Seroprevalence of Varicella in Pregnant Women and Newborns in a Region of Colombia.

We estimate the seroprevalence of IgG antibodies to varicella zoster virus (VZV) based on the first serological study in a cohort of pregnant women and newborns from the Aburrá Valley (Antioquia-Colombia) who attended delivery in eight randomly chosen hospitals. An indirect enzyme immunoassay was used to determine anti-VZV IgG antibodies. Generalized linear models were constructed to identify variables that modify seropositivity. In pregnant women, seropositivity was 85.8% (95% CI: 83.4-85.9), seronegativity was 12.6% (95% CI: 10.8-14.6), and concordance with umbilical cord titers was 90.0% (95% CI: 89-91). The seropositivity of pregnant women was lower in those who lived in rural areas (IRR: 0.4, 95% CI: 0.2-0.7), belonged to the high socioeconomic status (IRR: 0.4, 95% CI: 0.2-0.7), and had studied 11 years or more (IRR: 0.6, 95% CI: 0.4-0.8). Among newborns, seropositivity was lower in those who weighed less than 3000 g (IRR: 0.8, 95% CI: 0.6-1.0). The high seropositivity and seronegativity pattern indicates the urgent need to design preconception consultation and vaccination reinforcement for women of childbearing age according to their sociodemographic conditions, to prevent infection and complications in the mother and newborn.

Seroprevalence of hepatitis B and factors potentially associated in a population-based study in Medellin, Colombia.

The seroprevalence of hepatitis B (HB) and of potentially associated factors in Medellin, Colombia, were investigated 17years after the start of universal vaccination. Biological and sociodemographic data from a population survey with a multistage random sampling were analyzed in 6-64year old individuals. HB surface antigen, total HB core antibodies and HB surface antibodies, and in some cases IgM antibodies to HB core antigen, were tested in 2077 samples. Factors potentially associated with and natural, and vaccine immunity relative to susceptibility (absence of any marker) were analyzed using a multinomial logistic regression. The prevalence of serological patterns was: chronic infection 0.20% (95% CI 0.11-0.71), vaccine immunity 25.10% (95% CI 21.72-28.83) and natural immunity 2.60% (95% CI 1.80-3.74). No markers were detected in 71.30% (95% CI 67.70-74.83) of the individuals and evidence of recent infection was not detected. Relative to the absence of markers, natural immunity was potentially associated with age (6-17years and 41-64years) and sleeping less than 6 hours, while vaccine immunity was associated with age (6-17years), reporting vaccination against HB, belonging to high socioeconomic strata, home ownership and being obese, after adjusting for other variables. These results may be a population effect of mass vaccination. It is recommended to complete the vaccination schedule and to study in detail, persistence of antibodies and the role of obesity and socioeconomic strata in the vaccine immunity.

Seroprevalence of mumps in an epidemic period in Medellín, Colombia.

OBJECTIVE: We related seroprevalence and outbreaks data in order to identify factors that could explain the occurrence of outbreaks despite high vaccination coverage in Medellín Colombia. METHODS: Samples from a population seroprevalence data obtained in 2009 in a random survey were analyzed. IgG levels were determined for mumps using 2 commercial tests of 2119 individuals aged 6-64 years. A comparative analysis was undertaken using age-specific mumps seroprevalence data and information of 98 epidemiological investigations of mumps outbreaks reported in 2009. RESULTS: Overall, seroprevalence was 91.6% (95% CI=89.3-93.5%). The age-specific seronegativity was 20.3% and 20.6% in age groups 11-15 years and 16-20 years respectively. Individuals aged 6-20 years were the most affected during outbreaks. In individuals born in 2003, a year after the change in the booster schedule from 10 to 5 years, the proportion of unvaccinated individuals (14%) and those who received only one dose of MMR (45%) increased substantially. On average, 23.5 days elapsed between the onset of symptoms in secondary cases and the outbreak investigation. CONCLUSION: Potential contributing factors for the occurrence of outbreaks of mumps were the relatively high prevalence of seronegativity among individuals aged 11-20 years, delays in investigation and control of outbreaks, and incomplete vaccination schedules.

[Seroprevalence of rubella in Colombia: a birth-year cohort analysis]. / Seroprevalencia de rubeola en Colombia: un análisis por cohorte de nacimiento.

