Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, U.S. Virgin Islands and Venezuela. “If you are pregnant and scheduled to travel to a destination outside the U.S. that is affected by Zika virus, you and your travel companions can request a refund. To qualify, you must provide a doctor’s note confirming your pregnancy and stating your inability to travel due to Zika virus,” American Airlines said. The other companies which apply similar measures are: United Airlines, Delta, LATAM and Norvegian Cruise Line Holdings and Carnival Corp. The level of alarm regarding Zika virus spreading explosively is now extremely hight. The WHO said it could infect as many as 3 million to 4 million people within 12 months. Complications of infection are severe, from a brain abnormality called microcephaly in children to paralysis in adults. United States has 31 confirmed cases in 11 states and the District of Columbia. President Obama on Tuesday convened a group of scientists and public health officials to discuss efforts to combat the disease. However, mosquito control is difficult even in the U.S.