Risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation: results from the contact tracing strategy of the CoVIDA epidemiological surveillance study in Bogotá, Colombia, in 2020-2021.

OBJECTIVES: To estimate the risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation, participants of the CoVIDA study, in Bogotá D.C., Colombia. SETTING: The CoVIDA study was the largest COVID-19 intensified sentinel epidemiological surveillance study in Colombia thus far, performing over 60 000 RT-PCR tests for SARS-CoV-2 infection. The study implemented a contact tracing strategy (via telephone call) to support traditional surveillance actions performed by the local health authority. PARTICIPANTS: Close contacts of participants from the CoVIDA study. PRIMARY AND SECONDARY OUTCOME MEASURES: SARS-CoV-2 testing results were obtained (RT-PCR with CoVIDA or self-reported results). The secondary attack rate (SAR) was calculated using contacts and primary cases features. RESULTS: The CoVIDA study performed 1257 contact tracing procedures on primary cases. A total of 5551 close contacts were identified and 1050 secondary cases (21.1%) were found. The highest SAR was found in close contacts: (1) who were spouses (SAR=32.7%; 95% CI 29.1% to 36.4%), (2) of informally employed or unemployed primary cases (SAR=29.1%; 95% CI 25.5% to 32.8%), (3) of symptomatic primary cases (SAR of 25.9%; 95% CI 24.0% to 27.9%) and (4) living in households with more than three people (SAR=22.2%; 95% CI 20.7% to 23.8%). The spouses (OR 3.85; 95% CI 2.60 to 5.70), relatives (OR 1.89; 95% CI 1.33 to 2.70) and close contacts of a symptomatic primary case (OR 1.48; 95% CI 1.24 to 1.77) had an increased risk of being secondary cases compared with non-relatives and close contacts of an asymptomatic index case, respectively. CONCLUSIONS: Contact tracing strategies must focus on households with socioeconomic vulnerabilities to guarantee isolation and testing to stop the spread of the disease.

Incidence of acute respiratory symptoms and COVID-19 infection in children in public schools in Bogotá, Colombia, from July to November, 2020 / Incidencia de síntomas respiratorios agudos y COVID-19 en niños de escuelas públicas de Bogotá, Colombia, entre julio y noviembre de 2020

Introduction: More than 90% of children infected with COVID-19 worldwide developed mild to moderate disease. In Colombia, during 2020, COVID-19 infections in children stayed below 9.2% of the total cases, with no trends for age group or sex. Objective: To estimate the incidence of acute respiratory symptoms and COVID-19 in children from public schools in Bogotá, Colombia during the second semester of 2020. Material and methods: A telephone survey was conducted in over 5,000 scholar children. Antecedents and use of health services were informed. Descriptive statistics were used. Results: A total of 151.470 persons per day accounting for an IR of 157,8 per 100,000 people; almost three times the rate reported by the official surveillance system in the city. Conclusion: A lack of diagnosis and consultation in children was found compared to the general population. Further research is needed to elucidate the true burden of the disease in children.

Introducción. Más del 90% de los niños infectados con COVID-19 en el mundo, desarrollaron enfermedad leve a moderada. En Colombia, durante el 2020, la infección del COVID-19 en niños se mantuvo por debajo de 9,2 % del total de los casos sin tendencias por grupo de edad o sexo. Objetivo. Estimar la incidencia de síntomas respiratorios agudos y COVID19 en niños de escuelas públicas en Bogotá (Colombia) durante el segundo semestre de 2020. Materiales y métodos. Se hizo una encuesta telefónica en más de 5.000 escolares. Se recolectó información de antecedentes médicos y uso de servicios de salud. La información obtenida se describió mediante estadística descriptiva. Resultados. Se contabilizó un total de 151.470 personas al día para una tasa de incidencia de 157,8 en 100.000 personas, casi tres veces la tasa reportada por el sistema de vigilancia oficial de la ciudad. Conclusión. Se encontraron deficiencias en el diagnóstico y consulta de los niños, al compararlos con la población general. Se necesita más investigación para dilucidar la verdadera carga de la enfermedad en la población infantil.

Understanding how socioeconomic inequalities drive inequalities in COVID-19 infections.

