Viral Infections USMLE Step 1 Practice Question

A 32-year-old woman at 8 weeks gestation presents to clinic with a 3-day history of low-grade fever (38.5°C), fine maculopapular rash beginning on the face and spreading to the trunk, polyarthralgias affecting the wrists and knees, and bilateral conjunctivitis without purulent exudate. She reports no exposure to sick contacts but recently traveled internationally. Vital signs are stable (HR 98, RR 16, BP 120/78). Serologic testing reveals negative IgM antibodies but positive IgG antibodies to the suspected pathogen. CBC shows a mild relative lymphopenia with normal hemoglobin and platelet count. Which of the following is the most likely diagnosis?