Travelers’ Health and Animal Importation Branch Reflects Changes in Global Travel

By Heather Bair-Brake

“In less time than the incubation period for most infectious diseases, people can travel from an area at high risk for tropical diseases to a part of the world where these diseases don’t normally occur. That creates challenges for tracking diseases and attempting to contain them.” --CDC/CCID Division of Global Migration and Quarantine Director Marty Cetron, MD

Global travel has reached unprecedented levels in the past decade, with international tourist arrivals worldwide increasing from 541 million in 1995 to more than 842 million in 2007. Each day commercial airlines carry 1.8 million passengers across international borders, making any traveler (human, animal, or pathogen) able to cross the globe in less than 12 hours.

In today’s increasingly globalized world, travelers from around the world bring together not only a diversity of cultures, but also a variety of medical and immunization backgrounds and health risk behaviors. In a short period, travelers can now visit multiple global destinations where differences in sanitation standards and disease prevalence can increase the chance exposure to and spread of communicable diseases. Travel itineraries are constantly expanding to include new locations previously inaccessible to most travelers, as well as making travel accessible to many new at-risk populations, such as children, older travelers, and travelers with chronic conditions.

International travelers, including business travelers and tourists, as well as immigrant, migrant, and refugee populations who travel abroad to visit friends and relatives, represent a rapidly growing risk group for acquiring vaccine-preventable and emerging diseases. To protect U.S. citizens as they travel abroad and to safeguard our borders against disease, a specific branch in the Division of Global Migration and Quarantine (DGMQ) is dedicated to travel health. Led by Dr. Nina Marano, a veterinarian with a wealth of clinical and epidemiologic experience, the branch, formerly known as the Geographic Medicine and Health Promotion Branch, now has a proposed new name—the Travelers’ Health and Animal Importation (THAI) Branch. THAI (proposed) encompasses four teams that focus on these areas:

• Travelers’ health research
• Zoonoses
• Communication and education
• Geographic disease risk assessment

Travelers’ Health Research Team

Tens of millions of people from developed nations travel to the developing world each year for tourism, commerce, research, education, and aid/voluntary missions. Quality of health care and disease risks differ, depending on the location. But, regardless of the destination, travel medicine’s primary goal is keeping travelers safe and healthy. This task is impossible to accomplish without knowing the most significant health risks facing travelers or whether existing preventive measures are working.

To better understand travel-related illness and to detect emerging infectious diseases, CDC’s DGMQ and the International Society of Travel Medicine (ISTM) partnered to establish the GeoSentinel Network Surveillance System in May 1996. GeoSentinel collects information from travel/tropical medicine clinics around the world to generate surveillance data for travel-related illness and emerging infections. The core operational programs of GeoSentinel are:

• Surveillance—Response: Real-time reporting of disease events and dissemination of alerts and advisories
• Surveillance—Ongoing Trends: Evaluating thousands of patient medical records for trends in emerging infectious diseases
• Analysis of illness and estimating risk in travelers: Learning about disease ecology in order to develop educational messages for travelers and clinicians.

Today, the network includes 41 sentinel surveillance sites as well as 200 travel/tropical medicine clinics in 75 countries. An additional 2,500 ISTM members are linked by a listserv to rapidly communicate and disseminate information during an emergency. One of the most valuable components of GeoSentinel is its ability to rapidly institute enhanced surveillance for clinical syndromes of interest. For example, GeoSentinel clinics detected the first cases of dengue from Easter Island and identified traveler-related cases of SARS from multiple locations.

The Travelers’ Health Research Team also works in partnership with other branches at CDC to better elucidate the risks of travel-related diseases, such as yellow fever, dengue, and malaria. The team also does research to improve the evidence base for travel health recommendations given by healthcare practitioners to the traveling public.