Across the world, the COVID-19 pandemic has disproportionately affected economically disadvantaged groups. This differential impact has numerous possible explanations, each with significantly different policy implications. We examine, for the first time in a low- or middle-income country, which mechanisms best explain the disproportionate impact of the virus on the poor. Combining an epidemiological model with rich data from Bogotá, Colombia, we show that total infections and inequalities in infections are largely driven by inequalities in the ability to work remotely and in within-home secondary attack rates. Inequalities in isolation behavior are less important but non-negligible, while access to testing and contract-tracing plays practically no role because it is too slow to contain the virus. Interventions that mitigate transmission are often more effective when targeted on socioeconomically disadvantaged groups.

COVID-19 spread, detection, and dynamics in Bogota, Colombia.

Latin America has been severely affected by the COVID-19 pandemic but estimations of rates of infections are very limited and lack the level of detail required to guide policy decisions. We implemented a COVID-19 sentinel surveillance study with 59,770 RT-PCR tests on mostly asymptomatic individuals and combine this data with administrative records on all detected cases to capture the spread and dynamics of the COVID-19 pandemic in Bogota from June 2020 to early March 2021. We describe various features of the pandemic that appear to be specific to a middle income countries. We find that, by March 2021, slightly more than half of the population in Bogota has been infected, despite only a small fraction of this population being detected. The initial buildup of immunity contributed to the containment of the pandemic in the first and second waves. We also show that the share of the population infected by March 2021 varies widely by occupation, socio-economic stratum, and location. This, in turn, has affected the dynamics of the spread with different groups being infected in the two waves.

Incidence of acute respiratory symptoms and COVID-19 infection in children in public schools in Bogotá, Colombia, from July to November, 2020 / Incidence of acute respiratory symptoms and COVID-19 infection in children in public schools in Bogotá, Colombia, from July to November, 2020

INTRODUCTION: More than 90% of children infected with COVID-19 worldwide developed mild to moderate disease. In Colombia, during 2020, COVID-19 infections in children stayed below 9.2% of the total cases, with no trends for age group or sex. OBJECTIVE: To estimate the incidence of acute respiratory symptoms and COVID-19 in children from public schools in Bogotá, Colombia during the second semester of 2020. MATERIAL AND METHODS: A telephone survey was conducted in over 5,000 scholar children. Antecedents and use of health services were informed. Descriptive statistics were used. RESULTS: A total of 151.470 persons per day accounting for an IR of 157,8 per 100,000 people; almost three times the rate reported by the official surveillance system in the city. CONCLUSION: A lack of diagnosis and consultation in children was found compared to the general population. Further research is needed to elucidate the true burden of the disease in children.

Introducción. Más del 90% de los niños infectados con COVID-19 en el mundo, desarrollaron enfermedad leve a moderada. En Colombia, durante el 2020, la infección del COVID-19 en niños se mantuvo por debajo de 9,2 % del total de los casos sin tendencias por grupo de edad o sexo. Objetivo. Estimar la incidencia de síntomas respiratorios agudos y COVID19 en niños de escuelas públicas en Bogotá (Colombia) durante el segundo semestre de 2020. Materiales y métodos. Se hizo una encuesta telefónica en más de 5.000 escolares. Se recolectó información de antecedentes médicos y uso de servicios de salud. La información obtenida se describió mediante estadística descriptiva. Resultados. Se contabilizó un total de 151.470 personas al día para una tasa de incidencia de 157,8 en 100.000 personas, casi tres veces la tasa reportada por el sistema de vigilancia oficial de la ciudad. Conclusión. Se encontraron deficiencias en el diagnóstico y consulta de los niños, al compararlos con la población general. Se necesita más investigación para dilucidar la verdadera carga de la enfermedad en la población infantil.

Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Among Adults in a Tropical City of the Caribbean Area, Colombia: Are We Much Closer to Herd Immunity Than Developed Countries?

A serological survey was carried out in Monteria (500 000 population), a mid-size city in Colombia. An overall prevalence of 55.3% (95% confidence interval, 52.5%-57.8%) was found among a sample of 1.368 people randomly selected from the population. Test positivity was related to economic characteristics with the highest prevalence found in the most impoverished areas, representing 83.8% of the city's population. We found a prevalence that might be associated with some important level of population immunity.

