Protocolo del Sistema Nacional de Vigilancia Epidemiológica: enfermedades transmitidas por agua y alimentos. No. 03 / Protocol of the National Epidemiological Surveillance System: water and foodborne diseases. No. 03

Estos protocolos están dirigido a personal médico, paramédico y otros profesionales que realizan acciones gerenciales y operativas de vigilancia epidemiológica en los servicios de salud del país, y están divididos en varios tomos para dar a conocer y actualizar la identificación y medidas de control para diversos padecimientos a fin de continuar con el mejoramiento de las capacidades técnicas de los trabajadores de salud, que permita planificar la prestación de servicios con decisiones partiendo de un enfoque epidemiológico comprobado, para responder a los cambios de tendencias epidemiológicas y con ello contribuir al fortalecimiento de prácticas asertivas de la salud pública de nuestro país. Las enfermedades transmitidas por alimentos y agua (ETA´s), constituyen un importante problema de Salud Pública, debido a su magnitud, trascendencia, tendencia fluctuante y aumentos en su comportamiento durante el año, lo que ha significado etapas de emergencia, re emergencia, aparición de agentes nuevos con potencial epidémico y el incremento a la resistencia a los antimicrobianos con impacto negativo económico, en grupos de población. Las enfermedades transmitidas por alimentos y agua, se registran entre las primeras diez causas de morbilidad y mortalidad en el país; evento notificado como enfermedad diarreica, con frecuencia los servicios de salud tienen poca capacidad de respuesta para identificación del agente etiológico, limitándose a implementar medidas de control eficientes de las fuentes de infección o contaminación y divulgación de acciones dirigidas a minimizan los factores de riesgo identificados.

Typhoid fever & vaccine development: a partially answered question.

Typhoid fever is a systemic disease caused by the human specific Gram-negative pathogen Salmonella enterica serovar Typhi (S. Typhi). The extra-intestinal infections caused by Salmonella are very fatal. The incidence of typhoid fever remains very high in impoverished areas and the emergence of multidrug resistance has made the situation worse. To combat and to reduce the morbidity and mortality caused by typhoid fever, many preventive measures and strategies have been employed, the most important being vaccination. In recent years, many Salmonella vaccines have been developed including live attenuated as well as DNA vaccines and their clinical trials have shown encouraging results. But with the increasing antibiotic resistance, the development of potent vaccine candidate for typhoid fever is a need of the hour. This review discusses the latest trends in the typhoid vaccine development and the clinical trials which are underway.

Inmunizaciones: [revisión] / Immunizations: [review]

Los avances en la prevención de la enfermedad diarreica aguda con el uso de vacunas orales están presentes gracias a las investigaciones en el área de los trabajos realizados en cólera, fiebre tifoidea y con más éxito en la prevención de la diarrea por rotavirus. en este consenso desarrollamos los elementos actualizados en la inmunización contra cólera, fiebre tifoidea, indicaciones y futuras vacunas. en especial, se hace referencia a la vacunación contra rotavirus, sus estudios iniciales, evaluación de la investigación en fase III (realizada en Venezuela), las características particulares de cada vacuna desarrollada y en uso hoy en día, su aplicación y seguimiento una vez iniciado el plan nacional de vacunación, finalizando con los estudios de impacto económico y costo-efectividad.

Advances in prevention of acute diarrheal disease with the use of oral vaccines have been accomplished thanks to research in cholera, typhoid fever and, with more success, in the prevention of rotavirus diarrhea. This consensus addresses updates in immunization against cholera, typhoid fever, indications and future vaccines. In particular, we refer to vaccinations against rotavirus, their initial studies, research evaluation in phase III (held in Venezuela), particular characteristics of each vaccine developed and in use today, and the follow up of its implementation once the national vaccination plan is initiated. Final considerations in relation to the economic impact and cost effectiveness studies are stated.

