Factors Associated with Chikungunya Relapse in Acapulco, Mexico: A Cross-Sectional Study

Objective:To estimate the occurrence of self-reported chikungunya relapse and identify associated factors. Materials and Methods:A cross-sectional study in December 2015 included 1305 homes in eight urban clusters considered representative of Acapulco in southern Mexico. Administered questionnaires collated information on 5870 individuals, including sociodemographic variables, a history of chronic conditions, and the self-reporting of chikungunya. Bivariate and multivariate analyses relied on a cluster-adjusted Mantel-Haenszel procedure to identify the factors associated with chikungunya and its relapse. Results:Some 66% (3531/5870) of the population reported suffering chikungunya and 31.1% (1098/3531) reported a relapse. Factors associated with relapse included the severity of the chikungunya case (odds ratio [OR]: 3.35; clusters adjusted 95% confidence interval [95% CIca]: 3.16-3.55); history of arthralgia (OR: 2.96; 95% CIca: 2.27-3.86); age 30 years or older (OR: 1.85; 95% CIca: 1.72-1.98); female (OR: 1.64; 95% CIca: 1.42-1.90); and higher education households (OR: 1.18; 95% CIca: 1.11-1.27). Conclusions:The high occurrence of chikungunya and its relapse are a public health problem. The factors associated with relapse do not immediately suggest specific prevention strategies but emphasize the dire need for effective approaches to vector control.