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Résumé Un rapprochement est proposé entre le concept d’anthropocène, ère géologique nouvelle centrée sur l’Homme et son emprise grandissante sur l’environnement depuis le milieu du siècle dernier, et l’émergence accrue de virus nouveaux, pathogènes pour l’Homme et pour l’animal.

Résumé En 2012, une nouvelle maladie virale émergente est apparue au Moyen-Orient, le MERS, abréviation en anglais pour « Syndrome respiratoire du Moyen-Orient ». Au 9 janvier 2014, elle avait déjà touché 178 personnes dans le monde, dont 75 étaient décédées dans un tableau d’insuffisance respiratoire et de diarrhée. La nouvelle maladie ressemblait cliniquement au SRAS (2002–2003), de sinistre mémoire, et comme le SRAS, était provoquée par un Betacoronavirus nouveau. On a donc pensé que des chiroptères pouvaient être à l’origine du MERS. D’ailleurs, de nouvelles études ont montré qu’en Arabie Saoudite un exemplaire de la chauve-souris Taphozous perforatus hébergeait un segment de quelques nucléotides identique au segment homologue de la souche isolée du cas-index de l’épidémie. De plus, de nombreuses souches de Betacoronavirus, plus ou moins proches génétiquement de celles responsables du MERS chez l’Homme, ont été isolées de chauves-souris en Afrique, en Asie et en Europe. Mais, une autre hypothèse a été proposée simultanément incriminant le dromadaire (Camelus dromedarius L) comme acteur très vraisemblable dans la transmission de la maladie. Elle est basée sur des observations épidémiologiques et les résultats de plusieurs enquêtes sérologiques. Un bilan des autres zoonoses virales dans lesquelles le dromadaire est plus ou moins impliqué renforce cette hypothèse: le MERS-CoV, l’agent étiologique du nouveau syndrome, pourrait bien être véhiculé par cet animal.

En 1926, deux medecins francais travaillant en Indochine, R. Pons et L. Chastel, ont propose de traiter la lepre par des injections sous-cutanees de BCG. Ce traitement s’est montre efficace dans un premier temps: les lesions lepromateuses se sont rapidement effacees et le bacille de Hansen a disparu du mucus nasal. Ces resultats, rapidement confirmes par d’autres auteurs, etaient d’autant plus interessants qu’a l’epoque, on ne disposait que de l’huile de Chaulmoogra et de ses derives, peu efficaces sinon mal toleres. Malheureusement ces resultats n’etaient pas durables. Toutefois, bien qu’il ne s’agisse pas d’une panacee, le BCG a permis de ne pas laisser a l’abandon des malades deja stigmatises par leur maladie, en attendant qu’au debut des annees 1950, on puisse enfin disposer d’un traitement curatif, avec les sulfones.

During the past two decades, a number of mosquito-borne flaviviruses, mainly of African origin, have invaded new geographical areas where they have never been active. This was the case for the Japanese encephalitis virus which reached the northeastern part of Australia (1995) and, above all, for the West Nile virus which, since 1999, entirely colonized the American continent. Then, the Usutu virus invaded a large part of the Western Europe (2001) while the Zika virus caused a large epidemic in an island of Micronesia (2007). Finally, in 2010, the Tembusu virus devastated many duck farms in China while the Bagaza virus, after having provoked human encephalitis in India, reached the southern part of Spain. In the affected areas, new pathogenic outcomes were observed in humans and animals while new vertebrate hosts and mosquito species were infected. Moreover, unusual ways of contamination were described. The origins of this unprecedented evolution remain to be clarified.

In mosquito-borne arbovirus infections in man the asymptomatic cases are much more frequent than the symptomatic ones, but their true role in the introduction and subsequent spread of such diseases in non-endemic areas remains to be clarified. We have collected pertinent data from English and French literature from 1952 to 2010 through Pubmed and other bibliographic sources. Data were analysed to assess if viremia in asymptomatic human arbovirus infections might be sufficient to represent a true risk for introduction in non-endemic areas. During dengue and chikungunya fever outbreaks, humans are believed to be the only vertebrate hosts. Since a very large number of individuals are infected and since viremic levels are known to vary by many orders of magnitude in symptomatic patients, it is reasonable to augur that a proportion of asymptomatic cases might reach levels of viremia sufficient to infect competent mosquitoes. Moreover, in both dengue and chikungunya fever, nosocomial infections have been identified representing an alternative opportunity for virus introduction in non-endemic areas. In zoonotic mosquito-borne arbovirus infections such as Japanese encephalitis or West Nile infection, the situation is quite different since humans are considered as "dead-end" hosts. However, the very large number of asymptomatic cases arising during outbreaks and the existence of newly recognised ways of contamination (blood transfusion, organ transplantation, transplacental way etc.) may also ensure their introduction and subsequent spread in new areas.

