ABSTRACT
BACKGROUND: Vaccination is one of the most effective measures to prevent influenza illness and its complications; influenza vaccination remained important during the COVID-19 pandemic to prevent additional burden on health systems strained by COVID-19 demand. OBJECTIVES: We describe policies, coverage, and progress of seasonal influenza vaccination programs in the Americas during 2019-2021 and discuss challenges in monitoring and maintaining influenza vaccination coverage among target groups during the COVID-19 pandemic. METHODS: We used data on influenza vaccination policies and vaccination coverage reported by countries/territories via the electronic Joint Reporting Form on Immunization (eJRF) for 2019-2021. We also summarized country vaccination strategies shared with PAHO. RESULTS: As of 2021, 39 (89 %) out of 44 reporting countries/territories in the Americas had policies for seasonal influenza vaccination. Countries/territories adapted health services and immunization delivery strategies using innovative approaches, such as new vaccination sites and expanded schedules, to ensure continuation of influenza vaccination during the COVID-19 pandemic. However, among countries/territories that reported data to eJRF in both 2019 and 2021, median coverage decreased; the percentage point decrease was 21 % (IQR = 0-38 %; n = 13) for healthcare workers, 10 % (IQR = -1.5-38 %; n = 12) for older adults, 21 % (IQR = 5-31 %; n = 13) for pregnant women, 13 % (IQR = 4.8-20.8 %; n = 8) for persons with chronic diseases, and 9 % (IQR = 3-27 %; n = 15) for children. CONCLUSIONS: Countries/territories in the Americas successfully adapted influenza vaccination delivery to continue vaccination services during the COVID-19 pandemic; however, reported influenza vaccination coverage decreased from 2019 to 2021. Reversing declines in vaccination will necessitate strategic approaches that prioritize sustainable vaccination programs across the life course. Efforts should be made to improve the completeness and quality of administrative coverage data. Lessons learned from COVID-19 vaccination, such as the rapid development of electronic vaccination registries and digital certificates, might facilitate advances in coverage estimation.
Subject(s)
COVID-19 , Influenza Vaccines , Influenza, Human , Child , Humans , Female , Pregnancy , Aged , COVID-19/epidemiology , COVID-19/prevention & control , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Seasons , Pandemics/prevention & control , COVID-19 Vaccines , Vaccination , Americas/epidemiologyABSTRACT
BACKGROUND: eHealth interventions may help increase vaccination uptake and health literacy related to immunization and improve immunization program efficiency. OBJECTIVES: To see where and how eHealth technologies have had a positive impact on immunization practices-using eHealth strategies to increase vaccination uptake, improve immunization program efficiency and advance heath literacy related to immunizations. METHODS: An overview of systematic reviews was conducted, searching PubMed, Scopus, Embase, and Web of Science for systematic reviews published through August 2017 for eHealth and immunizations (using pre-determined concepts for each). Two independent reviewers selected studies based on a priori criteria; disagreement was resolved by consensus. The quality of the included studies was evaluated using the Measurement Tool to Assess Systematic Reviews (AMSTAR). RESULTS: The primary search identified 198 results. After eliminating duplicates 158 remained. Upon applying the a priori set criteria to these, six articles were left to analyze. Four articles showed a positive relationship (a demonstrated benefit, improvement, increase in vaccination uptake, etc. when using eHealth technologies for immunization), one showed a promising relation / with potential, and one showed unknown effects as it focused on the difficulty of analyzing cost-benefits of immunization information systems (IIS). CONCLUSION: The review leads to a recommendation of using eHealth technologies to encourage immunizations and increase vaccination adherence and uptake and to continue assessing and documenting the use of eHealth for immunization.
Subject(s)
Immunization Programs , Telemedicine , Vaccination Coverage/statistics & numerical data , Cost-Benefit Analysis , Efficiency, Organizational , Humans , Systematic Reviews as Topic , Vaccination Coverage/methodsABSTRACT
As part of regional commitments in the Americas aimed at elimination of rubella and congenital rubella syndrome, and consolidation of measles elimination, Colombia conducted mass vaccination of males and females aged 14-39 years in 2005-2006. The target population included 18,238< 443 persons (44% of the entire population). Vaccination activities were extended because of limited participation and public concerns about vaccine safety. Over a 10-month peroid, 17,697,717 doses of measles-rubella vaccine were administered, reaching 97% of the target population, including 96.4% of females and 97.6% of males. Estimated coverage exceeded 95% in 33 of 36 departments and districts, and in 3 others, it ranged from 92% to 95%. In rapid monitoring conducted in 504 (45%) of 1119 municipalities, 95% of persons in the target population were vaccinated. The Colombian experience underscores the importance of social mobilization at the local level, political commitment, and microplanning and offers lessons for future mass vaccination campaigns.