Inequalities on mortality due to acute respiratory infection in children: A Colombian analysis / Desigualdades en la mortalidad debidas a la infección respiratoria aguda en niños: análisis de la situación en Colombia

Introduction: Acute respiratory infections (ARI) are a leading public health issue worldwide. Objective: To explore the inequalities in ARI mortality rates in under-5, according to socioeconomic characteristics. Materials and methods: We conducted an ecological analysis to study inequalities at municipal level due to ARI mortality in children under 5 years. The data were obtained from official death records of the Departamento Administrativo Nacional de Estadística. The analysis of inequalities in the under-5 mortality rate (U5MR) included: 1) Classification of the population in different socio-economic strata, and 2) measurement of the degree of inequality. We used the ARI-U5MR as an outcome measurement. The mortality rates were estimated at national and municipal levels for the years 2000, 2005, 2010, and 2013. Rate ratios, rates differences, and concentration curves were calculated to observe the inequalities. Results: A total of 18,012 children under 5 years died by ARI in Colombia from 2000 to 2013. ARIU5MR was greater in boys than in girls. During this period, an increase in the infant mortality relative gap in both boys and girls was observed. In 2013, the U5MR evidenced that for boys from municipalities with the highest poverty had a 1.6-fold risk to die than those in municipalities with the lowest poverty (low tercile). In girls, the ARI-U5MR for 2005 and 2013 in the poorest tercile was 1.5 and 2 times greater than in the first tercile, respectively. Conclusion: Colombian inequalities in the ARI mortality rate among the poorest municipalities compared to the richest ones continue to be a major challenge in public health.

Introducción. Las infecciones respiratorias agudas (IRA) son un importante problema de salud pública a nivel mundial. Objetivo. Explorar las desigualdades de la tasa de mortalidad debida a IRA en niños menores de 5 años según las variables socioeconómicas. Materiales y métodos. Se hizo un análisis ecológico para estudiar las desigualdades a nivel municipal de las tasas de mortalidad por IRA en menores de 5 años. Los datos se obtuvieron a partir de los registros de muertes del Departamento Administrativo Nacional de Estadística. El análisis de desigualdades incluyó la clasificación de la población por estatus socioeconómico y la medición del grado de desigualdad. Como resultado en salud se utilizó la tasa de mortalidad por IRA en menores de 5 años. Se estimaron tasas a nivel nacional y municipal para 2000, 2005, 2010 y 2013. Se calcularon razones y diferencias de tasas y curvas de concentración para observar las desigualdades. Resultados. Entre 2000 y 2013 murieron por IRA en Colombia 18.012 menores de 5 años. La tasa de mortalidad por ARI fue mayor en niños que en niñas. En el periodo, se observó un incremento en la brecha de mortalidad infantil en ambos sexos. En el 2013, la tasa de niños que murieron en municipios con mayor pobreza fue 1,6 veces mayor que la de niños en aquellos con menos pobreza. En niñas, en el 2005 y el 2013, la tasa en el tercil más pobre fue 1,5 y 2 veces mayor que la del primer tercil, respectivamente. Conclusión. Las desigualdades en la tasa de mortalidad por IRA de los municipios más pobres en comparación con la de los más ricos, continúan siendo un reto importante en salud pública.

Exploring scenarios of chikungunya mitigation with a data-driven agent-based model of the 2014-2016 outbreak in Colombia.

New epidemics of infectious diseases can emerge any time, as illustrated by the emergence of chikungunya virus (CHIKV) and Zika virus (ZIKV) in Latin America. During new epidemics, public health officials face difficult decisions regarding spatial targeting of interventions to optimally allocate limited resources. We used a large-scale, data-driven, agent-based simulation model (ABM) to explore CHIKV mitigation strategies, including strategies based on previous DENV outbreaks. Our model represents CHIKV transmission in a realistic population of Colombia with 45 million individuals in 10.6 million households, schools, and workplaces. Our model uses high-resolution probability maps for the occurrence of the Ae. aegypti mosquito vector to estimate mosquito density in Colombia. We found that vector control in all 521 municipalities with mosquito populations led to 402,940 fewer clinical cases of CHIKV compared to a baseline scenario without intervention. We also explored using data about previous dengue virus (DENV) epidemics to inform CHIKV mitigation strategies. Compared to the baseline scenario, 314,437 fewer cases occurred when we simulated vector control only in 301 municipalities that had previously reported DENV, illustrating the value of available data from previous outbreaks. When varying the implementation parameters for vector control, we found that faster implementation and scale-up of vector control led to the greatest proportionate reduction in cases. Using available data for epidemic simulations can strengthen decision making against new epidemic threats.

Hepatitis B infection control in Colombian Amazon after 15 years of hepatitis B vaccination. Effectiveness of birth dose and current prevalence.

