[Wild rabbit, Oryctolagus cuniculus L., and arboviruses in southeast France. Results of two serologic investigations]. / Lapin de garenne, Oryctolagus cuniculus L. et arbovirus dans le sud-est de la France. Résultats de deux enquêtes sérologiques.

Sera from 269 wild rabbit (Oryctolagus cuniculus L.) trapped in 1985 and 1986 in Camargue and Vaucluse, France, were studied for antibody against 9 arboviruses. By inhibition haemagglutination test, positive reactions were found only against West-Nile (0.37%). By complement fixation test, antibodies were detected against Eyach (0.92%) and Tribec (0.46%). These results are discussed according to arboviruses isolated in France, to previous serosurveys in rabbits and other mammals and to potential vectors known to occur in France. Potential impact on rabbit population is also discussed.

[Chiroptera viruses transmitted or not transmitted by arthropods]. / Virus des chiroptères transmis ou non par arthropodes.

The authors make a review of literature on viruses isolated from chiroptera's tissues. They study especially two of these viruses: a true arbovirus, the Japanese B encephalitis virus and a virus of the same genus but not arthropod-borne, the Rio Bravo virus. They consider successively for each virus: isolations from bats, serosurveys in bat and in man, and experimental studies with these viruses, allowing to estimate the role of chiroptera in the diffusion and the maintenance of some arboviruses. They also report some personal results of serosurveys in bats from Tunisia and Spain.

[Encephalitic syndrome caused by flavivirus diagnosed after return from a voyage to South India: probably dengue with neurological manifestations]. / Syndrome encéphalitique attribuable un flavivirus observé au retour d'un voyage en Inde du sud: dengue probable à expression neurologique.

The authors report the case of a flavivirus encephalitis (probable Dengue) in a 70 year old female, occurring twenty days after a fewer of unknown origin, contracted in the South of India. Most of the cases of such encephalitis have been reported from children, but they may occur also in adults.

[Serologic survey on arbovirus infections in patients presenting with uveitis]. / Enquête sérologique sur les infections à arbovirus chez les patients présentant une uvéite.

Viruses have been demonstrated or suspected as the causative agents of various types of uveitis. Some arboviruses can be responsible for ocular manifestations. In Brittany, both serosurveys and virus isolations were positive for arboviruses. These results led us to look for the possible role of arboviruses in the aetiology of uveitis. For this, we performed a serosurvey on 131 patients with uveitis of unknown aetiology. Patients were examined in the Ophthalmologic Department of the Brest University Hospital from May 1979 to May 1983. Serum samples were studied: by haemagglutination inhibition (HI) tests against thirteen antigens; by complement fixation (CF) tests against six antigens. The HI and CF tests were performed using micromethods. HI tests revealed antibodies against one or more flaviviruses antigens in thirteen patients: nine monospecific reactions against Yellow Fever virus (as a consequence of a vaccination) and four reactions against several flaviviruses. The four positive reactions are easily explainable by previous trips in countries where several arboviruses are endemic. By CF test we found antibodies at a low titer in two patients: the first one had antibodies against the Zaliv Terpeniya virus and the second against the Avalon virus. Signification of these results is discussed. Our study shows that in Brittany uveitis of unknown aetiology do not seem to be due to arboviruses, at least those tested in this survey or antigenically related.

[Visualization of the Soldado virus by electron microscopy in the tissues of the vector tick Ornithodoros (Alectorobius) maritimus Vermeil and Marguet, 1967]. / Visualisation du virus soldado par la microscopie électronique dans les tissus de la tique vectrice Ornithodoros (Alectorobius) maritimus Vermeil et Marguet, 1967.

By means of transmission electron microscopy, it was possible to visualize typical viral particles of Soldado virus (Bunyaviridae, Nairovirus ) in the tissues of a naturally infected Ornithodoros ( Alectorobius ) maritimus tick.

[Diagnostic value of serum IgM determination in human infections caused by Flaviviruses]. / Intérêt diagnostique de la recherche des IgM sériques au cours des infections humaines à Flavivirus.

