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Introduction: Brucellosis in marine mammals (cetacean and pinnipeds) has emerged in a very significant way during the last two decades. Currently Brucella ceti and Brucella pinnipedialis are the two recognized species in marine mammals, but available information is still limited. Several genotypes have been identified, and studies on the relationship between sequence type (ST) and organ pathogenicity or tropism have indicated differences in pathogenesis between B. ceti sequences in cetaceans. The zoonotic potential of this disease is based on the identification of the main sources of introduction and spread of Brucella spp. in the marine environment as well as on the factors of exposure of marine mammals and humans to the bacteria., Bibliographic Review: This article is a bibliographical review on marine mammal brucellosis, including the features, sources and transmission modes of each Brucella species, as well as their potential pathogenicity in animals and humans., Conclusion: Different genotypes of marine Brucella spp have been isolated from marine mammal species but without any evidence of pathology induced by these bacteria. Associated lesions are variable and include subcutaneous abscesses, meningo-encephalomyelitis, pneumonia, myocarditis, osteoarthritis, orchitis, endometritis, placentitis and abortion. The isolation of marine B. spp from marine mammal respiratory parasites associated to lung injury has raised the intriguing possibility that they may serve as a vector for the transmission of this bacterium.The severity of marine B. spp remains unknown due to the lack of an estimate of the prevalence of this disease in marine mammals. The number of suspected human cases is still very limited. However, by analogy with other germs of the genus Brucella responsible for abortion in ruminants and for a febrile and painful state in human beings, prevention measures are essential. The significant increase in the number of strandings coupled with a high seroprevalence in certain species of marine mammals must be considered for people in direct or indirect contact with these animals. Ongoing epidemiological monitoring combined with extensive post-mortem examinations (necropsy, bacteriology and sequencing) of all species of stranded marine mammals would deepen knowledge on the zoonotic potential of marine Brucella species., (Copyright © 2024 SFMTSI.)

Poxvirus (PXV) infections are a common cause of cutaneous signs. In France, certain forms of poxvirus are frequent and benign (molluscum contagiosum), while others are rare but potentially serious (cowpox virus [CPXV]). Whereas only smallpox and molluscum contagiosum viruses have a human reservoir and are transmitted between humans, most poxvirus infections are zoonoses having only animal reservoirs. Only a small number of poxviruses are responsible for infection in humans, but the increasing number of new pets, some of which are exotic, coupled with the rapid rise in international travel are creating a greater risk of transmission of zoonotic PXV to new vectors and of spread of these diseases to new regions throughout the world. In France, molluscum contagiosum, orf and milkers' nodule give rise to numerous consultations and are well known to dermatologists. However, dermatologists must also be able to identify other parapoxviruses of similar presentation to orf; thus, CPXV and monkeypox are considered potentially emergent viruses with a high risk of epidemic and spread due to increasing international transport and the loss of the maximum protection against smallpox. Finally, despite its declared eradication, smallpox is currently being monitored because of the potential risk of reintroduction, whether accidentally or deliberately through bioterrorism., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Usutu virus, an arbovirus discovered in Africa in 1959, has spread over a large part of Europe over the last twenty years causing significant bird mortality as reported in France since 2015. The zoonotic risk, associated with this succession of avian epizootics in Europe, deserves to be taken into account even if human cases remain rare to date. Human infections are most often asymptomatic or present a benign clinical expression. However, neurological complications such as encephalitis or meningoencephalitis have been described. In addition, the recent description of an atypical case of facial paralysis in France suggests that the clinical spectrum of infections caused by Usutu virus is not fully characterized. Finally, the recent history of other arboviral outbreaks invites the scientific community to be extremely vigilant., (© 2018 médecine/sciences – Inserm.)