Zoonoses Team

• According to the U.S. Fish and Wildlife Service, more than 300 million wild animals are legally imported into the United States each year. In addition, tens of thousands of dogs, cats, and other domestic animals are imported, often for commercial sale as pets. This tremendous volume increases the potential for the introduction of infectious diseases. DGMQ is one of the few divisions at CDC with regulatory authority. The Zoonoses Team (Z-Team) has regulatory authority for importation of certain animal species, such as nonhuman primates, and is tasked with protecting U.S. borders against zoonotic diseases carried by animals and animal products. Z-Team tasks include
• Overseeing the nonhuman primate import quarantine program to ensure that animals used in research are healthy and free of diseases that could harm people
• Working to decrease the risk of zoonotic disease via imported animals and cargo
• Ensuring the health of those who work with imported animals through epidemiologic investigations and scientific research
• Conducting active surveillance for infectious diseases among imported animals.

Recently, Z-Team members were called upon to track down a shipment of pet dogs and cats arriving from Baghdad. A shipment of adopted pets from Iraq included one rabid animal. To prevent the spread of rabies among the animals and their adoptive families, the Z-Team spent hours working with state health officials, tracking down every animal in the shipment and recommending mandatory 6-month quarantine. The team continues to protect U.S. borders by working on legislation that would tighten entry requirements for dogs, cats, and rodents.

One of the Z-Team’s premier programs is to monitor nonhuman primate (NHP) imports into the United States. Every importer of NHPs must be registered with CDC. The Z-Team is responsible for maintaining the registration program which includes a review of standard operating procedures. Additionally, they make site visits to registered NHP importers across the United States to inspect facilities and review recordkeeping and to ensure that animals are quarantined appropriately and that required recordkeeping procedures are followed. The business of importing NHPs has steadily increased since 1989, and in 2007 more than 26,000 NHPs were imported.

Communication and Health Education Team

The Who, Where, and Why of international travel is becoming increasingly varied. Therefore, the development and delivery of health information must be tailored to a diverse travel audience. To meet this challenge, the Communication and Health Education (C&E) team

• Responds to inquiries from the public and healthcare providers
• Publishes CDC Health Information for International Travel (the Yellow Book)
• Develops health education messages for travelers
• Conducts formative research to improve travel health messages.

The Travelers’ Health website is consistently among CDC’s top five most visited websites. It provides country-specific information on disease outbreaks, insect bite prevention, food and water precautions, and vaccine recommendations. The Yellow Book, which is published every other year, has been the gold standard for travel health recommendations for more than 40 years. It is available online and as a hardcopy in bookstores. The 2010 edition is already under way and will be printed and available next May. This edition is charting a new course by including two non-CDC editors who are internationally renowned travel medicine experts. Their fresh approach is giving the 2010 edition a more practical, desk-reference look and feel for the practicing clinician.

The C&E team has been particularly busy this year, preparing educational materials for travelers heading to the 2008 Olympic and Paralympic Games in Beijing, China. Members of the team have been working closely with U.S. and Chinese Olympic officials to develop a brochure on travel health for U.S. athletes, as well as e-cards, posters, podcasts, information tailored for kids, and web pages. Three CDC homepage features this past summer have been dedicated to providing information on travel for the Olympic and Paralympic Games.

Risk Assessment Team

Finally, THAI has recently established a new team—the Risk Assessment Team—which covers global situational awareness of health-related topics. As the name suggests, this team will keep abreast of all the varied factors impacting the health of mobile populations around the world. Activities will include

• Global disease tracking, especially significant outbreaks for travelers
• Risk assessments of travel destinations
• Refinement of travel advice and vaccine recommendations based on risk assessments.

To achieve these goals, the team has already begun forging relationships both within CDC and with external partners.

The speed and volume of travel are principal contributors to the global emergence of infectious disease and highlight the vital need to monitor the health and safety of all travelers. The THAI Branch at CDC is committed to keeping U.S. travelers safe and healthy while traveling and living overseas and to preventing the importation of disease via animals and animal products.

About the author

LCDR Heather Bair-Brake is a veterinary officer in the Communication and Health Education Team of the Travelers’ Health and Animal Importation Branch (proposed), Division of Global Migration and Quarantine, National Center for Preparedness, Detection, and Control of Infectious Diseases.