Segunda encuesta nacional de infecciones parasitarias intestinales en Cuba, 2009 / Second national survey of intestinal parasitic infections in Cuba, 2009

Introducción: en Cuba las parasitosis intestinales continúan siendo endémicas, con una mayor frecuencia en zonas rurales y montañosas. Después de haber transcurrido casi 25 años desde la última encuesta nacional, se hizo necesario hacer una nueva encuesta para conocer los índices de prevalencia de las parasitosis intestinales y comparar los resultados obtenidos entre ambos estudios. Tal conocimiento resultaría de gran valor para elaborar estrategias de salud y el diseño de programas de control de las infecciones parasitarias intestinales. Objetivo: determinar los índices actuales de prevalencia de las parasitosis intestinales, y comparar los resultados con los de la encuesta anterior luego de haber transcurrido 25 años. Métodos: se realizó un estudio descriptivo de corte trasversal durante los meses de mayo a agosto de 2009 en una muestra de la población cubana. A cada uno se le recogió una muestra de heces que fue analizada por el método de examen directo, la técnica de concentración de Willis y el examen de Kato-Katz; también se le llenó un cuestionario. Resultados: al comparar los resultados de las encuestas nacionales de infecciones parasitarias intestinales realizadas en 1984 y 2009, se encontró que en general disminuyeron las infecciones por parásitos, tanto los helmintos como los protozoos patógenos, aunque los infectados con comensales aumentaron su frecuencia en la de 2009. También se produjo una disminución de las frecuencias de infecciones por todas las especies de geohelmintos, Trichuris trichiura, Ascaris lumbricoides, ancylostomídeos, y Strongyloides stercoralis, así como por los protozoos patógenos Giardia lamblia y Entamoeba histolytica/E. dispar, y los comensales: Endolimax nana y Entamoeba coli en 2009. La única especie de parásito intestinal que aumentó su frecuencia con respecto a la encuesta de 1984 fue Enterobius vermicularis. En ambos estudios la frecuencia de infección con parásitos o comensales fue mayor en el grupo de 5 a 14 años (edad escolar). Conclusiones: al comparar los resultados de las encuestas nacionales de infecciones parasitarias intestinales realizadas en 1984 y 2009, se encontró que en general disminuyeron las frecuencias de infecciones con parásitos intestinales. El hallazgo en ambos estudios de una frecuencia mayor de infección con parásitos o comensales en el grupo de 5 a 14 años (edad escolar), respalda la recomendación de poner énfasis en los programas de control para las parasitosis intestinales en este grupo de edad.

Introduction: the intestinal parasitic infections are still endemic in Cuba, with a higher frequency in rural and mountain regions. Twenty five years after the last national survey, it deemed necessary to carry out a new national survey in order to know the prevalence of intestinal parasitic infections and to compare the obtained results between both studies. That knowledge would be valuable to work out strategies of health and to design a control program for intestinal parasitic infections in Cuba. Objective: to determine the current prevalence of intestinal parasitic infections in Cuba and to compare these results with those obtained from the previous survey after a 25 year-period. Methods: a cross sectional study was conducted from May to August of 2009 in a sample of Cuban population. A stool sample was collected from each individual, which was analyzed by direct examination, Willis' brine flotation method and the Kato-Katz thick smear technique. Additionally, a questionnaire was administered. Results: the comparison between 1984 and 2009 surveys showed a general decrease of frequencies of intestinal parasitic infections caused by both helminths and pathogenic protozoa; however, the percentage of infections with commensal protozoa increased in 2009. In this last survey, there was observed decline of frequencies of infections with soil transmitted species, Trichuris trichiura, Ascaris lumbricoides, hookworm, and Strongyloides stercoralis and the pathogenic protozoa: Giardia lamblia, Entamoeba histolytica/E. dispar, and the commensals: Endolimax nana and Entamoeba coli. The intestinal parasite Enterobius vermicularis was the only parasitic species that increased the frequency of infections with respect to the 1984 survey. The frequencies of parasitic and commensal infections in both studies were higher in the 5-14 y age group (school age). Conclusions: the comparison between the intestinal parasitic infections surveys of 1984 and 2009 showed a reduction in the frequencies of intestinal parasitic infections in the last survey. The finding in both studies of a higher frequency of pathogenic parasitic infections and commensal infections in the 5-14 y age group (school age) supports the recommendation of making emphasis on the control programs for intestinal parasitic infections in this age group.