Introduction: A female jogger was attacked by a common buzzard (Buteo buteo) and was scratched lightly at the back of the head. One week later she was taken ill with high fever and headache which was later diagnosed as ulcero-glandular tularemia in regional lymph nodes, caused by Francisella tularensis. Recovery was only achieved after several weeks of systemic antibiotic treatment (Gentamicin/ Ciprofloxacine). Tularemia is a well known zoonotic disease, called "rabbit fever", mainly affecting rabbits and hares, but also small rodents. Human infection occurs often following tick bites or bloodsucking insects, or in hunters or slaughterers handling infected animals. Bites by mice have also been reported as a cause of tularemia. For the first time we report this case of tularemia as a result of an attack by a bird of prey. We assume that the bird acted as a vector just carrying the F. tularensis on its claws or beak, but we cannot exclude an infection of the bird itself. Several other joggers had also been attacked by a common buzzard in the same area shortly after the above described event and one of these also became infected with F. tularensis.

With more than 1 200 species, bats and flying foxes (Order Chiroptera) constitute the most important and diverse order of Mammals after Rodents. Many species of bats are insectivorous while others are frugivorous and few of them are hematophagous. Some of these animals fly during the night, others are crepuscular or diurnal. Some fly long distances during seasonal migrations. Many species are colonial cave-dwelling, living in a rather small home range while others are relatively solitary. However, in spite of the importance of bats for terrestrial biotic communities and ecosystem ecology, the diversity in their biology and lifestyles remain poorly known and underappreciated. More than sixty viruses have been detected or isolated in bats; these animals are therefore involved in the natural cycles of many of them. This is the case, for instance, of rabies virus and other Lyssavirus (Family Rhabdoviridae), Nipah and Hendra viruses (Paramyxoviridae), Ebola and Marburg viruses (Filoviridae), SARS-CoV and MERS-CoV (Coronaviridae). For these zoonotic viruses, a number of bat species are considered as important reservoir hosts, efficient disseminators or even directly responsible of the transmission. Some of these bat-borne viruses cause highly pathogenic diseases while others are of potential significance for humans and domestic or wild animals; so, bats are an important risk in human and animal public health. Moreover, some groups of viruses developed through different phylogenetic mechanisms of coevolution between viruses and bats. The fact that most of these viral infections are asymptomatic in bats has been observed since a long time but the mechanisms of the viral persistence are not clearly understood. The various bioecology of the different bat populations allows exchange of virus between migrating and non-migrating conspecific species. For a better understanding of the role of bats in the circulation of these viral zoonoses, epidemiologists must pay attention to some of their biologic properties which are not fully documented, like their extreme longevity, their diet, the population size and the particular densities observed in species with crowded roosting behavior, the population structure and migrations, the hibernation permitting overwintering of viruses, their particular innate and acquired immune response, probably related at least partially to their ability to fly, allowing persistent virus infections and preventing immunopathological consequences, etc. It is also necessary to get a better knowledge of the interactions between bats and ecologic changes induced by man and to attentively follow bat populations and their viruses through surveillance networks involving human and veterinary physicians, specialists of wild fauna, ecologists, etc. in order to understand the mechanisms of disease emergence, to try to foresee and, perhaps, to prevent viral emergences beforehand. Finally, a more fundamental research about immune mechanisms developed in viral infections is essential to reveal the reasons why Chiroptera are so efficient reservoir hosts. Clearly, a great deal of additional work is needed to document the roles of bats in the natural history of viruses.

Vector-borne diseases are principally zoonotic diseases transmitted to humans by animals. Pathogens such as bacteria, parasites and viruses are primarily maintained within an enzootic cycle between populations of non-human primates or other mammals and largely non-anthropophilic vectors. This 'wild' cycle sometimes spills over in the form of occasional infections of humans and domestic animals. Lifestyle changes, incursions by humans into natural habitats and changes in agropastoral practices create opportunities that make the borders between wildlife and humans more permeable. Some vector-borne diseases have dispensed with the need for amplification in wild or domestic animals and they can now be directly transmitted to humans. This applies to some viruses (dengue and chikungunya) that have caused major epidemics. Bacteria of the genus Bartonella have reduced their transmission cycle to the minimum, with humans acting as reservoir, amplifier and disseminator. The design of control strategies for vector-borne diseases should be guided by research into emergence mechanisms in order to understand how a wild cycle can produce a pathogen that goes on to cause devastating urban epidemics.