BACKGROUND: Hepatitis B virus (HBV) infection is highly endemic in the Colombian Amazon basin. In Colombia, the universal hepatitis B vaccination in that area has been active since 1993. The program targets children aged under five years. Newborns receive at least three doses, and in 2001, HBV vaccine birth dose was included. This study aimed to evaluate the advances on HBV control in the Colombian Amazon. METHODS: A population-based cross-sectional study was conducted in children less than 11 years old in rural areas of the Colombian Amazon, in order to assess the current levels of HBV prevalence and evaluate the effectiveness of HBV vaccination. Participants were selected from villages scattered along the Amazon, Putumayo and Loretoyaco Rivers. Blood samples were taken from children. All the samples were examined for surface antigen (HBsAg) and IgG antibodies against core antigen (AntiHBc) of HBV. Data on HBV vaccination status and other risk factors were also collected. RESULTS: Blood samples from 1275 children were included in the study. The positivity for IgG AntiHBC and HBsAg was 3.8% and 0.5%, respectively. It was observed that receiving a dose of HBV vaccine within 48 h after birth decreased the risk of HBV infection and carriage by 95%. Being born to an AntiHBc positive mother increased 8 times the risk of HBV infection (OR = 7.8 CI 95% 3.3-10.2) and 7 times the risk of HBsAg carriage (OR = 6.6 CI 95% 2.1-10.1). CONCLUSION: The prevalence of HBV infection and HBsAg carriage continues to decrease among children living in the Colombian Amazon. The high protective effectiveness of an HBV birth does suggest that perinatal transmission is important in endemic areas of Latin America, an aspect that has not been fully studied in the region.

Inequalities on mortality due to acute respiratory infection in children: A Colombian analysis. / Desigualdades en la mortalidad por infección respiratoria aguda en niños: un análisis colombiano

INTRODUCTION: Acute respiratory infections (ARI) are a leading public health issue worldwide. OBJECTIVE: To explore the inequalities in ARI mortality rates in under-5, according to socioeconomic characteristics. MATERIALS AND METHODS: We conducted an ecological analysis to study inequalities at municipal level due to ARI mortality in children under 5 years. The data were obtained from official death records of the Departamento Administrativo Nacional de Estadística. The analysis of inequalities in the under-5 mortality rate (U5MR) included: 1) Classification of the population in different socio-economic strata, and 2) measurement of the degree of inequality. We used the ARI-U5MR as an outcome measurement.The mortality rates were estimated at national and municipal levels for the years 2000, 2005, 2010, and 2013. Rate ratios, rates differences, and concentration curves were calculated to observe the inequalities. RESULTS: A total of 18,012 children under 5 years died by ARI in Colombia from 2000 to 2013. ARIU5MR was greater in boys than in girls. During this period, an increase in the infant mortality relative gap in both boys and girls was observed. In 2013, the U5MR evidenced that for boys from municipalities with the highest poverty had a 1.6-fold risk to die than those in municipalities with the lowest poverty (low tercile). In girls, the ARI-U5MR for 2005 and 2013 in the poorest tercile was 1.5 and 2 times greater than in the first tercile, respectively. CONCLUSION: Colombian inequalities in the ARI mortality rate among the poorest municipalities compared to the richest ones continue to be a major challenge in public health.

Introducción. Las infecciones respiratorias agudas (IRA) son un importante problema de salud pública a nivel mundial. Objetivo. Explorar las desigualdades de la tasa de mortalidad debida a IRA (TM-IRA) en <5 años, de acuerdo a variables socioeconómicas. Materiales y métodos. Se realizó un análisis ecológico para estudiar las desigualdades a nivel municipal de las TM-IRA en <5 años. Los datos se obtuvieron a partir de registros de muertes del Departamento Administrativo Nacional de Estadística. En análisis de desigualdades en <5 incluyó: 1) Clasificación de la población por estatus socioeconómico y 2) Medición del grado de desigualdad. Como resultado en salud se utilizó la TM-IRA en <5 años. Se estimaron tasas a nivel nacional y municipal para 2000, 2005, 2010, 2013. Se calcularon razones y diferencias de tasas y curvas de concentración para observar las desigualdades. Resultados. Entre 2000-2013 murieron en Colombia por IRA 18.012 <5 años. La TM-ARI fue mayor en niños que en niñas. En el periodo, se observó un incremento en la brecha de mortalidad infantil en ambos sexos. En 2013, la tasa en niños que murieron en municipios con mayor pobreza fue 1,6 veces mayor que la de niños en aquellos con menor. En niñas, para 2015 y 2013, la tasa en el tercil más pobre fue 1,5 y 2 veces mayor que la del primer tercil, respectivamente. Conclusión. Las desigualdades en la TM-IRA entre los municipios más pobres en comparación con los más ricos continúan siendo un reto importante en salud pública.

