Zika virus infection in travelers returning from countries with local transmission, Guangdong, China, 2016.

BACKGROUND: Zika virus (ZIKV) is a mosquito-borne virus spreading rapidly in the Americas, Africa, and Asia. No indigenous ZIKV infection had been seen in China. We monitored ZIKV infection among travelers returning to Enping county from ZIKV transmitting countries from 1 March to 10 April 2016.

METHODS: We analyzed data including interviews; conducted laboratory test on blood, urine, saliva, conjunctival swab or semen specimens for evidence of ZIKV infection; evaluated household for presence of Aedes mosquitoes or larvae.

RESULTS: A total of 925 individuals were screened, 507 (54.8%) were interviewed, 400 (43.2%) provided samples, of which 13 (3.3%) tested positive for ZIKV including 3 asymptomatic. Rash, conjunctivitis, sore throat, fever were the common symptoms; rash was more pronounced in adults than in children. ZIKV RNA was detected for 1-4 days in blood, but longer in urine and saliva (3-32 days and 2-10 days). Among interviewed, 57.0% had good knowledge about ZIKV, 45.8% were worried about ZIKV, 99.2% would go to hospital if they had infection. Aedes mosquitoes or larvae were detected in townships of infected returners.

CONCLUSIONS: ZIKV was imported to China. Screening by symptoms alone is inadequate for detecting ZIKV infection. ZIKV surveillance, health-education, and vector control are necessary to decrease risk of ZIKV transmission.