close to sheep, may be infected by Coxiella burnetii and should be considered as possible sources of infection for humans.

The invasive behaviour of Cryptococcus neoformans: a possibility of direct access to the central nervous system?

Cryptococcocal meningoencephalitis is always considered secondary to initial lung infection. Because of the unquestionable evidence of haematogenious spread from the lungs, few publications have reported about other possible primary sites of infection or other routes to the central nervous system. This study was designed to investigate the infiltrative pattern of C. neoformans in immunocompromised mice by treatment with dexamethasone. The infection was performed by nasal instillation (30 mice) or injection into the retro-orbital space (12 mice). From the group infected intranasally, 3 mice presented diffuse invasive fungal colonisation of the mucosa and submucosa. The histologic findings showed infiltrative growth along the periosteum, sometimes surrounded nervous endings of submucosa, invasion along the olfactory nerve and simultaneous meningeal involvement in 2 mice on the 6th and 8th day of infection. All mice infected into the retro-ocular space developed lesions containing numerous cryptococci in the local of the inoculum. Out of the main lesion we observed preferential growth along the perineural spaces with adherence to the perineurium, perivascular spaces and sometimes along aponeurosis. Simultaneous invasion of trigeminal ganglio and trigeminal branches was observed in 4 mice. These morphologic patterns suggest the hypothesis of direct infiltrative invasion of the central nervous system.