Subject(s)
Rubella Syndrome, Congenital/epidemiology , Rubella Syndrome, Congenital/prevention & control , Rubella Vaccine/administration & dosage , Rubella Vaccine/immunology , Adolescent , Adult , Colombia/epidemiology , Communicable Disease Control/methods , Communicable Disease Control/organization & administration , Female , Health Policy , Humans , Male , Mass Vaccination , Population Surveillance , Pregnancy , Rubella Vaccine/adverse effects , Time Factors , Young AdultABSTRACT
BACKGROUND: Hepatitis A vaccination is justified in areas with an intermediate endemicity of the infection. AIM: To estimate the epidemiological impact of hepatitis A infection in Colombia. MATERIAL AND METHODS: Epidemiological indicators of hepatitis A infection prevalence by age, morbidity by age, and lethality by age were estimated from a literature search. These measures were projected on a hypothetical cohort of children followed from birth until 15 years of age. The number of cases of infection, jaundice, hepatic failure, hospitalizations and deaths were estimated. RESULTS: From birth to adolescence, a cohort of 872 923 urban children in Colombia would generate between 312,331 and 598,591 infections, between 13,586 and 25,960 hospitalizations, between 213 and 407 hepatic failures and between 107 and 204 deaths. CONCLUSIONS: The impact of hepatitis A infection in Colombia, is important. Introducing hepatitis A vaccination would reduce a substantial number of severe hepatitis A cases.
Subject(s)
Hepatitis A/epidemiology , Models, Theoretical , Adolescent , Age Distribution , Child , Child, Preschool , Colombia/epidemiology , Hepatitis A/mortality , Hospitalization/statistics & numerical data , Humans , Infant , Infant, Newborn , Logistic Models , Prevalence , Urban Population/statistics & numerical dataABSTRACT
Background: Hepatitis A vaccination is justified in areas with an intermediate endemicity of the infection. Aim: To estimate the epidemiological impact of hepatitis A infection in Colombia. Material and Methods: Epidemiological indicators of hepatitis A infection prevalence by age, morbidity by age, and lethality by age were estimated from a literature search. These measures were projected on a hypothetical cohort of children followed from birth until 15 years of age. The number of cases of infection, jaundice, hepatic failure, hospitalizations and deaths were estimated. Results: From birth to adolescence, a cohort of 872 923 urban children in Colombia would generate between 312,331 and 598,591 infections, between 13,586 and 25,960 hospitalizations, between 213 and 407 hepatic failures and between 107 and 204 deaths. Conclusions: The impact of hepatitis A infection in Colombia, is important. Introducing hepatitis A vaccination would reduce a substantial number of severe hepatitis A cases.
Subject(s)
Adolescent , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Hepatitis A/epidemiology , Models, Theoretical , Age Distribution , Colombia/epidemiology , Hepatitis A/mortality , Hospitalization/statistics & numerical data , Logistic Models , Prevalence , Urban Population/statistics & numerical dataABSTRACT
A complete economic study was carried out to assess the economical impact of two rotavirus vaccine in Colombia. A Markov decision model was built to assess the health outcomes from birth to 24 months of age for three hypothetical cohorts: one unvaccinated, one vaccinated with 2 doses of Rotarix and the third, with 3 doses of Rotateq. Without vaccination, the annual number of medical visits by diarrhea in children under 2 years would be 1,293,159 cases, with 105,378 medical visits and 470 deaths (IC95% 295-560) related to rotavirus. Without vaccination, rotavirus disease would cost around USD$8 millions including direct and indirect costs. Assuming a cost per dose of USD$7.5, average cost-effectiveness ratio would be USD$663/DALY with Rotarix and USD$1391 with Rotateq. When price per dose falls below USD$7 both vaccines yield a similar average cost-effectiveness ratio (USD$1063/DALY). Incremental cost-effectiveness ratio of Rotateq versus Rotarix was USD$7787/DALY. Cost-effectiveness ratio was influenced mainly by vaccine cost and cost per case hospitalized. Other programmatic aspects such as number of doses to be applied, likelihood of completing vaccination schedule with shorter versus longer schedules, and storage space within the chain cold should be considered to make decisions on which vaccine should be introduced. In conclusion, vaccinating against rotavirus in Colombia with either vaccine would be very cost effective. If cost per vaccinated children falls below USD$3 per dose vaccination would be cost saving.