Resume Contrairement aux autres emergences virales recentes qui etaient pour la plupart dues a des virus a ARN, le monkeypox est provoque par un virus a ADN, un orthopoxvirus proche des virus de la vaccine et de la variole, dont il existe deux variants genomiques. Ce virus, isole inopinement chez des singes asiatiques en captivite, fut d’abord considere comme une curiosite de laboratoire, mais son pouvoir pathogene pour l’homme a ete reconnu en Afrique tropicale, a partir de 1970. Il y provoquait des infections sporadiques de contact avec la foret pluvieuse (chasse) et plus rarement des epidemies par transmission interhumaine comme celle apparue en 1996 en Republique democratique du Congo. Le monkeypox humain, impossible a distinguer cliniquement de la variole (eradiquee de la planete en 1977), faisait seulement l’objet d’une surveillance epidemiologique attentive mais ne semblait pas representer une menace serieuse, au plan mondial. Tout a change en 2003, lorsque le monkeypox a ete introduit aux Etats-Unis par des rongeurs sauvages infectes, provenant d’Afrique et s’est etendu a 11 Etats de l’Union grâce au commerce des petits animaux sauvages de compagnie. Provoquant 82 infections chez des enfants et des adultes, cette epidemie a permis de prendre conscience des dangers sanitaires lies au trafic international des animaux sauvages et a suscite toute une serie de travaux scientifiques qui ont considerablement accru nos connaissances sur cette zoonose.

Résumé L’Afrique tropicale n’est pas la seule région du monde où des virus dangereux pour l’homme aient récemment émergé. L’Asie, en particulier la Chine et le Sud-est asiatique, a également connu l’émergence de viroses humaines graves, telles que la dengue hémorragique (les Philippines, 1954) ou plusieurs pandémies grippales, la grippe asiatique (N2H2) en 1957, la grippe de Hong-Kong (H3N2) en 1968, et la grippe russe (H1N1) en 1977. Mais, c’est surtout au cours des dix dernières années que les émergences virales s’y sont multipliées avec l’apparition de la fièvre hémorragique à virus Alkhurma en Arabie Saoudite (1995), de la grippe aviaire H5N1 à Hong-Kong, en 1997, de l’encéphalite à virus Nipah en Malaisie, en 1998, et surtout du SRAS, en Chine du sud en 2002. Les facteurs climatiques n’ont probablement joué qu’un rôle réduit dans le succès émergentiel de ces viroses, favorisé plutôt par des facteurs humains : le développement d’élevages industriels d’animaux de basse cour augmentant les risques d’épizooties, les habitudes alimentaires, les pressions économiques et démographiques, les négligences dans la surveillance épidémiologique et la déclaration des premiers cas.

On August 1991, three spiroplasmas (Tab 2A, Tab 2B and Tab 4C) were isolated from Haematopota sp. flies collected from Indre-et-Loire, France. Isolations were made at 28 degrees C in MD1 medium from ground individual flies, but not from external washings. All isolates adapted well to SP4 medium at 30 and 37 degrees C and were triple cloned before serological identification. Using the cross deformation test, the 3 isolates were compared with 42 known spiroplasmas isolated from diseased plants, flowers, various insects and ticks belonging to 25 serological groups. Each isolate cross-reacted with others and exhibited weak 1-way reactions with TABS-2 or PLHS-1, two spiroplasmas isolated in the United States from respectively Tabanus abactor Philip and Panorpa helena L, a scorpion-fly. These results suggest that Tab 2A, Tab 2B and Tab 4C together with TABS-2 and PLHS-1 may represent, members of a new serological supergroup.

Resume L;auteur fait une analyse aussi objective que possible des observations recemment publiees en Grande-Bretagne, concernant une nouvelle forme de maladie de Creutzfeldt-Jakob. Le tres jeune âge des malades, le tableau anatomo-clinique particulier qui rappelle celui du Kuru, l'evolution et l'epidemiologie de cette affection, en font incontestablement une nouvelle maladie emergente dont les liens avec l'encephalopathie spongiforme bovine semblent evidents. Les raisons pour lesquelles une telle evolution a pu se produire sont analysees.

Summary Links between mycoplasmas and viruses are ancient, multiple and complex, from past confusions during the first decades of the virus era to present realities illustrated by the possible implication of mycoplasms as co-factors in natural infections of AIDS. Mycoplasma viruses (phages) may also be responsible for modifying the pathogenic power of mycoplasmas, at least for plants and insects. In addition, several mycoplasmas are able to act as undesirable cell culture contaminants that induce erroneous results in both applied and general virology. These problems are examined within a historical context.

