Laboratorio Central de Epidemiología, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico.
PLoS Negl Trop Dis. 2021 Dec 2;15(12):e0009922. doi: 10.1371/journal.pntd.0009922. eCollection 2021 Dec.
With the arrival of chikungunya (CHIKV) and zika (ZIKV) viruses in Mexico, there was a decrease in diagnosed dengue virus (DENV) cases. During the first years of cocirculation (2015-2017), the algorithms established by epidemiological surveillance systems and the installed capacity limited us to one diagnostic test per sample, so there was an underestimation of cases until September 2017, when a multiplex algorithm was implemented. Therefore, the objective of this study was determine the impact of the introduction of CHIKV and ZIKV on the incidence of diagnosed DENV in endemic areas of Mexico, when performing the rediagnosis, using the multiplex algorithm, in samples from the first three years of co-circulation of these arboviruses.
For this, 1038 samples received by the Central Laboratory of Epidemiology between 2015 and 2017 were selected for this work. Viruses were identified by multiplex RT-qPCR, and the χ2 test was used to compare categorical variables. With the new multiplex algorithm, we identified 2.4 times the rate of arbovirosis as originally reported, evidencing an underestimation of the incidence of the three viruses. Even so, significantly less dengue was observed than in previous years. The high incidence rates of chikungunya and Zika coincided with periods of dengue decline. The endemic channel showed that the cases caused by DENV rose again after the circulation of CHIKV and ZIKV decreased. In addition, 23 cases of coinfection were identified, with combinations between all viruses.
The results obtained in this study show for the first time the real impact on the detected incidence of dengue after the introduction of CHIKV and ZIKV in Mexico, the degree of underestimation of these arboviruses in the country, as well as the co-infections between these viruses, whose importance clinical and epidemiological are still unknown.
基孔肯雅热（CHIKV）和寨卡热（ZIKV）病毒在墨西哥出现后，登革热病毒（DENV）确诊病例有所减少。在共同流行的最初几年（2015-2017 年），流行病学监测系统建立的算法和已安装的能力限制了我们对每个样本进行一次诊断测试，因此直到 2017 年 9 月实施多重算法之前，都低估了病例。因此，本研究的目的是确定在共同流行这些虫媒病毒的前三年，使用多重算法对样本进行重新诊断时，CHIKV 和 ZIKV 的引入对墨西哥流行地区诊断出的 DENV 发病率的影响。
为此，选择了 2015 年至 2017 年期间中央流行病学实验室收到的 1038 个样本进行这项工作。通过多重 RT-qPCR 鉴定病毒，并使用卡方检验比较分类变量。使用新的多重算法，我们发现虫媒病毒病的发病率是最初报告的 2.4 倍，这表明对三种病毒发病率的低估。即便如此，观察到的登革热病例明显少于前几年。基孔肯雅热和寨卡热的高发率与登革热下降的时期相吻合。流行渠道表明，在 CHIKV 和 ZIKV 流行减少后，DENV 引起的病例再次上升。此外，还确定了 23 例合并感染，涉及所有病毒的组合。
本研究首次获得了在墨西哥引入 CHIKV 和 ZIKV 后，对检测到的登革热发病率的实际影响的结果，以及该国对这些虫媒病毒的低估程度，以及这些病毒之间的合并感染，其临床和流行病学意义仍不清楚。
