Arboviral Infections Following the 2016 Olympic and Paralympic Games in a Cohort of US Athletes and Support Staff

Background The 2016 Olympic and Paralympic games were held in Brazil after the peak of an explosive Zika virus (ZIKV) outbreak. The risk to US athletes and support staff of travel-associated ZIKV and other arboviral infections was unknown but concern was high. Methods Individuals traveling with the US Olympic Committee (USOC), including Olympic and Paralympic athletes and support staff were enrolled. Participants provided a pre- and post-travel (2–12 weeks) blood samples, and were also counseled about mosquito avoidance. Participants completed pre- and post-travel surveys detailing demographics, health history, vaccination, mosquito protection, and symptoms during and up to 2 weeks after travel to Brazil. Blood samples were tested at ARUP Laboratories, Utah, for ZIKV IgM and for Chikungunya (CHKV), Dengue (DENV), and West Nile (WNV) viruses IgM and IgG. Recent infection was defined as the presence of IgM in a post-travel blood sample and or IgG seroconversion. Results A total of 950 individual subjects provided pre-travel samples and surveys. Of these, 457 (48%) also provided post-travel samples. No ZIKV infections were detected by IgM. However, 48 (11%) participants had antibody evidence of other arboviral infections; 4 (0.9% tested) with CHKV, 6 (1.3%) with DENV, and 39 (9%) with WNV. Of these, new travel-associated infection was confirmed in 32 (7%); 3 of 4 CHKV, 2 of 6 DENV, and 27 of 39 WNV. Twelve (38%) of the subjects with travel associated arbovirus infection submitted post-travel surveys; 3 (25%) respondents had symptoms of arboviral infection during or within 2 weeks after travel; 2 (16%) CHKV, and 1 (8%) WNV. Those with travel-associated arboviral infections had similar demographics, and exposure whilst in Brazil, but were less likely to use mosquito repellent than athletes without arboviral infection (7/12 (58%) vs. 130/154 (84%), OR 0.26, P = 0.04). Conclusion ZIKV was not detected in the USOC athletes or staff traveling to Brazil. Other arboviral infections were detected in 7% of travelers, with WNV being most common. The use of mosquito repellent was associated with decreased risk of infection. This study demonstrates multiple arboviruses in addition to ZIKV were circulating simultaneously in Brazil and has implications for pre- and post-travel counseling. Disclosures C. L. Byington, BioFire: Collaborator and Grant Investigator, Licensing agreement or royalty and Research grant