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.

Data and product needs for influenza immunization programs in low- and middle-income countries: Rationale and main conclusions of the WHO preferred product characteristics for next-generation influenza vaccines.

In 2017, WHO convened a working group of global experts to develop the Preferred Product Characteristics (PPC) for Next-Generation Influenza Vaccines. PPCs are intended to encourage innovation in vaccine development. They describe WHO preferences for parameters of vaccines, in particular their indications, target groups, implementation strategies, and clinical data needed for assessment of safety and efficacy. PPCs are shaped by the global unmet public health need in a priority disease area for which WHO encourages vaccine development. These preferences reflect WHO's mandate to promote the development of vaccines with high public health impact and suitability in Low- and Middle-Income Countries (LMIC). The target audience is all entities intending to develop or to achieve widespread adoption of a specific influenza vaccine product in these settings. The working group determined that existing influenza vaccines are not well suited for LMIC use. While many developed country manufactures and research funders prioritize influenza vaccine products for use in adults and the elderly, most LMICs do not have sufficiently strong health systems to deliver vaccines to these groups. Policy makers from LMICs are expected to place higher value on vaccines indicated for prevention of severe illness, however the clinical development of influenza vaccines focuses on demonstrating prevention of any influenza illness. Many influenza vaccine products do not meet WHO standards for programmatic suitability of vaccines, which introduces challenges when vaccines are used in low-resource settings. And finally, current vaccines do not integrate well with routine immunization programs in LMICs, given age of vaccine licensure, arbitrary expiration dates timed for temperate country markets, and the need for year-round immunization in countries with prolonged influenza seasonality. While all interested parties should refer to the full PPC document for details, in this article we highlight data needs for new influenza vaccines to better demonstrate the value proposition in LMICs.

Costo de infección de vías urinaria universitario de Santander, Colombia / Costs of infection associated with urinary bladder probes in a teaching hospital in Santander, Colombia

Objetivo Estimar el exceso de costos de la infección de vías urinarias asociada al uso de catéter y las intervenciones clínicas que más influyen en los costos. Métodos Se realizó un estudio de cohortes pareadas por tiempo de aparición del evento nosocomial. Los expuestos fueron pacientes con infección de vías urinarias asociada a catéter, y los no expuestos, pacientes sin infección nosocomial, con diagnóstico de ingreso similar al expuesto. En las dos cohortes se evaluaron los costos directos de atención hospitalaria. Resultados El exceso de costo total de atención de una Infección de vías urinarias asociada a catéter fue de $ 2 460 168 pesos colombianos para 2009. El mayor porcentaje fue atribuido a los días de hospitalización en sala general con un 71,8 %, las valoraciones diarias contribuyeron con el 19,1 %, siguieron los antibióticos con un 6 %, los hemocultivos 5 %, los gases arteriales 2 %, los restantes contribuyeron con menos del 1 % cada uno. Discusión Se obtuvo un costo más cercano al real, usando variables como ecografía, gases arteriales entre otras, no usadas en estudios previos, además de las variables frecuentes como días de estancia hospitalaria, y consumo de antibióticos. En nuestro conocimiento este es el primer estudio de micro costos de infecciones nosocomiales que se ha realizado en el país, usando como diseño una cohorte. Conclusión Se encontró que una infección de vías urinarias no asociada a catéter tiene un exceso de costos directo de $2 460 168,9 pesos (1 329 dólares de 2009).(AU)

