On Thursday, officials said that they have trapped the first mosquitoes that have tested positive for the Zika virus in the Miami, Florida area. The discovery further confirmed recent reports of local transmission of the illness in the United States. The Florida Department of Health said this week that so far, there have been 47 cases of the Zika virus in people believed to have contracted it in a small area of Miami. But until now, the department had not found infected mosquitoes. The health department added in a statement Friday it had tested over 40,000 mosquitoes in Florida since May, and that the three samples were the first to test positive.