Coquimbo Region Of Chile Research Articles

Urban domestic dog populations as a source of canine distemper virus for wild carnivores in the Coquimbo region of Chile

Urban areas can support dog populations dense enough to maintain canine distemper virus (CDV) and can be a source of infection for rural dogs and free-ranging carnivores. The aim of this study was to investigate the relationships between urban and rural domestic dog and wild carnivore populations and their effects on the epidemiology of CDV to explain retrospectively a CD outbreak in wild foxes in 2003. From 2005 to 2007 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge National Park (FJNP) in the Coquimbo region, Chile. Blood samples were collected from unvaccinated dogs at surveyed households and from free-ranging foxes in rural areas along the transects. The seroprevalence of CDV in domestic dogs was higher in urban than in rural areas and in the later was highest in dogs born before 2001–2002. The seroprevalence of CDV in foxes was higher in areas closer to human settlements. A high seroprevalence in dogs born before 2001–2002 further supports a link between CDV patterns in rural dog and fox populations. In our study area, urban dogs are proposed to be the source of CDV infection to wild carnivores. The large dog population size and density detected in Coquimbo and Ovalle provides optimal conditions for maintaining a large and dense susceptible population of dogs, which can act as a reservoir for highly infectious diseases and could have been the source of infection in the CD outbreak in wild foxes.

Echinococcus granulosus infection in domestic dogs in urban and rural areas of the Coquimbo region, north-central Chile

Hydatidosis is a zoonotic disease caused by the cystic stage of the cestode parasite Echinoccocus granulosus, in which the definitive hosts are mainly domestic dogs. This parasite is regarded mainly as a rural disease, where man is exposed through contact with eggs excreted by definitive hosts; however, some studies have shown that domestic dogs can get infected within urban areas. This study was conducted to assess differences in prevalence of E. granulosus in urban and rural sites in Coquimbo region of Chile. From 2005 to 2006 a cross-sectional household questionnaire survey was conducted in Coquimbo and Ovalle cities, in three towns and in rural sites along two transects from these cities to the Fray Jorge NP in the Coquimbo region. Faecal samples were collected from dogs during the questionnaire survey and tested for Echinococcus coproantigens. Positive dogs were found in urban areas. Analysis of risk factors indicated that dogs inhabiting the borders of urban areas were at greater risk of being coproantigen positive than those in the centre of these areas. These results are likely to be related to the custom of slaughtering livestock at home in urban areas during local celebrations, which could favour the importation of E. granulosus to urban areas by acquiring livestock contaminated with cysts from rural sites. This study shows that surveillance and control measures in livestock and domestic dogs need to be introduced in urban areas as well as rural areas of the Coquimbo region to reduce the public health risk of hydatid disease.

VEGETATIVE GROWTH AND EARLY PRODUCTION OF SIX OLIVE CULTIVARS, IN SOUTHERN ATACAMA DESERT, CHILE

Tree survival, early fruit production, vegetative growth and alternate bearing were examined in six different olive cultivars (Barnea, Biancolilla, Coratina, Empeltre, Koroneiki and Leccino) under intensive agronomic conditions i southern Atacama Desert, in the Coquimbo Region of Chile. The cultivars were evaluated over four successive years and had a high survival rate (93%) confi rming their potential for these dry-lands. Fruit production (recorded over the growing seasons 2002-2003), vegetative growth (2000-2003) and alternate bearing differed signifi cantly among cultivars. Olive selection in intensively managed planting at the southern part of the Atacama Desert depends on matching specifi c cultivars to sites on which they perform the best.

Andacollo copper–gold district, La Serena, Chile: preliminary data from the porphyry copper and possible relationships between Cu and Au mineralization

The Andacollo mining district is located in the Coquimbo region of Chile at 30°14’ south, 71°06’ west, some 55 km southeast of La Serena, at a mean elevation of 1030 m within a semi-arid hilly landscape (Fig. 1). Current mining activity in the district is concentrated on copper and gold. These metals are mined, respectively, from a porphyry copper deposit and epithermal, manto and vein gold deposits of adularia–sericite type.11,13 Other types of mineralization include mercury veins hosted by carbonate rocks. The gold veins are controlled by a northwest-trending set of normal faults, whereas the manto-type mineralization is strata-bound and largely confined to andesite breccias, dacites and sites of strong fracturing. The lateral and vertical continuity of the mantos is strongly controlled by rock type, faulting and intensity of fracturing. The gold deposits have been the focus of a recent study,11 but comparable information on the Andacollo porphyry has not become available. A brief, updated geological perception of the porphyry is now presented and possible relationships between the copper and gold deposits are analysed.