Estimating the burden of arboviral diseases in Colombia between 2013 and 2016

Cost of dengue in Colombia: A systematic review

BACKGROUND

Dengue is hyperendemic in Colombia. It imposes a substantial economic burden on patients, caregivers, society, and the national health system. We intend to identify and synthesize the evidence regarding the economic burden of dengue in Colombia.

METHODS

A systematic review (PROSPERO CRD42021257985) of economic studies was performed. A comprehensive search was completed in PubMed, EMBASE, the Cochrane Library, the LILACS, and SciELO databases. Study selection and data extraction was made by two researchers.

RESULTS

160 records were identified. Of these, 14 studies were selected for data extraction. Direct medical cost of dengue is mainly represented by hospitalization (USD 823 to 1,754). The annual aggregated cost is near to USD 159.6 million, with ambulatory care (USD 90.1 million) and fatal cases (USD 30.7 million) representing 75% of the total cost. The aggregate indirect cost (due to loss in income while sick or as a caretaker) was USD 92.8 million. Vaccination seems to reduce the economic cost of dengue.

CONCLUSIONS

Dengue financial burden could be challenging for low-income communities as those affected in Colombia. An integrated approach including vector control and the introduction of a vaccine for dengue has the potential to reduce the economic burden of the disease.

High-Sensitivity RT-LAMP for Molecular Detection of O'nyong-nyong (Alphavirus onyong)

Mosquitoes serve as vectors for many arthropod-borne viruses (arboviruses) that are responsible for millions of human infections and thousands of deaths each year. Among these arboviruses, O'nyong-nyong virus (ONNV) is an African alphavirus mainly transmitted by Anopheles mosquitoes. ONNV can be detected through serological or molecular tests, the first showing cross-reactivity to co-circulating alphaviruses and requiring technically demanding confirmation, while the latter, usually based on real-time PCR, are costly and demand specific equipment. Isothermal amplification approaches, such as Loop-Mediated Isothermal Amplification (LAMP), should therefore provide a cost-effective, sensitive, and specific alternative for virus detection, suitable for the resource-limited regions where ONNV circulates up to the present time. Here, we describe the development and optimization of a rapid and highly sensitive (10 pfu/reaction) RT-LAMP assay for ONNV detection. Additionally, we demonstrate that it is possible to bypass the RNA extraction step, reducing sample handling time and costs. The final RT-LAMPONNV is a promising field detection tool for ONNV, enabling a better understanding of its impact and serving as a point-of-care diagnostic method.

High Seroprevalence to Aedes-borne arboviruses in Ethiopia: a Cross-sectional Survey in 2024

Aedes-borne diseases infect millions of people each year. In the last decade several arbovirus outbreaks have been reported in Ethiopia. Arbovirus diagnosis and surveillance is lacking and the true burden is unknown. In this study we conducted a seroprevalence survey using a commercially available test kit that that tests for immunological responses to IgM and IgG for dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV) viruses in Dire Dawa city, eastern Ethiopia. We found a high IgG seroprevalence for DENV (76%), CHIKV (44%), and ZIKV (38%), and <20% IgM seropositivity across all viruses. As a comparison, we conducted serosurveillance in Addis Ababa, the national capital with no reported history of arbovirus outbreaks. The highest seropositivity we found was to IgM for DENGV at approximately 3%. Our results suggest both past and recent widespread exposure to these arboviruses, underscoring the need for improved surveillance and public health interventions in Ethiopia.

