[Not Available]. / Importance de l'implication de la faune sauvage dans les zoonoses émergentes ou résurgentes.

Important preventive measures carried out in the herds of domestic animals have found improving the health status of farms, particularly for contagious diseases subject to mandatory declaration and accompanying drastic but necessary eradication measures in infected flocks. However it is more difficult to apply these same biosecurity measures on wildlife that may have been contaminated or not by domestic animals. The growing number of emerging infectious diseases of wildlife may reflect increased vigilance, but most often the result of a change in the ecology of the host, the causative agent or both. So, wildlife may be reservoirs of pathogens that can infect domestic herds again but mostly for the majority of them contaminating humans. This is the case, for example, of West Nile virus (WNV), avian influenza virus, rabies virus, Nipah virus, diseases transmitted by ticks, tuberculosis, brucellosis, hepatitis E or some parasitic zoonoses.

[Viral gastroenteritis in domestic animals and zoonoses]. / Gastro-entérites virales des animaux domestiques et zoonoses.

Etiologic investigations of infectious diarrhea were long limited to bacteria and protozoa. The advent of electron microscopy and molecular biology showed that diarrhea could also be caused by viruses, both in humans and in other animals. In 1969, electron microcopy was used to show, for the first time, the responsibility of a virus in a case of calf diarrhea. This "reo-like virus "was subsequently identified as a rotavirus, and was shown only four years later to be responsible for severe diarrhea in young children. Noroviruses, and particularly the human virus Norwalk, were subsequently discovered, followed by coronavirus, sapovirus, pestivirus, astrovirus, enteric adenoviruses, torovirus, and picobirnavirus. Some of viruses found in animals, and particularly rotaviruses, can also infect humans. Rotaviruses have been identified in numerous animal species and are generally host-specific, but zoonotic transmission has been suggested by cross-infection (especially in experimental models), by genetic studies showing a close relationship between certain human and animal rotaviruses, and by the discovery of new animal genotypes during epidemiological surveillance of human rotaviroses. Some animal strains of norovirus, sapovirus, picobirnavirus and astrovirus are genetically related to human strains, but their human transmission has not been demonstrated.

[Importation of infectious diseases to Europe via animals and animal products: risks and pathways]. / Risques d'introduction et d'implantation en Europe de maladies infectieuses exotiques.

Importation of tropical infectious diseases to Europe via animals and animal products. Most emerging and resurgent diseases observed in France in recent decades have been zoonoses, and some have caused unprecedented health crises. The growing international trade in domestic and wild animals and foodstuffs of animal origin is contributing to the emergence or resurgence of such zoonoses, along with accidental or deliberate introduction of certain species into new geographical areas, and the recent craze for exotic pets. Thus, in France, we have witnessed the introduction and sometimes the establishment of new diseases through insect vectors (e.g. bluetongue), foodstuffs of animal origin intended for human or animal consumption (e.g. bovine spongiform encephalopathy and trichinellosis), and diseased or asymptomatically infected animals. This is notably the case of the highly pathogenic influenza virus subtype H5N1 carried by poultry and wild birds, and also pathogens carried by imported pet species (e.g. rabid dogs illegally imported from Morocco, and pet rats infected with cowpox virus). Globalization and global warming will also favor the emergence of new tropical diseases in Europe, and especially African diseases such as Rift Valley fever. Finally, it should be remembered that some diseases with potentially severe economic consequences have disappeared from Europe while remaining active on other continents. This is the case of rinderpest, for example, which led to the creation of the first veterinary school in the world (in Lyon, France) nearly 250 years ago, and which has now been eradicated from Europe.

Structure-activity studies of heparan mimetic polyanions for anti-prion therapies.

Polysulfated molecules, as the family of heparan mimetics (HMs) and pentosan polysulfate, are considered among the more promising drugs used in experimental models of prion diseases. Regardless of their therapeutic potential, structure-function studies on these polyanions are still missing. Here, we report the syntheses of a library of HMs of different molecular sizes, containing various sulfation and carboxylation levels, and substituted or not by different hydrophobic cores. The HMs capacities to inhibit the accumulation of PrPres in chronically infected cells (ScGT1-7) and their PrPc binding abilities were examined. Our results showed that an optimal size and sulfation degree are needed for optimum activity, that incorporation of hydrophobic moieties increases compounds efficacy and that the presence of carboxymethyl moieties decreases it. These structural features should be considered on the modelling of polyanionic compounds for optimum anti-prion activities and for advancing in the understanding the mechanisms involved in their biological actions.

[Update on transmissible spongiform subacute encephalopathies (TSSE)]. / Actualités sur les encéphalopathies spongiformes subaiguës transmissibles (ESST).

This update concerns human and ruminant transmissible spongiform subacute encephalopathies (TSSE). The latest data on variant Creutzfeldt-Jakob disease confirm that new cases are less frequent than feared some years ago, but subclinical carriers could be a source of iatrogenic infection. The macaque is a good model of human oral transmission of bovine spongiform encephalopathy (BSE). The latest data on BSE in Europe confirm the effectiveness of precautionary measures taken in 1996 and 2000. Concerns in other ruminants include a chronic wasting disease of Cervidae in North America, the discovery of a BSE-like agent associated with natural scrapie in a French goat, maternal transmission of natural scrapie in sheep, with an exceptionally short incubation period (6.5 months), and doubts over the efficacy of genetic selection for combating ovine scrapie (atypical cases in " resistant " sheep, especially with the scrapie strain Nor 98 in Europe). These data demonstrate the value of active European surveillance of scrapie in small ruminants.

[Highly pathogenic avian influenza in poultry (fowl plague); implications for human health]. / L'influenza aviaire hautement pathogene ou peste aviaire et le risque pour l'homme.

Since 1997, high-pathogenicity avian influenza (HPAI) virus infection in poultry "avian plague" has emerged as a potential threat to human health, with some fatal cases of bird-to-human transmission. These sporadic infections are caused by H7N7 and H5N1 viruses in Europe and Asia, respectively. The persistence of H5N1 viruses in poultry in several Asian countries, and their appearance in Europe, has raised concerns that the virus might mutate or recombine to create a human pandemic influenza A virus. Wild waterfowl are the natural reservoir of all influenza A viruses, and rarely develop the disease. Since 2002, some H5N1 HPAI viruses have become lethal for waterfowl, cats and humans, indicating an expanding host range. Transmission of H5N1 HPAI viruses from domestic poultry back to resistant domestic and wild ducks and to terrestrial birds (sparrows, pigeons, falcons, etc.) has increased the risk of geographic spread in Asia. These viruses spread through fecal contamination of the environment (particularly groundwater). Low-pathogenicity avian influenza (LPAI) viruses cause localized respiratory and gastrointestinal tract infection and, unlike HPAI viruses, are not detected in blood, muscle or eggs. Detection of HPAI viruses in meat, blood and internal organs of chickens and ducks raises public health concerns and underlines the need to thoroughly cook poultry and eggs consumed in Asia. The last case of HPA1 virus infection in France was notified in 1955.