There are few applications of virology to clinical medicine that have received more attention than the laboratory diagnosis of rubella. Many laboratories attempt it and most readers of this journal will be familiar with the techniques that have been used. It would therefore be superfluous to review the ‘state of the artm’ had there not recently been an innovation that is likely to alter laboratory practice in this field.

An antibody capture radioimmunoassay was established for the detection of coxsackievirus B4 and B5-specific IgM. A significant feature of the assay was the use of an unrefined coxsackievirus B (CBV) antigen. The antigen was prepared by freeze thawing, ultrasonication and low speed centrifugation of infected Vero cells with no purification or concentration of the antigen being performed. Results of sera tested were expressed as a serum ratio (SR) by comparison with a low positive control serum. To establish an SR indicating positivity in the assays, 100 antenatal sera collected in late February were tested. The mean SR was calculated and the mean plus three standard deviations was taken as the minimum SR indicating positivity. Although resulting in a relatively insensitive assay, such a value was required to exclude sera giving a low level of reactivity which may be due to residual enterovirus-specific IgM resulting from a remote infection.

The homologous CBV-IgM assay was positive in four cases of CBV4 infection and six cases of CBV5 infection. For the CBV4 IgM assay, ten of 20 (50%) sera from infections with CBV other than CBV4 were positive and nine of the 13(69%) sera from infections with echoviruses or coxsackieviruses A were positive. Five of 18 (27%) sera with an elevated CBV neutralization titre were positive in the CBV4-IgM assay. For the CB5-IgM assay seven of 18(39%) sera from infections with CBV other than CBV5 were positive and nine of 13 (69%) sera from infections with echoviruses or coxsackieviruses A were positive. The nine sera that were positive from this group in the CBV5-IgM assay were the same nine as were positive in the CBV4-IgM assay. Two of the 18(11%) sera with an elevated CBV neutralization titre were positive in the CBV5-IgM assay. These two sera were also positive in the CBV4-IgM assay and had an elevated monotypic CBV4 neutralization titre. None of the sera giving positive results gave significant reactivity when tested with control antigen. Twelve rheumatoid factor containing sera and 46 sera from other infections were negative in both assays. Of 24 sera from confirmed CBV infection, seven gave a positive monotypic CBV4 or 5-IgM response, ten were positive in both assays and seven were negative in both assays. The positive results seen with sera from cases of heterologous enterovirus infection may result from an anamnestic IgM response or, more likely, IgM directed against enterovirus cross-reacting antigens. The absence of homologous neutralizing antibody at a dilution of 1:20 in nine of 20 sera that gave a positive CBV-IgM result and the presence of positive results for CBV4 and 5-IgM in a 14 month old infant who had echovirus 7 infection indicates that the IgM need not be directed against neutralizing antigens.

Thus the CBV4 and 5-IgM assays developed appeared to be specific for an enterovirus infection but because of the cross-reactivity were not type-specific or group-specific.

Some of the factors influencing the isolation rate of Bordetella pertussis during a whooping cough epidemic in West Glamorgan, Wales, are reported. The organism was isolated from 39% of patients with clinical whooping cough, pernasal swabbing being much more successful than cough plates. Isolation rates were increased in the non-immunized, particularly in the first year of life. Erythromycin and co-trimoxazole significantly reduced the isolation rate of B. pertussis but this did not occur with penicillin. In this study 20 % of patients were culture positive 6 weeks after the onset of their infection. It is suggested that the Department of Health and Social Security recommendation of a minimum period of three weeks exclusion of children from school is inadequate. During the epidemic, the proportion of strains of B. pertussis containing antigen 2 more than doubled.

An inhibitor ‘fingerprinting’ technique was used to test 120 group B and 50 group C streptococcus strains for production of inhibitory activity. The incidence of inhibitor production was low. Five of 70 group B streptococci of animal origin and one of 50 from human sources consistently produced inhibitory activity. Six of 20 animal strains and three of 30 human strains of group C streptococci were inhibitor producers. These included two Streptococcus dysgalactiae, three S. equisimilis and four S. zooepidemicus.

The temperature of incubation and species of origin of the blood used in the culture medium were critical determinants of inhibitor production. Investigation of inhibitors for their spectrum of activity, heat stability, sensitivity to trypsin, dialysability and mode of action indicated that five of the group B and seven of the group C streptococci produced inhibitors that had bacteriocin-line properties. Three bovine strains of group B streptococci produced very similar inhibitory activity. A greater variety of bacteriocin-like substances was detected in the group C streptococcus strains. Two of the S. zooepidemicus strains were each found to Produce more than one inhibitory substance.

Particular epidemiological features of Mycobacterium bovis infection in cattle herds in Great Britain during the period 1972–8 were examined. During these seven years 1099 herds became infected, the mean annual incidence of herd infection being of the order of one infected herd per 1000 cattle herds.

Infection in herds was predominantly a sporadic occurrence; 938 (85·4%) herds experienced only one incident of infection which persisted for less than 12 months. The concentration of infected herds in localized areas of the south-west region England, where infected badgers were the most significant attributed source infection, is demonstrated.

