Eosinophilia prevalence and related factors in travel and immigrants of the network +REDIVI.

The population movements during the last decades have resulted in a progressively increasing interest in certain infectious diseases. Eosinophilia is a common finding in immigrants and travellers. One of the most common causes of eosinophilia is helminth infection, and some intestinal protozoa. The aim of this paper is to describe the epidemiological characteristics of cases with eosinophilia and its association with the presence of parasites in the REDIVI data network. This is a multicentre prospective observational study that includes patients diagnosed with eosinophilia registered in the cooperative network for the study of infectious diseases in travellers and immigrants (+REDIVI) from January 2009 to December 2012. A total of 5,255 episodes were recorded in the network during the study period, and eosinophilia was observed in 8.1-31.3% of cases (depending on the immigration group). There were 60.2% men, with a median age of 31years. There were 72.4% immigrants, and 81.2% were asymptomatic. The most commonly identified parasites were S.stercoralis (34.4%), Schistosoma sp. (11.0%), and hookworm (8.6%). The relationship between eosinophilia and parasite infection was significant for all helminths (except for cutaneous larva migrans). The symptoms and duration of the journey did not significantly determine the presence of eosinophilia. In the case of eosinophilia in a person who has lived in helminth endemic areas, it is advisable to carry out targeted studies to diagnose the infection, regardless of immigration type, length of stay, or the presence of symptoms.