Subject(s)
Diarrhea, Infantile/economics , Rotavirus Infections/economics , Rotavirus Vaccines/economics , Vaccination/economics , Colombia/epidemiology , Cost of Illness , Cost-Benefit Analysis , Diarrhea, Infantile/epidemiology , Diarrhea, Infantile/prevention & control , Diarrhea, Infantile/virology , Humans , Immunization Programs/economics , Immunization, Secondary , Infant , Markov Chains , Models, Economic , Rotavirus Infections/epidemiology , Rotavirus Infections/prevention & control , Rotavirus Vaccines/administration & dosage , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/economicsABSTRACT
BACKGROUND: There are important gaps in our understanding of the epidemiology of respiratory virus infections in tropical countries. In September 2003, the Colombian epidemiological surveillance system was notified of several deaths from an acute respiratory disease (ARD). METHODS: In order to identify the agents associated with ARD cases, a clinical and laboratory-based surveillance system was implemented throughout the country. RESULTS: Between September 19 and December 31, 2003, 64 suspected cases of ARD were reported; of these reported cases, 21 (33%) died. Among 25 patients who underwent virus studies, influenza A (H3N2) (n=7) was the most frequently identified agent. Other viruses included parainfluenza (4), influenza B (1), and respiratory syncytial virus (3). The peak occurrence of cases and deaths coincided with the replacement of the influenza A (H3N2) Panama strain, which had been circulating in Colombia since 1999, by three new influenza A (H3N2) strains (Korea, Fujian, and Wyoming). CONCLUSIONS: This outbreak led to the strengthening of surveillance for respiratory viruses and to new national recommendations for influenza vaccination in Colombia.
Subject(s)
RNA Viruses , Severe Acute Respiratory Syndrome/epidemiology , Severe Acute Respiratory Syndrome/virology , Adolescent , Adult , Age Distribution , Aged , Colombia/epidemiology , Comorbidity , Disease Outbreaks , Female , Humans , Male , Middle Aged , Nasopharynx/virology , RNA Viruses/isolation & purification , Sentinel Surveillance , Severe Acute Respiratory Syndrome/diagnosis , Sex DistributionABSTRACT
Antecedentes: el 9 de enero se confirma un caso de fiebre amarilla en la sierra nevada de Santa Marta cuya circulación viral es la continuación de la presentada en el 2003 en la región del Catatumbo. En la región no se confirmaban casos desde el año 1979 y el comportamiento del brote es similar al presentado en dicho año. Metodología: estudio descriptivo longitudinal de casos captados mediante vigilancia activa comunitaria, estudio de casos y vigilancia pasiva. Los casos son confirmados por IgM, inmunohistoquímica y patología. Se realizaron acciones del fortalecimiento de la vigilancia de febriles icterohemorrágicos, entomológica, vectorial y de epizootias. Igualmente acciones de intensificación de la inmunización de susceptibles y educación a la comunidad. Resultados: se confirmó la circulación del virus en epizootias ocurridas en tres zonas de la región (Municipios de Valledupar, La Paz y Santa Marta). Por fecha de inicio de síntomas los casos comenzaron en la semana 51 de 2003 y el pico epidémico fue en la semana 1 de 2004; el último caso se confirmó el 22 de enero de 2004. Se confirmaron 29 casos de 787 notificados (15 del distrito de Santa Marta, 8 del departamento del Cesar y 6 de La Guajira); 20% de los casos fueron captados por vigilancia activa. El 28% fue confirmado por patología e inmunohistoquímica y el restante por IgM. El grupo de edad con mayor incidencia fue 15 a 44 años (75%), hombres (72%) y agricultores (45%). La letalidad fue 28%...