The risk of zoonose transmitted from cats and dogs has increased as these animals have been more and more included in family life to become real household members. This paper reviews the main bacterial, parasitic, viral and fungal infections that could be transmitted to humans by these pet animals in different situations. Although the risk of human disease is relatively low for most of the presented infections, its recognition is important to prevent some exposures, to apply correct prophylactic measures after bites, and to include these zoonoses in the differential diagnosis in case of illnesses that could have an infectious origin, particularly in immunocompromised patients.

Trypanosomes are principally responsible for two human diseases: human African trypanosomiasis (HAT) or sleeping sickness (caused by Trypanosoma brucei gambiense and T. b. rhodesiense), and Chagas disease, also called South American trypanosomiasis (T. cruzi). However, some trypanosomes that are natural parasites only of animals can sometimes infect humans and cause the so-called "atypical human trypanosomiases" (aHT). T. evansi, the agent causing surra in camels, horses, dogs, and bovines, and T. lewisi, a cosmopolite rat parasite, are the most frequently involved. These atypical infections involve no or only minor symptoms, but major symptoms are sometimes present. Parasite elimination is generally spontaneous, but can require treatment. Molecular tools, such as polymerase chain reaction, have improved the accuracy of parasite identification. Immunological techniques, mainly immunoenzymatic assays, can detect asymptomatic subjects. Several causes, most often concomitant, have been hypothesized, including immune immaturity, immunodeficiency, and close contact with infected animals. Innate immunity to animal trypanosomes depends on a trypanolytic factor called apolipoprotein L-I, present in human serum. A deficit in both apolipoprotein L-I alleles has been reported in an Indian patient infected by T. evansi. The prevalence of aHT is probably underestimated. Moreover, these trypanosomes might become potential emerging zoonotic pathogens, due to their ability to invade new hosts. An international network has been set up to survey these aHT (NAHIAT: Network on Atypical Human Infections by Animal Trypanosomes).

A large proportion of viral pathogens that have emerged during the last decades in humans are considered to have originated from various animal species. This is well exemplified by several recent epidemics such as those of Nipah, Severe Acute Respiratory Syndrome, Avian flu, Ebola, Monkeypox, and Hantaviruses. After the initial interspecies transmission per se, the viruses can disseminate into the human population through various and distinct mechanisms. Some of them are well characterized and understood, thus allowing a certain level of risk control and prevention. Surprisingly and in contrast, the initial steps that lead to the emergence of several viruses, and of their associated diseases, remain still poorly understood. Epidemiological field studies conducted in certain specific high-risk populations are thus necessary to obtain new insights into the early events of this emergence process. Human infections by simian viruses represent increasing public health concerns. Indeed, by virtue of their genetic andphysiological similarities, non-human primates (NHPs) are considered to be likely the sources of viruses that can infect humans and thus may pose a significant threat to human population. This is well illustrated by retroviruses, which have the ability to cross species, adapt to a new host and sometimes spread within these new species. Sequence comparison and phylogenetic studies have thus clearly showed that the emergence of human immunodeficiency virus type 1 (HIV-1) and HIV-2 in humans have resulted from several independent interspecies transmissions of different SIV types from Chimpanzees and African monkeys (including sooty mangabeys), respectively, probably during the first part of the last century. The situation for Human T cell Lymphotropic virus type 1 (HTLV-1) is, for certain aspects, quite comparable. Indeed, the origin of most HTLV-1 subtypes appears to be linked to interspecies transmission between STLV-1-infected monkeys and humans, followed by variable periods of evolution in the human host. In this review, after an introduction on emerging viruses, we will briefly present the results of a large epidemiological study performed in groups of Bantus and Pygmies living in villages and settlements located in the rain forest of the South region of Cameroon. These populations are living nearby the habitats of several monkeys and apes, often naturally infected by different retroviruses including SIV, STLV and simianfoamy virus. Most of the persons included in this study were hunters of such NHPs, thus at high risk of contact with infected body fluids (blood, saliva,...) during hunting activities. After reviewing the current available data on the discovery, cross-species transmission from monkeys and apes to humans of the simian foamy retroviruses, we will report the results of our study. Such infection is a unique natural model to study the different mechanisms of restriction of retroviral emergence in Humans.

