RESUMO
OBJECTIVE: To estimate the age-specific incidence of symptomatic dengue and chikungunya in Colombia. METHOD: A passive facility-based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture-recapture methods. RESULTS: Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients. CONCLUSIONS: These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.
Assuntos
Febre de Chikungunya/diagnóstico , Febre de Chikungunya/epidemiologia , Dengue/diagnóstico , Dengue/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Colômbia/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Vigilância da População , Adulto JovemRESUMO
BACKGROUND: Dengue fever has been a major public health concern in Colombia, Thailand, and Vietnam. Unlike other infectious diseases, dengue vaccines had not been available for a long time, causing difficulties to control the disease. However, the first live attenuated, tetravalent dengue vaccine (CYD-TDV) became available in 2016 and has been already licensed in some dengue-endemic countries. Because several second-generation dengue vaccines are also in the pipeline, it is critical to understand the efficient allocation of dengue vaccines considering the geographical variation of the disease. METHODS: The Climate Risk Factor (CRF) index was created using the climate and non-climate factors in the three countries. A random-coefficient negative binomial model was chosen to validate the relationship between the CRF index and dengue incidence proxy. Given the statistical significance of the CRF index, high risk areas for dengue fever were identified at the 5â¯km by 5â¯km resolution and used to estimate vaccination coverage rates and the number of doses required for various types of vaccination scenarios by country. RESULTS AND CONCLUSIONS: Based upon a three-dose scheme, the estimated number of vaccines required for routine vaccination targeting 9 years old ranged from 1 to 2.6 million doses across the countries during the first year of introduction. A one-off catch-up campaign targeting the age group of 10-17 year olds would require 8 to 18 million additional doses. Routine vaccination (with or without a catch-up campaign) covered 63%, 90%, and 91% of the targeted age group populations in Colombia, Thailand, and Vietnam respectively. Given that many dengue-endemic countries face limited resources and that the costs for mass vaccination campaigns may not be trivial, the findings of this study can guide the decision makers in the three countries regarding the efficient distribution of vaccines by identifying populations at high risk at 5â¯km by 5â¯km resolution.
Assuntos
Vacinas contra Dengue/provisão & distribuição , Dengue/prevenção & controle , Adolescente , Adulto , Criança , Clima , Colômbia/epidemiologia , Dengue/epidemiologia , Doenças Endêmicas , Epidemias , Feminino , Humanos , Masculino , Tailândia/epidemiologia , Vietnã/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Dengue fever is a major public health concern in many parts of the tropics and subtropics. The first dengue vaccine has already been licensed in six countries. Given the growing interests in the effective use of the vaccine, it is critical to understand the economic burden of dengue fever to guide decision-makers in setting health policy priorities. METHODS/PRINCIPAL FINDINGS: A standardized cost-of-illness study was conducted in three dengue endemic countries: Vietnam, Thailand, and Colombia. In order to capture all costs during the entire period of illness, patients were tested with rapid diagnostic tests on the first day of their clinical visits, and multiple interviews were scheduled until the patients recovered from the current illness. Various cost items were collected such as direct medical and non-medical costs, indirect costs, and non-out-of-pocket costs. In addition, socio-economic factors affecting disease severity were also identified by adopting a logit model. We found that total cost per episode ranges from $141 to $385 for inpatient and from $40 to $158 outpatient, with Colombia having the highest and Thailand having the lowest. The percentage of the private economic burden of dengue fever was highest in the low-income group and lowest in the high-income group. The logit analyses showed that early treatment, higher education, and better knowledge of dengue disease would reduce the probability of developing more severe illness. CONCLUSIONS/SIGNIFICANCE: The cost of dengue fever is substantial in the three dengue endemic countries. Our study findings can be used to consider accelerated introduction of vaccines into the public and private sector programs and prioritize alternative health interventions among competing health problems. In addition, a community would be better off by propagating the socio-economic factors identified in this study, which may prevent its members from developing severe illness in the long run.
Assuntos
Dengue/economia , Adolescente , Adulto , Colômbia , Efeitos Psicossociais da Doença , Feminino , Humanos , Renda , Masculino , Saúde Pública/economia , Tailândia , Vietnã , Adulto JovemRESUMO
BACKGROUND: Dengue has been prevalent in Colombia with high risk of outbreaks in various locations. While the prediction of dengue epidemics will bring significant benefits to the society, accurate forecasts have been a challenge. Given competing health demands in Colombia, it is critical to consider the effective use of the limited healthcare resources by identifying high risk areas for dengue fever. METHODS: The Climate Risk Factor (CRF) index was constructed based upon temperature, precipitation, and humidity. Considering the conditions necessary for vector survival and transmission behavior, elevation and population density were taken into account. An Early Warning Signal (EWS) model was developed by estimating the elasticity of the climate risk factor function to detect dengue epidemics. The climate risk factor index was further estimated at the smaller geographical unit (5 km by 5 km resolution) to identify populations at high risk. RESULTS: From January 2007 to December 2015, the Early Warning Signal model successfully detected 75% of the total number of outbreaks 1 ~ 5 months ahead of time, 12.5% in the same month, and missed 12.5% of all outbreaks. The climate risk factors showed that populations at high risk are concentrated in the Western part of Colombia where more suitable climate conditions for vector mosquitoes and the high population level were observed compared to the East. CONCLUSIONS: This study concludes that it is possible to detect dengue outbreaks ahead of time and identify populations at high risk for various disease prevention activities based upon observed climate and non-climate information. The study outcomes can be used to minimize potential societal losses by prioritizing limited healthcare services and resources, as well as by conducting vector control activities prior to experiencing epidemics.
Assuntos
Dengue/epidemiologia , Animais , Clima , Colômbia/epidemiologia , Culicidae , Surtos de Doenças , Humanos , Umidade , Densidade Demográfica , Fatores de Risco , Temperatura , Tempo (Meteorologia)RESUMO
BACKGROUND: The rise in dengue fever cases and the absence of dengue vaccines will likely cause governments to consider various types of effective means for controlling the disease. Given strong public interests in potential dengue vaccines, it is essential to understand the private economic benefits of dengue vaccines for accelerated introduction of vaccines into the public sector program and private markets of high-risk countries. METHODOLOGY/PRINCIPAL FINDINGS: A contingent valuation study for a hypothetical dengue vaccine was administered to 400 households in a multi-country setting: Vietnam, Thailand, and Colombia. All respondents received a description of the hypothetical dengue vaccine scenarios of 70% or 95% effectiveness for 10 or 30 years with a three dose series. Five price points were determined after pilot tests in order to reflect different local situations such as household income levels and general perceptions towards dengue fever. We adopted either Poisson or negative binomial regression models to calculate average willingness-to-pay (WTP), as well as median WTP. We found that there is a significant demand for dengue vaccines. The parametric median WTP is $26.4 ($8.8 per dose) in Vietnam, $70.3 ($23.4 per dose) in Thailand, and $23 ($7.7 per dose) in Colombia. Our study also suggests that respondents place more value on vaccinating young children than school age children and adults. CONCLUSIONS/SIGNIFICANCE: Knowing that dengue vaccines are not yet available, our study provides critical information to both public and private sectors. The study results can be used to ensure broad coverage with an affordable price and incorporated into cost benefit analyses, which can inform prioritization of alternative health interventions at the national level.