Tracing Airline Travelers for a Public Health Investigation: Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection in the United States, 2014.

OBJECTIVE: CDC routinely conducts contact investigations involving travelers on commercial conveyances, such as aircrafts, cargo vessels, and cruise ships. METHODS: The agency used established systems of communication and partnerships with other federal agencies to quickly provide accurate traveler contact information to states and jurisdictions to alert contacts of potential exposure to two travelers with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) who had entered the United States on commercial flights in April and May 2014. RESULTS: Applying the same process used to trace and notify travelers during routine investigations, such as those for tuberculosis or measles, CDC was able to notify most travelers of their potential exposure to MERS-CoV during the first few days of each investigation. CONCLUSION: To prevent the introduction and spread of newly emerging infectious diseases, travelers need to be located and contacted quickly.

Notes from the field: reports of expired live attenuated influenza vaccine being administered--United States, 2007-2014.

Annual influenza vaccination is recommended for all persons aged ≥6 months. Two vaccine types are approved in the United States, injectable inactivated influenza vaccine (IIV) and live attenuated influenza vaccine (LAIV), which is administered intranasally. Influenza vaccine typicaly becomes widely available beginning in late summer or early fall. IIV has a standard expiration date of June 30 for any given influenza season (July 1 through June 30 of the following year). In contrast, after release for distribution, LAIV generally has an 18-week shelf life (Christopher Ambrose, MedImmune, personal communication, 2014). Because of its relatively short shelf life, LAIV might be more likely than IIV to be administered after its expiration date. To assess that hypothesis, CDC analyzed reports to the Vaccine Adverse Event Reporting System (VAERS) of expired LAIV administered during July 1, 2007, through June 30, 2014.

Measles outbreak associated with adopted children from China--Missouri, Minnesota, and Washington, July 2013.

On July 5, 2013, CDC was notified of two cases of laboratory-confirmed measles in recently adopted children from an orphanage in Henan Province, China. To find potentially exposed persons, CDC collaborated with state and local health departments, the children's adoption agency, and airlines that carried the adoptees. Two additional measles cases were identified, one in a family member of an adoptee and one in a third adopted child from China. To prevent further importation of measles, CDC worked with health officials in China, including "panel physicians" contracted by the U.S. Department of State to conduct the overseas medical examinations required for all immigrants and refugees bound for the United States. The following measures were recommended: 1) all adoptees examined at panel physician facilities should be screened for fever and rash illness, 2) measles immunity should be ensured among all adoptees from Henan Province who are scheduled for imminent departure to the United States, and 3) all children at the orphanage in Henan Province should be evaluated for measles. This report summarizes the results of the outbreak investigation and underscores the importance of timely routine vaccination for all international adoptees.

Measles transmission during air travel, United States, December 1, 2008-December 31, 2011.

BACKGROUND: Flight-related measles contact investigations in the United States are coordinated by the Centers for Disease Control and Prevention (CDC). To evaluate the efficiency of CDC's measles protocol, we analyzed data from contact investigations conducted December 2008-December 2011. METHODS: Cases were defined as travelers diagnosed with measles that were infectious at the time of the flight. Passengers seated within 2 rows of the case-traveler and all babies-in-arms were defined as contacts. Contact information obtained from airlines was distributed to US health departments; reporting of outcomes was requested. We cross-referenced the National Notifiable Diseases Surveillance System and CDC's National Center for Immunization and Respiratory Diseases to identify unreported cases in passenger-contacts and in passengers not identified as contacts. RESULTS: Our evaluation included 74 case-travelers on 108 flights. Information for 2673 (79%) of 3399 passenger-contacts was provided to health departments; 9 cases of secondary measles were reported. No additional cases were identified. CONCLUSION: Our evaluation provided evidence of measles transmission related to air travel. CDC's protocol efficiently identifies passengers most at risk of exposure and infection for flights into and within the United States.

Influenza A(H1N1)pdm09 during air travel.

The global spread of the influenza A(H1N1)pdm09 virus (pH1N1) associated with travelers from North America during the onset of the 2009 pandemic demonstrates the central role of international air travel in virus migration. To characterize risk factors for pH1N1 transmission during air travel, we investigated travelers and airline employees from four North American flights carrying ill travelers with confirmed pH1N1 infection. Of 392 passengers and crew identified, information was available for 290 (74%) passengers were interviewed. Overall attack rates for acute respiratory infection and influenza-like illness 1-7 days after travel were 5.2% and 2.4% respectively. Of 43 individuals that provided sera, 4 (9.3%) tested positive for pH1N1 antibodies, including 3 with serologic evidence of asymptomatic infection. Investigation of novel influenza aboard aircraft may be instructive. However, beyond the initial outbreak phase, it may compete with community-based mitigation activities, and interpretation of findings will be difficult in the context of established community transmission.

No evidence of mumps transmission during air travel, United States, November 1, 2006-October 31, 2010.

Since November 2006, flight-related mumps contact investigations were conducted in the United States only for flights ≥5 h long after an investigation showed minimal risk of mumps transmission on flights <5 h. Because the transmission risk on longer flights had not been evaluated, we investigated whether there was evidence to support the guidelines. We examined data from mumps contact investigations that were initiated by the US Centers for Disease Control and Prevention (CDC) from November 2006 to October 2010. We also cross-referenced passenger-contact data with data on mumps cases in the National Notifiable Diseases Surveillance System (NNDSS). Twenty-seven cases met inclusion criteria. Of 246 passengers identified as contacts, 166 (67%) were distributed to a US health department for contact tracing. Outcomes were reported for 21 (13%) of those 166 passengers. No secondary cases of mumps among passenger contacts were reported or identified by cross-referencing NNDSS data. The findings suggested that in-flight risk of mumps transmission is not high. Furthermore, these investigations have low yield, are resource intensive, there is no post-exposure prophylaxis, and mumps transmission has not been eliminated in the United States. Therefore, CDC discontinued conducting flight-related mumps contact investigations in May 2011.