Evaluation of fluoride exposure using disability-adjusted life years and health risk assessment in south-western Iran: A novel Monte Carlo simulation

Consumption of fluoride-contaminated water is a worldwide concern, especially in developing countries, including Iran. However, there are restricted studies of non-single-value health risk assessment and the disease burden regarding fluoride intake nationwide. Prolonged exposure to excessive fluoride has been linked to adverse health effects such as dental and skeletal fluorosis. This can lead to under-mineralization of hard tissues, causing aesthetic concerns for teeth and changes in bone structure, increasing the risk of fractures. As such, we aimed to implement probability-based frameworks using Monte Carlo methods to explore the potential adverse effects of fluoride via the ingestion route. This platform consists of two sectors: 1) health risk assessment of various age categories coupled with a variance decomposition technique to measure the contributions of predictor variables in the outcome of the health risk model, and 2) implementing Monte Carlo methods in dose-response curves to explore the fluoride-induced burden of diseases of dental fluorosis and skeletal fractures in terms of disability-adjusted life years (DALYs). For this purpose, total water samples of 8053 (N=8053) from 57 sites were analyzed in Fars and Bushehr Provinces. The mean fluoride concentrations were 0.75 mg/L and 1.09 mg/L, with maximum fluoride contents of 6.5 mg/L and 3.22 mg/L for the Fars and Bushehr provinces, respectively. The hazard quotient of the 95th percentile (HQ>1) revealed that all infants and children in the study area were potentially vulnerable to over-receiving fluoride. Sobol' sensitivity analysis indices, including first-order, second-order, and total order, disclosed that fluoride concentration (Cw), ingestion rate (IRw), and their mutual interactions were the most influential factors in the health risk model. DALYs rate of dental fluorosis was as high as 981.45 (uncertainty interval: UI 95 % 353.23-1618.40) in Lamerd, and maximum DALYs of skeletal fractures occurred in Mohr 71.61(49.75-92.71), in Fars Province, indicated severe dental fluorosis but mild hazard regarding fractures. Residents of the Tang-e Eram in Bushehr Province with a DALYs rate of 3609.40 (1296.68-5993.73) for dental fluorosis and a DALYs rate of 284.67 (199.11-367.99) for skeletal fractures were the most potentially endangered population. By evaluating the outputs of the DALYs model, the gap in scenarios of central tendency exposure and reasonable maximum exposure highlights the role of food source intake in over-receiving fluoride. This research insists on implementing defluoridation programs in fluoride-endemic zones to combat the undesirable effects of fluoride. The global measures presented in this research aim to address the root causes of contamination and help policymakers and authorities mitigate fluoride's harmful impacts on the environment and public health.

Prevention of multiple whole blood donations by an individual at the same month through the creation of a national Deferred Donor Registry (DDR)

INTRODUCTION

The Colombian National Institute of Health administers the National Information System of Haemovigilance (SIHEVI-INS). Today, SIHEVI-INS constitutes a national blood donor and recipient database, which contains a national deferred donor registry (DDR), allowing blood banks to take acceptance or rejection decisions of a potential donor in real time. The study aimed to determine the rate of people who have made more than one whole blood donation monthly in Colombia, violating the national guideline of intervals between donations (three months for men and four for women), since DDR implementation.

METHODS

We detected the unique personal identification number of people who, in 30 calendar days, made more than one whole blood donation at any of the 83 blood banks set up in Colombia. There were three comparison periods: 01/01/2018-08/31/2019 (launch of SIHEVI-INS and first national feedback); 09/01/2019-12/31/2020 (second feedback) and 01/01/2021-09/30/2022 (massive incorporation of web services).

RESULTS

For the first period, blood banks accepted 18.0 donations per 1000 people. There was a rate of 28.8 people/10,000 donations who had donated whole blood twice within 30 days. In the second period, there were 17.0 donations/1000 people and a rate of 2.1 people/10,000 donations (OR:14.0 CI95 %:12.2-16.0). For the last period, there were 18.2 donations/1000 people and a rate of 0.9 individuals/10,000 donations (OR:31.3 CI95 %:26.6-36.9, p < 0.001).

CONCLUSION

DDR reduced by 31 times the acceptance of blood donors who made more than one whole blood donation in the same month. It was necessary to provide periodic feedback and promote web service implementation to reduce this risky behavior.

