A model to predict SARS-CoV-2 infection based on the first three-month surveillance data in Brazil.

OBJECTIVE: COVID-19 diagnosis is a critical problem, mainly due to the lack or delay in the test results. We aimed to obtain a model to predict SARS-CoV-2 infection in suspected patients reported to the Brazilian surveillance system. METHODS: We analysed suspected patients reported to the National Surveillance System that corresponded to the following case definition: patients with respiratory symptoms and fever, who travelled to regions with local or community transmission or who had close contact with a suspected or confirmed case. Based on variables routinely collected, we obtained a multiple model using logistic regression. The area under the receiver operating characteristic curve (AUC) and accuracy indicators were used for validation. RESULTS: We described 1468 COVID-19 cases (confirmed by RT-PCR) and 4271 patients with other illnesses. With a data subset including 80% of patients from Sao Paulo (SP) and Rio Janeiro (RJ), we obtained a function which reached an AUC of 95.54% (95% CI: 94.41-96.67%) for the diagnosis of COVID-19 and accuracy of 90.1% (sensitivity 87.62% and specificity 92.02%). In a validation dataset including the other 20% of patients from SP and RJ, this model exhibited an AUC of 95.01% (92.51-97.5%) and accuracy of 89.47% (sensitivity 87.32% and specificity 91.36%). CONCLUSION: We obtained a model suitable for the clinical diagnosis of COVID-19 based on routinely collected surveillance data. Applications of this tool include early identification for specific treatment and isolation, rational use of laboratory tests, and input for modelling epidemiological trends.

OBJECTIF: Le diagnostic du COVID-19 est un problème critique, principalement dû au manque ou au retard dans les résultats du test. Nous visions à obtenir un modèle pour prédire l'infection par le SRAS-CoV-2 chez les patients suspects signalés au système de surveillance brésilien. MÉTHODES: Nous avons analysé les patients suspects signalés au Système National de Surveillance qui correspondaient à la définition de cas suivante: patients présentant des symptômes respiratoires et de la fièvre, qui se sont rendus dans des régions à transmission locale ou communautaire ou qui ont eu des contacts étroits avec un cas suspect ou confirmé. Sur la base de variables collectées en routine, nous avons obtenu un modèle multiple en utilisant la régression logistique. L'aire sous la courbe caractéristique de fonctionnement du récepteur (AUC) et les indicateurs de précision ont été utilisés pour la validation. RÉSULTATS: Nous avons décrit 1.468 cas de COVID-19 (confirmés par RT-PCR) et 4.271 patients atteints d'autres maladies. Avec un sous-ensemble de données comprenant 80% de patients de Sao Paulo (SP) et de Rio de Janeiro (RJ), nous avons obtenu une fonction qui atteignait une AUC de 95,54% (IC95%: 94,41% - 96,67%) pour le diagnostic de COVID- 19 et une précision de 90,1% (sensibilité 87,62% et spécificité 92,02%). Dans un ensemble de données de validation incluant les 20% restants de patients de SP et de RJ, ce modèle présentait une AUC de 95,01% (92,51% - 97,5%) et une précision de 89,47% (sensibilité 87,32% et spécificité 91,36%). CONCLUSION: Nous avons obtenu un modèle adapté au diagnostic clinique du COVID-19 sur la base des données de surveillance collectées en routine. Les applications de cet outil comprennent l'identification précoce pour un traitement et un isolement spécifiques, l'utilisation rationnelle des tests de laboratoire et des données pour modéliser les tendances épidémiologiques.

Determinants of felt demand for dengue vaccines in the North Caribbean region of Colombia.