Subject(s)
Yellow FeverABSTRACT
Severity of acute respiratory infection is higher in developing countries, especially among the socioeconomically underprivileged. Viral pneumonias are more common, especially among children. A prospective hospital-based case control study was undertaken in Bogota between November 2000 and August 2001, aimed to identify factors related to severe low acute respiratory infection (SLARI). Cases were limited to children aged between 2 months and 5 years who filled WHO criteria for SLARI. Controls were children at the same hospital with ARI in a similar age range, but without symptoms of chest drawing. A total of 638 children (277 cases and 361 controls) were included. The most important risk factors included the following: living in borrowed houses (odds ratio (OR) = 2.7; 95% Confidence Interval (CI): 1.06-7.07), sharing the bed (OR = 1.88, CI: 1.0-3.7), living with more than 9 people (OR = 1.82, CI: 1.0-3.51), and living with smokers (OR = 1.4, CI: 1.0-2.05). Of the 114 samples collected (from children at third day after beginning of symptoms), 98 had viruses, sincitial respiratory virus was the most frequently identified virus (41.8%), followed by influenza A virus (3.1%) and influenza B virus (1%). All positive isolates for influenza A and B were sent to the United States Center for Disease Control (CDC) in Atlanta, where they were classified as influenza A/PANAMA/2007/99-like and influenza B/SICHUAN/379/99-like, respectively.
Subject(s)
Respiratory Tract Infections/epidemiology , Case-Control Studies , Child, Preschool , Colombia , Female , Humans , Infant , Male , Prospective Studies , Risk Factors , Severity of Illness Index , Urban PopulationABSTRACT
Little is known about the role of IgA in the immune response against Giardia duodenalis infection. The current study identified the antigens of Colombian G. duodenalis isolates which stimulate the production of IgA anti-G. dudoenalis. Cyst and trophozoite stage proteins were separated by SDS-PAGE and their antigenicity was determined by Western blot. Without 2-mercapto ethanol (2-ME), the protein profile of the cyst stage showed 24 proteins within a molecular weight range of 23-270 kDa; with 2-ME, 35 polypeptides ranging from 22 to 241 kDa were distinguished. The trophozoite stage protein profile without 2-ME was formed by 16 proteins within the range of 24-270 kDa; with 2-ME, 45 proteins were present between 18 and 241 kDa. The identification of 20 and 29 antigens from the cyst and trophozoite stage, respectively, suggested that G. duodenalis stimulates a specific humoral immune response in the human host. The antigens of 31, 57, 110, 133, and 170 kDa recognized by anti-G duodenalis IgA in both cysts and trophozoites corresponded with G. duodenalis isolates from other geographic regions, whereas those of 35, 38, 43, 45, 49, 52, 60, 62, 65, 72, 82, 99, 145, 155, and 185 kDa seemed specific to Colombian isolates. This indicated that antigens of 57, 65, 145, and 170 kDa, recognized by anti-G. duodenalis IgA antibodies in cysts (with frequencies between 82% and 96%) and trophozoites (with frequencies between 86% and 97%) can be considered identification markers for G. duodenalis infections.
Subject(s)
Antigens, Protozoan/analysis , Giardia lamblia/immunology , Immunoglobulin A/immunology , Animals , Antigens, Protozoan/immunology , Antigens, Protozoan/isolation & purification , Colombia , Giardia lamblia/growth & development , HumansABSTRACT
La gravedad de la infección respiratoria aguda (IRA) es mayor en países en desarrollo, sobre todo entre grupos social y económicamente pobres. Las neumonías virales son las más comunes, especialmente en niños. Con el fin de medir algunos factores asociados con formas graves de infección respiratoria baja realizamos un estudio de casos y controles prospectivo y de base hospitalaria en Bogotá entre noviembre de 2000 y agosto de 2001. Los casos fueron niños entre 2 meses y 5 años que llenaban los criterios de la OMS para IRA grave o muy grave. Los controles eran niños con IRA en el mismo rango de edad, que consultaban al mismo hospital y que no presentaban tirajes. Se estudiaron 638 niños entre los 2 meses y los 5 años de edad (277 casos y 361 controles). Los factores más importantes fueron: vivienda en préstamo (OR2,7; IC95 por ciento: 1,06-7,07), compartir la cama (OR1,88; IC95 por ciento: 1,0-3,7), más de 9 personas en la misma casa (OR1,82; IC95 por ciento: 1,0-3,51) y fumadores en la vivienda (OR1,4; IC95 por ciento: 1,0-2,05). Se tomaron 114 muestras nasofaríngeas (niños con 3 días de haber iniciado síntomas) y se obtuvieron virus en 98 de ellas, y se identificó el virus sincitial respiratorio en 41,8 por ciento, virus influenza A en 3,1 por ciento y virus influenza B en 1 por ciento. El 100 por ciento de los aislamientos positivos para influenza A y B fueron enviados al CDC en Atlanta, donde fueron clasificados como influenza A/PANAMA/2007/99-like e influenza B/SICHUAN/379/99-like, respectivamente.
