The impact of the climate on the epidemiology of Dirofilaria immitis in the pet population of the Canary Islands.

Cardiopulmonary dirofilariosis (heartworm) is a zoonotic vector borne disease caused by Dirofilaria immitis which affects domestic dogs and cats. Two of the seven Canary Islands are historically hyperendemic areas of dirofilariosis, although no epidemiological study has ever been carried out which includes the other islands. The aim of the study was to complete the epidemiological status of cardiopulmonary dirofilariosis in the canine and feline population throughout all the Canary Islands. 1643 client-owned dogs and 707 client-owned cats were tested for D. immitis antigens (dogs), and anti-D. immitis and anti-Wolbachia antibodies (cats). The prevalence of canine dirofilariosis in the Canary Islands was 15.7%, and the seroprevalence of feline dirofilariosis was 18.1%. A remarkable disparity was found when evaluating the results by island separately, which ranged from from 0% in Lanzarote and El Hierro, low prevalences and seroprevalences in Fuerteventura (1.8% and 2.5% in dogs and cats, respectively), to higher prevalences on the other 4 islands; ranging between 15.7% (dogs) and 14.3% (cats) in La Palma 22.5% (dogs) and 24.1% (cats) in Tenerife. In addition, prevalences and seroprevalences were very variable within each island, these differences being associated to local climate conditions. The distribution and prevalence of dirofilariosis in the Canary Islands is heterogeneous and related to climate, demographic factors and management of pets in the studied areas. Dirofilariosis remains hyperendemic in 4 of the 7 Islands. Since D. immitis is a zoonosis, veterinary and health authorities should be aware of the current prevalence and seroprevalence of animal dirofilariosis. The results show the need for awareness raising campaigns to promote the implementation of prophylactic measures in pets, in order to achieve a decrease in the prevalence of animal dirofilariosis in the Canary Islands.

Genetic Structure of Peruvian Populations of Phytophthora infestans.

ABSTRACT Isolates of the late blight pathogen Phytophthora infestans (n = 327) from the central to southern Peruvian Andes were systematically collected in 1997 to 1999 and analyzed to determine the pathogen's population structure at its host's center of diversity. No isolates of the A2 mating type were detected. Cluster analysis of DNA fingerprinting data indicated that the collection consisted of five major groups that were interpreted to be clonal lineages. Two of the lineages (US-1 and EC-1) have been previously described, and three (PE-3, 5, and 6) are described here for the first time. Collections from three areas in the central Peruvian Andes, including two key sites used in an international potato breeding program, consisted of isolates of the EC-1 lineage, which has been reported to dominate the pathogen population in Andean countries to the north of Peru. The collections from Cusco and Puno were more diverse. More than one lineage was detected in 10 of the 20 fields sampled in Cusco. Data on virulence, metalaxyl sensitivity, and band data for allozymes, mitochondrial DNA, and ipiB1 suggested that PE-3 may have been produced through recombination events between US-1 and EC-1. Restriction fragment length polymorphism and amplified fragment length polymorphism marker data were not consistent with this hypothesis.

TSP, PM10 and PM10/TSP ratios in the Mexico City Metropolitan area: a temporal and spatial approach.

Data for PM10 and TSP collected from SEDUE's (Secretary of Urban Development and Ecology) five principal air monitoring stations from March of 1988 to March of 1989 were analyzed with an emphasis on spatial and temporal distributions. The Mexico City sites consisted of a mixed residential and industrial setting in the NW, a highly industrialized area in the NE, the commercial and administrative district downtown, and areas in the SW and SE dominated by residential neighborhoods. High volume samplers for TSP and PM10 running in parallel were used following a protocol similar to the one specified by the U.S. Environmental Protection Agency. The individual data collected ranged from 24 to 1494 micrograms/m-3 for TSP and from 17 to 607 micrograms/m-3 for PM10. The PM10-to-TSP ratios ranged from 0.104 to 0.914 for a one year period, 0.495 being the overall mean ratio. Seasonal and geographical differences in this ratio may reflect the range of sources, transport and transformations of primary and secondary particles. High concentrations of particles were found during the winter and early spring, followed by relatively low concentrations during the summer. Statistically significant differences were found for the two most contrasting sites, the NE and SW areas of the city. The northern and eastern parts were the most impacted by particulate matter, while the area at the southwestern edge of the city was least polluted by fine and total suspended particles. Two interesting observations have emerged from this analysis. First, there is the exceedingly high daily and annual values for both TSP and PM10, relative to the Mexican and U.S. standards and WHO criteria for particulate matter. Second, although the SW area of Mexico City had the lowest fine suspended particle concentrations, it is in this area that the highest concentrations of ozone have been observed.