BACKGROUND: The increasing burden associated with dengue in Latin America makes it essential to understand the community's interest in acquiring vaccines, as an input to plan its introduction in endemic regions. The objective of this study is to learn the felt demand for dengue vaccines by estimating the willingness to pay and its associated factors in endemic communities of the North Caribbean region of Colombia. METHODS: A population survey was administered from October to December 2015, including 1037 families in 11 municipalities in Colombia. One adult per family was interviewed on their perception and history of dengue. Participants received a description of four hypothetical scenarios of dengue vaccines, administered in a single dose or in 3 doses, with an effectiveness of 70% for 5 years or 95% for 30 years. The willingness to pay for each one of these vaccines was inquired vs. 5 hypothetical prices in Colombian pesos. RESULTS: Most participants recognized dengue as a serious disease in children (99.3%) and adults (98.6%). 33 (3.2%) of the total respondents reported having suffered dengue and 19 (57.6%) of them required hospitalization. The price of the vaccine was inversely related to the willingness to pay. In addition, single dose vaccines (compared to 3 doses) and one with a protection of 95% for 30 years (compared to an effectiveness of 70% for 5 years), were associated with greater willingness to pay. Greater willingness to pay was observed among the respondents who considered it likely to get the disease, either themselves (OR 1.56; CI 95% 1.08-2.26) or their children (OR 1.89; CI 95% 1.28-2.81), in the next 5 years. The participants who have been diagnosed with dengue also showed greater willingness to pay (OR 1.89; CI 95% 1.01-3.54) compared to those who did not have this history. CONCLUSION: Factors such as price, number of doses and effectiveness can independently influence the decision to purchase a vaccine against an endemic disease, such as dengue. Additionally, this study reveals that background and perceptions of the disease can affect individuals' interest in acquiring this type of preventive interventions.

Mercury Exposure in Women of Reproductive Age in Rondônia State, Amazon Region, Brazil.

Environmental contamination by mercury (Hg) is a problem of global scale that affects human health. This study's aim was to evaluate Hg exposure among women of reproductive age residing in the Madeira River basin, in the State of Rondônia, Brazilian Amazon. This longitudinal cohort study used linear regression models to assess the effects on Hg levels of breastfeeding duration at 6 months, and of breastfeeding duration and number of new children at 2-year and 5-year. Breastfeeding duration was significantly associated with maternal Hg levels in all regression models (6 months, 2 years and 5 years) and no significant association was observed between the number of children and the change in maternal Hg levels in the 2-year and 5-year models. This longitudinal cohort study evaluated Hg levels and contributing factors among pregnant women from different communities (riverine, rural, mining and urban) in Rondônia, Amazon Region, for 5 years. A well-coordinated and designed national biomonitoring program is urgently needed to better understand the current situation of Hg levels in Brazil and the Amazon.

A simple method for estimating relative risk using logistic regression.

BACKGROUND: Odds ratios (OR) significantly overestimate associations between risk factors and common outcomes. The estimation of relative risks (RR) or prevalence ratios (PR) has represented a statistical challenge in multivariate analysis and, furthermore, some researchers do not have access to the available methods. OBJECTIVE: To propose and evaluate a new method for estimating RR and PR by logistic regression. METHODS: A provisional database was designed in which events were duplicated but identified as non-events. After, a logistic regression was performed and effect measures were calculated, which were considered RR estimations. This method was compared with binomial regression, Cox regression with robust variance and ordinary logistic regression in analyses with three outcomes of different frequencies. RESULTS: ORs estimated by ordinary logistic regression progressively overestimated RRs as the outcome frequency increased. RRs estimated by Cox regression and the method proposed in this article were similar to those estimated by binomial regression for every outcome. However, confidence intervals were wider with the proposed method. CONCLUSION: This simple tool could be useful for calculating the effect of risk factors and the impact of health interventions in developing countries when other statistical strategies are not available.

Environmental factors associated with the time to tuberculosis diagnosis in prisoners in São Paulo, Brazil.

BACKGROUND: Environmental conditions play an important role in the high incidence of tuberculosis in prisons. We estimated the effect of environmental factors, including measurements based on cell dimensions, on the time to tuberculosis diagnosis in prison population of Brazil. METHODS: This is a retrospective cohort of 2,257 prisoners diagnosed with tuberculosis in 2014 and 2015. We collected environmental data from 105 prisons and linked with routine tuberculosis surveillance and prison data. We estimated tuberculosis-free survival time with Cox risk models, guided by a validated directed acyclic graph. RESULTS: The median disease-free time was 1.71 years (95% confidence interval [95% CI] 1.64-1.78). Each 50% increase in occupancy-rate, increased the tuberculosis speed incidence by 16% (95% CI 8%-25%) in the first 2 years, and 9% (95% CI 3%-16%) up to 5 years. An increase in the cell area per person (ln[m2/person]) reduced the hazard of tuberculosis by 13% (95% CI 3%-23%) for up to 2, and 12% (95% CI 3%-21%) for up to 5 years. DISCUSSION: Most tuberculosis cases were diagnosed within 2 years of incarceration. Prison overcrowding and physical space per person in the cell were associated with the tuberculosis-free disease time. CONCLUSIONS: Interventions to reduce overcrowding or increase physical space are crucial to prevent tuberculosis in prisons.