OBJECTIVE: To estimate the seroprevalence of rubella and associated factors. METHODS: Population-based seroprevalence study in a random sample of 2,124 individuals, aged six to 64 years, representative by age, sex and area in Medellín, Colombia, 2009. Biological and socioeconomic variables were analyzed for their association with serum protection against rubella, according to birth-year cohort; those born before (1954-1990) and after (1991-2003) the introduction of universal immunization. Titer of IgG antibodies against the rubella virus was detected using a high sensitivity (AxSYM® Rubella IgG--Abbott Laboratories) and a high specificity test (VIDAS RUB IgG II®--BioMerieux Laboratories). Proportions and weighted averages derived from a complex sample, including a correction factor for differences in gender participation, were estimated. Association with protection for groups of biological and social variables according to birth cohort was analyzed using a logistic regression model. RESULTS: Titers of IgG antibodies were higher in those born before (mean 110 UI/ml, 95%CI 100.5;120.2) compared to those born after (mean 64 UI/ml; 95%CI 54.4;72.8; p = 0.000) the introduction of mass immunization. The proportion of protection increased from 88.9% in those born 1990-1994, to 89.2% in those born 1995-1999 and to 92.1% in those born between 2000 and 2003, possibly due to boosters being administered from 1998 onwards. In those born before the introduction of the immunization, seroprotection was associated with previous contact with cases (OR 2.6; 95%CI 1.1;5.9), self-perceived health status (OR 2.5; 95%CI 1.05;6.0), educational level (OR 0.2; 95%CI 0.08;0.8) and years of residence in the neighborhood (RD 0,96; 95%CI 0.98;1.0) after adjusting for all variables. In those born after, serum protection was associated with effective sleep time (OR 1,4; 95%CI 1.09;1.8) and self-perceived health status (OR 5.5; 95%CI 1.2;23.8). CONCLUSIONS: The seroprevalence profile changed with the mass immunization plan, with higher titers of IgG antibodies in those born before the start of the immunization. It is recommended that the level of long-term protection be monitored and concerted action taken to improve potentially associated socioeconomic conditions.

[Health and informal work conditions among recyclers in the rural area of Medellin, Colombia, 2008]. / Condiciones de salud y de trabajo informal en recuperadores ambientales del área rural de Medellín, Colombia, 2008.

OBJECTIVE: To characterize the work, health and occupational risk conditions of recyclers from the rural area. METHODS: Cross-sectional study, with the participation of one hundred informal recyclers in five corregimientos (small administrative units) of Medellin in 2008. The source of information was primary: a structured survey on work, health and occupational risk conditions and also on perceived morbidity, which enabled to characterize the population's risks through descriptive statistics and approach the relationships and associations of the risks with the morbidity in the population. RESULTS: One hundred and four people were engaged in recycling, and 100 of them were included in the study: 34 people belonged to community-based organizations and 66 people worked independently. Social security affiliation, fulfillment of basic needs, work satisfaction, access to training activities and periodic provision of work supplies presented differences according to group (p < 0.05). The biological risks, associated with inadequate body postures, and physical and chemical risks had a particular frequency of exposure according to group. The knowledge and use of safety measures for occupational risks differed statistically among the analyzed groups (p < 0.05). CONCLUSIONS: Recyclers are a potential support to integral waste management in rural areas of Medellin, although the informal nature of their work exposes them to working conditions that directly affect their health and the health of their families. The social recognition of recycling goes hand in hand with the improvement in the working conditions of the people engaged in this activity. The environmental recycling workers, even if belonging to a union, have precarious work and health conditions. The transformation of these conditions should be one of the State's priorities.

[Herd immunity against rubella according to a survey of the population in Medellin, Colombia]. / Inmunidad colectiva contra la rubéola según una encuesta poblacional en Medellín, Colombia.

OBJECTIVE: Calculate the critical proportion (Pc) for achieving herd immunity based on a 2009 population study conducted in Medellin, Colombia, by age, globally and disaggregated by sex, location, and socioeconomic stratum. METHODS: A survey of seroprevalence in the population was conducted by means of a random sample of 2 124 individuals aged 6 to 64 that was representative of age, sex, and location. The basic reproduction number was estimated using a quadratic regression of the average IgG titers for rubella by age in unvaccinated individuals with titers greater than or equal to 15 IU/ml. The effective reproduction number (Re) was calculated with the data on the weighted proportion of protection by age, sex, location, and socioeconomic stratum. RESULTS: Overall, the Pc was 90.0% (95% CI, 88.6-95.2%) and the Re was 0.95 (95% CI, 0.8-1.8), for a weighted proportion of protection of 89.4% (95% CI, 86.8- 91.6%). Protection was lower than the expected Pc in both sexes, in high and low socioeconomic strata, and in the rural area. In the urban area, protection was greater than the Pc (89.4%, with a 95% CI, 86.6-91.7%, compared to 87.4% and a 95% CI, 85.2-87.8%). CONCLUSIONS: The urban area has made progress toward herd immunity, but the overall proportion of protection in women, the rural area, and the high socioeconomic strata must be increased. The effective number may be greater than one, indicating the potential for the spread of the disease.