Subject(s)
Child , Pneumonia , Respiratory Tract Infections , Colombia , Risk FactorsABSTRACT
Se conoce poco acerca del papel de la IgA en la respuesta inmune de la giardiosis. El propósito de este trabajo fue identificar los antígenos estimuladores de la producción de IgA anti-Giardia duodenalis de aislamientos colombianos del par sito. Se realizó separación de proteínas de quistes y trofozoítos mediante SDS-PAGE y su antigenicidad se determinó por electroinmunotransferencia. El perfil de proteínas de quistes mostró 24 proteínas en un rango de 23-270 kDa sin 2-mercaptoetanol (2-ME) y 35 polipéptidos en un rango de 22-241 kDa con 2-ME. Los trofozoítos revelaron 16 proteínas en un rango de 24-270 kDa sin 2-ME y 45 proteínas en un rango de 18-241 kDa con 2-ME. La identificación de 20 y 29 antígenos en quistes y trofozoítos de G. duodenalis, respectivamente, permite sugerir que los aislamientos colombianos de G. duodenalis pueden inducir una respuesta inmune humoral específica en el hospedero. Los antígenos de 31, 57, 110, 133 y 170 kDa reconocidos por IgA anti-Giardia simultáneamente en quistes y trofozoítos son compartidos con aislamientos de Giardia circulantes en otras regiones geográficas mientras que los de 35, 38, 43, 45, 49, 52, 60, 62, 65, 72, 82, 99, 145, 155 y 185 kDa son específicos de los aislamientos colombianos. Esto sugiere que los antígenos de 57, 65, 145 y 170 kDa, reconocidos por IgA anti-G. duodenalis en quistes (frecuencias entre 82 por ciento y 98 por ciento) y trofozoítos (frecuencias entre 86 por ciento y 97 por ciento), podrían ser los más indicativos de infección.
Subject(s)
Humans , Giardia , Giardiasis , Cysts , Immunoelectrophoresis , Immunoglobulin alpha-Chains , ImmunoglobulinsABSTRACT
Colombia es un país afectado por el desplazamiento como consecuencia del conflicto armado interno; desde 1985 hasta la fecha, se estima que se han desplazado 1'500.000 personas. Con el fin de caracterizar la situación de salud de esta población altamente vulnerable y con tendencia al incremento, se realizó un estudio descriptivo de corte transversal en un barrio de Cartagena entre septiembre y diciembre de 2000. El tamaño de la muestra se calculó para una precisión del 2 por ciento, 40 por ciento de prevalencia máxima esperada, efecto de diseño de 2 y 15 por ciento de pérdida de información, para un total de 1.600 encuestas de hogar. Se realizó un muestreo monoetápico con reemplazo por conglomerados. A las variables socioeconómicas, ambientales, de morbilidad por grupos de edad y salud metal se les hizo análisis univariado y se determinaron frecuencias, tendencia central y dispersión; análisis bivariado, determinando c2 o prueba exacta de Fisher y valores de p y análisis estratificado. Se encontró deterioro grave en las condiciones socioeconómicas, alta exposición a la violencia, 80 por ciento de las personas entrevistadas refirieron exposición a la violencia antes del desplazamiento y el asesinato fue la causa del 60 por ciento de las muertes reportadas por la comunidad en adolescentes y adultos durante el tiempo de estudio - pero este fenómeno afecta aún a niños menores de 4 años -, disgregación familiar, pésimas condiciones de saneamiento básico, alta prevalencia de enfermedades trazadoras en todos los grupos de edad (80 por ciento de los niños menores de 5 años referían síntomas respiratorios, 30 por ciento diarrea y 32 por ciento lesiones purulentas en piel en los 15 días anteriores a la encuesta), deserción escolar (20 por ciento de los escolares y 16 por ciento de los adolescentes), escolaridad tardía, pobre desempeño escolar, proporción importante de niños trabajadores (4 por ciento de los escolares y 20 por ciento de los adolescentes), falta de afiliación a la seguridad social (sólo 20 por ciento de los niños menores de 5 años y 50 por ciento de los adultos), poca cobertura y escaso acceso a los servicios de salud, entre muchos otros factores, que pueden actuar sinérgicamente afectando la salud física y mental de la población. Se encontró dificultad para identificar tempranamente a la población desplazada por el conflicto armado interno.