Co-infection of hepatitis A and E with Salmonella infection; a case report

Ours is a developing country so infectious diseases contribute maximum to the morbidity and mortality. Among these, water borne diseases like diarrhea, typhoid, infectious hepatitis etc. are on rise. Sometimes more than one type of infection coexists which makes the diagnosis and management a challenging task. We report a case of Coinfection of Salmonella typhi with Hepatitis A and E. A 5 year old male child came to us with complaints of fever and jaundice for last 9 days. Blood culture of patient was positive for Salmonella typhi. Viral markers turned out to be positive for Hepatitis A and E. To the best of our knowledge coinfection of Hepatitis A and E with Salmonella has rarely been reported earlier. In view of the restricted finances in our country vaccines against typhoid and Hepatitis A can not be incorporated in the national immunization schedule at present but these vaccines can be offered on an individual basis

The feasibility of a school-based VI polysaccharide vaccine mass immunization campaign in Hue City, central Vietnam: streamlining a typhoid fever preventive strategy.

We report the coverage, safety, and logistics of a school-based typhoid fever immunization campaign that took place in Hue City, central Vietnam; a typhoid fever endemic area. A cluster-randomized evaluation-blinded controlled trial was designed where 68 schools (cluster) were randomly allocated the single dose Vi polysaccharide vaccine (Typherix) or the active control hepatitis A vaccine (Havrix). A safety surveillance system was implemented. A total of 32,267 children were immunized with a coverage of 57.5%. Strong predictors for vaccination were attending primary schools, peri-urban location of the school, and low family income. Human resources were mainly schoolteachers and the campaign was completed in about 1 month. Most adverse events reported were mild. Safe injection and safe sharp-waste disposal practices were followed. A typhoid fever school-based immunization campaign was safe and logistically possible. Coverage was moderate and can be interpreted as the minimum that could have been achievable because individual written informed consent procedures were sought for the first time in Hue City and the trial nature of the campaign. The lessons learned, together with cost-effectiveness results to be obtained by the end of follow-up period, will hopefully accelerate the introduction of Vi typhoid fever vaccine in Vietnam.

Bacteriological analysis of water samples from tsunami hit coastal areas of Kanyakumari district, Tamil Nadu.

Water borne diseases such as cholera, enteric fever and dysentery were expected after the tsunami, which hit the coastal areas of Kanyakumari district, Tamil Nadu. In the present study 151 drinking water sources were collected from the tsunami affected villages and relief shelters and tested for coliforms and pathogens. Nine well water samples were also collected for specific bacteriological analysis. Presence of coliforms was detected in 56 (37%) water samples. One isolate each of Salmonella Paratyphi B and NAG Vibrio were isolated from two well water samples. There was no report of acute diarrhoeal diseases or typhoid illness during the post tsunami period monitored by a field microbiology laboratory for a month.

Salmonella como vetor de vacinas vivas orais / Live oral vaccines using salmonella

Hß alguns anos, foram desenvolvidas as primeiras linhagens atenuadas de Salmonella para serem utilizadas como candidatas a vacinas vivas orais contra a febre tifóide. No início, ainda eram desconhecidas as mutações responsáveis pelo fenótipo atenuado, mas, com o acúmulo de conhecimento sobre a genética associada à virulência, surgiram novas linhagens com atenuações geneticamente definidas. Muitas linhagens de S. enterica sorotipo Typhimurium e S. enterica sorotipo Typhi já foram bem estudadas quanto à capacidade de induzir resposta imunológica em modelos animais e em humanos. Com o desenvolvimento de sistemas de clonagem e expressão eficientes, o uso destas linhagens vacinais extrapolou o problema das salmoneloses, uma vez que tornou-se possível a produção e administração de antígenos de diferentes agentes patogênicos. Recentemente, uma nova tecnologia que vem sendo explorada é o uso de Salmonella como carreadora de vacinas de DNA. Tais vacinas já se mostraram capazes de induzir potentes respostas humorais e celulares contra antígenos heterólogos nos organismos hospedeiros. Todo este progresso nos estudos com as linhagens vacinais de Salmonella demonstra o potencial que elas possuem para a produção das futuras vacinas contra doenças infecciosas, parasitárias e até mesmo contra o câncer.