The risk of herd infection in relation to badger sett density was also examined in Cornwall, Gloucestershire/Avon and counties in England and Wales outside south-west region of England. The numbers of herds at risk in six categories badger sett density in these three areas were estimated from three random samples of herds drawn from the annual agricultural census. In Cornwall and Gloucestershire/Avon herd infection, associated with infected badgers or for which no source of infection could be found, was positively associated with badger sett density. A similar association between herd infection, not attributable to a source of infection, and badger sett density was found in counties in England and Wales outside the south-west region of England.

Groups of volunteers were immunized subcutaneously with one of three inacti vated influenza virus A/USSR/77 (HlNl) vaccine preparations; a whole virus vaccine, a surface-antigen subunit adsorbed vaccine, or an aqueous surface-antigen subunit vaccine. The reactions to immunization were recorded, and the antibody response was measured 1 month later. A fourth group of volunteers were inoculated intranasally with live attentuated A/USSR/77 (H1N1) influenza virus; the reactions and antibody response of these volunteers were also measured. One month after immunization, the incidence of infection by challenge with homologous live attentuated virus was determined for all groups of volunteers. The results showed that all four vaccines used were relatively non-reactogenic, and that inactivated vaccines induced higher titres of serum antibody than the live attenuated vaccine. All the vaccines induced significant protection against challenge virus infection which was directly related to the level of serum HI antibody response.

An investigation into the incidence of hydatid disease was carried out in the Hebridean islands of Lewis and Skye. The results showed that 20% of the sheep were infected and 10% of the dogs harboured Echinococcus granulosus. Sporadic human cases continue to occur but using serological tests we were unable to show evidence of subclinical infection in the population sampled.

The majority of Shigella flexneri strains isolated in England and Wales are from infections contracted abroad. Most of these strains are drug-resistant, over 75% being resistant to streptomycin and sulphonamides, sulphonamides alone or streptomycin, sulphonamides and tetracyclines. A selection of resistant strains was tested for resistance transfer and the plasmids identified were characterized by compatibility grouping.

Streptomycin and sulphonamide resistance was usually determined by a non-autotransferring plasmid which may be mobilized by standard transfer factors, or by the plasmid which conferred tetracycline resistance where this was present. The remaining resistant strains were predominantly resistant to four or more drugs. These strains carried autotransferring plasmids of a variety of compatibility groups, of which groups B, I1 and FII were the most common.

Groups of volunteers were immunized with one of three influenza virus vaccines, and the resistance to challenge infection with attenuated influenza A (H1N1) virus was measured 8 months later. The vaccines were aqueous subunit influenza A/USSR/77 (H1N1) vaccine, aqueous subunit influenza B/Hong Kong/73 vaccine, or attenuated influenza virus A (H1N1) vaccine. The B virus vaccine was included as a control to assess the incidence of natural A virus infection during the study period. A proportion of the B virus vaccinees had pre-existing A (H1N1) virus antibody and were used to study the immunity conferred by natural infection to the live virus challenge. The serum antibody responses were measured at 1 and 8 months after immunization. The results showed that all the vaccines induced serum HI antibody in a proportion of the volunteers; however, after 1 month, higher titres of serum antibody were found in volunteers given inactivated A vaccine than in those given live attenuated A virus vaccine. Eight months post-immunization the titres of serum antibody in volunteers given inactivated vaccine had declined significantly, but there were no changes in the antibody titres of those given live virus vaccine. The incidence of infection by the challenge virus at 8 months post-immunization was directly related to the serum antibody titres 1 month post-immunization; no evidence was obtained to suggest that those given live virus vaccine had a more solid immunity than those given inactivated vaccine.

Newborn calves were bled at monthly intervals and examined for serum antibodies to bluetongue virus (BTV). Maternal immunity persisted for 3 months and it was possible to calculate decay rates for virus neutralizing antibody. Calves were subclinically infected with BTV within a few months of becoming susceptible and neutralization tests were used to deduce the serotype responsible. A profile of virus activity was built up over a 12 month period. Frequent light trap catches were used to examine the population dynamics of suspected Culicoides vector species. Two species, imicola and schultzei were present throughout the wet and dry seasons and survival rates were sufficiently long to account for virus transmission at any time of the year.

A microagglutination method for determining the agglutinating and ‘blocking’ antibodies to Brucella abortus is described. A collection of sera from healthy blood donors in two rural areas of New Zealand were tested by the microagglutination methods and the standard methods in tube. The results are compared and show that where discrepancies occur, these are due to the microagglutination methods being more sensitive. It is concluded that these are suitable methods for screening populations.

Serological responses to three bivalent aqueous equine influenza vaccines of different potency and an adjuvanted bivalent vaccine containing inactivated A/equine/Prague/56 (H7N7) and A/equine/Miami/63 (H3N8) viruses, were examined in seronegative ponies. Potencies of the vaccines, measured by single-radial-diffusion tests, ranged from 4 to 56 μg of haemagglutinin (HA) antigen activity/virus strain per dose. Serological responses to vaccination were examined by haemagglutination-inhibition (HI) and single-radial-haemolysis (SRH) tests.