Since 1977, we have performed arboviruses' serosurveys in 330 patients by haemagglutination inhibition test. For 22 of them we have studied specific IgM antibodies against flavivirus. The separation was done by sucrose-gradient density ultracentrifugation and IgM antibodies were demonstrated by the HI test. The 22 IgM tested sera were distributed as follows: 1) 7 positive sera corresponding to patients with a recent flavivirus infection; 2) 12 sera to test with a HI titer greater than or equal to 20 against one or more flaviviruses on a single serum; and 3) 3 negative control sera corresponding to patients with a past known flavivirus infection. For the first group of sera, IgM assay was used to help to determine the causal virus and for the sera to test, it led to conclude to a recent infection in one case and to a past infection in eleven others.

[Small wild mammals and arboviruses in Italy]. / Petits mammifères sauvages et arbovirus en Italie.

In 1980 and 1981, sera of 256 small wild mammals (rodentia, insectivora, carnivora) were collected in Piemonte and Southern Italy. They were then tested for antibody against 12 arboviruses by haemagglutination inhibition and complement fixation tests. In the North of the country, 42.8% of sera were found positive against Tahyna or Sicilian Sandfly fever viruses. In the Southern provinces, 44.3% of sera reacted with Bhanja, West Nile or other flaviviruses, Tahyna, Sicilian Sandfly fever and Arumowot viruses. These results lead to suspect the possible role of some small mammals (muridae, Clethrionomys glareolus, Talpa caeca, Talpa romana) in circulating these arboviruses in Italy.

[Ecology of Soldado virus: apparent lack of a viral inhibitor in th tissues of the vector tick Ornithodoros (Alectorobius) maritimus Vermeil and Marguet 1967]. / Ecologie du virus Soldado: absence apparente d'un inhibiteur du virus dans les tissus de la tique vectrice Ornithodoros (Alectorobius) maritimus Vermeil et Marguet 1967.

It was previously postulated by others that suspensions of ticks O. (A.) maritmus may contain virucidal material (viral inhibitor) for Soldado virus leading to observe different infection rates according as the ticks were tested individually or in pools. In order to test this hypothesis, suspensions of nymphs of this species originating from a laboratory breeding stock, were mixed with Soldado virus before inoculation to suckling mice. No difference in mortality was observed between the mice receiving the virus exposed to tick suspensions and the controls. So, it seems unlike a viral inhibitor was responsible for the phenomenon. Other factors involved in Soldado virus ecology and possibly influencing the virus isolation efficiency are briefly discussed.

[Arbovirus infections in Spain: serological survey on small mammals]. / Infections à arbovirus en Espagne: enquête sérologique chez les petits mammifères.

Sera of 386 small mammals (rodents, insectivora, small carnivora and cheiroptera) trapped in Spain in 1978 and 1979 were studied for antibody against 10 arboviruses. Positive reactions were found against flaviviruses: West Nile (3.1%), dengue type 2 (0.5%), tick-borne encephalitis, European type (0.2%), together with Tahyna (6.5%), Uukuniemi (2%) and Bhanja (1%) viruses. The animal species concerned by positive reactions were essentially Mus spretus and Apodemus sylvaticus which were also the more numerous species trapped during the survey. In addition, in Crocidura russula, an unique reaction against West Nile virus was found. Results of our serosurvey in small mammals correlated well with those of previous reports in men or animals, from Portugal and from north-western Spain.

[Mixed sero-epidemiologic study of arbovirus-arenavirus in the small mammals of Tunisia]. / Enquête séro-épidémiologique mixte arbovirus-arénavirus chez les petits mammifères de Tunisie.

Blood samples of 156 small mammals caught in Tunisia in 1976 and 1977 were examined for the presence of antibodies to some arboviruses and arena-viruses. Haemagglutination-inhibiting antibodies against West Nile virus were detected in 19.8 0/0 of examined sera, mainly from Mus sp., Rattus rattus, Eliomys tunetae in the northern part of the country and from Ctenodactylus gundi and Pipistrellus kuhli in the south. In addition, antibodies against Uukuniemi and Bhanja were found in 3.2 0/0 and 4.5 0/0 respectively of the same sera.