By Margaret A. Varnell
ATLANTA (Reuters Health) - An American church tour group brought home an uncomfortable souvenir from Ireland last October--the first cases of influenza B seen in the United States during the last flu season.
``International travelers can unknowingly bring home diseases,'' Dr. Joseph Perz told Reuters Health.
Perz, a US Centers for Disease Control and Prevention (CDC) epidemiologist, and colleagues from Vanderbilt University in Nashville and the Tennessee Department of Health presented data this week at the International Conference on Emerging Infectious Disease documenting the importation of parainfluenza type 1 and influenza B into the US by a Nashville, Tennessee church group who traveled to Ireland in the fall of 1999.
Thirty church tour group members returned to the US on October 1 and 2, 1999, and dispersed to Tennessee, New Jersey and Connecticut. By October 6, the Tennessee Health Department began receiving reports of a preseasonal outbreak of an influenza-like illness. Disease surveillance data pointed health officials to the recently returned Tennessee church group.
Perz and his colleagues reviewed nasopharyngeal and throat cultures from infected group members in Tennessee and also conducted telephone interviews with group members in other states. ``We were specifically looking for respiratory viruses,'' Perz said. ``We identified parainfluenza type 1 from six cultures, and influenza B from three others.''
The investigators defined an active case of influenza as an individual with a positive laboratory culture or a cough or sore throat beginning September 29 - October 5. Eighteen (60%) of the 30 tourists met the criteria of active cases and were ill. Of these, two-thirds had come down with the flu within 24 hours of their return from Ireland. On average, the individuals experienced the usual flu symptoms including cough, fatigue, sore throat, hoarseness and fever for 13 days. The researchers note 39% sought medical relief for their symptoms, but no hospitalizations or deaths occurred.
``This investigation highlighted the potential for the dissemination of respiratory illness via international travel,'' the team concludes.
Perz believes that rapid identification and reporting of such outbreaks is crucial to protecting the health and well-being of US citizens. He also encourages healthcare providers and patients to use laboratory tests in cases of acute illness when the individual has a history of recent foreign travel.
``International travelers should consult their physicians before departure,'' Perz added. ``They should be aware of any illnesses that are endemic to their destination as well as any vaccines or precautions they may benefit from. Reviewing the health status of an area should be as routine a part of travel planning as booking airline tickets or making hotel reservations.''
The CDC reports that the risk for exposure to influenza during travel varies depending on the time of year, destination, and type of travel. Officials recommend that travelers at high risk for influenza complications who were not vaccinated during the previous flu season consider receiving the influenza vaccine at least 2 weeks before their departure. These individuals include: persons aged 50 years or older; residents of nursing homes and any extended care facility; adults and children who have chronic disorders of the pulmonary or cardiovascular systems, including children with asthma; and individuals with chronic metabolic diseases (including diabetes mellitus), renal dysfunction, hemoglobinopathies, immunosuppression; and women who will be in their second or third trimester of pregnancy during the influenza season.
Individuals traveling to the tropics at any time of year and, in particular, those traveling to the Southern Hemisphere from April through September, should also consider vaccination. Travelers may check the destinations portion of the CDC Web site: http://www.cdc.gov/travel/destinat.htm for specific information about health information for travel destinations.