By 1926, two French physicians working in Indochina, R. Pons and L. Chastel, have suggested to treat leprosy by subcutaneous injections of bacillus Calmette-Guerin. This treatment appeared efficient since the lepromatous lesions quickly regressed and the Hansen bacillus disappeared from the nasal mucus. These results were quickly confirmed by other authors. They were all more appreciated than, at this time, the Chaulmoogra oil and its products, the only available drugs, were poorly efficient against the disease. Nevertheless, although not a panacea, the BCG therapy allowed to relieve these unfortunate patients until the beginning of the 1950's when an effective treatment by sulfones was at length available.

During the past two decades, a number of mosquito-borne flaviviruses, mainly of African origin, have invaded new geographical areas where they have never been active. This was the case for the Japanese encephalitis virus which reached the northeastern part of Australia (1995) and, above all, for the West Nile virus which, since 1999, entirely colonized the American continent. Then, the Usutu virus invaded a large part of the Western Europe (2001) while the Zika virus caused a large epidemic in an island of Micronesia (2007). Finally, in 2010, the Tembusu virus devastated many duck farms in China while the Bagaza virus, after having provoked human encephalitis in India, reached the southern part of Spain. In the affected areas, new pathogenic outcomes were observed in humans and animals while new vertebrate hosts and mosquito species were infected. Moreover, unusual ways of contamination were described. The origins of this unprecedented evolution remain to be clarified.

Spiroplasma strain CC-1T, isolated from the gut of the soldier beetle Cantharis carolinus, was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of strain CC-1T were shown by light microscopy to be helical, motile filaments. Electron microscopy showed that the cells were bounded by a single cytoplasmic membrane, with no evidence of a cell wall. The organism was insensitive to penicillin. Strain CC-1T grew well in SM-1, M1D, and SP-4 liquid media under aerobic or anaerobic conditions. The strain also grew in 1% serum fraction medium. Optimal growth occurred at 32°C, with a doubling time of 2.6 h, but the strain multiplied at temperatures of 10 to 37°C. Strain CC-1T produced acid from glucose but hydrolyzed neither arginine nor urea. The guanine-plus-cytosine (G+C) content of the DNA was 26± 1 mol%. Other uncloned isolates from C. carolinus exhibited similar or identical serological patterns. On the basis of the data presented here, strain CC-1T (= ATCC 43207), previously proposed as the representative strain of subgroup XVI-1, is designated the type strain of a new species, Spiroplasma cantharicola.

Some group XVI spiroplasmas, such as strains CC-1 (Spiroplasma cantharicola) and CB-1, are associated with cantharid beetles. Fifteen related but heterogeneous strains have been isolated from mosquitoes, other insects, and a flower in France and the United States. In the present study, these seventeen strains have been compared by deformation and metabolism inhibition serological tests, by one-dimensional protein sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and by determination of the guanine-plus-cytosine content of their DNA. Five of the 17 strains were further compared by DNA-DNA hybridization and by restriction enzyme (EcoRI and HindIII) analysis of their DNA. On the basis of the resulting data, we propose that group XVI be subdivided into three subgroups. Subgroup XVI-I is represented by strain CC-1 (ATCC 43207) from a cantharid beetle in the United States, and strain MQ-6 from a wasp; subgroup XVI-2 is represented by strain CB-1 (ATCC 43208) from a cantharid beetle and two strains from mosquitoes, all in the United States; and subgroup XVI-3 is represented by strain Ar-1357 (ATCC 51126) and contains 11 strains from mosquitoes and 1 strain from a flower, all from the Savoy region of France.

A candidate biocontrol agent of mosquito vectors Spiroplasma taiwanense, was demonstrated not to persist (31 days post‐inoculation) or to reduce body weight of intra‐cerebrally inoculated suckling Swiss mice or suckling Sprague‐Dawley rats. It did not multiply or persist in mouse neuroblastoma 2A cells in vitro, nor did it reduce survival of the domestic honey bee Apis mellifera caucasica (a beneficial insect species). Preparations of this organism used throughout this study were verified for pathogenicity in female Aedes aegypti mosquitoes. S. taiwanense, originally isolated from mosquitoes, may thus prove to possess pathogenicity restricted to mosquitoes. S. melliferum was used as a positive control for intra‐cerebral re‐isolation and pathogenicity in mice, rats and mouse neuroblastoma cells.

