This study reports the prevalence of antibodies to hepatitis B virus (HBV) and C virus (HCV). and the frequency of potential exposure to these viruses among patients and staff in six long-stay wards of a hospital caring for mentally handicapped adults from the Mersey region. A retrospective survey of risk behaviour among 134 patients and questionnaire survey of 75 nursing staff was performed. Serum samples from both groups were tested for HBV markers and patient sera for antibodies to HCV by enzyme-linked immunosorbent assay (ELISA). None of the 102 patients tested had antibodies against HCV. although 17 had detectable antibody to HBV core (anti-HBc). Seven out of the 17 were positive for HBV surface antigen. None was positive for IgM antibody to HBV core. Only 1 out of 61 staff had anti-HBc and none was positive for surface antigen. Twenty-nine of 75 (39%) staff reported bites sufficient to break the skin and 52 (69%) significant other injuries from patients; 25 (31%) of staff had not received HBV vaccination. None of the patients had received HBV vaccine.

We conclude that HCV does not appear to be a major hazard in this closed community but the prevalence of HBV markers indicating past exposure among patients is high, vaccine uptake is incomplete and incidents which may allow viral transmission are frequent.

Plaque purification of foot-and-mouth disease (FMD) type O viruses isolated from cattle in Saudi Arabia showed the presence of mixed serotype infections. Sixteen out of 31 samples collected between 1985 and 1991 also contained Asia 1 virus, a serotype which had previously only been isolated from a single outbreak in that country in 1980. Nucleotide sequences of the Asia 1 component of all these samples revealed little variation and showed that they were closely related to both a Russian lapinized vaccine virus strain (Asia 1/Tadzhikistan/64), and to a field isolate from Turkey (Asia 1/TUR/15/73). Although mixed FMD infections have been observed previously this is a first report of a serotype, considered to be exotic to a country, co-existing undetected for an extended period of time.

The sequence of 165 nucleotides at the 3´ end of the 1D (VP1) gene of foot-and-mouth disease (FMD) virus was determined for 44 type Asia 1 strains isolated from throughout Asia between 1954–92. Analysis of the relationships between the virus genomes showed epidemiological links not previously evident. The possible origin of the only outbreak of FMD Asia 1 to have occurred in Europe, in Greece in 1984, was identified because the nucleotide sequence of this virus was closely-related to the sequences of those present in the Middle East between 1983–5.

Variation in the region sequenced was not as great as that seen in the other FMDV serotypes and all viruses shared greater than 85% nucleotide identity. Thus all the virus isolates examined were considered to belong to a single genotype.

A database of Asia 1 virus sequences has been established which will facilitate the rapid analysis of new outbreaks strains.

Monoclonal antibody–based competitive ELISA (C–ELISA) have been used for the specific measurement of antibodies to both rinderpest and peste des petits ruminants (PPR) viruses in cattle, sheep and goats. Examination of serum samples from sheep and goats in Gambia, before and after vaccination with rinderpest vaccine, suggested that antibodies to PPR virus could prevent an immune response to the rinderpest vaccine. Cattle sera from Nigeria and Ghana showed a high prevalence of antibody against PPR virus which may explain the difficulty experienced in some countries in achieving high post-vaccination immunity levels against rinderpest. Because antibodies against PPR virus are both cross–neutralizing and cross-protective against rinderpest virus further vaccination in the presence of antibodies against PPR virus may be a waste of national resources. This paper presents serological evidence for the transmission of PPR virus from sheep and goats to cattle and highlights the need to include PPR serology in the sero-monitoring programme to give a better indication of national herd immunity.