Epidemiology and Economic Burden of Chikungunya: A Systematic Literature Review

Chikungunya (CHIK) is a re-emerging viral infection endemic in tropical and subtropical areas. While the typical clinical presentation is an acute febrile syndrome, long-term articular complications and even death can occur. This review characterizes the global epidemiological and economic burden of chikungunya. The search included studies published from 2007 to 2022 in MEDLINE, Embase, LILACS, and SciELO for a thorough evaluation of the literature. Rayyan software was used for data analysis, and data were summarized descriptively and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seventy-six publications were included. Chikungunya is widely distributed in the tropics, including Africa, Asia, South America, and Oceania/the Pacific Islands, and co-circulates with other simultaneous arboviruses such as DENV, ZIKV, and YFV. Chikungunya infection can lead to chronic articular manifestations with a significant impact on the quality of life in the long term. In addition, it generates absenteeism and economic and social losses and can cause fatal infections in vulnerable populations, mainly in high-risk patients with co-morbidities and at the extremes of age. Reported costs associated with CHIKV diseases are substantial and vary by region, age group, and public/private delivery of healthcare services. The chikungunya disease burden includes chronicity, severe infections, increased hospitalization risks, and associated mortality. The disease can impact the economy in several spheres, significantly affecting the health system and national economies. Understanding and measuring the full impact of this re-emerging disease is essential.

Identification of Hazard and Socio-Demographic Patterns of Dengue Infections in a Colombian Subtropical Region from 2015 to 2020: Cox Regression Models and Statistical Analysis

Dengue is a disease of high interest for public health in the affected localities. Dengue virus is transmitted by Aedes species and presents hyperendemic behaviors in tropical and subtropical regions. Colombia is one of the countries most affected by the dengue virus in the Americas. Its central-west region is a hot spot in dengue transmission, especially the Department of Antioquia, which has suffered from multiple dengue outbreaks in recent years (2015-2016 and 2019-2020). In this article, we perform a retrospective analysis of the confirmed dengue cases in Antioquia, discriminating by both subregions and dengue severity from 2015 to 2020. First, we conduct an exploratory analysis of the epidemic data, and then a statistical survival analysis is carried out using a Cox regression model. Our findings allow the identification of the hazard and socio-demographic patterns of dengue infections in the Colombian subtropical region of Antioquia from 2015 to 2020.

The Influence of Anthropogenic and Environmental Disturbances on Parameter Estimation of a Dengue Transmission Model

Some deterministic models deal with environmental conditions and use parameter estimations to obtain experimental parameters, but they do not consider anthropogenic or environmental disturbances, e.g., chemical control or climatic conditions. Even more, they usually use theoretical or measured in-lab parameters without worrying about uncertainties in initial conditions, parameters, or changes in control inputs. Thus, in this study, we estimate parameters (including chemical control parameters) and confidence contours under uncertainty conditions using data from the municipality of Bello (Colombia) during 2010-2014, which includes two epidemic outbreaks. Our study shows that introducing non-periodic pulse inputs into the mathematical model allows us to: (i) perform parameter estimation by fitting real data of consecutive dengue outbreaks, (ii) highlight the importance of chemical control as a method of vector control, and (iii) reproduce the endemic behavior of dengue. We described a methodology for parameter and sub-contour box estimation under uncertainties and performed reliable simulations showing the behavior of dengue spread in different scenarios.

Spatio-temporal clusters and patterns of spread of dengue, chikungunya, and Zika in Colombia

Background

Colombia has one of the highest burdens of arboviruses in South America. The country was in a state of hyperendemicity between 2014 and 2016, with co-circulation of several Aedes-borne viruses, including a syndemic of dengue, chikungunya, and Zika in 2015.