Segunda encuesta nacional de infecciones parasitarias intestinales en Cuba, 2009 / Second national survey of intestinal parasitic infections in Cuba, 2009

Introducción: en Cuba las parasitosis intestinales continúan siendo endémicas, con una mayor frecuencia en zonas rurales y montañosas. Después de haber transcurrido casi 25 años desde la última encuesta nacional, se hizo necesario hacer una nueva encuesta para conocer los índices de prevalencia de las parasitosis intestinales y comparar los resultados obtenidos entre ambos estudios. Tal conocimiento resultaría de gran valor para elaborar estrategias de salud y el diseño de programas de control de las infecciones parasitarias intestinales. Objetivo: determinar los índices actuales de prevalencia de las parasitosis intestinales, y comparar los resultados con los de la encuesta anterior luego de haber transcurrido 25 años. Métodos: se realizó un estudio descriptivo de corte trasversal durante los meses de mayo a agosto de 2009 en una muestra de la población cubana. A cada uno se le recogió una muestra de heces que fue analizada por el método de examen directo, la técnica de concentración de Willis y el examen de Kato-Katz; también se le llenó un cuestionario. Resultados: al comparar los resultados de las encuestas nacionales de infecciones parasitarias intestinales realizadas en 1984 y 2009, se encontró que en general disminuyeron las infecciones por parásitos, tanto los helmintos como los protozoos patógenos, aunque los infectados con comensales aumentaron su frecuencia en la de 2009. También se produjo una disminución de las frecuencias de infecciones por todas las especies de geohelmintos, Trichuris trichiura, Ascaris lumbricoides, ancylostomídeos, y Strongyloides stercoralis, así como por los protozoos patógenos Giardia lamblia y Entamoeba histolytica/E. dispar, y los comensales: Endolimax nana y Entamoeba coli en 2009. La única especie de parásito intestinal que aumentó su frecuencia con respecto a la encuesta de 1984 fue Enterobius vermicularis. En ambos estudios la frecuencia de infección con con parásitos o comensales fue mayor en el grupo de 5 a 14 años...(AU)

Introduction: the intestinal parasitic infections are still endemic in Cuba, with a higher frequency in rural and mountain regions. Twenty five years after the last national survey, it deemed necessary to carry out a new national survey in order to know the prevalence of intestinal parasitic infections and to compare the obtained results between both studies. That knowledge would be valuable to work out strategies of health and to design a control program for intestinal parasitic infections in Cuba.Objective: to determine the current prevalence of intestinal parasitic infections in Cuba and to compare these results with those obtained from the previous survey after a 25 year-period.Methods: a cross sectional study was conducted from May to August of 2009 in a sample of Cuban population. A stool sample was collected from each individual, which was analyzed by direct examination, Willis' brine flotation method and the Kato-Katz thick smear technique. Additionally, a questionnaire was administered.Results: the comparison between 1984 and 2009 surveys showed a general decrease of frequencies of intestinal parasitic infections caused by both helminths and pathogenic protozoa; however, the percentage of infections with commensal protozoa increased in 2009. In this last survey, there was observed decline of frequencies of infections with soil transmitted species, Trichuris trichiura, Ascaris lumbricoides, hookworm, and Strongyloides stercoralis and the pathogenic protozoa: Giardia lamblia, Entamoeba histolytica/E. dispar, and the commensals: Endolimax nana and Entamoeba coli. The intestinal parasite Enterobius vermicularis was the only parasitic species that increased the frequency of infections with respect to the 1984 survey. The frequencies of parasitic and commensal infections in both studies were higher in the 5-14 y age group (school age).Conclusions: the comparison between the intestinal parasitic infections...(AU)

Epidemiological studies on dengue virus type 3 in Playa municipality, Havana, Cuba, 2001-2002.