During 1989 and 1990, tabanid flies were collected from two different areas in Western France and assayed for spiroplasmas. From Central Britanny 62 flies of 9 different species yielded 20 spiroplasma isolates belonging to 6 different serogroups : VIII, XIV, XXIII, HYOS, TABS 1, TAAS. From Atlantic biotopes 81 flies of three different species yielded 58 isolates belonging mainly to serogroup IV, but also TABS 1, HYOS and XIV. All the 78 French isolates were able to multiply in vitro at 37° C.Of 240 flower or plant specimens tested from « Briere » none yielded spiroplasmas.81 animal sera from « Briere » were also examined. Using the Deformation test and 11 different spiroplasmas from honey bees, mosquitoes and tabanids, 61/76 bovine sera (or 80,3 %) were found to be positive but exclusively for the spiroplasma Ar 1357, a mosquito spiroplasma belonging to serogroup XVI3 and previously isolated in France from Aedes mosquitoes.At present we have no explanation for the paradoxical absence of antibody to tabanid spiroplasmas in cattle since all French tabanid spiroplasmas are able to multiply in vitro at 37° C and, at least for three isolates, in suckling mice.

In mosquito-borne arbovirus infections in man the asymptomatic cases are much more frequent than the symptomatic ones, but their true role in the introduction and subsequent spread of such diseases in non-endemic areas remains to be clarified. We have collected pertinent data from English and French literature from 1952 to 2010 through Pubmed and other bibliographic sources. Data were analysed to assess if viremia in asymptomatic human arbovirus infections might be sufficient to represent a true risk for introduction in non-endemic areas. During dengue and chikungunya fever outbreaks, humans are believed to be the only vertebrate hosts. Since a very large number of individuals are infected and since viremic levels are known to vary by many orders of magnitude in symptomatic patients, it is reasonable to augur that a proportion of asymptomatic cases might reach levels of viremia sufficient to infect competent mosquitoes. Moreover, in both dengue and chikungunya fever, nosocomial infections have been identified representing an alternative opportunity for virus introduction in non-endemic areas. In zoonotic mosquito-borne arbovirus infections such as Japanese encephalitis or West Nile infection, the situation is quite different since humans are considered as "dead-end" hosts. However, the very large number of asymptomatic cases arising during outbreaks and the existence of newly recognised ways of contamination (blood transfusion, organ transplantation, transplacental way etc.) may also ensure their introduction and subsequent spread in new areas.

Vertical transmission of arboviruses, mainly those transmitted by mosquitoes, was considered for a long time as an exceptional event in pregnant women. However, during the recent years, as a result of the global upsurge of these viral infections, several surveys and reports clearly demonstrated that the resulting pathologies were increasing in both severity and frequency in endemic countries where pregnant women are at risk. In order to better assess such new epidemiological trends, the authors performed a general review as exhaustive as possible of the pathological consequences of the infection during pregnancy caused by the four dengue viruses and Japanese encephalitis, West Nile and Chikungunya viruses. At the therapeutic and preventive levels we are quite unarmed in the face of such severe accidents as their pathogenesis remains presently unclear

De 1981 a 1989, 78 specimens de la tique Ixodes pari (= I. frontalis) ont ete recoltes chez 20 oiseaux provenant principalement de l’Ouest de la France. Ceci nous a permis d’etudier le retentissement pathologique pour l’oiseau de l’infestation par cette tique et son role vecteur eventuel pour les arbovirus. Il apparait que I. pari est capable de provoquer des troubles pathologiques majeurs d’evolution mortelle dans certaines circonstances (hotes inhabituels ; fixation d’une ou plusieurs femelles en oviposition). Par contre, elle ne semble pas representer un vecteur majeur d’arbovirus. Cinq hotes probablement nouveaux de cette tique (Sylvia melanocephala, Alectoris rufa, Asio otus, Larus ridibundus et Alcedo atthis) sont decrits.

Strain A56 of the bee pathogen Spiroplasma melliferum was isolated from a honeybee (Apis mellifera) during ecological studies on mosquito spiroplasmas in Savoie (France). When inoculated intracerebrally (i.c.) into 48-h old suckling mice, this strain was found to replicate to very high titres and to persist in brain for up to 9 months in one individual. We attempted to increase the "neurotropism" of A56 by sequential i.c. passages. During the first two passages, multiplication of the organisms was observed at very high titres in suckling mouse brain (10(7) to 10(11) CCU/ml) generally without the appearance of antibody, thus mimicking the so-called "immunological tolerance" phenomenon. Intracerebral multiplication of A56 decreased during the third passage (10(2) to 10(4) CCU/ml) and ceased during the fourth passage. Spiroplasma multiplication in brain was apparently well tolerated, since brain lesions were minimal and clinical symptoms were limited to a clear, but only rarely significant, delay in growth curves of inoculated versus non-inoculated mice. Progressive spongiform encephalopathy was never observed. Strain A56 S. melliferum appears as the second spiroplasma, after the tick-derived Spiroplasma mirum capable of multiplying in both invertebrate and vertebrate hosts.

