Hong Kong is now requiring disinsection for all aircraft inbound from Zika-affected areas, mainly countries in South and Central America, Africa and Asia, according to Flight Services Bureau. Compliance requires either residual or non-residual anti-virus treatment, the flight-planning company said.

Residual disinsection involves spraying the internal surfaces of the aircraft, excluding food preparation areas, with World Health Organization-approved residual pesticides at intervals not exceeding eight weeks. Operators who choose that optionmust provide Hong Kong officials with their disinsection certificates upon request.

Non-residual disinsection can be performed using WHO-approved pesticides either before takeoff after the cabin doors are closed, at top of descent or upon arrival. Those business jet operators choosing the two former options should submit the health part of the aircraft general declaration and the photos of empty or partially used insecticide cans to Hong Kong officials by email. On-arrival treatment is carried out after landing with passengers on board by the crew under supervision of Hong Kong officials.

For aircraft disinsection, WHO currently recommends permethrin (2 percent) for residual disinsection and d-phenothrin (2 percent) for non-residual spraying.