OBJECTIVES: Recognizing the uniqueness of secondary dengue virus (DENV)-1/3 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases at an interval of 24 years, we sought to estimate DENV infections as well as the ratios between mild disease and DHF/DSS by DENV infection sequence in Playa District (Havana, Cuba) during the 2001-2002 outbreak of dengue virus type 3 (DENV-3). METHODS: A retrospective seroepidemiological study was conducted in 2003 in Playa District. Blood samples were collected from a 1% random sample of residents and were studied for the prevalence of dengue neutralizing antibodies. RESULTS: DENV-3 was found to have infected 7.2% (95% confidence interval (95% CI) 6.0-8.4%) of susceptible individuals (the entire cohort), the majority of whom experienced silent infections. Virtually every individual who had a secondary infection in the sequence DENV-1 then DENV-3 became ill, with a ratio of severe to mild cases of 1:35 (95% CI 1:67-1:23). Secondary infections in the sequence DENV-2/3 were less pathogenic than DENV-1/3. Mild disease accompanying secondary DENV2/3 occurred at a ratio of 1:4.49 infections (95% CI 1:5.77-1:3.42) secondary infections. CONCLUSIONS: The results obtained highlight the role of the infecting serotype and also the sequence of the viral infection in the clinical outcome of a dengue infection.

Prevalence of febrile syndromes in dengue surveillance, havana city, 2007.

OBJECTIVE: Determine point prevalence of febrile syndromes and compare with prevalence reported by habitual clinical and seroepidemiologic dengue surveillance system in Havana City. METHODS: In October 2007, a descriptive, cross-sectional study was carried out in a representative sample, calculating prevalences of febrile syndromes and undifferentiated febrile syndromes. Chi-square analysis was used for rate comparisons. RESULTS: Point prevalences of febrile syndromes and undifferentiated febrile syndromes were 352.6 and 144.2 times greater, respectively, than those reported by the habitual clinical and seroepidemiologic dengue surveillance system; these differences were statistically significant (p < 0.001). CONCLUSIONS: Point prevalence of febrile syndromes was far greater than prevalence reported by the habitual clinical and seroepidemiologic dengue surveillance system, an indication of underreporting.

Virus role during intraepidemic increase in dengue disease severity.

Dengue epidemics in Cuba have repeatedly demonstrated a month-to-month increase in clinical severity during secondary infections. The dengue 2 outbreak that occurred in Santiago de Cuba in 1997 was accompanied by the most severe intraepidemic increase in disease severity reported to date. It was initially proposed that the appearance of neutralization escape mutants during the course of the epidemic might explain this phenomenon. Recent studies have revealed that during the course of this epidemic, nucleotide substitutions appeared only in nonstructural (NS) genes, most of which were silent, except for one change in the NS1 gene. To study whether or not variation in the NS1 gene might be associated with increased disease severity during the epidemic, this gene was partially sequenced from 15 isolates obtained at different times during the 1997 epidemic. Early epidemic isolates differed from those obtained later by replacement only of threonine with serine at position 164 in the NS1 protein, an amino acid rarely found in any genotype of dengue 2 virus. All viruses isolated from patients located in Health Districts, where dengue 2 transmissions occurred late in the epidemic, contained Serine at position 164, indicating that this change was fixed within a few months. Here we argue that this single mutation contributes to viral survival or replication efficiency, resulting in enhanced infection in the presence of enhancing antibodies, a phenomenon that we term increased virus "fitness" in contrast to "virulence," an intrinsic property of the virus.