Comparison of clinical tools for dengue diagnosis in a pediatric population-based cohort.

BACKGROUND: We aimed to estimate and compare the ability of clinical tools for dengue diagnosis in a pediatric population. METHODS: We prospectively evaluated episodes of acute febrile syndrome identified during the follow-up of a population-based cohort of children and adolescents residing in a dengue endemic city. We estimated the area under the receiver operating characteristic curve (AU-ROC) for dengue diagnosis of three clinical tools: the summation of manifestations of the WHO case definition, a predefined clinical scale and a logistic regression model obtained in this study. RESULTS: We compared 219 dengue cases (confirmed by laboratory) and 286 patients with other febrile illnesses. In a multiple model, variables independently associated with dengue included the duration of fever, sleepiness and exanthema. Rhinorrhea, cough and minimal leukocyte count were inversely associated with dengue. This model reached an accuracy of 84.2% (for a cut-off of >0.5, sensitivity: 79.5%, specificity: 87.9%, positive predictive value: 83.7%, negative predictive value: 84.6%). The AU-ROC of this model (89.8%) was significantly higher than that obtained with either the predefined scale (82.1%) or the WHO definition manifestations (77%). CONCLUSION: We validated a predefined scale and identified a multiple model suitable for the clinical diagnosis of dengue in the pediatric population.

Impact of alcohol disorder and the use of illicit drugs on tuberculosis treatment outcomes: a retrospective cohort study.

BACKGROUND: Alcohol and illicit drugs are associated with the discontinuation of tuberculosis (TB) treatment and can compromise the immune system. We estimated the impact of alcohol disorder and the use of illicit drug on TB treatment outcomes, considering the interaction of both substances in patients from São Paulo state, Brazil. METHODS: This is a retrospective cohort of patients diagnosed with TB from 2011 to 2015. We estimated the relative risk (RR) of an unsuccessful outcome associated with alcohol disorder, use of illicit drugs and their interaction using a multiple regression model. We used the adjusted RR to estimate the population attributable fraction. RESULTS: Out of a total 77,212 TB patients, 22.2% used at least one of the substances of interest during treatment, while 17% presented an unsuccessful outcome of TB treatment. Compared with no exposure to any substance, alcohol disorder alone (adjusted RR: 1.48; 95% CI: 1.4-1.56), drug use alone (adjusted RR: 2.1; 95% CI: 1.98-2.21) and exposure to both substances (adjusted RR: 2.09; 95% CI: 1.97-2.21) were all associated with a higher risk of an unsuccessful outcome. The adjusted RR of an unsuccessful outcome for people exposed to both substances was 32.7% (95% CI: 26.8-38.2%) and 15.8% (95% CI: 11.5-20.1%) lower than expected on the multiplicative and additive scales respectively. Among all TB patients, 15.8% (95% CI: 15-16.5%) of unsuccessful outcomes was attributable to those exposures. CONCLUSIONS: We identified a negative interaction between alcohol disorder and the use of illicit drugs on TB treatment outcomes. Despite this, interventions to reduce substance use in TB patients could have a meaningful contribution to preventing unsuccessful treatment outcomes.

Respiratory Condition of Family Farmers Exposed to Pesticides in the State of Rio de Janeiro, Brazil.

Pesticide exposure is a growing public health concern. Although Brazil is the world’s largest consumer of pesticides, only a few studies have addressed the health effects among farmers. This study aimed to evaluate whether pesticide exposure is associated with respiratory outcomes among rural workers and relatives in Brazil during the crop and off-seasons. Family farmers (82) were interviewed about occupational history and respiratory symptoms, and cholinesterase tests were conducted in the crop-season. Spirometry was performed during the crop and off-season. Respiratory outcomes were compared between seasons and multiple regressions analysis were conducted to search for associations with exposure indicators. Participants were occupationally and environmentally exposed to multiple pesticides from an early age. During the crop and off-season, respectively, they presented a prevalence of 40% and 30.7% for cough, 30.7% and 24% for nasal allergies, and 24% and 17.3% for chest tightness. Significant associations between spirometry impairments and exposure indicators were found both during the crop and off-season. These findings provide complementary evidence about the association of pesticide exposure with adverse respiratory effects among family farmers in Brazil. This situation requires special attention as it may increase the risk of pulmonary dysfunctions, and the morbidity and mortality burden associated with these diseases.

