Eco-epidemiología del virus encefalitis st. Louis en Córdoba, Argentina.

LORENA I. SPINSANTI; LUIS A. DIAZ; MARTA S. CONTIGIANI

Revista de la Facultad de Ciencias Médicas (Córdoba, Argentina)

Facultad de Ciencias Médicas, Universidad Nacional de Córdoba

Lugar: Córdoba, Argentina; Año: 2009 vol. 66 p. 52 - 59

0014-6722

St. Louis encephalitis virus (SLEV) belongs to Flavivirus genus, Flaviviridae family. It is endemic in the American continent. Most of infections by SLEV are asymptomatic, however clinical outcome include encephalitis, aseptic meningitis and febrile cephalea. The susceptibility to acquired neurological infection increase with age. In the USA, SLEV is maintaining through Culex spp mosquitoes and passeriformes and columbiformes birds species. In Argentina, viral strains has been isolated from humans and mosquitoes (virulent strains) and from rodents (attenuated strains). Serological surveillance carried out in Cordoba city indicate an endemic and extended activity of SLEV. In contrast to the USA, encephalitis outbreak by SLEV are uncommon in the rest of the continent. However, an unexpected outbreak occurred in Cordoba province during summer-fall of 2005. Overall, 49 symptomatic cases were reported and two viral strains were isolated from Culex quinquefasciatus mosquitoes. Ecological studies allowed us to identify the main urban and periurban mosquito vector (Culex quinquefasciatus) and avian hosts (Eared doves and Picui ground dove) for SLEV in Córdoba. Our results pointed out that introduction of a new more viremogenic genotype and a high proportion of susceptible birds host availability previous the outbreak would be some of the causes for the SLEV re emergence in Córdoba.