Evidencia serológica de circulación del virus de la encefalitis de San Luis en aves de la Ciudad Autónoma de Buenos Aires, Argentina / Serological evidence of St. Louis encephalitis virus circulation in birds from Buenos Aires City, Argentina

Nuestro objetivo fue conocer la presencia de anticuerpos neutralizantes contra el virus de la encefalitis de San Luis (St. Louis encephalitis virus [SLEV]) y el virus del Nilo Occidental (West Nile virus [WNV]) en sueros de aves silvestres y domésticas de la Ciudad Autónoma de Buenos Aires, Argentina. Desde octubre del 2012 hasta abril del 2013 se colectaron 180 muestras que fueron procesadas por la técnica de microneutralización. El 7,2% de las aves muestreadas resultaron seropositivas para SLEV, mientras que no se detectaron aves seropositivas para WNV

Our goal was to determine the presence of neutralizing antibodies against St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) in sera of wild and domestic birds from Buenos Aires City, Argentina. From October 2012 to April 2013, 180 samples were collected and processed by the microneutralization technique. A 7.2 % of the sampled birds were seropositive for SLEV, while no seropositive birds for WNV were detected

South-South Cooperation: Brazilian experiences in South America and Africa / Cooperação Sul-Sul: experiências brasileiras na América do Sul e na África

Over recent years Brazil has played an increasingly active role internationally, the result of its model of integration and its foreign policy directives. The health sector is a valuable and strategic area for Brazilian technical cooperation to achieve various objectives, including its development goals. This article describes the main directives of Brazilian foreign policy, conceptually defining and characterizing South-South Cooperation, illustrated through an analysis of two Brazilian technical cooperation initiatives in healthcare: one in South America, the other in Africa. The study concludes that, irrespective of the interests and power asymmetries existing in South-South Cooperation, the objectives of this cooperation were achieved through the technical work.

Nos últimos anos, o Brasil foi ativo no âmbito internacional, tanto por seu modelo de inserção como pelas diretrizes de política externa. O setor saúde é uma ferramenta valiosa e estratégica utilizada pela cooperação técnica brasileira para lograr seus objetivos de desenvolvimento. Este artigo descreve as principais diretrizes de política externa brasileira, conceitua e caracteriza a Cooperação Sul-Sul, ilustrada mediante análise de duas iniciativas de cooperação técnica em saúde do Brasil: na América do Sul e na África. O estudo conclui que, independentemente dos interesses e das assimetrias de poder que existem na Cooperação Sul-Sul, os objetivos dessa cooperação foram alcançados por meio do trabalho técnico.

Serological detection of St. Louis encephalitis virus and West Nile virus in equines from Santa Fe, Argentina

St. Louis encephalitis virus (SLEV) and West Nile virus (WNV) present ecological and antigenic similarities and are responsible for serious human diseases. In addition, WNV is a significant pathogen in terms of equine health. The purpose of our study was to analyse the seroprevalence of SLEV and WNV in equine sera collected in Santa Fe Province, Argentina. The seroprevalence determined using the plaque reduction neutralisation test was 12.2% for SLEV, 16.2% for WNV and 48.6% for a combination of both viruses. These results provide evidence of the co-circulation of SLEV and WNV in equines in Santa Fe.

Presencia del virus del oeste del Nilo en el noreste de México / Presence of west Nile virus in northeast Mexico

OBJETIVO: Detectar la presencia del virus del oeste del Nilo (VON) en aves, equinos y seres humanos en el noreste de México. MATERIAL Y MÉTODOS: Se buscó en diferentes localidades del noreste de México la presencia de anticuerpos antivirus del oeste del Nilo (anti-VON) en suero de 33 aves, 24 caballos y 237 personas mediante pruebas de ELISA durante el periodo de julio de 2003 a julio de 2006. En los sueros humanos se buscó también el RNA-VON mediante RT-PCR. RESULTADOS: Se encontraron tres aves seropositivas y 15 equinos. En el hombre, 40 por ciento de los sueros fue positivo para anticuerpos IgG y ninguno para anticuerpos IgM. CONCLUSIONES: El VON se encuentra activo en México y se suma a otras enfermedades emergentes transmitidas por vectores que representan un reto a la investigación y a los programas de prevención.

OBJECTIVE: To investigate the presence of WNV in birds, horses and humans in northeast Mexico. MATERIAL AND METHODS: Serum samples from 33 birds, 24 horses and 237 humans were screened by ELISA for Anti-WNV antibodies. Human serum samples were also screened for WNV RNA using an RT-PCR assay. RESULTS: Positive sera were found in three birds and 15 horses. Forty percent of the human serum samples were positive for IgG antibodies and 0 percent for IgM antibodies and viral RNA. CONCLUSIONS: The results of this study show that WNV is present in northeast Mexico and it is a new emergent infectious agent that represents a challenge for research and prevention programs in Mexico.

