Zoonosis: Update on Existing and Emerging Vector-Borne Illnesses in the USA.

PURPOSE OF REVIEW: This review describes mosquito- and tick-borne diseases found in the Western Hemisphere. It focuses on emerging diseases and recent geographic shifts in the presence of disease vectors. RECENT FINDINGS: Mosquito and tick vectors have become more widespread as environmental conditions have become more favorable. Zika recently has emerged as a concern for fetal anomalies. West Nile Virus has become widespread. Lyme disease and other tick-borne diseases are more prevalent in areas previously inhospitable to these ticks. SUMMARY: Healthcare providers must consider the possibility of mosquito- and tick-borne diseases in broader geographic areas and council patients traveling to endemic areas on precautions against these diseases. Treatment for suspected cases of serious tick-borne illnesses should not be delayed pending culture results.