Prevalencia de síndromes febriles en la vigilancia del dengue.: Ciudad de La Habana, 2007 / Prevalence of febrile syndrome in dengue surveillance.: Havana City, 2007

Objetivo: Determinar la prevalencia puntual de síndromes febriles (SF) y compararla con la del sistema habitual de vigilancia clínico y seroepidemiológica del dengue en Ciudad de La Habana. Métodos: Se realizó un estudio descriptivo de corte transversal en octubre del 2007, en una muestra representativa, en el que se calcularon las tasas de prevalencia de síndromes febriles y síndromes febriles inespecíficos, utilizando la prueba de Chi cuadrado para comparar las diferencias entre ellas. Resultados: Las diferencias encontradas entre las tasas de prevalencia puntual y las reportadas por el sistema habitual de vigilancia clínico-seroepidemiológica del dengue, tanto para los síndromes febriles como para los síndromes febriles inespecíficos, resultaron ser 352,6 y 144,2 veces mayor, respectivamente, diferencias estadísticamente significativas (p<0,001). Conclusiones: La prevalencia puntual de SF encontrada, resultó ser muy superior a la reportada por el sistema habitual de vigilancia clínico-seroepidemiológica del dengue, lo que evidencia subregistro en la notificación.

Objective: To determine the prevalence of Febrile Syndromes and compare it with that of the clinical habitual and seroepidemiological Dengue surveillance system in Havana City. Methods: A descriptive cross-sectional study was conducted in October 2007, on a representative sample, to calculate the prevalence rates of febrile syndromes and nonspecific febrile syndromes, using the Chi-square test in order to compare the differences among them. Results: The differences found among the point prevalence rates and the reported by the seroepidemiological clinical habitual surveillance system of Dengue, both for Febrile Syndromes and for Nonspecific Febrile Syndromes, turned out to be 352.6 and 144.2 times greater, statistically significant differences (p<0,001). Conclusions: The point prevalence of FS, found turned out to be much higher than the reported by the seroepidemiological clinical habitual surveillance system of Dengue, which shows underreporting in the report.

Prevalencia de síndromes febriles en la vigilancia del dengue: Ciudad de La Habana, 2007 / Prevalence of febrile syndrome in dengue surveillance: Havana City, 2007

Objetivo: Determinar la prevalencia puntual de síndromes febriles (SF) y compararla con la del sistema habitual de vigilancia clínico y seroepidemiológica del dengue en Ciudad de La Habana. Métodos: Se realizó un estudio descriptivo de corte transversal en octubre del 2007, en una muestra representativa, en el que se calcularon las tasas de prevalencia de síndromes febriles y síndromes febriles inespecíficos, utilizando la prueba de Chi cuadrado para comparar las diferencias entre ellas. Resultados: Las diferencias encontradas entre las tasas de prevalencia puntual y las reportadas por el sistema habitual de vigilancia clínico-seroepidemiológica del dengue, tanto para los síndromes febriles como para los síndromes febriles inespecíficos, resultaron ser 352,6 y 144,2 veces mayor, respectivamente, diferencias estadísticamente significativas (p<0,001). Conclusiones: La prevalencia puntual de SF encontrada, resultó ser muy superior a la reportada por el sistema habitual de vigilancia clínico-seroepidemiológica del dengue, lo que evidencia subregistro en la notificación(AU)

Objective: To determine the prevalence of Febrile Syndromes and compare it with that of the clinical habitual and seroepidemiological Dengue surveillance system in Havana City. Methods: A descriptive cross-sectional study was conducted in October 2007, on a representative sample, to calculate the prevalence rates of febrile syndromes and nonspecific febrile syndromes, using the Chi-square test in order to compare the differences among them. Results: The differences found among the point prevalence rates and the reported by the seroepidemiological clinical habitual surveillance system of Dengue, both for Febrile Syndromes and for Nonspecific Febrile Syndromes, turned out to be 352.6 and 144.2 times greater, statistically significant differences (p<0,001). Conclusions: The point prevalence of FS, found turned out to be much higher than the reported by the seroepidemiological clinical habitual surveillance system of Dengue, which shows underreporting in the report(AU)

Secondary heterologous dengue infection risk: Disequilibrium between immune regulation and inflammation?

Increased serum levels of cytokines released by cells of the immune response have been detected in patients suffering from dengue disease. Likewise, secondary infections by a different dengue virus serotype result in a highest risk of development of the severe dengue disease. Both findings suggest that the memory immune response is one of the key players in the pathogenesis of this disease. Here we take advantage of the particular Cuban epidemiological situation in dengue to analyze a broad spectrum of cell-mediated immune response mediators at mRNA and protein level. Evidences for a regulatory immune pattern in homologous (TGF-beta, IL-10) vs. pro-inflammatory pattern (IFN-gamma, TNF-alpha) in heterologous dengue virus re-challenge were found, suggesting a possible association with the higher incidence of severe dengue cases in the latter case.