As aquaculture production and the consumption of aquaculture products increase, the possibility of contracting zoonotic infections from either handling or ingesting these products also increases. The principal pathogens acquired topically from fish or shellfish through spine/pincer puncture or open wounds are Aeromonas hydrophila, Edwardsiella tarda, Mycobacterium marinum, Streptococcus iniae, Vibrio vulnificus and V. damsela. These pathogens, which are all indigenous to the aquatic environment, have also been associated with disease outbreaks in food fish. Outbreaks are often related to management factors, such as the quality and quantity of nutrients in the water and high stocking density, which can increase bacterial loads on the external surface of the fish. As a result, diseased fish are more likely to transmit infection to humans. This review provides an account of human cases of zoonoses throughout the world from the principal zoonotic pathogens of fish and shellfish.

The objective of this study was to evaluate the systemic insecticidal activity of an imidacloprid-treated rodent oral bait, against Phlebotomus papatasi Scopoli, 1786 vector of Leishmania major Yakimoff & Schokhor, 1914 (Kinetoplastida: Trypanosomatidae), etiologic agent of zoonotic cutaneous leishmaniasis (ZCL). Shaw's gerbil Meriones shawi Duvernoy, 1842 (Rodentia, Gerbillidae) were treated with imidacloprid-treated bait (0.05%). In the laboratory, effects on adult and larval of Phlebotomus papatasi fed on treated M. shawi and on its faeces were studied. The effectiveness of this approach was tested under field conditions. In the laboratory, 100% of P. papatasi were killed within 24 hours after blood feeding on Meriones shawi treated up to four weeks prior with a single application of imidacloprid (0.05%) bait. In addition, none of the P. papatasi larvae that consumed feces from M. shawi treated with the imidacloprid bait survived to pupation. In the field, application of the imidacloprid bait resulted in a 90% reduction in the P. papatasi population up to four weeks prior with a single application of imidacloprid (0.05%) bait. This is the first study to demonstrate field efficacy of insecticide-treated rodent baits for P. papatasi control and the first study to evaluate this approach in M. shawi, a principal ZCL reservoir host. These results suggest that insecticide-treated rodent baits could be used to effectively reduce the populations of P. papatasi associated with M. shawi in ZCL endemic areas.

An entomological investigation was performed in 2004 in the region of Rmilia, home to well-known zoonotic cutaneous leishmaniasis, located in Central Tunisia. The authors confirm the presence of Sergentomyia (Sintonius) clydei (Sinton, 1928). Thus, the sand fly fauna list of Tunisia includes 17 species.

Background: The current trend of keeping "exotic" pets has led to the emergence of new types of fungal species that may be transmitted to humans [1]. We describe a form of dermatophytosis transmitted by a Guinea pig and caused by a new variety of dermatophyte., Case Report: A 13-year-old girl developed multiple erythematosquamous and vesicular lesions with a highly inflammatory edge several weeks after acquiring a Guinea pig of apparently healthy appearance. Direct examination and culture tests demonstrated the presence of a dermatophyte closely related to the erinacei variant of Trichophyton mentagrophytes, from which it differed in terms of microscopic and macroscopic characteristics. The condition resolved on therapy with topical imidazole., Discussion: This new type of dermatophyte has been identified in many patients coming into close contact with Guinea pigs in the region of Nancy. We would suggest the emergence of a novel variety of T. mentagrophytes, which has adapted to its new host following transmission to Guineas pigs from hedgehogs. We propose that it be named T. mentagrophytes var. porcellae., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

The aim of xenotransplantation is to allow the transplantation of animal organs or cells to humans. This approach would immediately eliminate the human organ shortage that is responsible for a significant mortality of patients on the waiting list for transplantation of organs. The immune differences between pig and human induce an immediate rejection of porcine tissues by humans. This rejection has recently been partially controlled by genetic engineering of pigs, the use of new immunosuppressive drugs and encapsulation of isolated cells. However, due to the risk of transmission of animal infectious agents to humans, the WHO recommends that clinical application of xenotransplantation only takes place if adequate regulations are in place.

