Infectious diseases acquired by international travellers visiting the USA†
Authors: Stoney Rhett J , Esposito Douglas H , Kozarsky Phyllis , Hamer Davidson H , Grobusch Martin P , Gkrania-Klotsas Effrossyni , Libman Michael , Gautret Philippe , Lim Poh Lian , Leder Karin , Schwartz Eli , Sotir Mark J , Licitra Carmelo ,   GeoSentinel Surveillance Network, Goorhuis Abraham , McCarthy Anne , Thomas Ashley , Warne Ben , Connor Brad , Schade Larsen Carsten , Wejse Christian , Perret-Perez Cecilia , Yansouni Cedric , Rapp Christophe , Ficko Cecile , Lalloo David , Beeching Nicholas , Anderson Susan , Javelle Emilie , Bottieau Emmanuel , Clerinx Joannes , Caumes Eric , Perignon Alice , Castelli Francesco , Matteelli Alberto , Chappuis Francois , Mockenhaupt Frank , Harms-Zwigenberger Gundel , von Sonnenburg Frank , Rothe Camilla , Asgeirsson Hilmir , Glans Hedvig , Siu Hugo , Manuel Valdez Luis , Haulman Jean , Terry Anne , Vincelette Jean , Barkati Sapha , Cahill John , McKinley George , Flores-Figueroa Jose , Torresi Joseph , Plewes Katherine , Ghesquire Wayne , Mirzanejad Yazdan , Kain Kevin , Boggild Andrea , Mendelson Marc , Parker Salim , Shaw Marc , Jensenius Mogens , Schlagenhauf Pat , Weber Rainer , Kelly Paul , Van Genderen Perry , Hoang Phu Phi Truong , Pandey Prativa , Murphy Holly , Lopez-Velez Rogelio , Norman Francesca , Jordan Sabine , Vinnemeier Christof , Borwein Sarah , Kanagawa Shuzo , Kato Yasuyuki , Kuhn Susan , Piyaphanee Watcharapong , Silachamroon Udomsak , Yoshimura Yokihiro , Tachikawa Natsuo 
Published: July 2018

Abstract

Background
Estimates of travel-related illness have focused predominantly on populations from highly developed countries visiting low- or middle-income countries, yet travel to and within high-income countries is very frequent. Despite being a top international tourist destination, few sources describe the spectrum of infectious diseases acquired among travellers to the USA.

Methods
We performed a descriptive analysis summarizing demographic and travel characteristics, and clinical diagnoses among non-US-resident international travellers seen during or after travel to the USA at a GeoSentinel clinic from 1 January 1997 through 31 December 2016.

Results
There were 1222 ill non-US-resident travellers with 1393 diagnoses recorded during the 20-year analysis period. Median age was 40 (range 0–86 years); 52% were female. Patients visited from 63 countries and territories, most commonly Canada (31%), Germany (14%), France (9%) and Japan (7%). Travellers presented with a range of illnesses; skin and soft tissue infections of unspecified aetiology were the most frequently reported during travel (29 diagnoses, 14% of during-travel diagnoses); arthropod bite/sting was the most frequently reported after travel (173 diagnoses, 15% after-travel diagnoses). Lyme disease was the most frequently reported arthropod-borne disease after travel (42, 4%). Nonspecific respiratory, gastrointestinal and systemic infections were also among the most frequently reported diagnoses overall. Low-frequency illnesses (&lt;2% of cases) made up over half of diagnoses during travel and 41% of diagnoses after travel, including 13 cases of coccidioidomycosis and mosquito-borne infections like West Nile, dengue and Zika virus diseases.

Conclusions
International travellers to the USA acquired a diverse array of mostly cosmopolitan infectious diseases, including nonspecific respiratory, gastrointestinal, dermatologic and systemic infections comparable to what has been reported among travellers to low- and middle-income countries. Clinicians should consider the specific health risks when preparing visitors to the USA and when evaluating and treating those who become ill.