Yellow fever is a mosquito-borne hemorrhagic fever caused by a virus belonging to the flavivirus genus, Flaviviridae family, which is still active today in tropical areas in Africa and America. It is a very severe disease with a mortality rate that can reach 30% or more. First recorded in 1648 on the Yucatan peninsula, this scourge occurred in large urban outbreaks in the Americas during the seventeenth, eighteenth, nineteenth, and early twentieth centuries. Infected crews of merchant vessels spread it to European harbors as well. The viral nature of the disease and its specific mode of transmission by the mosquito Aedes aegypti L were not elucidated before the twentieth century. Although preventable by immunization of persons at risk, yellow fever will never be eradicated because the virus is maintained in nature among wild mosquitoes and monkeys in both Africa and the Americas.

Field studies on the ecology of mosquito spiroplasmas (Mollicutes) were carried out on a number of swampy biotopes along the Atlantic coast of France and the banks of the Loire River (Loire-Atlantique). Spiroplasma sabaudiense and the Cantharis spiroplasma were isolated from Aedes detritus and Ae. caspius during May and June 1988 but disappeared in August and September.These data confirm the results of previous surveys performed in Savoia, Northern Alps, among other species of mosquitoes. It is possible that mosquitoes acquire their spiroplasma infections during the spring from flowers following their emergence and not from their aquatic environment.

Unlike other recent viral emergences, which were in majority caused by RNA viruses, the monkeypox results from infection by a DNA virus, an orthopoxvirus closely related to both vaccine and smallpox viruses and whose two genomic variants are known. Unexpectedly isolated from captive Asiatic monkeys and first considered as an laboratory curiosity, this virus was recognised in 1970 as an human pathogen in tropical Africa. Here it was responsible for sporadic cases following intrusions (for hunting) into tropical rain forests or rare outbreak with human-to-human transmission as observed in 1996 in Democratic Republic of Congo. As monkeypox in humans is not distinguishable from smallpox (a disease globally eradicated in 1977) it was only subjected to vigilant epidemiological surveillance and not considered as a potential threat outside Africa. This point of view radically changed in 2003 when monkeypox was introduced in the USA by African wild rodents and spread to 11 different states of this country. Responsible for 82 infections in American children and adults, this outbreak led to realize the sanitary hazards resulting from international trade of exotic animals and scientific investigations increasing extensively our knowledge of this zoonosis.

In December 2004, a very devastating tsunami struck the coasts of a number of countries along the Indian Ocean inducing about 280,000 deaths and at least 125,000 injured persons. As after such disaster the occurrence of large epidemics of cholera, malaria or arbovirus infections are to be expected. In fact, two years later, no outbreak has been reported among the exposed populations and this is probably the usual outcome for such disasters. However an real increase in number of cases of melioidosis and many bacterial or fungic infections affecting the pulmonary tract, the skin and the injured soft tissues, was noted mainly in repatriated tourists. These latter infections were due to rare or atypical, frequently multiresistant, microorganisms.

As he was beginning to sort a batch of Ixodid ticks, collected with the flagging technique, the operator noticed that a female tick identified as Ixodes frontalis had fixed itself rapidly on the top of one of his finger. That species is usually considered as "strict-specific to birds". The low frequency of such a fixing on human beings, as for as we know, is of limited value from an epidemiological point of view.

Since the Prehistoric times hunting has been a vital activity for man. However, this may account for the contamination of the hunter, his family and relatives. Infections may occur by direct contact with blood or tissues of infected animal during handling and cutting up preys and when preparing or eating meat, or also when bitten by injured animal. Apes and antelopes hunting in sub-Saharan Africa proves to be particularly important since it has been well established that the recent or previous emergence of some viral zoonosis (Ebola, Aids, T lymphotropic viruses and Monkeypox) resulted from hunting and poaching. Moreover predation among different species of non human primates such as that practised by chimpanzees against monkeys, has led to the construction of recombinant simian Lentiviruses, such as SIV cpz able to infect man and then spread over the entire mankind as it was the case with HIV-1. SARS is another possible example of the zoonotic risks represented by the sale, handling and cutting up Chinese wild animals such as Himalayan civets for culinary purposes.

