The mosquito-borne Zika virus has spread across 66 countries in the past nine years, the World Health Organization (WHO) said in a new situation report issued Thursday.
"From 1 January 2007 to 20 April 2016, Zika virus transmission was documented in a total of 66 countries and territories," WHO said.
Last week, the organization's list of countries affected by the virus stood at 64 countries, two more than in the week prior to that. The WHO declared an international health emergency over the outbreak on February 1.
Forty-two countries experienced their first Zika outbreak without previous evidence of circulation since 2015, the WHO said in its latest report. Prior to 2015, 16 countries had reported evidence of Zika transmission.
Eight countries across Latin America, the United States and Europe reported evidence of person-to-person transmission.
Zika, which is spread by the Aedes mosquito common in tropical areas of the Americas, affects newborns infected by mothers. Strong scientific consensus links Zika to neurological disorders including the Guillain-Barre Syndrome and microcephaly.