Transmission of zoonoses through immigration and tourism.

More than 200 of the documented zoonoses represent a high proportion of the infectious diseases that cause cases of morbidity and mortality and almost 75% are emerging infections. Immigration and tourism are human activities that are included in the broader field of human migration and travel. Travel plays a significant role in the emergence and spread of disease. The migration of humans has provided the route of spread for infectious diseases and zoonoses (for example, plague, yellow fever, monkey pox and severe acute respiratory syndrome). Tourism constitutes a small fraction of overall movements of humans but a point worthy of note is the number of international travellers has increased by more than 1 300% over the last 50 years. In addition, over 80 million people, mostly from developing countries, are legal or illegal immigrants. The consequences of travel extend beyond the traveller to the population visited and the ecosystem. Tourism and immigration may constitute an interface for mixing different genetic and ecological profiles, as well as cultural and social aspects, which is of particular interest in regard to zoonoses. Primary prevention, epidemiological surveillance and health education in the framework of intersectoral and international collaboration remain the cornerstone for response to and control of zoonoses in the context of tourism and immigration.

A pseudo-outbreak of human A/H5N1 infections in Greece and its public health implications.

The recent wide geographic spread of the highly pathogenic avian influenza A/H5N1 virus has important public health implications. Several wild migratory birds were confirmed to be infected with avian influenza A/H5N1 in Greece in February and March 2006. The aim of this paper is to report data from potential H5N1 human cases that presented to local hospitals during this period with a respiratory infection and expressing concern about exposure to avian influenza. A case-control investigation was conducted that included case identification with the use of a structured definition, review of epidemiological and clinical characteristics and molecular testing for avian influenza A/H5N1. The setting was the entire country of Greece during February and March 2006. The main outcomes were rates of possible cases (meeting both a clinical and an epidemiological criterion) and clinical or epidemiological characteristics differentiating them from potential cases that met either one of the criteria of a possible case, but not both. Twenty six potential patients (81% of whom met a clinical criterion, and 39% of whom met an epidemiological criterion) presented and most (85%) were admitted in local hospitals during the period of interest. The majority of cases (85%) were observed in northern Greece where most of the confirmed A/H5N1 avian cases were documented. Five of the 26 evaluated patients met the definition of a possible case. These clustered within the early period of confirmed A/H5N1 cases in wild migratory birds (P=0.05). Molecular testing was negative for all possible cases. Application of a revised case definition constructed according to newer European Union guidance resulted in the exclusion of two possible cases. Several potential A/H5N1 human cases were recently identified in Greece. Both the timing of identification and the geographical location of potential cases suggest an increased awareness on the part of the general public, as well as poor interpretation of the case definition by the clinicians.