Environmental and socio-economic determinants associated with the occurrence of cutaneous leishmaniasis in the northeast of Colombia.

Background: Cutaneous leishmaniasis (CL) is a vector-borne disease that is widely distributed in most tropical regions. Colombia has experienced an important increase in its incidence during the last decade. There are CL transmission foci in the Colombian departments of Santander and Norte de Santander. Objectives: To identify environmental and socio-economic variables associated with CL incidence in the municipalities of the northeast of Colombia between 2007 and 2016. Methods: This was an ecological study of CL cases aggregated by municipality. The cases reported during the study period were analyzed with a negative binomial regression to obtain the adjusted incident rate ratio for environmental and socio-economic variables. Findings: During the study period, 10 924 cases of CL were reported, and 110 (86.6%) municipalities reported at least one CL case. The coverages of forest (aIRR 1.05, 95% CI 1.03-1.07), heterogeneous agricultural zones (aIRR 1.04, 95% CI 1.02-1.06) and permanent crops (aIRR 1.07, 95% CI 1.02-1.12) were associated with a higher incidence of CL. Conversely, urban functionality (aIRR 0.95, 95% CI 0.92-0.96), minimal-altitude above sea level (aIRR 0.84, 95% CI 0.79-0.90) and shrub coverage (aIRR 0.98, 95% CI 0.95-1.0) were negatively associated with the incidence of CL in the municipality. Main conclusions: Our results confirm the importance of environmental determinants, such as height above sea level, and coverage of forest, permanent crops and heterogeneous agricultural zones, for the occurrence of CL; these findings also suggest the importance of shrub coverage. Furthermore, urban functionality was a socio-economic determinant independently associated with CL incidence.

Spatial distribution of Zika virus infection in Northeastern Colombia.

In this study, we investigated the weekly reported spatio-temporal distribution and topographic risk factors for Zika virus (ZIKV) infection in northeastern Colombia. Weekly reported surveillance data, including clinical, suspected and confirmed cases from the ongoing ZIKV epidemic in the Santander and Norte de Santander departments (Santanderes) in Colombia were used to estimate cumulative incidence rates. Spatial analysis was performed to develop hot spot maps and to identify spatial topographic risk factors for infection. From January 1, 2016 to March 19, 2016, 11,515 cases of ZIKV were reported in Santanderes, with cumulative rates of 316.07 cases/100,000 population for the region (representing 18.5% of the cases of the country). Five municipalities (four in Norte de Santander) reported high incidence of ZIKV infection (>1,000 cases/100,000 pop); these municipalities are close to the border with Venezuela. Most of the cases reported occurred mainly in low altitude areas, and persistent hot spots were observed. Higher infection rates were reported in the Northeastern part of the study area. Use of risk maps can help guide decisions for the prevention and control of ZIKV. Hotspots on the Colombia-Venezuela border can have implications for international spread.

Dengue Patients Treated with Doxycycline Showed Lower Mortality Associated to a Reduction in IL-6 and TNF Levels.

OBJECTIVE: To determine the effect of doxycycline treatment on cytokine levels, including tumor necrosis factor (TNF) and interleukin 6 (IL-6), and mortality in dengue patients at high risk of complication. METHODS: A group of dengue hemorrhagic fever patients (n=231) were randomized to receive either standard supportive care or supportive care in addition to oral doxycycline twice daily for 7 days. Dengue virus infection was confirmed by PCR using multiple primers. Serum samples were obtained at days 0, 3, 5 and 7 and tested for levels of TNF and IL-6. RESULTS: Doxycycline-treated group presented a 46% lower mortality than that observed in the untreated group (11.2% [13/116] vs 20.9% [24/115], respectively, p=0.05). Moreover, administration of doxycycline resulted in a significant (p<0.01) decrease in levels of TNF and IL-6 versus controls in the tests performed during follow-up (day 3, 5 and 7). Patients who died in both groups possessed significantly (p<0.01) higher levels of TNF and IL-6 compared to those who survived at all-time points. CONCLUSION: The above findings suggest that doxycycline can provide a clinical benefit to dengue patients at high risk of complications. This effect could be mediated by decreasing pro-inflammatory cytokine levels.

