Comparative analysis of dengue versus chikungunya outbreaks in Costa Rica

Abstract

For decades, dengue virus has been a cause of major public health concern in Costa Rica, due to its landscape and climatic conditions that favor the circumstances in which the vector, Aedes aegypti, thrives. The emergence and introduction throughout tropical and subtropical countries of the chikungunya virus, as of 2014, challenged Costa Rican health authorities to provide a correct diagnosis since it is also transmitted by the same vector and infected hosts may share similar symptoms. We study the 2015-2016 dengue and chikungunya outbreaks in Costa Rica while establishing how point estimates of epidemic parameters for both diseases compare to one another. Longitudinal weekly incidence reports of these outbreaks signal likely misdiagnosis of infected individuals: underreporting of chikungunya cases, while overreporting cases of dengue. Our comparative analysis is formulated with a single-outbreak deterministic model that features an undiagnosed class. Additionally, we also used a genetic algorithm in the context of weighted least squares to calculate point estimates of key model parameters and initial conditions, while formally quantifying misdiagnosis.1991 Mathematics Subject Classification. 92B05 and 37N25 and 62P10.

Mathematical and Statistical models as tools for the control of mosquito-borne diseases: The experience of Costa Rica

“…Point estimates of key model parameters showed that individuals were being diagnosed at a faster rate for the dengue virus. Both data anomalies suggest that dengue cases were over reported in the 2015–2016 outbreak [7].…”

“…In [29], the authors explore a single-outbreak deterministic model with state variables describing the host and vector dynamics of dengue and chikungunya. The estimated parameters were: the transmission rate, the diagnosis rate, the average vector infectious period and the initial value of the susceptible population.…”

“…In 2014, with the introduction of the Chikungunya virus into national territory, Costa Rican health authorities faced the circulation of two pathogens with similar clinical manifestations, temporal and spatial distribution, as the dengue virus has been endemic since 1993. Under this scenario, the use of a single-outbreak deterministic model, allowed to study and compare the trend of dengue and chikungunya reported cases in Costa Rica during the 2015-2016 outbreak [7].…”

Parameter estimates of the 2016-2017 Zika outbreak in Costa Rica: An Approximate Bayesian Computation (ABC) Approach

“…There is an ample history of mathematical models for vector-borne diseases [44,45,46,47,48,49,50,51,52,53], among others. Moreover, other models specifically on estimating parameters for dengue, chikungunya and Zika include: [53,54,55,56,57,58]. We introduce a nonlinear differential equation single-outbreak epidemic model that describes the Zika dynamics with sexual transmission and host availability for mosquito feeding in Costa Rica.…”

“…On the other hand, many of these methods are based on sequential algorithms that allow the approximation of the posterior density using sampling schemes such as rejection sampling, MCMC or sequential Monte Carlo sampling (see [61] for an exhaustive summary of the subject). Some of the parameters were kept fixed in order to follow the ecology constraints of the vector, as well as some conditions of the transmission dynamics of the disease that have been studied in previous articles ( [52], [58]). The total set of parameters (fixed and estimated), as well as the initial conditions of the system are presented in Table 2.…”