Dual infection with dengue virus 3 and human immunodeficiency virus 1 in Havana, Cuba.

Although dengue virus (DEN) endemic regions overlap with human immunodeficiency virus 1 (HIV) high incidence areas, little has been documented on HIV and DEN mixed infection. Here we report DEN/HIV concurrent infections recorded during the DEN-3 epidemic in 2001-2002 in Havana. Serologic-confirmed DEN is described in two HIV-infected subjects with dengue fever symptoms. Although patients had dengue disease, the CD4+ cells remained within normal levels and no accelerated progression of HIV disease was observed. To our knowledge, DEN cases caused by DEN-3 in HIV-infected individuals have not been reported previously. Further research is needed to diagnose this likely underreported mixed viral infection in DEN endemic areas.

Randomized, double-blind, placebo-controlled trial to evaluate the safety and immunogenicity of live oral cholera vaccine 638 in Cuban adults.

A randomized, double-blind, placebo-controlled clinical trial was conducted to evaluate the safety, reactogenicity and the immunogenicity of a 2 x 10(9)CFU dose of the 638 lyophilized live attenuated cholera vaccine for oral administration, formulated and produced at Finlay Institute, City of Havana, Cuba. Thirty-six healthy female and male adult volunteers from 18 to 40 years old were involved, clinically examined and laboratory tested after the informed consent signature. Adverse events were monitored and seroconversion rates and geometrical mean titer (GMT) of vibriocidal antibodies were tested in volunteer's sera samples. Neither serious adverse events nor other damages to the volunteers due to vaccine or placebo feeding were reported during the clinical follow-up period of this study; none of the adverse events registered within the first 72 h after inoculation were life-threatening for volunteers. Neither severe nor moderate adverse events were reported. Sixty-one percent of subjects showed mild expected adverse events in an interval lower than 24h up to the first 72 h, 75% of these in the vaccinated group and 18% in the placebo group. Fourteen days after inoculation the GMT of vibriocidal antibodies in the vaccine group significantly increased in comparison to the placebo group. All subjects in the vaccine group (24) seroconverted (100%). Results show that this vaccine is safe, well tolerated and immunogenic in healthy female and male volunteers.

Dengue: where are we today?

Dengue is considered the main arthropod-borne viral disease of humans. In the last few years, an increasing number of reports of mild and severe cases have been reported. The growing dengue incidence observed in recent years has been accompanied by reports of new observations, findings and global initiatives with an improvement in our understanding of this phenomenon. The epidemiology and new clinical classification of dengue, advances in the diagnostic and pathogenesis knowledge, and vaccine development as well as control methods including new global initiatives are summarised here.

The role of disease-specific research: a developing-country perspective.

Over a decade ago, the Commission on Health Research for Development published a pioneering study on the gross imbalance between the world's research funding priorities and global disease burden distribution. This study reported that less than 10% of world resources for health research were being applied to the health problems of developing countries, where 90% of the avoidable burden of ill-health was to be found. What became known as the "10/90 gap" has captured the attention and imagination of those committed to global health equity everywhere, searching for ways to incline the research agenda towards "diseases of the poor".

[A community education strategy to promote participation in dengue prevention in Cuba]. / Estrategia de educación popular para promover la participación comunitaria en la prevención del dengue en Cuba.