Infecciones tropicales en viajeros a Latinoamérica: parte II / Tropical diseases in travelers to Latin America: part II

Las infecciones permanecen como una de las más importantes causas de morbilidad entre los viajeros. Los países de América Latina son uno de los puntos de destino más importantes. Las dos enfermedades de mayor frecuencia son malaria y diarrea del viajero; sin embargo, Latinoamérica es aún un importante lugar de transmisión de fiebre amarilla, dengue, leishmaniasis, hepatitis por virus A, hepatitis por virus B y enfermedades de transmisión sexual. Alrededor del 7 por ciento de los casos de malaria en el viajero en todo el mundo, se adquirieron en Sudamérica y 40 a 60 por ciento de ellos son causados por Plasmodium falciparum. Se deben suministrar a los viajeros recomendaciones adecuadas de vacunación, quimioprofilaxis y medidas de protección individual, orientadas a sus lugares de destino. Un problema interesante de discutir es la enfermedad en el viajero que retorna a casa

Infecciones tropicales en viajeros a Latinoamérica: parte I / Tropical diseases in travelers to Latin America: part I

Las infecciones permanecen como una de las más importantes causas de morbilidad entre los viajeros. Los países de América Latina son uno de los puntos de destino más importante. Las dos enfermedades de mayor frecuencia son malaria y diarrea del viajero; sin embargo, Latinoamérica es aún un importante lugar de transmisión de fiebre amarilla, dengue, leishmaniasis, hepatitis por virus A, hepatitis por virus B y enfermedades de transmisión sexual. Alrededor de 7 por ciento de los casos de malaria en el viajero en todo el mundo se adquieren en Sudamérica, y 40 a 60 por ciento de ellos son causados por Plasmodium falciparum. Se deben suministrar a los viajeros recomendaciones adecuadas de vacunación, quimioprofilaxis, y medidas de protección individual, orientados a sus lugares de destino. Un problema interesante a discutir es la enfermedad en el viajero que retorna a casa

Molecular characterization and optimization of VI-capsular polysaccharide of salmonella typhi TY6S production in bioreactor

The role of Vi-capsular polysaccharide [Vi-CPS] in human immunity against infection caused by Salmonella typhi is well known. The downstream process of purification generally causes depolymerization of Vi-CPS to a nonimmunogenic low molecular weight form. In the present study, a standard strain of Sal. typhiTy6s was grown under submerge cultural conditions in a pilot-plant scale of 90 liter fermentor. At the late exponential growth phase, crude polysaccharide was obtained from fermentation broth by detergent-phenol extraction method and purified by ultracentrifuge differentiation technique. Analytical data reveals that by optimization of fermentation parameters, not only was the yield of production increased from 1.6 mg/L to 4.9 mg/L, but also the polysaccharide retained its native molecular stability and immunogenicity. Therefore, purified Vi-CPS can be regarded as a reliable immunogen to control typhoid fever in man

Immunogenicity of Vi capsular polysaccharide vaccine evaluated for three years in Korea

The immunogenicity of a single dose of Salmonella typhi(S.typhi) Vi capsular polysaccharide(CPS) vaccine was evaluated before, and at 1, 3, 12, and 36 months after vaccination. Eighty-five adults(20-28 years of age) and sixty-four children(8-16 years of age) received a single dose of 25 micrograms Vi CPS vaccine intramuscularly, and antibody titers to Vi CPS were measured by passive hemagglutination. Of 149 vaccinees, 138(92.6%) showed seroconversion at 1 month after vaccination, and then 138 out of 141(97.9%) did at 3 months. Of 137 vaccinees, 116(84.7%) maintained a persistent rise in Vi antibody titer 12 months after vaccination, and 55 out of 100(55.0%) had a 4-fold or greater rise at 36 months. No significant adverse reactions were observed. Booster injection may be needed 3-5 years after vaccination.