Epidemiological description of the sea lice (Caligus rogercresseyi) situation in southern Chile in August 2007.

Salmon sea lice represent one of the most important threats to salmon farming throughout the world. Results of private monitoring efforts have shown an increase in the number of positive cages and cage-level abundance of sea lice in southern Chile since 2004. As a consequence, the Chilean Fisheries Service implemented an Official Surveillance Program in the main salmon production area of southern Chile to assess the situation of sea lice in fish farms. Results showed that the prevalence of sea lice in the fish farms was 53.4%, ranging from 3.5% in Puerto Aysén to 100% in the Seno de Reloncaví zone. The average sea lice abundance was 11.8 per fish (Geometrical mean (GM)=8.61, 95% CI (2.1-6.9)). The highest levels were found in Seno de Reloncaví (GM=24.99, 95% CI (15.9-39.2)), Hornopirén (GM=14.7, 95% CI (10.4-20.8)) and Chiloé norte (GM=9.75, 95% CI (1-1.9)), and the lowest loads were observed in Puerto Aysén (GM=1.35, 95%CI (1-1.9)) and Puerto Cisnes (GM=1.67, 95%CI (1.1-2.6)). Salmo salar and Oncorhynchus mykiss had the highest abundance levels (GM=6.93, 95% CI (5.7-8.5), and (GM=5.55, 95% CI (3.6-8.5), respectively). O. kisutch showed lower levels (GM=1.34, 95% CI (1-1.7)), apparently being more resistant to infestation. Sea lice in farmed salmon are widely distributed in different zones of southern Chile, and are becoming a serious threat to this industry. Prevalence and abundance levels were found to be generally high, decreasing in southern zones.

Veterinary epidemiology in Latin America.

Veterinary epidemiology began in different Latin American countries during the 1960s and the 1970s in different universities and state-run institutes of animal health. The discipline evolved as a continuation of the activities veterinarians carried out in the areas of public health, infectious diseases, biostatistics, and the planning and administration of animal health programs. From the outset, the concepts were oriented towards covering the whole spectrum of factors involved in animal health, including political and social factors. Subsequently, the aforementioned factors were complemented with scientific and methodological support, backed by post graduate qualifications offered by the North America and European universities, together with financial support from intergovernmental organizations. One important contribution for the Latin American veterinary epidemiology and economics community was the ISVEE 10 which took place in Chile in 2003, which served to link many professionals and scientists with the world of people working in those themes. Whilst the study programs of veterinarians of the Latin American universities have different forms and depths when delivering competencies in epidemiology, most have similar conceptual and methodological elements. Ideally, the profile of an epidemiology teacher should include the qualities of dreamer and explorer of new theme worlds, combined with simplicity and openness to the world. A teacher's knowledge should transcend worlds and be enriched by what takes place outside the bounds of their geographic or university frontiers.

Diagnostic efficiency of Brucella soluble antigens in immunodiffusion tests and ability to differentiate Brucella abortus strain 19 vaccinated cattle

Foram comparados três antígenos solúveis: um hapteno nativo (NH) de B. melitensis 16M, um polissacarídeo (PS) obtido de B. abortus 1119-3 e outro polissacarídeo de cadeia O (O-Chain) originado também da última Brucella. Os testes de imunodifusão radial (RID) e imunodifusão em gel de ágar (AGID) foram confrontados com as três classes de soros bovinos: a) infectados naturalmente (n = 76), b) não infectados (n = 130) e c) vacinados com B19 (n = 61) reagindo a testes sorológicos clássicos. Foram determinadas a sensibilidade (Se), a especificidade (Sp) e a capacidade para discriminar vacinados (ADV). A Se mais alta (84,3%) no teste RID foi demonstrada pelo antígeno NH, enquanto os três antígenos tiveram 100% de Sp. O antígeno O-Chain teve 100% de ADV nesse teste. O teste AGID com estes antígenos demonstrou 100% Sp e ADV, enquanto o antígeno PS mostrou uma melhor Se (86,6%). Finalmente, por sua qualidade de produção e eficiência, os antígenos PS e NH representam uma alternativa segura e econômica para o diagnóstico suplementar da brucelose.