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CDC Warns of Possible Exposure to Mumps During Recent Air Travel

By Eric Toner, M.D., April 13, 2006

As the largest outbreak of mumps in the U.S. in decades continues to spread in the Midwest [1], the CDC has issued a warning that airline passengers may have been exposed on several flights in late March/early April. As reported in an April 11 MMWR dispatch, the Iowa Department of Health has identified two people with mumps who were potentially infectious during travel on 9 different commercial flights, on two airlines, between March 26 and April 2, 2006. [2]. The commercial airline flights on which exposure may have occurred are listed below by carrier, date, flight number and itinerary:

Northwest Airline (NWA) flights: 

  • March 26, NWA (Mesaba) #3025 from Waterloo, Iowa to Minneapolis, Minnesota 

  • March 26, NWA #760 from Minneapolis, Minnesota, to Detroit, Michigan 

  • March 27, NWA #0260 from Detroit, Michigan, to Washington, DC (Reagan National)

  • March 29, NWA #1705 from Washington, DC (Reagan National) to Minneapolis, Minnesota

  • March 29, NWA (Mesaba) #3026 from Minneapolis, Minnesota, to Waterloo, Iowa

American Airline (AA) flights:

  • April 2, AA #1216 from Tucson, Arizona, to Dallas, Texas (DFW) 

  • April 2, AA #3617 from DFW to Lafayette, Arkansas (Northwest Arkansas Regional) (NAR) 

  • April 2, AA #5399 from NAR to St. Louis, Missouri 

  • April 2, AA #5498 from St. Louis, Missouri, to Cedar Rapids, Iowa

Should passengers who were on these flights have symptoms consistent with mumps within 21 days of travel, the CDC recommends prompt evaluation, and suspected cases should be reported immediately to public health officials.

Mumps is typically characterized by a nonspecific febrile prodrome, followed by acute onset of unilateral or bilateral tender swelling of parotid or other salivary glands. While most cases of mumps involve acute parotitis, a significant percentage is associated with only nonspecific symptoms or primarily respiratory symptoms, and up to 20% of infections are asymptomatic. Complications include orchitis, oophoritis, mastitis, meningitis/encephalitis, spontaneous abortion, and deafness [2].

Transmission occurs primarily by respiratory droplets or saliva. The incubation period is quite long for a respiratory virus, typically 14 to18 days. It is important to note that patients may be infectious for up to 3 days before the onset of symptoms and may remain infectious for as long as 9 days after the onset of symptoms [2].

According to the CDC, as of April 10, a total of 515 possible mumps cases had been reported in Iowa since the start of the year, and an additional 89 cases had been reported in 6 neighboring states as well: Nebraska (43), Kansas (33), Illinois (4), Missouri (4), Wisconsin (4) and Minnesota (1).

The CDC and the affected state health departments have initiated an investigation to identify and notify passengers who are at highest risk of exposure due to being seated in close proximity to the index cases.


  1. Mumps Epidemic--Iowa, 2006. MMWR 2006;55; (dispatch) 1-3. Available at: Accessed April 12, 2006.

  2. Exposure to Mumps During Air Travel - United States, April 2006. MMWR;55(dispatch), 1-2. Available at: Accessed April 12, 2006.