Reactividad de sueros de ratones inmunizados con vesículas de membrana externa derivadas de Salmonella entérica / Reactivity of sera from mice immunized with outer membrane vesicles derived from Salmonella enterica

La fiebre tifoidea causada por Salmonella Paratyphi A (fiebre paratifoidea) es indistinguible de la producida por Salmonella Typhi y el grado de incidencia ha aumentado en los últimos años, especialmente en el sudeste asiático. Por otro lado, la diarrea y otras complicaciones entéricas causadas por Salmonella Enteritidis y Salmonella Typhimurium continúan siendo un problema de salud grave, especialmente en países subdesarrollados. Las vacunas continúan siendo la forma más efectiva de prevenir estas enfermedades. Existen vacunas basadas en el polisacárido capsular de Salmonella Typhi que protegen contra la fiebre tifoidea; sin embargo, no hay vacunas efectivas licenciadas para uso en humanos que prevengan las enfermedades producidas por los serotipos de Salmonella no tifoideas. El desarrollo de una formulación con capacidad para proteger contra estas enfermedades sigue siendo un desafío para la comunidad científica. En este trabajo se evaluó, mediante Western blot, la reactividad de los sueros de ratones inmunizados por vía subcutánea con formulaciones basadas en vesículas de membrana externa derivadas de Salmonella Paratyphi A, Salmonella Enteritidis y Salmonella Typhimurium, contra los respectivos lisados celulares, para identificar la formulación que induce la mejor respuesta inmunológica cruzada. Los resultados obtenidos indicaron una alta reactividad de todos los sueros a los lisados, sin una diferencia aparente entre ellos. Sin lugar a dudas, se deberán realizar pruebas de inmunogenicidad seguidas de pruebas de retos cruzados para identificar un candidato vacunal. Estos resultados sugieren que las vesículas de membrana externa empleadas en este estudio están compuestas por antígenos posiblemente conservados en los tres serotipos de Salmonella y que pueden inducir una respuesta inmune de amplio espectro y protección cruzada(AU)

Typhoid fever caused by Salmonella Paratyphi A (paratyphoid fever) is indistinguishable from that caused by Salmonella Typhi and the degree of incidence has increased in recent years, especially in Southeast Asia. On the other hand, diarrhea and other enteric complications caused by Salmonella Enteritidis and Salmonella Typhimurium continue to be a serious health problem, especially in underdeveloped countries. Vaccines continue to be the most effective way to prevent these diseases. There are vaccines based on Salmonella Typhi capsular polysaccharide, which protects against typhoid fever; however, there are no effective vaccines licensed for use in humans to prevent disease caused by nontyphoidal Salmonella serotypes. Developing a formulation capable of protecting against these diseases remains a challenge for the scientific community. In this work, the reactivity of the sera of mice immunized subcutaneously with formulations based on Outer Membrane Vesicles (OMV) derived from Salmonella Paratyphi A, Salmonella Enteritidis and Salmonella Typhimurium, was evaluated by Western blot, against the respective cell lysates to identify the formulation that induces the best cross immune response. The results obtained indicated a high reactivity of all the sera to the lysates; without an apparent difference between them. Undoubtedly, immunogenicity tests followed by cross-challenge tests should be performed to identify a vaccine candidate. These results suggest that the OMV used in this study are composed of possibly conserved antigens in the three Salmonella serotypes and that they can induce a broad-spectrum immune response and cross protection(AU)

Localised transmission hotspots of a typhoid fever outbreak in the Democratic Republic of Congo

Introduction: in a semi-urban setting in the Democratic Republic of Congo, this study aims to understand the dynamic of a typhoid fever (TF) outbreak and to assess: a) the existence of hot spots for TF transmission and b) the difference between typhoid cases identified within those hot spots and the general population in relation to socio-demographic characteristics, sanitation practice, and sources of drinking water.Methods: this was a retrospective analysis of TF outbreaks in 2011 in Kikwit, DRC using microbiological analysis of water sources and a structured interview questionnaire.Results: there were a total of 1430 reported TF cases. The outbreak's epidemic curve shows earliest and highest peak attack rates (AR) in three military camps located in Kikwit (Ebeya 3.2%; Ngubu 3.0%; and Nsinga 2.2%) compared to an average peak AR of 0.6% in other affected areas. A total 320 cases from the military camps and the high burden health areas were interviewed. Typhoid cases in the military camps shared a latrine with more than one family (P<0.02). All tap water sources in both the military camps and general population were found to be highly contaminated with faecal coliforms.Conclusion: the role of military camps in Kikwit as early hotspots of TF transmission was likely associated with lower sanitary and hygiene conditions. The proximity of camps to the general population might have been responsible for disseminating TF to the general population. Mapping of cases during an outbreak could be crucial to identify hot spots for transmission and institute corrective measures