Israel turkey meningo-encephalitis (ITME) virus was detected in pools of Ochlerotatus caspius Pallas and Culicoides imicola Kieffer trapped at a turkey run at Nir David during an outbreak in August 1995. Experimental membrane feeding on a blood ITME suspension showed that Culex pipiens L. became harbored virus for at least 14 d. When Phlebotomus papatasi Scopoli were fed on an infected turkey, they became infected and harbored the virus for at least 7 d. Because Phlebotomines are trapped frequently at turkey runs in Israel, they should be suspected as potential vectors of ITME.

The number of persons suffering from tick-borne diseases has notably increased in the French region of Lorraine since the mid 1990s. Greater awareness of the pathology is insufficient to explain such an increase in incidence. Instead, the proliferation of ticks is a major factor in the increased incidence of cases, and is mainly due to a modification of the ecosystem. Prophylaxis is based upon appropriate information for persons concerned and requires a sound understanding of the biology and habits of the vector ticks. Numerous factors--anthropogenic, natural, social--may contribute to the destabilisation of a well-balanced ecosystem, but all are more or less the direct result of human activity. The geographic specificities of this region may be an additional factor in the emergence of tick-borne diseases.

Resume La frequence des infections a Lactobacillus est probablement sous-evaluee, en particulier chez les malades immunodeprimes. Les auteurs rapportent une observation de septicemie a Lactobacillus casei var. rhamnosus chez une malade leucemique en aplasie ayant subi une decontamination intestinale et une antibiotherapie inadaptee. La presence dans les selles de la malade d'un germe ayant exactement les memes caracteres bacteriologiques rend tres vraisemblable une translocation du tube digestif vers la circulation sanguine.

In 1900 the role of a particular mosquito called Stegomyia fasciata in the transmission of yellow fever was proved by a board of American medical officers. This discovery was the beginning of several scientific missions in South America, mostly in Brazil. As yellow fever was increasing in its West African colonies, the French government decided to send a scientific mission to Rio de Janeiro, to find new ways of prevention against the disease. Under the authority of the Institut Pasteur, Paul-Louis Simond, who had just discovered the role of the flea in the transmission of plague, was designated to carry through this mission together with Emile Marchoux and Alexandre Salimbeni, eminent Pasteurians like him. From November 1901 to May 1905, the three men studied the epidemiological and clinical aspects of the disease in Rio. They worked on the intermediate host's entomology, the Stegomyia female mosquito, improving the knowledge of yellow fever and its means of transmission. They also realized experiments on 25 healthy volunteers, submitting them to the bite of infected mosquitoes. They were among the first to proceed to yellow féver vaccinations by means of virulent serum heated to 55 degrees C or filtered. Their work led to the establishment of new sanitary rules to prevent the spread of the disease. This contributed to the success of the "yellow fever campaign" initiated by Oswaldo Cruz in the town of Rio. One of the most original contribution of their studies was to show that the yellow fever agent (which was still unknown) could be transmitted from an infected female Stegomyia to its eggs and larvaes. After this mission, the French authorities were able to fight yellow fever efficiently in their African colonies as well as in the West Indies and French Guyana.

The outbreak of yellow fever that struck Barcelona in 1821 followed a typical pattern for the times: a brick from Cuba introduced the disease in the port docks; the epidemic first reached the poor suburbs, and finally the center of the city. It was assumed that at least 20,000 inhabitants died from the scourge, that is a sixth of the total population of the city estimated 120,000. French authorities promptly took emergency measures at land and maritime borders by locking French ports to Catalan vessels and defining a quarantine line along the Pyrenean border controlled by an army 15,000 strong. French medical team including six physicians and two nuns was sent to Barcelona to provide assistance. Long after the epidemic had receded, the Pyrenean quarantine line was maintained by the French authorities for a hidden political purpose: Paris wished to contain Spanish Liberalism, a "revolutionary pest". French troops engaged in the so-called quarantine line were used in 1823 for invading the Spanish kingdom, while French physicians returning to Paris were celebrated as heroes and benefactors of the mankind although they had not provided any serious contribution to the therapeutics or the epidemiology of yellow fever. They were glorified in publications of the time without reserve. This unexpected manifestation of nationalism was welcomed and encouraged by the government of Louis XVIII who felt himself threatened by the liberal opposition.

A few million years ago, when primates moved from the east African forest to the savannah, they were already infected with endogenous viruses and occultly transmitted them to the prime Homo species. However it was much later with the building of the first large cities in Mesopotamia that interhuman viral transmission began in earnest. Spreading was further enhanced with the organization of the Egyptian, Greek, Roman, and Arab empires around the Mediterranean. Discovery of the New World in 1492 led to an unprecedented clash of civilizations and the destruction of pre-Columbian Indian civilizations. It also led to a rapid spread of viruses across the Atlantic Ocean with the emergence of yellow fever and appearance of smallpox and measles throughout the world. However the greatest opportunities for worldwide viral development have been created by our present, modern civilization. This fact is illustrated by epidemic outbreaks of human immunodeficiency virus, Venezuela hemorrhagic fever, Rift valley fever virus, and monkey pox virus. Close analysis underscores the major role of human intervention in producing these events.