[The influence of cardiac rehabilitation on acute myocardial infarction patients' readmission rate in Santander, Colombia]. / Influencia de la rehabilitación cardíaca sobre la tasa de re-hospitalización en pacientes con infarto agudo de miocardio, Santander, Colombia.

OBJECTIVE: Estimating the effect of post-infarction cardiac rehabilitation (CR) on readmission/re-hospitalization rates according to intervention level. METHOD: This was a prospective cohort study of patients diagnosed as suffering acute myocardial infarction (AMI). Data concerning infarction severity, previous illness, medical history, hospital course, Killip classification, length of hospital stay and condition on discharge. Medical records and telephone contact were used to confirm whether a patient had received CR and ascertain pertinent components. Follow-up was extended to one year. RESULTS: 96 AMI patients of both genders were included; information about CR was available for 72 of them,5 of whom had received CR based only on physical activity. 49 patients received complete CR based on education, physical activity, psychological and nutritional assessment. 18 patients had not received CR. One death and 10 new admissions/hospitalizations were recorded during follow-up. A Poisson regression model showed that patients who had received CR based only on physical activity presented significantly higher re-hospitalization rates than patients who had received a complete CR scheme (rate ratio 5.89:1.14-30.4995 % CI; p=0.04). CONCLUSIONS: A multidisciplinary approach must bead opted to CR involving physical activity, education and psychological and nutritional assessment.

Influencia de la rehabilitación cardíaca sobre la tasa de re-hospitalización en pacientes con infarto agudo de miocardio, Santander, Colombia / The influence of cardiac rehabilitation on acute myocardial infarction patients' readmission rate in Santander, Colombia

Objetivo Estimar el efecto de la rehabilitación cardiaca (RC) pos-infarto, según sus niveles de intervención, sobre las tasas de re-hospitalización. Métodos Estudio de cohorte prospectiva de pacientes con diagnóstico de IAM. Se obtuvieron datos sobre gravedad del infarto, antecedentes, historia médica, evolución intrahospitalaria, clasificación Killip, estancia y condición de egreso. A través de la historia clínica electrónica y mediante contacto telefónico se constató si el paciente recibió RC y cuáles fueron sus componentes; el seguimiento se extendió hasta por un año. Resultados Se incluyeron 96 pacientes de ambos sexos con IAM. En 72 se contó con información sobre RC; 5 de los cuales recibieron RC basada únicamente en actividad física; 49 pacientes recibieron una RC más completa que integró actividad física, educación, psicología y nutrición; 18 pacientes no recibieron RC. Durante el seguimiento, se registraron 10 nuevas hospitalizaciones y una muerte. En un modelo de Poisson, los pacientes cuya RC se basó sólo en la actividad física presentaron una tasa de re-hospitalizaciones significativamente mayor que la de los pacientes que recibieron un esquema completo de RC (Razón de tasas: 5,89; IC 95 %:1,14-30,49; ρ=0,04). Conclusiones La RC debe tener un enfoque multidisciplinario, que además del componente físico, incluya el psicológico, nutricional y educativo.

Objective Estimating the effect of post-infarction cardiac rehabilitation (CR) on readmission/re-hospitalization rates according to intervention level. Method This was a prospective cohort study of patients diagnosed as suffering acute myocardial infarction (AMI). Data concerning infarction severity, previous illness, medical history, hospital course, Killip classification, length of hospital stay and condition on discharge. Medical records and telephone contact were used to confirm whether a patient had received CR and ascertain pertinent components. Follow-up was extended to one year. Results 96 AMI patients of both genders were included; information about CR was available for 72 of them,5 of whom had received CR based only on physical activity. 49 patients received complete CR based on education, physical activity, psychological and nutritional assessment. 18 patients had not received CR. One death and 10 new admissions/hospitalizations were recorded during follow-up. A Poisson regression model showed that patients who had received CR based only on physical activity presented significantly higher re-hospitalization rates than patients who had received a complete CR scheme (rate ratio 5.89:1.14-30.4995 % CI; p=0.04). Conclusions A multidisciplinary approach must bead opted to CR involving physical activity, education and psychological and nutritional assessment.