Four weeks after a primary dose, HI responses to both vaccine viruses were barely detectable; after a second dose the HI responses to A/Miami/63 virus were low or undetectable but HI responses to A/Prague/56 virus were higher (17/20 ponies with titres ≤ 1:16). In contrast SRH tests revealed dose-related antibody responses to both virus strains after one and two vaccine doses; levels after the second dose were 2- to 5-fold higher than after the primary dose. Highest post-vaccination antibody titres were obtained with the adjuvanted vaccine which contained 2- to 4-fold less antigen (13–23 μg HA) than the most potent aqueous vaccine. Post-vaccination antibody reacted well in SRH tests with recent antigenic variants of equine influenza virus. A remarkable finding was the high rate of decline in antibody, detected by HI or SRH tests, following one or two doses of vaccine. Even in animals with the highest post-vaccine antibody levels 2–4 weeks after a booster dose, antibody levels had declined to low or undectable levels 14 weeks later. The low antibody titres detected at 14–32 weeks after vaccination were nevertheless vaccine dose-related.

One hundred and thirty-one strains of Escherichia coli isolated from the cerebrospinal fluid of patients in the United Kingdom were tested for resistance to 13 antimicrobial drugs. Sixty-four strains (49%) were resistant to one or more drugs and 44 (34%) were resistant to three or more drugs. Resistance to ampicillin, sulphonamides, streptomycin and tetracycline occurred most frequently.

When a 1:5 mixture of trimethoprim (TMP) and sulphadiazine was fed to pigs intra-nasally infected with Bordetella bronchiseptica, 10 mg/kg/day was shown to be highly effective in suppressing the organism. This dose level had little effect on numbers of TMP-resistant coliforms in faeces, but oral doses of 30 mg/kg/day eventually selected a resistant population. It is suggested that the proliferation of resistant coliforms would be minimized by administration of the lowest oral dose rates of antibacterial drugs compatible with efficacy.

Well water was sampled from all four major wards in Katsina town. All 20 samples taken showed high coliform counts. Sixty-five per cent contained ≥ 2400 coliforms per 100 ml while the remainder had counts ranging from 79 to 920. Faecal coliforms and non-cholera vibrios were detected in all samples. There was no significant relationship between the coliform counts and the distances of latrines to wells, water table to ground level, slope relationship between wells and latrines, the pH of water and whether the wells were left permanently open or not. Salmonella sp., Enterobacter sp. and Pseudomonas sp. were each isolated from about 10% of the samples, while Proteus sp. was isolated from 40%, Citrobacter sp. 15%, Alcaligenes sp. 5% and an unidentified Gram-negative rod from 5%.

Only 2 (10%) of the sampled households, representing 23 (9·6%) of the 239 people exposed to well-water had pipeborne water in addition. It was concluded that well water in Katsina town could be a human health hazard.

Forty ponies immunized with inactivated virus vaccine containing A/equine/Miami/63 (H3N8) virus and six unvaccinated, seronegative ponies were experimentally challenged with a representative of recent equine H3N8 virus isolates, A/equine/Newmarket/79. All unvaccinated ponies became infected as judged by virus excretion, febrile responses and antibody responses, but only two of the vaccinated ponies were fully protected. Pre-challenge antibody levels to A/Newmarket/79 virus detected by single radial haemolysis (SRH) correlated well with the degree of clinical protection but the levels required for complete protection (SRH zones > 65 mm2) were high. The importance of these results in relation to conventional vaccination procedures against equine influenza is discussed.

Sera from 96 patients with Mycoplasma pneumoniae infection were examined for specific IgM antibody. The complement fixation test was used to measure the IgM after separation by ultracentrifugation through sucrose density gradients. Of patients under the age of 20 years 78 % displayed positive specific IgM titres. In older patients only 34% were IgM positive. The specific IgM remained detectable, but at decreasing levels, during the follow-up period of 5 months. This diagnostic technique appears to be of value in children and young adults experiencing primary infection with M. pneumoniae.

During the ten-year period 1971–80 isolates of meningococci from 85 cases of meningococcal disease (MD) in South Australia, from 66 children, 6 adolescents and 13 adults, were examined. These comprised 69 cases of meningitis and 16 cases of bacteraemia without meningitis. Thirty-three (39%) of all cases of MD occurred in children less than 1 year of age, the median age was 19 months. Serogroup B accounted for 61 (72%) cases of MD, group A seven (8%), group C seven (8%), group W135 five (6%), group Y three (4%) and group X one (1%); in addition there was a single case of Neisseria lactamica infection.

The annual prevalence of MD in South Australia for the period was 11 cases per 100000 for children under the age of 2 years and 0·7 cases per 100000 overall. The prevalence was highest in winter (45% cases) and spring (26%) and lowest in summer (13%). The overall mortality rate was 8%. Four of the 21 infants under the age of 6 months died (mortality rate 19 %) whereas none of the 32 children aged from 6 months to 14 years died (P = 0·02). Amongst the survivors, three children had deafness, which was bilateral and severe in two.