Minería de oro y aumento de la malaria: ¿qué ocurre en Chocó? / Gold mining and increased malaria: what happens in Chocó?

La minería de oro a cielo abierto se ha asociado a diversos problemas de salud en la población, entre esos la proliferación de enfermedades infecciosas como la malaria. El departamento del Chocó, uno de los más importantes productores de oro del país, ha venido siendo afectado por un aumento en el número de casos y muertes por Malaria. Con el fin de poner a prueba si estos dos eventos se encuentran relacionados el ONS llevó a cabo un estudio para evaluar la asociación entre los niveles de producción de oro en los municipios del Chocó y los casos de malaria. El estudio encontró que los municipios con mayor producción de oro también presentan en promedio el mayor número de casos de malaria anualmente. De acuerdo con los hallazgos de este y otros estudios es importante para el control de la malaria abrir los espacios necesarios para discutir la minería de oro como un factor determinante en la propagación de la malaria en el departamento del Chocó y probablemente otras regiones mineras de Colombia.

Characterization of hepatitis B virus in Amerindian children and mothers from Amazonas State, Colombia.

BACKGROUND: Hepatitis B Virus (HBV) infection is a worldwide public health problem. In the 1980's a highly effective and safe vaccine against HBV was developed, although breakthrough infection still occasionally occurs because of the emergence of escape mutants. The aim of this study was to identify HBV genotypes and escape mutants in children and their mothers in Amerindian communities of the Amazonas State, Southern Colombia. METHODS: Blood specimens collected from children and mothers belonging to 37 Amerindian communities in Amazonas state, were screened for HBsAg and anti-HBc using ELISA. The partial region containing the S ORF was amplified by nested PCR, and amplicons were sequenced. The phylogenetic analysis was performed using the MEGA 5.05 software. RESULTS: Forty-six children (46/1275, 3.6%) and one hundred and seventy-seven mothers (177/572, 30.9%) were tested positive for the anti-HBc serological marker. Among them, 190 samples were tested for viral genome detection; 8.3% (2/31) serum samples obtained from children and 3.1% (5/159) from mothers were positive for the ORF S PCR. The predominant HBV genotype in the study population was F, subgenotype F1b; in addition, subgenotype F1a and genotype A were also characterized. Two HBV escape mutants were identified, G145R, reported worldwide, and W156*; this stop codon was identified in a child with occult HBV infection. Other mutations were found, L109R and G130E, located in critical positions of the HBsAg sequence. CONCLUSIONS: This study aimed to characterize the HBV genotype F, subgenotypes F1b and F1a, and genotype A in Amerindian communities and for the first time escape mutants in Colombia. Further investigations are necessary to elucidate the frequency and the epidemiological impact of the escape mutants in the country.

Is Colombia reaching the goals on infant immunization coverage? A quantitative survey from 80 municipalities.

OBJECTIVES: This study aimed to evaluate the coverage of the Colombian Expanded Program on Immunization among children less than 6years old, to evaluate the timeliness of immunization, to assess the coverage of newly introduced vaccines, and to identify factors associated with lack of immunization. METHODS: We conducted a cross-sectional survey in 80 municipalities of Colombia, using a two-stage cluster random sampling. We attempted to contact all children less than 6years old living in the sampled blocks, and asked their caregivers to provide immunization record cards. We also collected basic sociodemographic information. RESULTS: We reached 81% of the attempted household contacts, identifying 18,232 children; of them, 14,805 (83%) had an immunization record card. Coverage for traditional vaccines was above 90%: BCG (tuberculosis) 95.7% (95%CI: 95.1-96.4), pentavalent vaccine 93.3% (92.4-94.3), MMR (measles, mumps, rubella) initial dose 94.5% (93.5-95.6); but it was lower for recently introduced vaccines: rotavirus 80% (77.8-82.1), influenza 48.4% (45.9-50.8). Results for timely vaccination were not equally successful: pentavalent vaccine 44.2% (41.4-47.1), MMR initial dose 71.2% (68.9-73.4). Mother's education was significantly associated with higher immunization odds. Older age, a greater number of siblings, low socioeconomic status, and not having health insurance were significantly associated with lower immunization odds. There was significant heterogeneity in immunization rates by municipality across the country. CONCLUSIONS: Although absolute immunization coverage for traditional vaccines met the goal of 90% for the 80 municipalities combined, disparities in coverage across municipalities, delayed immunization, and decline of coverage with age, are common problems in Colombia that may result in reduced protection. Newly introduced vaccines require additional efforts to reach the goal. These results highlight the association of health inequities with low immunization coverage and delayed immunization. Identification of vulnerable populations and their missed opportunities for vaccination may help to improve the reach of immunization programs.

