Travel-associated Diseases, Indian Ocean Islands, 1997–2010

Hélène Savini

, Philippe Gautret, Jean Gaudart, Vanessa Field, Francesco Castelli, Rogelio López-Vélez, Poh Lian Lim, Marc Shaw, Frank von Sonnenburg, Louis Loutan, Fabrice Simon, and for the GeoSentinel Surveillance Network

Author affiliations: Laveran Military Teaching Hospital, Marseille, France (H. Savini, F. Simon); University Hospital Institute Méditerranée Infection, Marseille (P. Gautret); Aix Marseille University, Marseille (J. Gaudart); University College London, London, UK (J. Gaudart); InterHealth, London (V. Field); National Travel Health Network and Centre, London (V. Field); University of Brescia, Brescia, Italy (F. Castelli); Ramón y Cajal Hospital, Madrid, Spain (R. López-Vélez); Tan Tock Seng Hospital, Singapore (P.L. Lim); Worldwise Travellers Health Center, Auckland, New Zealand (M. Shaw); Ludwig Maximilian University of Munich, Munich, Germany (F. von Sonnenburg); Geneva University Hospital, Geneva, Switzerland (L. Loutan); University of Geneva, Geneva (L. Loutan)

Abstract

Data collected by the GeoSentinel Surveillance Network for 1,415 ill travelers returning from Indian Ocean islands during 1997–2010 were analyzed. Malaria (from Comoros and Madagascar), acute nonparasitic diarrhea, and parasitoses were the most frequently diagnosed infectious diseases. An increase in arboviral diseases reflected the 2005 outbreak of chikungunya fever.

The outbreak of chikungunya fever in Indian Ocean islands (IOI) provides new insights on emerging infections in this geographic region (1). We present data collected over 14 years from travelers to IOI who visited GeoSentinel clinics.

The Study

GeoSentinel sites are specialized travel clinics providing surveillance data for ill travelers. Detailed methods for recruitment of patients for the GeoSentinel database are described elsewhere (2). Demographics, travel characteristics, and individual medical data were obtained from travelers to Comoros (including Mayotte), Madagascar, Maldives, Mauritius, Réunion Island, and Seychelles during March 1, 1997–December 31, 2010. Statistical significance was determined by using Fisher exact test for categorical variables and Kruskal-Wallis test for quantitative variables. A 2-sided significance level of p< 0.05 was considered significant.
This study comprised 1,415 ill patients (Table 1). Demographic data varied according to the visited island. Median age was 36 years, and the male to female ratio was 1.1:1.0. The most common reason for travel was tourism (44.5%), followed by visiting friends and relatives (VFR) (30.8%). Only 43.0% of travelers had a pre-travel encounter with a travel medicine specialist or general practitioner.