Climate changes, environment and infection: facts, scenarios and growing awareness from the public health community within Europe

Abstract

Climate change is a current global concern and, despite continuing controversy about the extent and importance of causes and of its effects, it seems likely that it will affect the incidence and prevalence of both residual and imported infections in Europe. Climate affects mainly the range of infectious diseases, whereas weather affects the timing and intensity of outbreaks. Climate change scenarios include a change distribution of infectious diseases with warming and changes in outbreaks associated with weather extremes. The largest health impact from climate change for Europe doesn't come from vector borne infectious diseases. This does not mean that these types of health impacts will not arise in Europe. The ranges of several vector-borne diseases or their vectors are already changing in altitude due to warming. In addition, more intense weather events create conditions conductive to outbreaks of infectious diseases: Heavy rains leave insect breeding sites, drive rodents from burrows, and contaminate clean water systems. The incidence of mosquito-borne parasitic and viral diseases, are among those diseases most sensitive to climate. Climate change affect disease transmission by shifting the vector's geographic range and by shortening the pathogen incubation period. climate-related increases in temperature in sea surface and level would lead to higher incidence of waterborne infectious and toxin-related illnesses, such as cholera and seafood intoxication. Climate changes all around the world with impact in Europe are demonstrated by the fact that recent cases of cholera have been imported to Europe from Kenya, where spreading epidemic has been linked to the El Niño phenomenon, originated from the Pacific Ocean. Human migration and damage to health infrastructures from aberrant climate changes could indirectly contribute to disease transmission. Human susceptibility to infections might be further compounded by alterations in the human immune system caused by increased exposure to ultraviolet radiation and malnutrition due to alterations in agricultural products. Different kind of incidents in Europe with extreme weather events demonstrated effects on public health. The recent outbreak of the insect-borne Chikungunya virus in Italy in 2007 is an example of the kind of new health threat that the EU must be vigilant to confront. In addition, health effects of flooding, have been related to an excess cases of leptospirosis and campylobacter enteritis. Such examples have been demonstrated reported after flooding in the Czech Republic. Similarly, an increase of cryptosporidiosis in the United Kingdom has been related to flooding. Changing vector distributions associated with tickborne encephalitis and malaria have also been demonstrated in EU. A recently reported case of malaria in Italy in June 2008, suspected to be indigenously acquired, has shown how easily malaria could be reintroduced into several countries in the region. Another case of malaria in Greece in May 2010 affecting a young man living in a forestry region was claimed at KEELPNO-the Greek Center for disease control. Would this latest case be considered closely related to the one from Italy? If yes, then Public Health Services should elaborate plans to affront possible tickborne diseases. Heat waves are important causes of mortality on mortality are important. The deaths seen in France in 2003 from a heat wave are projected to be repeated, as heat waves become more severe. However, heat waves impacts on the transmission and severity of infectious diseases have not been elucidated. Finally scientific challenges include the elucudation of climate changes and extreme weather condition impact on infection transmission and outcome, human immune system changes and infection response, outbreak scenarios, animal and plant health and public health preparedness. European action plans to affront climate changes related health and infection problems are developed by the EU Commission at different levels and jointly by different DGs. In a few words within the EU the following points on human, animal and plant health are considered a priority: * Strengthening cooperation between the services of these three branches of health (human, animals, plants); * Developing action plans in the event of extreme weather conditions, in order to be better prepared and to react in the best way; * Gathering more reliable information on the risks of climate change whilst maintaining international cooperation, in particular with the WHO, as cooperation beyond that between Member States will be required to be more effective; * Providing additional effort to identify the most effective measures; * Improving the surveillance and the control of the animal diseases. The European Commission has decided to consider climate change, and the consequences it has on health, with greater importance whilst being aware that it is at the root of numerous diseases.