Objective To estimate the excess costs of urinary tract infection associated with catheter use and clinical interventions that influence costs the most. Methods A study of cohorts paired by the time of occurrence of the nosocomial event was carried out. Those exposed were patients with urinary tract infection associated with catheters and those unexposed were patients without nosocomial infection, admitted with a similar diagnosis. In both cohorts the direct costs of hospital care were evaluated. Results Excess total cost of care for a urinary tract infection associated with catheter was 2 460 168 (Colombian pesos in 2009). The highest percentage (71.8 %) was attributed to the days of hospitalization in the general ward; daily valuations contributed 19.1%, followed by antibiotics (6%), blood cultures (5 %), arterial blood gases (2 %). The remaining cost categories contributed less than 1 % each. Discussion This study tried to get closer to the actual cost, using variables such as ultrasound, arterial blood gases and others unused in previous studies in addition to the common variables such as length of hospital stay, and consumption of antibiotics. To our knowledge this is the first study of micro costs of nosocomial infections that has been done in the country, using a cohort as a design. It was found that urinary tract infection associated with catheter use had a direct excess of costs of 2 460 168 Colombian pesos (US$ 1 329 dollars in 2009) It was found that urinary tract infection associated with catheter had a direct excess of costs of 2 460 168 Colombian pesos (US$ 1 329 dollars in 2009).(AU)

[Costs of infection associated with urinary bladder probes in a teaching hospital in Santander, Colombia]. / Costo de infección de vías urinaria universitario de Santander, Colombia.

Objective To estimate the excess costs of urinary tract infection associated with catheter use and clinical interventions that influence costs the most. Methods A study of cohorts paired by the time of occurrence of the nosocomial event was carried out. Those exposed were patients with urinary tract infection associated with catheters and those unexposed were patients without nosocomial infection, admitted with a similar diagnosis. In both cohorts the direct costs of hospital care were evaluated. Results Excess total cost of care for a urinary tract infection associated with catheter was 2 460 168 (Colombian pesos in 2009). The highest percentage (71.8 %) was attributed to the days of hospitalization in the general ward; daily valuations contributed 19.1%, followed by antibiotics (6%), blood cultures (5 %), arterial blood gases (2 %). The remaining cost categories contributed less than 1 % each. Discussion This study tried to get closer to the actual cost, using variables such as ultrasound, arterial blood gases and others unused in previous studies in addition to the common variables such as length of hospital stay, and consumption of antibiotics. To our knowledge this is the first study of micro costs of nosocomial infections that has been done in the country, using a cohort as a design. Conclusion It was found that urinary tract infection associated with catheter use had a direct excess of costs of 2 460 168 Colombian pesos (US$ 1 329 dollars in 2009) It was found that urinary tract infection associated with catheter had a direct excess of costs of 2 460 168 Colombian pesos (US$ 1 329 dollars in 2009).

Hepatitis D virus and hepatitis B virus infection in Amerindian communities of the Amazonas state, Colombia.

BACKGROUND: In Colombia, cases of Hepatitis D virus (HDV) infection have been officially described since 1985 mainly in Amerindian population from Sierra Nevada de Santa Marta (North Caribbean Coast), Uraba (North West), and Amazon (South East). The last official report of a clinical case of HDV infection in Colombia was registered in 2005. OBJECTIVES: The aims of this study were to identify cases of HDV and/or Hepatitis B virus (HBV) infection in asymptomatic Amerindians from Amazonas state, South East Colombia, and to describe the circulating viral genotypes in this population. STUDY DESIGN: The study population was recruited in 19 Amerindian communities in the Amazonas state. Individuals over 18 years old were screened by rapid test for Hepatitis B surface Antigen (HBsAg). Blood samples obtained from individuals positives for HBsAg in the rapid-test assay were analyzed for HBsAg, anti-HBc, anti-HDV IgM/IgG by ELISA. The detection of HBV DNA and HDV RNA was performed by PCR amplification. The viral genotype was determined by sequencing and phylogenetic analysis. RESULTS: A total of 23/861 individuals were positive for HBsAg detection by rapid test. Serological and/or molecular markers of HDV infection were demonstrated in 43.5 % (10/23) of samples from Amerindians. The phylogenetic analysis demonstrated the exclusive circulation of HBV subgenotype F1b of and HDV 3 in this population. CONCLUSIONS: A high frequency of HBV/HDV infection was found in Amerindian population from Amazonas State, Colombia (43.5 %, 10/23). Nine cases were identified in a population of 861 asymptomatic Amerindian individuals; one symptomatic case (with diagnosis of end-stage hepatic disease) was also identified in the study. The circulation of HDV 3 and HBV subgenotype F1b suggests a constant flow of these viral genotypes as a result of the interaction of the Amerindian populations from Amazon basin. Further studies are necessary to confirm whether HBV subgenotype F1b is the prevalent in the population from South East region in Colombia.