Compliance with birth dose of Hepatitis B vaccine in high endemic and hard to reach areas in the Colombian amazon: results from a vaccination survey.

BACKGROUND: Hepatitis B vaccination was introduced into the Expanded Program of Immunization in Colombia in 1992, in response to WHO recommendations on hepatitis B immunization. Colombia is a low endemic country for Hepatitis B virus infection (HBV) but it has several high endemic areas like the Amazon basin where more than 70 % of adults had been infected. A cross- sectional study was carried out in three rural areas of the Colombian Amazon to evaluate compliance with the recommended schedule for hepatitis B vaccine in Colombian children (one monovalent dose given in the first 24 h after birth + 3 doses of a pentavalent containing Hepatitis B. (DPT + Hib + Hep B). METHODS: A household survey was conducted in order to collect vaccination data from children aged from 6 months to <8 years. Vaccination status was related to sociodemographic data obtained from children caretakers. RESULTS: Among 938 children above 6 months and < 8 years old studied, 79 % received a monovalent dose of hepatitis B vaccine, but only 30.7 % were vaccinated in the first 24 h after birth. This proportion did not increase by age or subsequent birth cohorts. Coverage with three doses of a DTP-Hib-HepB vaccine was 98 %, but most children did not receive them according to the recommended schedule. Being born in a health facility was the strongest predictor of receiving a timely birth dose. CONCLUSIONS: This study suggests that more focused strategies on improving compliance with hepatitis B birth dose should be implemented in rural areas of the Amazon, if elimination of perinatal transmission of HBV is to be achieved. Increasing the proportion of newborns delivered at health facilities should be one of the priorities to reach that goal.

[Cost-effectiveness of vaccinating pregnant women against pandemic influenza in Colombia]. / Costo-efectividad de la vacunación contra influenza pandémica en mujeres embarazadas en Colombia.

OBJECTIVE: Estimating the cost-effectiveness ratio of vaccinating pregnant women against the 2009 pandemic influenza A (H1N1) in Colombia during the second wave of the pandemic. METHODS: A decision tree was constructed, which simulated the health results (deaths and years of potential life lost [YPLL]) in two cohorts of pregnant women; one vaccinated, the other unvaccinated. The model's parameters were drawn from scientific literature and costs were estimated on the basis of a previous study. Incremental cost-effectiveness ratios (ICER) were calculated. RESULTS: Vaccinating pregnant women against pandemic flu would have prevented between 4 664 and 15 741 outpatient visits and between 119 and 401 hospitalizations. Between US$ 249 530 and US$ 842 163 in costs of care would have been avoided. For the base scenario, vaccinating pregnant women would be cost-effective (ICER/YPLL avoided US$ 7 657). This ICER was responsive to the disease's fatality rate; vaccination would not be cost-effective in Colombia in scenarios with a lower fatality rate. CONCLUSIONS: Vaccinating pregnant women against pandemic influenza is cost-effective in a scenario with a high mortality rate. The existing evidence that pregnant women are at increased risk of complications and that the vaccine is safe would justify its use in pregnant women.