Occupational hazards for surgeons

In spite of the radical advances made in the field of surgery to save lives, we find it is the surgeons who are becoming the patients by being exposed to a host of occupational hazards, which places them at a significant risk of acquiring many infectious diseases in addition to other safety threats. In context to guidelines set down by International Labor Organization the hazards a surgeon can face at work can be broadly categorized into Accidental, Chemical, Biological, and Ergonomic, Psychosocial and Organizational Hazards. To identify the occupational hazards surgeons face in our set-up and their inevitable consequences as compared to international standards. Setting The survey was carried out in a major tertiary care hospital of Lahore with inspection of operation theatres, surgical emergency room, and surgical wards. The surgeons in our setup are exposed to infectious diseases such as Hepatitis B and C, HIV and typhoid via accidental pinpricks from infected needles and s harps due to multiple hazards. Other risks include latex sensitization, back problems, post-traumatic stress syndrome and many others. Spread of awareness of these occupational hazards should be undertaken with a change in attitudes

Six month follow-up study on Salmonella typhi and Salmonella paratyphi. A infections for carrier state

Humans are the only natural reservoir of Salmonella typhi and Salmonella paratyphi A., therefore, the disease can be acquired through proximity with a person who is a chronic carrier. Most often this involves acquisition of organisms via ingestion of food or water contaminated with human excreta. A follow up study was carried out at the Armed Forces institute of Pathology [AFIP] Rawalpindi on 22 patients at two monthly intervals over a period of six months, with the objective to detect Salmonella typhi and Salmonella paratyphi A carrier state among these patients. Follow up investigations included stool cultures for both salmonella infections. None of our cases terminated as chronic carrier for Salmonella typhi and S. paratyphi A

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

Prevalence of typhoid fever among patients attending Saddam general hospital in Kirkuk

A retrospective study was carried out in Saddam general hospital at Kirkuk city for the period of January to September 1996 to investigate the prevalence of typhoid fever disease. A total of 136 patients were recognized as typhoid fever. Forty two were males while 94 were females. The age group of 20-29 years was the most frequent group [25%] and over 90% of cases were urban in residence while 38.2% of patients were housewives. The relation of some clinical symptoms and laboratory diagnosis with occurrence of disease was also studied

Vacunación contra la fiebre tifoidea / Vaccination against typhoid fever

La fiebre tifoidea es una enfermedad infecciosa aguda y febril causada por Salmonella typhi. La infección se adquiere por medio de la ingestión de alimentos o agua masivamente contaminados con la bacteria. Debido a que este microorganismo afecta sólo al ser humano y no hay reservorios animales, el elemento más importante en la cadena de transmisión son los individuos que no presentan sintomatología clínica pero son portadores y excretores activos del agente (portadores asintomáticos). En México, la enfermedad tiene características endémico-epidémicas relacionadas con deficiencias en el saneamiento ambiental y el aprovisionamiento de agua potable. La tasa de letalidad es de alrededor del 1 por ciento, sin embargo en los casos complicados puede ascender hasta el 30 por ciento. La vacuna que se utiliza más ampliamente en la actualidad es la inactivada por calor y fenol, la cual tiene efectos colaterales debido al LPS que siempre lo contamina. Además, confiere protección parcial y de corta duración, por lo tanto su empleo se ha limitado a grupos considerados como de alto riesgo y no está indicada en niños. La vacuna de Germanier -mutante avirulenta de Salmonella que se administra por vía oral- proteje hasta un 95 por ciento, siempre y cuando antes de administrarse se neutralice el jugo gástrico, aunque su utilización general en Salud Pública es impráctica. Ya que las porinas son buenos inmunógenos en modelos animales, la obtención de un conjugado antígenico Vi-porinas puede ser una excelente opción como vacuna contra la fiebre tifoidea

Typhoid fever in children of low and high socioeconomic strata: comparison of hygiene habits

Objetiva-se estudar a avaliar os hábitos de higiene de crianças que já frequentavam escola por um ou dois anos e que recentemente tiveram ffebre tifóide. Levantou-se a hipótese de que as crianças, independentemente do nível sócio-econômico, teriam adquirido febre tifóide devido as seus inadequados hábitos de higiene, os quais facilitaram o ciclo fecal-oral. A amostra foi formada por 40 díadas (mäe-filho): 20 de baixo nível sócio-econômico (grupo A) e 20 de alto nível sócio-econômico (grupo B) que haviam tido febre tifóide. Os resultados indicaram que os hábitos de higiene das crianças em relaçäo ao ciclo fecal-oral, as observaçöes sobre a limpeza do toalete e as explicaçöes das mäes a respeito dos hábitos higiênicos de seus filhos, säo semelhantes em ambos os grupos. Os resultados sugerem ser irrelevante o nível sócio-econômico, no caso da febre tifóide, mas que os hábitos de higiene säo importantes. Sugere-se que as políticas de saúde pública sejam modificadas, incluindo o ensino de hábitos de higiene adequados, principalmente aqueles que se referem ao ciclo fecal-oral .

Investigacion sobre el estado de portador de Salmonella typhi-paratyphi en pacientes intervenidos por patologia vesicular / Research on Salmonella typhi-paratyphi carrier state in patients submitted to surgery of gallbladder disease

La elevada morbilidad de la fiebre tifoidea en Chile, junto a los datos demostrativos de que existe una correlacion entre el estado de portador de S. typhi y las colecistopatias encontradas en otros lugares, condujo a analizar 1000 muestras de bilis de pacientes con colecistopatia. Los resultados indican que la prevalencia excepcionalmente elevada de colecistopatias en Chile constituye un factor importante en la transmision de la fiebre tifoidea