The agent of bovine tuberculosis, Mycobacterium bovis, is a zoonosis which can be transmitted to human beings. In France, the prevalence of tuberculosis due to M. bovis has drastically decreased, both for animals and humans, since public health measures were introduced to prevent its transmission. However, a new outbreak of the disease is noted among cattle in several French areas and more particularly in Aquitaine. In 2008, 40% of bovine tuberculosis French cases provided from Aquitaine. From November 2004 to October 2008, 15 cases were registered at Bordeaux's academic hospital (CHU). Thirteen of them were due to M. bovis and two to Mycobacterium caprae. It represents 2.9% of tuberculosis due to tuberculosis complex. An analysis of the 15 patients' medical files showed that it occurred either to old people who reactivated a former infection, or to younger ones who were born in countries with a strong M. bovis endemic disease. Extrapulmonary forms and especially ganglionics ones are the most frequent. M. caprae seems to be an emergent species among animal mycobacteries transmissible to human being. An epidemiological monitoring seems to be necessary to establish a relation between the regional outbreak of bovine tuberculosis and human tuberculosis., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Since a long time, Leishmania major and L. infantum foci in Algeria were geographically separated by the mountains of the Tell Atlas which represent a natural barrier. Recently, a new focus of cutaneous leishmaniasis (CL) has emerged in the village of El M'hir, located on the north side of the chain of the Tell Atlas, in the basin of the Soummam. During the period 2004-2010, 152 CL cases have been registered and 12 isolates were obtained from patients who declared never having been outside the village the last years. The identification of the parasites showed that all strains belonged to L major MON-25. Investigations on the reservoir hosts showed the presence of the sand rat (Psammomys obesus), for the first time, in this locality. Five strains isolated from this rodent belonged to L. major MON-25. The sand rat, which is usually observed around the chotts in the Saharan and steppe areas, acts as the main reservoir of L. major in Algeria. Its presence in the new focus of El M'hir is reported for the first time. Entomological surveys carried out in 2009 showed the predominance of two sandfly species: Phlebotomus papatasi and P. perniciosus. The first one is known as a vector of L major in the Algerian Sahara. This study highlights the spread of L. major from the arid zones towards the semi arid areas, particularly in the Soummam valley. Climate changes and desertification observed in the steppe area northern Sahara could play a role in the extension of the disease.

Control of human rabies in developing countries depends on prevention in dogs. The purpose of this study was to evaluate the cost-saving potential for the public health sector of intervention to control rabies in animal-host reservoirs. An existing deterministic model was adapted to allow study of dog-to-human rabies transmission. Model parameters were fitted to data from routine weekly reports on the number of rabid dogs and human rabies exposures in N'Djamena, Chad. At the onset of study, the estimated effective reproductive ratio (Re) was 1.01 indicating stable low-level endemic rabies transmission. Simulations were performed to determine what effects mass vaccination and culling of dogs would have on the incidence of human rabies. Findings showed that a mass campaign allowing single parenteral vaccination of at least 70% of the canine population would be sufficient to interrupt transmission of rabies to humans for at least 6 years. The cost-effectiveness of mass dog vaccination was compared to that of "postexposure prophylaxis" (PEP) which would not reduce future human exposure. Results showed that a sustained 5-year PEP program together with a dog-vaccination campaign would be as cost-effective as PEP alone. Beyond a time-frame of 7 years, combining parenteral dog vaccination campaigns with human PEP appeared to be more cost-effective than human PEP alone.