Methodology/Principal findings

We analyzed the cases of dengue, chikungunya, and Zika notified in Colombia from January 2014 to December 2018 by municipality and week. The trajectory and velocity of spread was studied using trend surface analysis, and spatio-temporal high-risk clusters for each disease in separate and for the three diseases simultaneously (multivariate) were identified using Kulldorff’s scan statistics. During the study period, there were 366,628, 77,345 and 74,793 cases of dengue, chikungunya, and Zika, respectively, in Colombia. The spread patterns for chikungunya and Zika were similar, although Zika’s spread was accelerated. Both chikungunya and Zika mainly spread from the regions on the Atlantic coast and the south-west to the rest of the country. We identified 21, 16, and 13 spatio-temporal clusters of dengue, chikungunya and Zika, respectively, and, from the multivariate analysis, 20 spatio-temporal clusters, among which 7 were simultaneous for the three diseases. For all disease-specific analyses and the multivariate analysis, the most-likely cluster was identified in the south-western region of Colombia, including the Valle del Cauca department.

Conclusions/Significance

The results further our understanding of emerging Aedes-borne diseases in Colombia by providing useful evidence on their potential site of entry and spread trajectory within the country, and identifying spatio-temporal disease-specific and multivariate high-risk clusters of dengue, chikungunya, and Zika, information that can be used to target interventions.

Dengue, chikungunya, and Zika are diseases transmitted to humans by the bite of infected Aedes mosquitoes. Between 2014 and 2016 chikungunya and Zika viruses started causing outbreaks in Colombia, one of the countries historically most affected by dengue. We used case counts of the diseases by municipality and week to study the spread trajectory of chikungunya and Zika within Colombia’s territory, and to identify space-time high-risk clusters, i.e., the areas and time periods that dengue, chikungunya, and Zika were more present. Chikungunya and Zika spread similarly in Colombia, but Zika spread faster. The Atlantic coast, a famous touristic destination in the country, was likely the place of entry of chikungunya and Zika in Colombia. The south-western region was identified as a high-risk cluster for all three diseases in separate and simultaneously. This region has a favorable climate for the Aedes mosquitoes and other characteristics that facilitate the diseases’ transmission, such as social deprivation and high population mobility. Our results provide useful information on the locations that should be prioritized for interventions to prevent the entry of new diseases transmitted by Aedes and to reduce the burden of dengue, chikungunya and Zika where they are established.

Endothelial Dysfunction, HMGB1, and Dengue: An Enigma to Solve

Dengue is a viral infection caused by dengue virus (DENV), which has a significant impact on public health worldwide. Although most infections are asymptomatic, a series of severe clinical manifestations such as hemorrhage and plasma leakage can occur during the severe presentation of the disease. This suggests that the virus or host immune response may affect the protective function of endothelial barriers, ultimately being considered the most relevant event in severe and fatal dengue pathogenesis. The mechanisms that induce these alterations are diverse. It has been suggested that the high mobility group box 1 protein (HMGB1) may be involved in endothelial dysfunction. This non-histone nuclear protein has different immunomodulatory activities and belongs to the alarmin group. High concentrations of HMGB1 have been detected in patients with several infectious diseases, including dengue, and it could be considered as a biomarker for the early diagnosis of dengue and a predictor of complications of the disease. This review summarizes the main features of dengue infection and describes the known causes associated with endothelial dysfunction, highlighting the involvement and possible relationship between HMGB1 and DENV.

Epidemiological burden of Chikungunya fever in Brazil, 2016 and 2017

OBJECTIVES

To describe Chikungunya fever (CHIKF) cases and estimate the burden of the disease in Brazil between 2016 and 2017.

METHODS

The first stage of this study consisted of a descriptive epidemiological study with estimations of incidence, mortality and case-fatality rates for each Brazilian state. The second stage provided estimates of the disease burden using DALY, an indicator that aggregates measures of morbidity (years lived with disability - YLD) and mortality (years of life lost - YLL) into a single value.

