While the US Congress dithers, the rest of the world is stepping up the fight against Zika virus. Countries vary in their concerns and measures. Some measures are more effective than others. In a world of international travel, the US is not immune from compliance with the laws of other countries.
Italy is concerned about the possibility of importing Zika infected mosquitoes that might spread the virus to their population. Not only are they concerned about infected travelers, they are also concerned that mosquitos carrying Zika might board a plane, fly to Italy and spread the virus. The government of Italy instituted a quarantine requiring all aircraft originating from countries reporting Zika virus to undergo disinsection (aerosol insecticide sprays inside the planes that kill mosquitoes). Almost immediately, Italy modified its quarantine to include aircraft originating from all foreign countries. This applies to military as well as business flights and US Air Force personnel are now spraying all Italy bound aircraft.
Costa Rica is treating aircraft with insecticide upon arrival from Zika infested countries with passengers, luggage, etc. still on board. Russia and China are inspecting aircraft arriving from Zika countries but have np quarantine or disinsection. Australia and New Zealand had preexisting quarantines and disinsection in place for other insects. Those are adequate for mosquitoes.
The insecticides used have little affect on people at the concentrations needed to kill mosquitoes and other insects. They can be an inconvenience for travelers. It is unknown if such measures will be effective, or if they will be discontinued if Zika manages to break quarantine in another way.