A new phlebovirus (Bunyaviridae family, Phlebovirus genus), provisionally designed Chizé virus, was isolated from a nymph of Ixodes (Trichotoixodes) frontalis collected on a wren (Troglodytes troglodytes) found dead in the Chizé forest, western France. Chizé virus produced a lethal encephalitis in one-day-old mice and cytopathic effect (CPE) in Vero cells. Extracellular particles with a mean diameter of 105 nm with surface spikes characteristic of Uukuniemi (UUK) serogroup viruses were observed in Vero cells. Chizé virus reacted in complement-fixation test with several UUK serogroup viruses but was readily distinguished from all registered viruses in the serogroup. I. frontalis is highly specific for birds and unlikely to transmit Chizé virus to humans or domestic animals; the pathogenicity of the new virus to wild birds remains to be clarified.

Eighteen patients with typical Herpes simplex virus dendritic keratitis confirmed by viral isolation were treated with corneal collagen shields presoaked with trifluorothymidine for 15 minutes and trifluorothymidine eye drops 5 times daily. The average healing time was 2.9 days (range 1-7 days). No allergic reactions were observed. Toxic punctate keratitis occurred in 3 eyes. The results of this open study suggest that the effect of collagen corneal shields in conjunction with trifluorothymidine shortens the average epithelial healing time compared with other studies that have used antiviral drugs alone.

Strain Tab4cT, a helical prokaryote that was isolated from the body of a Haematopota sp. fly collected in Champchevrier, Indre-et-Loire, Touraine, France, was found to be a member of the class Mollicutes. The cells of strain Tab4cT were small, motile helices that were devoid of a cell wall. The organism passed through filters with mean pore diameters as small as 0.20 mm. Strain Tab4cT grew rapidly in liquid SP-4 medium at both 30 and 37 degrees C. The organism fermented glucose but did not hydrolyse arginine or urea, and did not require serum for growth. In preliminary electrophoretic analyses, the cell protein patterns of strain Tab4cT were distinct from those of 14 other spiroplasmas found in mosquitoes, deer flies and horse flies from Europe and the Far-East. In reciprocal metabolism inhibition and deformation serological tests, employing antigens and antisera representative of spiroplasma groups I-XXXIII (including all sub-groups), plus ungrouped strains BARC 1901 and BARC 2649, no serological relationship with Tab4cT was found. The G + C content of the DNA of strain Tab4cT was about 25 +/- 1 mol% and its genome size was 1.305 kbp. It is proposed that spiroplasma strain Tab4cT be assigned to group XVII (presently vacant) and that strain (ATCC 700271T) is the type strain of a new species, Spiroplasma turonicum.

Two arboviruses have been isolated from Mayenne, western France, in 1981-1982, during systematic field surveys: Eyach virus, a cultivirus from Ixodes ricinus and I. ventalloi ticks, and Erve virus, a nairovirus from the tissues of white-toothed shrews, Crocidura russula. For many years, these two viruses were considered as "orphan viruses" without pathogenic power for man, since it became evident that they circulate actively in Europe among populations of wild small and large mammals. Moreover, these viruses are able to infect human beings and were responsible for severe neurological disorders. The presently known geographical distribution of these agents includes France, Germany, Netherlands and Czech Republic.

Dermatological injuries provoked by tick bites deserve more attention. The authors present the clinical observation of a young woman bitten in Brittany by the marine bird associated tick Ornithodoros (A.) maritimus and presenting pseudo-zoster skin lesions. Two other individuals working together with the patient and also bitten by this tick showed symptoms of prurigo, fever and vomiting. Marine bird associated ticks bites may also be responsible for the inoculation of a number of arboviruses along all the coasts of the world including those of islands of Indian Ocean. Pathogenesis of the skin lesions is discussed according to the authors' histo-pathological findings.

