Bluetongue virus in Lebanon.

Since 2000, several incursions of bluetongue virus (BTV) occurred in the Mediterranean Basin involving European and surrounding Countries. The Middle East represents one of the most important gateways for the access of BTV in Europe. Limited data on the BTV situation in this area are available. In this perspective, an epidemiological survey on the presence of BTV in Lebanon was conducted. Of the 181 serum samples tested, 97 (mean = 53.6%; 95% CI: 46.3-60.7) resulted positive when tested for the presence of BTV antibodies by c-ELISA, of these 42 (mean = 42%; 95% CI: 32.8-51.8) serum samples were from sheep and 55 (mean = 67.9%; 95% CI: 57.1-77.1) serum samples were from goats. Fourteen blood samples (14/110; mean = 12.7%; 95% CI: 7.8-20.3), 6 (6/66; mean = 9.1%; 95% CI: 4.4-18.5) from sheep and 8 (8/44; mean = 18.2%; 95% CI: 9.6-32.0) from goats, were positive by qRT-PCR. The results with serum-neutralization assay and typing performed by RT-PCR confirmed that six BTV serotypes are currently circulating in Lebanon, and these serotypes are as follows: 1, 4, 6, 8, 16 and 24. This study is the first report that confirms the presence and circulation of BTV in Lebanon.

Risk factors associated with the occurrence of undesired effects in sheep and goats after field vaccination with modified-live vaccine against bluetongue virus serotypes 2, 4 and 16.

In the 2004, the Sardinian bluetongue (BT) vaccination campaign used the combination of monovalent BTV-2, BTV-4 and BTV-16 modified-live vaccines manufactured by the Onderstepoort Biological Products in South Africa. Following vaccination, some herds showed temperature, oedema, lameness, hyperaemia and decrease in milk production, and some others remained perfectly healthy. This study aimed to evaluate whether important factors present in the herd at the time of vaccination could be associated to the occurrence of undesired effects observed after immunisation with BTV modified-live vaccines. A sample of 17 sheep and 4 goat flocks, for a total of 670 animals, were included in the study and risk factors such as presence of most important parasitic, bacterial and viral diseases as well as anomalies of biochemical and haematological parameters were associated to the presence or absence of side effects. For each factor the relative risk and 95% confidence interval were calculated. Following vaccination, bluetongue-like symptoms were observed in 13 flocks. In these flocks, a higher (P<0.05) proportion of animals had viraemia and showed higher titers to BTV-16 after immunisation. Positive association (RR=2.50, 1.17-5.04) was also found between flocks in which undesired effect were observed and positive serology against Maedi-Visna virus. On the contrary, presence of BTV genome fractions in the blood of animals at the time of vaccination was found to be protective (RR=0.7, 0.58-0.84) to the occurrence of undesired effect subsequent to BTV vaccination.

Virological and serological response of sheep following field vaccination with bivalent modified-live vaccine against bluetongue virus serotypes 2 and 9.

A group of 44 sheep was vaccinated with the bivalent modified-live vaccine against bluetongue virus (BTV) serotype 2 (BTV-2) and BTV-9 to evaluate viraemia and antibody kinetics. Blood samples were taken from the sheep three times a week for two months and screened for the presence of BTV and for antibody using the competitive enzyme-linked immunosorbent assay (c-ELISA) and the virus neutralisation (VN) test. Intravenous egg inoculation, followed by two blind passages in Vero cells, was used to isolate BTV-2 and BTV-9 from the ethylene-diaminetetra-acetic acid (EDTA) blood samples; virus titres were also determined in the viraemic animals. BTV was detected in the blood of 39 sheep between day 3 and day 24 post vaccination (pv). Viraemia peaked on day 7 pv with average titres of 10(5.3)TCID50/ml. Antibodies were first detected in the c-ELISA on day 6 pv and by day 16, all sheep were seropositive. Only 36 of the 44 inoculated sheep developed virus-neutralising antibodies against both BTV-2 and BTV-9 while 4 were positive to BTV-2 only; neutralising antibodies were not detected in the 4 remaining animals. Antibody titres were very low and unstable and often bordered on the negative/positive threshold.

Characterisation of Aujeszky's disease viruses isolated from domestic animals and from a wild boar (Sus scrofa) in Italy between 1972 and 1995.

Following the isolation of a group I Aujeszky's disease virus from a wild boar in 1993, an investigation was carried out on 30 Italian Aujeszky's disease viruses (ADV's), isolated over a 23-yr period in 12 Italian regions, by means of restriction endonuclease analysis. All strains isolated between 1972 and 1984 belong to group I. From 1984 onwards group II isolates (II and II intermediate) replace group I isolates. The isolation of a group I virus in 1993 from a wild boar supports the hypothesis that ADV's may persist for several years in wild boar populations and that wild boars should therefore be considered reservoirs of Aujeszky's disease virus.

Isolation and characterization of Aujeszky's disease virus in captive brown bears from Italy.

An epizootic of Aujeszky's disease (pseudorabies) in four captive European brown bears (Ursus arctos) in November 1994, in the Val di Non, Trentino Region, Italy, was linked to consumption of raw pork. Affected animals had severe pruritus resulting in self-mutilation, and all four died within 24 hr after onset of clinical signs. Aujeszky's disease virus was isolated on first passage from the brain and was characterized by means of restriction endonuclease analysis. Based on these data, we believe that bears are extremely susceptible to the disease, and that wildlife managers should consider pseudorabies as a potential risk for the captive and wild bear populations.

Isolation and characterization of an adenovirus associated with inclusion body hepatitis in psittacine birds.

An outbreak is reported of inclusion body hepatitis in psittacines from a private aviary, in which several birds aged between 35 and 75 days had died without showing any clinical signs. Histological examination of the livers revealed severe hepatic damage with presence of large basophilic intranuclear inclusion bodies. Avian adenoviruses were isolated from the affected livers. Characterization of the isolates by means of restriction endonuclease analysis showed that they were similar to reference strain SR49 (serotype 3) which is associated with inclusion body hepatitis in chickens. This finding was confirmed by the virus neutralization test.

A 'novel' infectious bronchitis strain infecting broiler chickens in Italy.

An outbreak of severe respiratory disease in flocks of broiler chickens was associated with the isolation of a 'novel' strain of infectious bronchitis virus (IBV). The isolate, designated 624/I, was isolated from 9 of the 11 flocks sampled. The results of cross neutralisation and haemagglutination-inhibition tests showed isolate 624/I to be antigenically distinct from several European and American strains. In a serological survey carried out on affected flocks, specific antibodies to IBV strain 624/I and turkey rhinotracheitis (TRT) virus were detected.