The purpose of this study is to describe the epidemiological profile of subjects exposed to rabies in the anti-rabies center of Abidjan in Ivory Coast. The paper is based on a cross-sectional study conducted among all people exposed to the risk of rabies and followed in the anti-rabies center from January to December 2008. During the study period, 2,673 subjects were exposed, i.e. 5 exposures for every 10,000 persons. 1,534 patients (57.4%) were male. The most exposed age groups were the 0-9 and 10-19 age groups (22.4% and 29.5% respectively). In Abidjan, 608 individuals (22.7%) were exposed in Cocody, 471 individuals (17.6%) in Abobo, and 310 individuals (11.6%) in Yopougon. Exposure occurred in 76.9% of cases (2,055 subjects) at home and exclusively concerned visitors of the family. Exposures by animal bites represented 88.1% (2,354 subjects) of all cases, while 23.2% (620 subjects) of exposures were category III. The average period between exposure and consultation was 10 days. Subjects were exposed as a result of contact with a dog in 92.1 % of cases (2,462 subjects). The animal was found alive in 74.9% (2,002 cases) and was not immunized in 87.2% of cases (2,331). Post-exposure prophylaxis was given up by 1,470 persons (55.2%). 13 subjects were received at the stage of clinical rabies. Increased knowledge of the epidemiological profile of rabies exposure will contribute to improving the management of the disease in Ivory Coast.

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.

The emergence in 2009 of a novel A(H1N1)v influenza virus of swine origin and the regular occurrence since 2003 of human cases of infection with A(H5N1) avian influenza viruses underline the zoonotic and pandemic potential of type A influenza viruses. Influenza viruses from the wild aquatic birds reservoir usually do not replicate efficiently in humans. Domestic poultry and swine can act as intermediate hosts for the acquisition of determinants that increase the potential of transmission and adaptation to humans, through the accumulation of mutations or by genetic reassortment. The rapid evolution of influenza viruses following interspecies transmission probably results from the selection of genetic variations that favor optimal interactions between viral proteins and cellular factors, leading to an increased multiplication potential and a better escape to the host antiviral response. Whereas influenza viruses usually cause asymptomatic infections in wild aquatic birds, they may be highly pathogenic in other species. Molecular determinants of host-specificity and pathogenesis have been identified in most viral genes, notably in genes that encode viral surface glycoproteins, proteins involved in the viral genome replication, and proteins that counteract the host immune response. However, our knowledge of these numerous and interdependant determinants remains incomplete, and the molecular mechanisms involved are still to be understood., (Copyright 2010 Elsevier Masson SAS. All rights reserved.)

Visceral leishmaniasis is endemic around Mediterranean and is considered by certain authors as an opportunist disease. We report on the case of a 7-year-old girl treated by anti-TNF for an idiopathic juvenile arthritis which has presented a visceral leishmaniasis. Four years later, she presented a pseudotumoral-like recurrence located in a nasal mucous membrane. Leishmania infantum is classically responsible for visceral leishmaniasis but pure mucocutaneous leishmaniasis has been described. It is, for our knowledge, the first observation of a recurrence of visceral leishmaniasis in a mucocutaneous location. Atypical leishmaniasis in the endemic zones can appear in immunodepressed patients and must be evoked when in doubt.

In France, Mediterranean spotted fever due to Rickettsia conorii is mainly observed in the South-east. Rhipicephalus sanguineus, the brown dog tick, is the vector and the reservoir of the disease. Clinical diagnosis relies on the association of fever, rash and inoculation's scar during summertime. Pathological lesion is a diffuse vasculitis. Severity is often explained by a delay in diagnosis, but prognosis is good in pediatrics. Treatment relies on doxycycline and on macrolids in children under eight.