Subject(s)
Conflict, Psychological , Refugees , Health Profile , Colombia , Mental Health , Nutritional Sciences , SanitationABSTRACT
Colombia faces internal displacement as a consequence of internal armed conflict. From 1985 to the present, it is estimated that 1,500,000 people have been displaced. A transversal descriptive study aimed at characterizing the health situation of this highly vulnerable and continually growing population was carried out in Cartagena between September and December, 2000. The sample size was calculated to meet a 2% precision, 40% of maximum expected prevalence, design effect of 2 and 15% of information loss, total sample size 1.600 home's interviews. Single-stage sampling with replacement was done by clusters. To socioeconomic, sanitary conditions, morbidity and mental health variables was done univariate analysis, determining frequencies, central trend and dispersion, as well as a bivariate analysis to determine X2 or Fisher exact test, p values and stratified analysis. The study found severe deterioration in socioeconomic conditions, high exposure to violence (80% was exposed to violence before displacement and murder cause 60% of deads in teenagers and adults after displacement but even children under 4 years-old was affected by this phenomenon), family disintegration, bad sanitary conditions, high prevalence of tracing diseases in all ages (80% of under 5 years-old had respiratory symptoms, 30% diarrhoea and 32% purulent lesions in skin), school desertion (20% children between 5 and 11 years and 16% teenagers), late schooling, poor performance at school, high proportion of working children (4% children between 5 and 11 years and 20% teenagers), low affiliation to social security systems (only 20% under 5 years-old children and 50% adults), low coverage and access to health services, among many other factors whose interaction affects this population's physical and mental health. We found that is difficult to make an early detection of internally displaced populations and thus provide adequate health care when such displacements are recent or involve individual persons. Results show that is essential to implement a surveillance system based on community leaders to increase efficiency, access and opportunity in health care for displaced populations.
Subject(s)
Refugees/statistics & numerical data , Warfare , Adolescent , Adult , Child , Child, Preschool , Colombia/epidemiology , Female , Humans , Male , Urban PopulationABSTRACT
Se llevó a cabo un estudio de seroprevalencia de la infección por el virus de la hepatitis B (VHB) en el hospital de Honda (Tolima). La población objetivo estaba compuesta por mujeres que consultaron a los servicios de ginecobstetricia de diciembre de 1992 a enero de 1993 A todas se les practicaron pruebas para detectar infección por el VHB (antígeno de superficie anticuerpo contra el antígeno central y anticuerpo contra el antígeno de superficie). En total, se encontraron 246 mujeres entre los 15 y los 50 años. La prevalencia encontrada fue de 13 por ciento (32 positivas), la mitad de las personas infectadas (16 pacientes) tenía el patrón de inmunidad adquirida por la infección mientras que el resto mostraba evidencia serológica de infección reciente (14 pacientes portaban el antígeno de superficie o el anticore). Los factores de riesgo diferían de acuerdo con el estado de infección analizado. En las personas con infección reciente, los factores de riesgo eran: tener tatuajes (CSP=14,8IC 95 por ciento 0,65-332); tener dos y más compañeos sexuales (CSP=4,3 IC 95 por ciento 0,99-12,9 y CSP=8, 1 IC 95 por ciento 1,1-61,1, respectivamente) (p de tendencia=0,01). En las personas con infección antigua, el factor de riesgo asociado fue el antecedente familiar de enfermedad hepática (CSP=3,57 IC 95 por ciento 1,19-10,5). Para los infectados (cualquier marcador positivo), el antecedente familiar de enfermedad hepática permanecía como factor de riesgo significativo (CSP=2,44 IC 95 por ciento 1,03-5,75). El patrón serológico compatible con infección reciente, en nuestro estudio, se relacionó con la actividad sexual, el efecto de dosis-respuesta hallado, entre mayor número de compañeros e infección, corrobora este hallazgo. Esta relación se diluye cuando se analizan los estadios de infección antigua o cuando se toma a todos como infectados. El uso de los diferentes estadios de infección por VHB como variables dependientes probó ser una manera más eficiente y más específica, desde el punto de vista biológico, de medir factores de riesgo que el considerar sólo como infección a cualquier marcador positivo