El virus del Oeste del Nilo: una realidad en México / West Nile virus: a reality in Mexico

El virus del Oeste del Nilo (VON) es un virus ARN perteneciente a la familia Flaviviridae del género Flavivirus que causa infección en aves, equinos y humanos. La infección por VON es transmitida por el mosquito Culex sp. El ciclo de vida del virus incluye a los mosquitos como vectores y a las aves como huéspedes naturales. El virus mantiene un ciclo de transmisión mosquito–ave-mosquito. Los seres humanos son huéspedes accidentales. Se han reportado epidemias en Rumania, Nueva York e Israel. Mediante el programa de vigilancia epidemiológica en nuestro país, se han reportado 90 muestras positivas en 1,223 casos estudiados en aves hasta el 15 de Septiembre del 2005. La enfermedad por el VON se presenta con fiebre, malestar general, anorexia, nausea, vómito, cefalea, mialgia, erupción cutánea y linfadenopatía. La principal entidad clínica descrita es la encefalitis y la parálisis flácida. A mayor edad, es mayor el riesgo de enfermedad neurológica y muerte. Los métodos diagnósticos incluyen determinación de anticuerpos IgM e IgG en suero y/o liquido cerebroespinal. No existe tratamiento antiviral para la infección por VON. Algunas terapias que se han utilizado incluyen interferón α2b e inmunoglobulina específica contra VON. La prevención juega un papel crucial.

West Nile virus (WNV) is a RNA virus of the Flaviridae, genus flavivirus family. It is a neuropathogenic virus causing disease in birds, horses and humans. WNVis transmitted by the vector mosquito Culex sp. The virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. Humans are accidental hosts. Since the introduction of the Epidemiological Surveillance Program at the Ministry ofHealth. we have documented 90 positive test results among birds out of 1,223 cases studied in Mexico as of September IS. 2005. The incubation period in humans after a mosquito bite ranges from 3 to 14 days. Disease is characterized by early onset fever, general malaise, decreased appetite, nausea, vomiting, headaches, myalgias, enlarged lymph nodes andrash. Neurological manifestations include encephalitis andflaccid paralysis, which are present in less than 1% of subjects infected with WNV. Older patients display more adverse outcomes including death. The diagnosis is made by the determination of specific IgM and JgG antibodies in serum and/or cerebrospinal fluid. There is no antiviral treatment to date against WNV but interferon ?2b, and WNVspec4ic-immunoglobulin have been used Prevention is therefore the key to control the infection.

West Nile virus activity in Latin America and the Caribbean

OBJETIVOS: El virus del Nilo occidental (VNO, familia Flaviviridae, género Flavivirus) se ha propagado rápidamente por toda la cuenca del Caribe desde que se detectó por primera vez en 2001. En este informe se resumen nuestros conocimientos actuales acerca de la transmisión del VNO en zonas tropicales del continente americano. MÉTODOS: Revisamos todo lo que se ha publicado sobre el tema y consultamos a autoridades de salud clave para obtener datos inéditos. RESULTADOS: Las infecciones por el virus del Nilo occidental aparecieron por primera vez en seres humanos residentes de las Islas Caimán y de los Cayos de la Florida en 2001, y en pájaros de aspecto sano de los cuales se obtuvieron muestras a principios de 2002. En 2002 se encontraron pruebas serológicas de infección por el VNO en caballos, pollos y aves de corral no estabuladas oriundas de Guadalupe, la República Dominicana y la parte oriental de México. En 2003, el VNO se diseminó dentro de México y por la parte norte de Centroamérica y se encontraron pruebas serológicas en las Bahamas, Puerto Rico y Cuba. En 2004, las primeras pruebas serológicas de actividad vírica en ecosistemas sudamericanos se detectaron en septiembre y octubre en Colombia y Trinidad, donde se observaron anticuerpos neutralizantes contra el VNO en animales domésticos. CONCLUSIONES: Estos informes esporádicos de enfermedad equina, humana y aviar en América Latina y el Caribe son desconcertantes. Es necesario aislar las cepas para determinar si la atenuación del virus u otro factor explica la carga de enfermedad reducida en ecosistemas tropicales.

Effect of bird-to-bird transmission of the West Nile virus on the dynamics of the transmission of this disease.

Two recent publications report that direct bird-to-bird transmission of West Nile virus is possible. The effect of a bird-to-bird transmission on the transmission dynamics of this virus is studied through mathematical modeling. The model still treats the bird-to-mosquito-to-bird as the main transmission route. The results of numerical calculations show that there are changes in the dynamics of the transmission of West Nile fever in humans when the non-mosquito transmission route becomes more important.

Transovarial transmission of West Nile virus in Culex vishnui mosquito.

The phenomenon of transovarial transmission (TOT) of West Nile (WN) virus in Culex vishnui was studied. The virus was detected in the progeny of both first and second gonotropic cycles (G1 and G2). About 5.56 per cent pools of F1 progeny from the parent females infected by the oral route were found positive for WN virus. This is the first report of TOT of WN virus in this species of mosquito. The occurrence of this phenomenon is of considerable importance in view of complex natural cycle of the virus and the high density of this vector species in nature. The results suggest that this mosquito may be involved in the maintenance of this virus in nature.