Co-circulating Arboviruses in Latin America: Zika Virus, Chikungunya Virus and Dengue Virus

Chikungunya (CHIKV), Dengue (DENV) and Zika (ZIKV) viruses have been of growing public health concern in Latin America. Increasing incidence of new infections alongside the continuing lack of licenced antivirals or vaccines have contributed to a rising burden of disease in populations and cost for healthcare systems. These burdens are further exacerbated due to the difficulty of achieving accurate diagnosis in settings where these viruses co-circulate. Thus, the aim of this research was to study co-circulating CHIKV, DENV and ZIKV in Latin America, particularly in relation to co-infections and the accurate identification of specific arbovirus infections. First, a systematic review of the published literature on ZIKV co-infections was conducted, assessing the co-infection frequency among ZIKV infected cases and the impact of co-infection on the clinical presentation of ZIKV. Second, the co-circulation of CHIKV and ZIKV in a cohort of pregnant women in Recife, Brazil from 2015-2017 was described and the potential to differentiate between infections at symptom presentation was assessed. The systematic review's main findings showed that the most frequent ZIKV co-infections occurred with CHIKV and DENV, and in some circumstances occurred in up to half of the ZIKV infections. Additionally, co-infection did not seem to affect the mild clinical presentation of ZIKV infections. However, the review was not able to assess a potential increase of complications associated with ZIKV co-infections compared to ZIKV mono-infections. Furthermore, the analysis of the cohort study showed that CHIKV and ZIKV infection were distinguishable upon clinical presentation in pregnant women. Our findings on ZIKV co-infections and the clinical presentation of ZIKV and CHIKV infected pregnant women contribute to improved patient management in settings of arbovirus co-circulation, through aiming to facilitate clinical diagnosis and guide laboratory testing, in order to administer appropriate follow up if needed, and consequently to reduce complications associated with arbovirus infection.