RESULTS

In Brazil, the incidence rate in 2016 was 114.70 per 100,000 inhabitants, while the mortality rate was 0.15 per 100,000, for a case-fatality rate of 0.13%. In 2017, these figures were 87.59 and 0.12 per 100,000 inhabitants and 0.14%, respectively. The estimated CHIKF burden for Brazil in 2016 was 77,422.61 DALY or 0.3757 per 1000 inhabitants. In 2016, the YLL share of DALY was 10.04%, with YLD accounting for the remaining 89.96%. In 2017, the estimated burden was 59,307.59 DALY or 0.2856 per 1000 inhabitants, with YLL accounting for 9.65% of the total and YLD for 90.35%.

CONCLUSION

CHIKF causes a significant disease burden in Brazil. The chronic phase of CHIKF is responsible for the largest portion of DALY. Deaths from CHIKF are a significant component of the disease burden, with YLL accounting for approximately 10% of the total DALY value.

Dengue, Severity Paradox, and Socioeconomic Distribution Among Afro-Colombians

BACKGROUND

The clinical presentation of dengue ranges from self-limited mild illness to severe forms, including death. African ancestry is often described as protective against dengue severity. However, in the Latin American context, African ancestry has been associated with increased mortality. This "severity paradox" has been hypothesized as resulting from confounding or heterogeneity by socioeconomic status (SES). However, few systematic analyses have been conducted to investigate the presence and nature of the disparity paradox.

METHODS

We fit Bayesian hierarchical spatiotemporal models using individual-level surveillance data from Cali, Colombia (2012-2017), to assess the overall morbidity and severity burden of notified dengue. We fitted overall and ethnic-specific models to assess the presence of heterogeneity by SES across and within ethnic groups (Afro-Colombian vs. non-Afro-Colombians), conducting sensitivity analyses to account for potential underreporting.

RESULTS

Our study included 65,402 dengue cases and 13,732 (21%) hospitalizations. Overall notified dengue incidence rates did not vary across ethnic groups. Severity risk was higher among Afro-Colombians (risk ratio [RR] = 1.16; 95% Credible Interval [95% CrI] = 1.08, 1.24) but after accounting for underreporting by ethnicity this association was nearly null (RR = 1.02; 95% CrI = 0.97, 1.07). Subsidized health insurance and low-SES were associated with increased overall dengue rates and severity.

CONCLUSION

The paradoxically increased severity among Afro-Colombians can be attributed to differential health-seeking behaviors and reporting among Afro-Colombians. Such differential reporting can be understood as a type of intersectionality between SES, insurance scheme, and ethnicity that requires a quantitative assessment in future studies.

Serological cross-reactivity using a SARS-CoV-2 ELISA test in acute Zika virus infection, Colombia

OBJECTIVES

We investigated seroreactivity by using a commercial SARS-CoV-2 ELISA test in samples collected from different groups of individuals, including patients diagnosed to have Dengue, Zika, and Chikungunya infection between 2015 and 2019, from an endemic area in the Caribbean Colombian region.

METHODS

A total of 127 sera samples obtained from six different groups of individuals were included in this study: Group A: patients with confirmed SARS-CoV-2 infection; Group B: patients with symptoms suggestive of COVID-19 or asymptomatic contacts with confirmed patients; Group C: patients with acute or recent dengue virus infection; Group D: patients with acute Zika virus infection; Group E: patients with previous Chikungunya virus infection; and Group F: individuals with exposure to spotted fever group rickettsiae.

RESULTS

Overall, group A, group B, and group D showed seroreactivity to SARS-CoV-2 in 92%, 75%, and 26% of samples, respectively; furthermore, group C, group E, and group F showed 100% seronegativity.

CONCLUSIONS

We found 26% of serological cross-reactivity in patients with acute Zika virus infection by using a commercial SARS-CoV-2 ELISA test. Further studies are needed to evaluate whether serological cross-reaction is maintained with time in nonacute patients with previous exposure to the Zika virus and its effect in SARS-CoV-2 serosurveys in endemic areas for this arbovirus.