Condiciones de salud y de trabajo informal en recuperadores ambientales del área rural de Medellín, Colombia, 2008 / Health and informal work conditions among recyclers in the rural area of Medellin, Colombia, 2008 / Condições de saúde e trabalho informal em recuperadores ambientais da área rural de Medellin, Colômbia, 2008

OBJETIVO: Caracterizar las condiciones de trabajo, salud y riesgos ocupacionales de recuperadores ambientales del área rural de Medellín. MÉTODOS: Estudio transversal con cien recuperadores ambientales informales en cinco corregimientos de Medellín en 2008. La fuente de información fue primaria: una encuesta estructurada sobre condiciones de trabajo, salud, riesgos ocupacionales y morbilidad sentida, que permitió caracterizar los riesgos de la población mediante estadística descriptiva y un acercamiento a las relaciones y asociaciones de los riesgos con la morbilidad en la población. RESULTADOS: Ciento cuatro personas ejercían el reciclaje, y 100 de estos se incluyeron en el estudio: 34 personas agremiadas en organizaciones de base comunitaria y 66 personas que ejercían la labor independientemente. La afiliación a seguridad social, suplencia de necesidades básicas, satisfacción en la labor, recibir capacitaciones y suministro periódico de elementos para su trabajo presentaron diferencias según grupo (p < 0,05). Los riesgos biológicos, relacionados con postura corporal inadecuada, riesgos físicos y químicos, tuvieran frecuencia particular de exposición según grupo. El conocimiento y uso de las medidas de protección para los riesgos de la labor difirieron estadísticamente entre los grupos (p < 0,05). CONCLUSÕES: Los recuperadores son potencial apoyo para la gestión integral de residuos en áreas rurales de Medellín, aunque su carácter informal los expone a condiciones de trabajo que repercuten directamente en su salud y la de sus familias. El reconocimiento social del reciclaje va de la mano con la mejora de las condiciones laborales de las personas dedicadas a esta actividad. Los recuperadores ambientales, aun agremiados, tienen condiciones laborales y de salud precarias. La trasformación de estas condiciones debería ser una de las prioridades del Estado.

OBJECTIVE: To characterize the work, health and occupational risk conditions of recyclers from the rural area. METHODS: Cross-sectional study, with the participation of one hundred informal recyclers in five corregimientos (small administrative units) of Medellin in 2008. The source of information was primary: a structured survey on work, health and occupational risk conditions and also on perceived morbidity, which enabled to characterize the population's risks through descriptive statistics and approach the relationships and associations of the risks with the morbidity in the population. RESULTS: One hundred and four people were engaged in recycling, and 100 of them were included in the study: 34 people belonged to community-based organizations and 66 people worked independently. Social security affiliation, fulfillment of basic needs, work satisfaction, access to training activities and periodic provision of work supplies presented differences according to group (p < 0.05). The biological risks, associated with inadequate body postures, and physical and chemical risks had a particular frequency of exposure according to group. The knowledge and use of safety measures for occupational risks differed statistically among the analyzed groups (p < 0.05). CONCLUSIONS: Recyclers are a potential support to integral waste management in rural areas of Medellin, although the informal nature of their work exposes them to working conditions that directly affect their health and the health of their families. The social recognition of recycling goes hand in hand with the improvement in the working conditions of the people engaged in this activity. The environmental recycling workers, even if belonging to a union, have precarious work and health conditions. The transformation of these conditions should be one of the State's priorities.

OBJETIVO: Caracterizar as condições de trabalho, saúde e riscos ocupacionais de recicladores da área rural. MÉTODOS: Estudo transversal, com participação de 100 recicladores informais em cinco vilarejos de Medellin, em 2008. Foi usada uma fonte de informação primária: questionários estruturados avaliando as condições de trabalho, saúde, eventos ocupacionais e morbidade para caracterizar os riscos da população por meio de estatística descritiva e estabelecer associações com a morbidade. RESULTADOS: A reciclagem era praticada por 104 pessoas, das quais 100 foram incluídas no estudo: 34 estavam agremiadas em organizações de origem comunitária e 66 exerciam o trabalho de forma independente. Afiliação à segurança social, abastecimento de necessidades básicas, satisfação no serviço, receber capacitações e fornecimento periódico de elementos para o trabalho apresentaram diferenças de acordo com o grupo (p < 0,05). Os riscos biológicos, relacionados com postura corporal inadequada, e os riscos físicos e químicos expressaram frequência de exposição de acordo com o grupo. O conhecimento e o uso das medidas de proteção para os riscos laborais foram diferentes entre os grupos (p < 0,05). CONCLUSIONES: Os recicladores são potencial apoio para a gestão integral de resíduos em áreas rurais de Medellin, embora seu caráter informal os exponha a condições de trabalho que afetam diretamente sua saúde e a de seus próximos. O reconhecimento social da reciclagem deve ser acompanhado do aprimoramento das condições de trabalho das pessoas envolvidas nessa atividade. Da mesma forma, os recicladores agremiados apresentam condições de trabalho e de saúde precárias. A transformação dessas condições deveria ser uma das prioridades do Estado.