Recent emerging zoonoses (hemorrhagic fevers due to Ebola or Marburg virus, encephalitis due to Nipah virus, severe acute respiratory syndrome due to SRAS virus...) outline the potential of bats as vectors for transmission of infectious disease to humans. Such a potential is already known for rabies encephalitis since seven out of the eight genotypes of Lyssavirus are transmitted by bats. In addition, phylogenetic reconstructions indicate that Lyssavirus have evolved in chiropters before their emergence in carnivores. Nevertheless, carnivores remain the most critical vectors for public health, in particular dogs that are originating 55.000 rabies deaths per year, essentially in developing countries. Rabies control in carnivores by parenteral (dog) or oral (wild carnivores) vaccination is efficacious and campaigns start to be more widely applied. On the other hand, rabies control in bat still remains non realistic, particularly as the pathogenicity of bat Lyssavirus for bats is still under debate, suggesting that a "diplomatic relationship" between partners would have arisen from a long term cohabitation. While comparing the interactions that humans and bats establish with Lyssavirus, scientists try to understand the molecular basis ofpathogenicity in man, a indispensable prerequisite to identify antiviral targets in a perspective of therapy.

In a context in which known and potential zoonoses are emerging (simian retrovirus infections, SRAS, West Nile, H5N1 avian influenza, etc.), French army veterinarians have been tasked with assessing epidemiological risks related to animals in proximity with troops, particularly during foreign operations. They have already completed surveys of more than 70 infections (toxoplasmosis, leishmaniasis, rickettiosis, leptospirosis, Q fever, hepatitis E, Rift valley fever, etc.). The strategy consists of detecting pathogenic agents ("the right sample, at the right time, and kept in the right conditions") in reservoir animals and vectors, upstream of epidemics. The authors propose to set up a flexible and mobile animal infection detection unit, working closely with hospital physicians, veterinarians and specialized microbiology laboratories. This would be an efficient tool for anticipating, preventing and combating zoonoses.

Organ transplantation has encountered great development during the 80's. However, the number of organ donations and transplantations performed stabilized during the 90ies, with a concomitant increase of patients on the waiting list. Xenotransplantation, i.e. the use of animal organs for transplantation to humans, is one among various alternatives to human organ donation. Xenotransplantation offers several advantages, e.g. it would be possible to transplant all patients at an early stage of their disease. The main barriers to xenotransplantation are the strong immunological responses that human develop against animal antigens and zoonoses. To overcome these hurdles, genetically modified pigs have been engineered by cloning and could allow the initiation of new clinical trials in a near future.

A given microbial pathogen usually targets a restricted number of animal species. Some pathogens can be transmitted to humans from another animal species, either directly (rabies, brucellosis, etc.) or through a vector (Lyme's disease, West Nile fever, etc.). Few infectious agents with animal reservoirs infect humans, and even fewer are capable of human-human transmission. This is attributed to the "species barrier", a simplistic concept that in fact involves a series of conditions for successful inter-species transmission. These include access to an infectable surface, multiplication on that surface, colonisation, invasion, multiplication inside the new host, and resistance to innate and adaptive immune mechanisms. Each of these steps requires a specific ligand-receptor interaction. The full series of events must be "reprogrammed" for efficient implantation in a new host. These changes occur through mutations or genetic exchanges. Direct human-to-human transmission often requires additional adaptive modifications.

Bacterial zoonoses are evolving with changes in society, climate and lifestyles. A hierarchy of non food-borne zoonoses was recently proposed in France, and includes characteristics such as severity criteria and bioterrorism potential. The creation of specific networks and reference centers has provided the means to monitor the emergence (or re-emergence) of zoonoses such as brucellosis and Q fever. Molecular tools have facilitated the detection of bacteria that are transmitted by arthropod vectors (ticks, fleas, etc.) and that cause diseases such as Lyme borreliosis, bartonellosis and ehrlichiosis.

Following an overview of some successful campaigns against zoonoses, this paper examines other zoonotic diseases that are likely to be brought under control in industrialized countries, such as brucellosis, tuberculosis and canine or wildlife rabies. The author goes on to explain the reasons for the failure to eradicate some other zoonoses in developing countries, and concludes by examining reasons for optimism or pessimism, taking into account new methods of prevention and control.