The Mexican Ministry of Health and the Centers for Disease Control and Prevention (CDC) are collaborating in a joint investigation of an outbreak of acute febrile respiratory illness among U.S. travelers returning from Acapulco, Mexico, during March.

This cluster of illness was reported to CDC after a number of U.S. university students, who traveled to Acapulco during March, sought medical care for acute febrile respiratory illness, with symptoms that included high fever, headache, dry cough, and chills. Laboratory testing for the cause of the illness is ongoing; initial tests indicate that, in most cases, the illness is histoplasmosis. Histoplasmosis is a disease caused by a fungus, Histoplasma capsulatum, and primarily affects the lungs. The time between exposure and onset of illness is frequently 10-14 days. The disease is not transmitted from an infected person to someone else. In addition, some students have tested positive for infection with Mycoplasma pneumoniae. At this time it is not known whether the Mycoplasma infections were acquired before, during, or after travel to Mexico.

At this time, information has revealed that virtually all illnesses occurred among American college students on spring break in Acapulco during the month of March. Most of these students were booked through a group tour and stayed at the Calinda Beach Hotel in Acapulco; however, to date, no obvious sources of exposure to Histoplasma have been identified at this hotel or elsewhere. There have been very few cases of acute febrile respiratory illness among Mexican guests or hotel workers who were in the hotel during the month of March. The Mexican Ministry of Health and CDC are continuing to investigate this situation

U.S. travelers to Acapulco since the beginning of March should consult their primary health care professionals if symptoms develop. In particular, students are advised to contact their college health clinics. CDC has contacted all 50 state epidemiologists to identify other possible persons with acute febrile respiratory illness who recently traveled to Acapulco. Further information concerning this outbreak can be obtained by contacting your state health department or by calling 1-888-688-2732. Information on histoplasmosis is available at: www.cdc.gov/ncidod/dbmd/diseaseinfo.