Yellow fever and dengue are two current viral diseases induced by flaviviruses and usually transmitted by the same mosquito vector, Aedes aegypti. From 1987 to 1991, 18,753 cases of yellow fever, mainly from Africa, have been notified to WHO, leading to 4,522 deaths. On the other hand, WHO estimates that 2.5 billions individuals living in tropical areas are at risk to contract dengue fevers. In fact, 500,000 patients are hospitalized each year for dengue hemorrhagic fever/dengue shock syndrome and 90% of them are children. Nevertheless, the control of these two viral diseases would be reached easily in destroying mechanically the mosquito larval resting places. Although superficially similar, the two entities are in fact quite different. Relatively few is known about the pathogenesis of yellow fever whereas, for dengue fevers, it is difficult to integrate so many results accumulated to explain the occurrence of haemorrhagic phenomena according to the two main theories so far proposed which are not exclusive. The immunological one (S.B. Halstead) tries to explain the pathological events by the effect of anti-dengue enhancing antibodies acquired during a previous exposure to one of the dengue viruses, whereas that of increased virus virulence (L. Rosen) refers to fast passages between individuals during explosive epidemics.

As he was beginning to sort a batch of Ixodid ticks, collected with the flagging technique, the operator noticed that a female tick identified as Ixodes frontalis had fixed itself rapidly on the top of one of his finger. That species is usually considered as "strict-specific to birds". The low frequency of such a fixing on human beings, as for as we know, is of limited value from an epidemiological point of view.

Three strains of nonhelical mollicutes previously isolated in France from two different mosquitoes and one tabanid fly were designated strains Ar 2328 (isolated from Aedes detritus), Ar 2392 (isolated from Aedes caspius), and CP 13 (isolated from Chrysops pictus). All of these strains exhibited properties of the genus Mesoplasma, a recently described genus of non-sterol-requiring mollicutes isolated from plants and insects. The results of metabolism inhibition and growth inhibition tests revealed that these strains and Mesoplasma entomophilum TAC or Mesoplasma florum L1 were not serologically related, but all three dipteran strains reacted strongly with Mesoplasma seiffertii F7T (T = type strain) antibodies. Using metabolism inhibition and growth inhibition tests, we found that the dipteran strains were related to each other and to strain F7T but were not identical. We also found that they were able to multiply and persist in the central nervous systems of suckling mice inoculated intracerebrally, a property that makes their use as biological control agents for pest dipterans inadvisable. Scanning electron microscopy revealed marked differences in the morphologies of the colonies of the different strains on SP4 solid medium. The levels of DNA-DNA homology for strains Ar 2328, Ar 2392, CP 13, and F7T were more than 70%, indicating that these strains are closely related members of the same species, M. seiffertii. In addition, one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that each strain produced about 40 protein bands. This technique also revealed differences between strains. Using the coefficient of Smeath-Jacquart, we constructed a dendrogram that allowed us to estimate of the levels of relatedness of these four strains. The results which we obtained were confirmed by two-dimensional protein electrophoresis results.

In this limited series of 23 patients suffering from severe or life-threatening intra-abdominal infection, piperacillin + tazobactam, together with adequate surgical drainage and resections, cured 78% of our patients and eradicated almost all the pathogens. Side effects included essentially eosinophilia and elevation of transaminases but was never severe. Piperacillin + tazobactam seem thus to be an acceptable treatment, associated with correct surgical drainage. This regimen has to be compared in appropriate trial versus gold standard therapy, such as imipenem, a beta-lactam with aminoglucoside and imidazole or clindamycin or with broad spectrum beta-lactam and other inhibitors or beta-lactamases, but our rate of cure is impressive in such a population.

The problem of arbovirus infections in Maghreb has been relatively neglected in the pst in spite of a rich diversity of biotopes, the presence of potential reservoirs and vectors, and their position on the flight path of the Palearctic-african bird migration systems, western branch. Moreover, West Nile virus has been isolated from southern Algeria since 1968. From 1979 to 1989, ticks were collected from wild birds, pigeons, bats, rodents, poultry, camels, wild boars, domestic mammals and man, and assayed for viruses. On the whole, 424 ticks were virologically studied from Morocco, 582 from Algeria and 601 from Tunisia. Four tick-borne arboviruses have been isolated so far: three from Morocco, Soldado (Nairovirus), Essaouria (Orbivirus) and Kala Iris (Orbivirus) from Ornithodoros (A.) maritimus ticks parasitizing marine birds, and one from Tunisia, Tunis (Phlebovirus), from Argas reflexus hermanni infesting domestic pigeons. Soldado virus may infect man working into colonies of gulls for ornithological or entomological purposes and this infection is associated with a self-limited febrile illness and pruritus. In addition, antibody to Essaouira virus was detected in a wild rodent in Morocco. On the contrary it is unlike that Tunis virus may infect man because A. r. hermanni is a strickly ornithophilic tick. However, Uukuniemi group antibody has been previously evidenced in wild rodents in Tunisia. Finally, it is not excluded that other, more pathogenic, arboviruses such as Congo-Crimean haemorrhagic fever might be accidentally introduced in this sensitive geographical area.