Returning to the United States last month I found some interesting public health information on the TV monitors at the United States Customs and Border Protection area at Philadelphia International Airport. There was a warning for Middle East Respiratory Syndrome (MERS), an acute viral illness found in countries in or near the Arabian Peninsula. There was a warning for chikungunya fever and Dengue fever, both viral infections spread by the Aedes aegypti mosquito—deemed the “Darth Vader of Mosquitoes” in this Miami Herald story. Dengue is common in tropical and subtropical areas and is widespread in South America.

Perhaps you've never heard of Chickungunya (pronounced chik-en-gun-ye), which typically causes fever and joint pain. It is found in Africa, Asia, and the Indian subcontinent and has spread to Europe and, late last year, the Caribbean. The Pennsylvania Department of Health sent a public health advisory the other day reporting that three cases were recently imported to this state by travelers returning from the Caribbean. New Jersey has five suspected cases.

Another illness warning on the airport monitor was for something I’ve actually had: measles! The measles vaccine, developed by John Enders and his colleagues, was licensed in 1963—just a little too late for me. There are 20 million measles cases globally each year and cases in the United States are linked to both importations from overseas and to those living in the United States who have not been vaccinated. Between January 1 and June 20 of this year there have been 16 measles outbreaks in the United States. Currently there is an outbreak in Ohio involving 341 cases linked to travelers to the Philippines.

Public health, as these warnings suggest, is a global health matter. The U.S. Centers for Disease Control and Prevention keeps watch over outbreaks and maintains a website with travel health notices. Watch 1 advises “Practice Usual Precautions,” Alert Level 2 advises “Practice Advanced Precautions,” and Warning Level 3 advises “Avoid Nonessential Travel.” The most recent warnings concern Ebola and Polio and are at alert Level 2. The World Health Organization also provides a list of recommended vaccines for travelers. Wondering where to get exotic vaccines? The Philadelphia Department of Public Health has a downloadable list of travel health clinics in the city. The International Society of Travel Medicine has an online list of travel clinics around the world.

So, if you are traveling abroad this summer (or at any time) safe travels! If you are returning to the United States or here as a visitor: welcome. Don't be scared by the warnings on the monitors you'll read as you stand in the customs line. View them as a reminder that public health is global health and that many national and international organizations and governments are working to ensure our health.

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