By Dean L. Winslow, MD, FACP, FIDSA, Chairman, Department of Medicine, Santa Clara Valley, Medical Center; Clinical Professor, Stanford University School of Medicine, Associate Editor of Infectious Disease Alert.. Dr. Winslow is a consultant for Siemens Diagnostic.
Synopsis: 42,173 ill returned travelers were seen between 2007 and 2011 at 53 travel or tropical disease sites. Asia and sub-Saharan Africa were the most common regions where illnesses were acquired.
Source: Leder K, et al. GeoSentinel surveillance of illness in returned travelers, 2007-2011. Ann Int Med 2013; 158: 456-468.
GeoSentinel sites are 53 specialized travel or tropical medicine clinics located in 24 countries (21 North America, 17 Europe, 10 Australasia, 3 Latin America, 1 in South Africa, and 1 in the Middle East). This consortium maintains a large database and has done so since the founding of this consortium in 1995 by the International Society of Tropical Medicine and the CDC. 42,173 ill travelers were seen during the latest 5 year period of this report (2007-2011).
Asia (33%) and sub-Saharan Africa (27%) were the regions where illnesses were commonly acquired. 34% of illnesses were gastrointestinal, 23% were febrile illness, and 20% were dermatologic. Only 41% of returning ill travelers reported pretravel medical visits. As in previous studies, travelers visiting friends and relatives in countries of origin made up a disproportionate number of serious febrile illnesses and only 18% of these patients sought pretravel advice.
Breakdown by region of acquisition of specific pathogens was interesting and will be helpful to clinicians prioritizing a differential diagnosis in an ill returning traveler. From sub-Saharan Africa, among the 4222 patients returning with febrile illness, P. falciparum was by far most common with rickettsial disease, dengue and P.vivax next most common. In South Asia, among 1535 travelers with febrile illness, enteric (Typhoid) fever was most common followed by dengue, P.vivax, chikungunya, and extrapulmonary TB. In Latin America and the Caribbean febrile returning travelers were most likely to have dengue followed by P. vivax. From the Middle East and North Africa hepatitis A followed by P. falciparum, brucellosis, enteric fever, dengue, and Q fever were seen. Travelers from Southeast Asia were most likely to have febrile illness due to dengue followed by P. falciparum, P.vivax, chikungunya, enteric fever, and leptospirosis.
Among gastrointestinal pathogens in all regions, Giardia, Strongyloides, Campylobacter, Salmonella and Shigella were commonly seen. Among dermatologic conditions Cutaneous larva migrans was commonly seen in most regions. Cutaneous leishmaniasis was seen in patients returning from South Asia, Latin America, Middle East and North Africa. A surprisingly large number of patients visiting all regions sustained animal bites necessitating rabies post-exposure prophylaxis. Among respiratory illnesses coming to medical attention influenza was seen in returning travelers from all regions and pulmonary TB was next most commonly seen.
This report contains a wealth of information and the reader is strongly encouraged to look up the article and carefully peruse the numerous tables and figures since they provide a wealth of detailed information further broken down by patient demographics and main reason for travel (tourism, visiting friends/relatives, business, missionary, student). Some take home points include the large amount of treatable severe disease in febrile returning travelers (chiefly Falciparum malaria and enteric fever) and less common illnesses like spotted fever group rickettsial disease due to Rickettsia africae (where a careful physical exam to look for an eschar is important). Many of the serious diseases encountered could also have been prevented if the travelers had availed themselves of a pretravel medical consultation. In addition to the obvious use of malaria chemoprophylaxis, using insect repellant and bed netting could prevent much of the vector-borne diseases, immunization will prevent hepatitis A and to some extent enteric fever, and common-sense behavioral and dietary precautions will prevent many of the other diseases reported.