NEW YORK (Reuters Health) - More accurate testing reveals that the incidence of dengue (DENV), chikungunya (CHIKV) and zika (ZIKAV) viruses in endemic areas of Mexico is likely higher than previously reported, a cross-sectional study shows.
Dr. Jose Esteban Munoz-Medina of the Mexican Institute of Social Security in Mexico City and colleagues note in PLOS Neglected Tropical Diseases that CHIKV and ZIKAV were first detected in Mexico in 2014 and 2015, respectively. However, diagnostic techniques used by the country's National Network of Public Health Laboratories focused solely on DENV until 2017. Prior to implementation of multiplex RT-qPCR testing, the true incidence of these three arboviruses, as well as the incidence of coinfections, was unknown.
Therefore, the team conducted a cross-sectional study of 1,038 serum samples (patients' mean age, 33; 38%, men) to confirm DENV, CHIKV, and ZIKAV diagnoses during the first three years of co-circulation of these arboviruses. The multiplex test can identify any of the three viruses in a single reaction.
The team found 243.8% more cases of arbovirus than originally reported, including coinfections (4.9% of positive samples), suggesting underestimation of the incidence of the three viruses. However, significantly less DENV was observed than in previous years, and the high incidence rates of CHIKV and ZIKAV coincided with periods of dengue decline.
