First documented case of Zika virus infection in a Polish patient - diagnostic traps. Case report.

Zika virus (ZIKV), a mosquito-borne virus of the Flaviviridae family, has been reported in 89 countries. While ZIKV is not endemic in Poland, travel to regions with Aedes mosquitoes prevalence, presents a risk. This case report describes Poland's first ZIKV case in a patient with past Dengue virus (DENV) infection, following travel with his wife in 2016 to the Dominican Republic. Symptoms included fever, maculopapular rash, muscle pain, enlarged cervical lymph nodes, and lumbar pain. Hospital tests confirmed ZIKV, as well as possible simultaneous DENV infection. Further RT-PCR and serology tests were performed to exclude cross-reactivity. After 12 weeks, ZIKV RNA was detected in seminal fluid. Elevated IgG levels indicated prior DENV infection, while Dengue virus' antigen of non-structural protein 1 (NS1) antigen tests ruled out acute DENV. These findings impacted the couple's reproductive plans due to potential ZIKV transmission and patient's risk of secondary infection.