On March 30, CDC was notified by the Pennsylvania Department of Health of an acute febrile respiratory illness characterized by fever, chills, dry cough, chest pain, and headache among college students who traveled to Acapulco during March 2001. Initial laboratory testing indicated that most students had histoplasmosis, an infection caused by the soil-inhabiting fungus, Histoplasma capsulatum. While in Acapulco, most ill students had stayed at the Calinda Beach Hotel. This report updates the investigation of the outbreak and presents possible evidence of ongoing transmission.1
As of May 1, 44 colleges in 22 states* and the District of Columbia have reported 229 students with acute febrile respiratory illness defined by fever for at least 3 days and one or more of the following symptoms: cough, shortness of breath, chest pain, or headache. Laboratory testing of serum specimens from many of these students is ongoing to confirm the cause of illness. Confirmation of histoplasmosis ideally requires testing of acute- and convalescent-phase serum specimens using complement fixation and immunodiffusion methods.2
To determine where the infection may have been acquired, a cohort study was conducted among students who stayed at three different hotels in Acapulco during the first 2 weeks of March. A total of 109 randomly selected students were interviewed using a standardized questionnaire about symptoms, daily activities, and environmental exposures while in Acapulco. Thirty-one students stayed at the Calinda Beach Hotel, and 78 stayed at other hotels; 58 (53%) were women, and the median age was 21 years (range: 17-25 years). Univariate analysis indicated that having stayed at the Calinda Beach Hotel was significantly associated with illness (22 [71%] of 31 versus four [5%] of 78; risk ratio [RR] = 13.8; p<0.001). Other activities (e.g., visiting clubs and restaurants) were not associated with illness.
During April, CDC and the Mexico Ministry of Health conducted a joint investigation of the Calinda Beach Hotel and surrounding areas to determine potential sources of H. capsulatum (e.g., construction sites and bird and bat roosts). No sources at the hotel or in its vicinity were identified. Reports of illness in travelers who visited the hotel during April are continuing to be obtained and investigated. To identify specific sources of infection, a cohort study is being conducted among college students who stayed at the hotel during March. This study involves administration of a detailed questionnaire about activities in and near the Calinda Beach Hotel and collection of serum specimens from ill and non-ill visitors. Environmental samples were collected from areas in and around the hotel that were frequented by the students; testing of these environmental specimens for H. capsulatum is difficult and requires intraperitoneal mouse inoculation. CDC is awaiting results of the cohort study to determine which samples to test.
On May 3, CDC was notified about two cases of histoplasmosis in a couple from California who had traveled to Acapulco during April 9-16 and had stayed at the Calinda Beach Hotel. The couple, both aged 26 years, had onset of symptoms consistent with acute histoplasmosis 8 days after returning from Acapulco. Urine antigen test for histoplasmosis3 at the Histoplasmosis Reference Laboratory (Indianapolis, Indiana) was positive for both persons. Although this test is not sensitive for diagnosis of acute pulmonary histoplasmosis, the test is very specific. These cases suggest ongoing transmission of histoplasmosis associated with the hotel.
Visitors to the Calinda Beach Hotel should be aware of the risk for histoplasmosis and should contact their physicians if they develop symptoms. Physicians should contact CDC's Mycotic Diseases Branch, telephone (404) 639-1299 or e-mail: email@example.com. Until further information is available, U.S. visitors to Acapulco are advised to avoid the area of the Calinda Beach Hotel.
Pennsylvania Dept of Health. Council of State and Territorial Epidemiologists. American College Health Association. Naval Medical Center, San Diego, California. Mycotic Diseases Br, Respiratory Diseases Br, Div of Bacterial and Mycotic Diseases, National Center for Infectious Diseases; and EIS officers, CDC.
Update: Outbreak of Acute Febrile Respiratory Illness Among College Students—Acapulco, Mexico, March 2001. JAMA. 2001;285(22):2850. doi:10.1001/jama.285.22.2850-JWR0613-3-1