OBJECTIVES: To document the process and analyze the results of implementing a strategy aimed at increasing community participation in the fight against the dengue mosquito vector. METHODS: From May 2002 to May 2004, an intervention was implemented to advance social action against dengue in three districts of the municipality of Playa, La Habana, Cuba. A learning group and community working groups (CWG) were organized in each location. A community education model was followed that combines putting the plan of action into practice, with sessions to reflect and learn from the results, and then reworking of the actions for subsequent stages. Diagnostic tools were developed for communities, preventative actions, communication, surveillance, and evaluation. Changes in participation were identified by applying the content analysis technique to the documents and through interviews with key informants. RESULTS: The community work advanced at a pace relative to the abilities and interests of each community with different areas of focus: healthy community, environmental risk, and entomological risk. Positive changes in the concept of participation were obtained, according to the five areas evaluated: leadership, needs assessment, organization, management, and mobilization of resources. At the end of two years of intervention, the rate of Aedes aegypti larvae and pupae deposits found per 100 households had declined 79% and cases of dengue were not detected in any of the districts. CONCLUSIONS: This strategy reduced mosquito vector infestation levels by increasing community participation in decision-making and strengthening the competencies of the medical teams and CWGs so that they lead participative processes in the community and raised confidence in their ability to achieve change with the appropriate resources and intersectoral support.

Estrategia de educación popular para promover la participación comunitaria en la prevención del dengue en Cuba / A community education strategy to promote participation in dengue prevention in Cuba

OBJETIVOS: Documentar el proceso y analizar los resultados de la aplicación de una estrategia dirigida a aumentar la participación comunitaria en la lucha contra el mosquito vector del dengue. MÉTODOS: Entre mayo de 2002 y mayo de 2004 se aplicó una intervención para transformar la acción social contra el dengue en tres circunscripciones del municipio Playa, Ciudad de La Habana, Cuba. Se conformó un grupo de aprendizaje y grupos de trabajo comunitario (GTC) en las localidades. Se siguió un modelo de educación popular que conjugaba la puesta en práctica de las acciones previstas con sesiones de reflexión y aprendizaje a partir de los resultados y la reformulación del trabajo para las etapas subsiguientes. Se desarrollaron diagnósticos comunitarios, acciones preventivas, de comunicación, vigilancia y evaluación. Los cambios en la participación se identificaron mediante la técnica de análisis de contenido de documentos y entrevistas a informantes clave. RESULTADOS: El trabajo comunitario avanzó de acuerdo con las capacidades y los intereses de cada comunidad con enfoques de trabajo diferentes: de comunidad saludable, de riesgo ambiental y de riesgo entomológico. Se constataron cambios positivos en el concepto de participación según las cinco dimensiones evaluadas: liderazgo, identificación de necesidades, organización, gestión y movilización de recursos. Al final de dos años de intervención, el índice de depósitos con larvas o pupas de Aedes aegypti por 100 viviendas inspeccionadas se redujo en 79 por ciento y no se detectaron casos de dengue en ninguna de las circunscripciones. CONCLUSIONES: La estrategia empleada permitió reducir el nivel de infestación con el mosquito vector mediante el aumento de la participación de la comunidad en la toma de decisiones, el fortalecimiento de las competencias de los equipos médicos y de los GTC para liderar procesos participativos en sus comunidades y la elevación de la confianza de los miembros de la...

OBJECTIVES: To document the process and analyze the results of implementing a strategy aimed at increasing community participation in the fight against the dengue mosquito vector. METHODS: From May 2002 to May 2004, an intervention was implemented to advance social action against dengue in three districts of the municipality of Playa, La Habana, Cuba. A learning group and community working groups (CWG) were organized in each location. A community education model was followed that combines putting the plan of action into practice, with sessions to reflect and learn from the results, and then reworking of the actions for subsequent stages. Diagnostic tools were developed for communities, preventative actions, communication, surveillance, and evaluation. Changes in participation were identified by applying the content analysis technique to the documents and through interviews with key informants. RESULTS: The community work advanced at a pace relative to the abilities and interests of each community with different areas of focus: healthy community, environmental risk, and entomological risk. Positive changes in the concept of participation were obtained, according to the five areas evaluated: leadership, needs assessment, organization, management, and mobilization of resources. At the end of two years of intervention, the rate of Aedes aegypti larvae and pupae deposits found per 100 households had declined 79 percent and cases of dengue were not detected in any of the districts. CONCLUSIONS: This strategy reduced mosquito vector infestation levels by increasing community participation in decision-making and strengthening the competencies of the medical teams and CWGs so that they lead participative processes in the community and raised confidence in their ability to achieve change with the appropriate resources and intersectoral support.