Characteristics of Zika virus infection among international travelers: A prospective study from a Spanish referral unit

From the first Zika virus (ZIKV) description, it has progressively widespread worldwide. We analyzed demographic, clinical, microbiologic and travel-related characteristic from returned patients from a ZIKV endemic country in a referral Tropical Medicine Unit. A prospective cohort study performed in a Spanish referral center with the aim of determining the significant factors associated with confirmed Zika virus (ZIKV) infection. 817 patients, (56% women, median age 36 [IQR, Interquartile Range: 32–42]) were enrolled. Most had returned from Latin America (n = 486; 59.4%), travelled for tourism (n = 404; 49.4%) and stayed a median of 18 days (IQR: 10–30). 602 (73.6%) presented symptoms, but only 25 (4%) were finally diagnosed with confirmed ZIKV infection (including two pregnant women, without adverse fetal outcomes), 88% (n:22) presented with fever and 92% (n:23) with rash. 56% (n:14) arthralgia and/or myalgia and 28% (n:7) conjunctivitis. The presence of conjunctivitis, fever and rash were associated with an 8.9 (95% CI: 2.2–34.9), 6.4 (95% CI: 1.2–33.3) and 72.3 (95% CI: 9.2–563.5) times greater probability of confirmed ZIKV infection, respectively. Travel characteristics and clinical presentation may help clinicians to optimize requests for microbiological testing. Diagnosis of arboviriasis in travellers arriving form endemic areas remains a challenge for clinicians, but must be detected for the possible transmission outside endemic areas, where the vector is present.