Costo-efectividad de la vacunación contra influenza pandémica en mujeres embarazadas en Colombia / Cost-effectiveness of vaccinating pregnant women against pandemic influenza in Colombia

OBJETIVO: Estimar la relación costo-efectividad de la vacunación contra influenza pandémica A (H1N1) 2009 en mujeres embarazadas en Colombia durante la segunda onda de la pandemia. MÉTODOS: Se construyó un árbol de decisiones que simulaba los resultados sanitarios (muertes y años potenciales de vida perdidos, APVP) en dos cohortes de mujeres embarazadas, una vacunada y otra sin vacunar. Los parámetros del modelo fueron extraídos de la literatura científica y los costos se estimaron a partir de un estudio previo. Se calcularon razones de costo-efectividad incrementales (RCEI). RESULTADOS: La vacunación de embarazadas contra influenza pandémica habría evitado entre 4 664 y 15 741 consultas ambulatorias y entre 119 y 401 hospitalizaciones. Los costos de atención evitados serían de US$ 249 530 a US$ 842 163. Para el escenario base, vacunar embarazadas sería costo-efectivo (RCEI/APVP evitado US$ 7 657). Esta RCEI fue sensible a la letalidad de la enfermedad; en escenarios de baja letalidad la vacunación no sería costo-efectiva en Colombia. CONCLUSIONES: La vacunación en embarazadas contra influenza pandémica es costo-efectiva en un escenario de alta mortalidad. La evidencia existente de que las mujeres embarazadas tienen mayor riesgo de presentar complicaciones y de que la vacuna es segura justificaría su uso en embarazadas.

OBJECTIVE: Estimating the cost-effectiveness ratio of vaccinating pregnant women against the 2009 pandemic influenza A (H1N1) in Colombia during the second wave of the pandemic. METHODS: A decision tree was constructed, which simulated the health results (deaths and years of potential life lost [YPLL]) in two cohorts of pregnant women; one vaccinated, the other unvaccinated. The model's parameters were drawn from scientific literature and costs were estimated on the basis of a previous study. Incremental cost-effectiveness ratios (ICER) were calculated. RESULTS: Vaccinating pregnant women against pandemic flu would have prevented between 4 664 and 15 741 outpatient visits and between 119 and 401 hospitalizations. Between US$ 249 530 and US$ 842 163 in costs of care would have been avoided. For the base scenario, vaccinating pregnant women would be cost-effective (ICER/YPLL avoided US$ 7 657). This ICER was responsive to the disease's fatality rate; vaccina tion would not be cost-effective in Colombia in scenarios with a lower fatality rate. CONCLUSIONS: Vaccinating pregnant women against pandemic influenza is cost-effective in a scenario with a high mortality rate. The existing evidence that pregnant women are at increased risk of complications and that the vaccine is safe would justify its use in pregnant women.

How protective is cervical cancer screening against cervical cancer mortality in developing countries? The Colombian case.

BACKGROUND: Cervical cancer is one of the top causes of cancer morbidity and mortality in Colombia despite the existence of a national preventive program. Screening coverage with cervical cytology does not explain the lack of success of the program in reducing incidence and mortality rates by cervical cancer. To address this problem an ecological analysis, at department level, was carried out in Colombia to assess the relationship between cervical screening characteristics and cervical cancer mortality rates. METHODS: Mortality rates by cervical cancer were estimated at the department level for the period 2000-2005. Levels of mortality rates were compared to cervical screening coverage and other characteristics of the program. A Poisson regression was used to estimate the effect of different dimensions of program performance on mortality by cervical cancer. RESULTS: Screening coverage ranged from 28.7% to 65.6% by department but increases on this variable were not related to decreases in mortality rates. A significant reduction in mortality was found in departments where a higher proportion of women looked for medical advice when abnormal findings were reported in Pap smears. Geographic areas where a higher proportion of women lack health insurance had higher rates of mortality by cervical cancer. CONCLUSIONS: These results suggest that coverage is not adequate to prevent mortality due to cervical cancer if women with abnormal results are not provided with adequate follow up and treatment. The role of different dimensions of health care such as insurance coverage, quality of care, and barriers for accessing health care needs to be evaluated and addressed in future studies.