title: Filariasis in travelers presenting to the GeoSentinel Surveillance Network.
abstract: BACKGROUND
  As international travel increases, there is rising exposure to many pathogens not traditionally encountered in the resource-rich countries of the world. Filarial infections, a great problem throughout the tropics and subtropics, are relatively rare among travelers even to filaria-endemic regions of the world. The GeoSentinel Surveillance Network, a global network of medicine/travel clinics, was established in 1995 to detect morbidity trends among travelers.
  
  
  RESULTS
  We examined data from the GeoSentinel database to determine demographic and travel characteristics associated with filaria acquisition and to understand the differences in clinical presentation between nonendemic visitors and those born in filaria-endemic regions of the world. Filarial infections comprised 0.62% (n = 271) of all medical conditions reported to the GeoSentinel Network from travelers; 37% of patients were diagnosed with Onchocerca volvulus, 25% were infected with Loa loa, and another 25% were diagnosed with Wuchereria bancrofti. Most infections were reported from immigrants and from those immigrants returning to their county of origin (those visiting friends and relatives); the majority of filarial infections were acquired in sub-Saharan Africa. Among the patients who were natives of filaria-nonendemic regions, 70.6% acquired their filarial infection with exposure greater than 1 month. Moreover, nonendemic visitors to filaria-endemic regions were more likely to present to GeoSentinel sites with clinically symptomatic conditions compared with those who had lifelong exposure.
  
  
  CONCLUSIONS
  Codifying the filarial infections presenting to the GeoSentinel Surveillance Network has provided insights into the clinical differences seen among filaria-infected expatriates and those from endemic regions and demonstrated that O. volvulus infection can be acquired with short-term travel.
authors.affiliation: Office of Global Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Ettie M
authors.initials: EM
authors.lastname: Lipner
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Law
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Barnett
authors.forename: Jay S
authors.initials: JS
authors.lastname: Keystone
authors.forename: Frank
authors.initials: F
authors.lastname: von Sonnenburg
authors.forename: Louis
authors.initials: L
authors.lastname: Loutan
authors.forename: D Rebecca
authors.initials: DR
authors.lastname: Prevots
authors.forename: Amy D
authors.initials: AD
authors.lastname: Klion
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Nutman
mesh_terms: D000293:Adolescent; D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D000368:Aged; D000818:Animals; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005260:Female; D005368:Filariasis / Q000453:epidemiology*; D014943:Global Health; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008117:Loa / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D017181:Onchocerca volvulus / Q000302:isolation & purification; D011159:Population Surveillance; D014195:Travel; D014958:Wuchereria bancrofti / Q000302:isolation & purification; D055815:Young Adult