Nine monoclonal antibodies directed against the flagella of Campylobacter jejuni strain 81116 have been investigated for serotypic and cross-reacting activity using a panel of 17 Penner serotype strains of C. jejuni. Four monoclonal antibodies were exclusively specific for serotype-6 strains, which was the serotype of C. jejuni strain 81116. Two monoclonal antibodies cross-reacted with all the flagellated strains of C jejuni tested. One of these cross-reacting monoclonal antibodies, CF5, was found to react with all other Campylobacter species except C. sputorum bulbulus but it did not react with other bacterial entcropathogens. An antigencapture ELISA technique was established, using this monoclonal antibody, which could detect flagellar antigen in human faecal material. These anti-flagella monoclonal antibodies therefore may be valuable in the diagnosis and serotyping of C. jejuni in clinical material.

A cross-sectional study of 447 laying hens (age range 0–65 weeks) and a longitudinal study of 164 similar birds showed that Campylobacter jejuni was not present in the faeces of newly hatched chicks, but that colonization arose after 5–9 weeks. A survey of 250 broilers obtained from four breeders showed that all were negative for C. jejuni before and after slaughter at the age of 5 weeks. Once C. jejuni had appeared in a flock, it rapidly spread to virtually all birds, but at the age of 42 weeks only 20–46% of birds remained colonized, possibly as a result of having developed immunity. Birds housed in the protective environment of a laboratory still became colonized (after 9 weeks). The mode of infection is unknown, but water and food were bacteriologically negative and were deemed to be unlikely sources. Transmission via attendants, flies or other insects remain possibilities. It is concluded that prevention of colonization might be possible within the life-span of broiler chickens (5–7 weeks), but that it would be difficult to extend this period. There is a need to define how colonization arises so that the feasibility and cost of possible preventive measures can be assessed.

This report presents the parasitological, bacteriological, mycological and physicochemical data obtained from both surface water and beach sand of a lake used for water sports. These show that the lake is contaminated in both winter and spring by water which overflows from the River Maine, and is self-purified by a mechanism of ‘lagunage’. In summer signs of pollution are at their lowest level although use of the complex is at its peak. Conversely, the amoebic flora, which is independent of the usual criteria of pollution, predominates in summer, and serves as a marker for the need for increased surveillance. The sand of the beaches does not appear to show any infectious hazard. Environmental pressure will doubtless change these data over a period of time, and it is planned to monitor this.

The brucellin skin test and the lymphocyte transformation test were compared in heifers infected with virulent Brucella abortus strain 544, heifers vaccinated against brucellosis and unexposed cattle. Results of the in vitro lymphocyte transformation test were consistently positive for all 9 Brucella-infected heifers while the skin test was consistently positive for 6 of the 9 heifers. In 7 heifers repeatedly vaccinated with B. abortus strain-19 vaccine the in vitro test classified 3 animals as positive whereas the skin test identified all the animals as infected during most of the experimental period. Four heifers injected with a single dose of B. abortus strain 19 were consistently negative to the lymphocyte transformation test while the skin test classified all the animals as infected during most of the experimental period. The skin test gave strong reactions indicative of Brucella infection in heifers vaccinated with ‘Duphavac’ and ‘Abortox’ vaccines whereas the lymphocyte transformation test was consistently negative with these vaccines. The two tests were negative in unexposed cattle. It was concluded that the in vitro test correlated better with Brucella isolation than the in vivo test did and that the lack of agreement between the results of the two tests is likely to be due to the different antigens used in the assays.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG antibodies to diphtheria toxin in human serum. Serum samples obtained from 557 normal persons aged 1–65 years from different areas in New Zealand showed maximum antibody levels in the 1–9 years age group (95·1%) and the least in the 60–65 years age group (38·1%). The indirect ELISA is suitable for sero-epidemiological survey study as it is simple to perform, economical and precise.

Five hundred strains of methicillin-resistant Staphylococcus aureus were tested against various anti-staphylococcal agents. Vancomycin, fusidic acid and fosfomycin were found to be the most effective. Only 1 strain out of 500 was resistant to fosfomycin. Three patients with methicillin-resistant Staphylococcus aureus septicaemia were successfully treated by fosfomycin. We conclude that fosfomycin could be the drug of choice for methicillin-resistant Staphylococcus aureus infection.

The relative efficiencies of three commercially available dehydrated Rappaport–Vassiliadis media have been compared with a similar medium prepared from individual constituents in our own laboratory. An inoculation ratio of 1 : 100 was found to be optimal for each of the media tested. Laboratory produced RV-medium was significantly better than the three commercial preparations after 24 h incubation. However, when the duration of incubation was extended to 48 h, there was no significant difference in the number of salmonella isolates obtained when using our own RV medium and that produced by Oxoid Ltd and Difco Ltd (P > 0·05). All of these three media were, however, significantly more effective than the medium produced by Lab.M.(P <0·01).

DNA restriction endonuclease analysis was used for intra-specific typing of Mycobacterium bovis isolates from 83 brush-tailed possums (Trichosurus vulpecula) obtained between 1982 and 1984 from the three major regions in New Zealand with endemic bovine tuberculosis. All the isolates were found to be genetically very similar. Differentiation of the isolates into 33 restriction types was achieved by using high-resolution electrophoresis and the combined results from separate digestions with the restriction enzymes Bst EII, Pvu II and Bcl I. The typing system was entirely reproducible. Isolates of the same type were usually found in adjacent localities and were always limited to one of the three major regions. In some cases, isolates of the same type were found in both 1982 and 1984. The phenotypic significance of the small genetic differences identified between different isolates is unknown. The typing system will be useful for monitoring the transmission of M. bovis to other species and the future spread of different M. bovis types through possum populations.

Young adult mice were inoculated intravenously with strains JB or Peter C of Mycoplasma pulmonis. A few were inoculated intranasally with strain JB. This strain but not Peter C was isolated for 50 days or more from the urines of more than half of the mice. Those of strains TO, C3H and CBA, but not CFLP, were susceptible. Recovery of mycoplasmas was intermittent and sometimes the numbers isolated varied within individual mice and between mice of a particular strain, ranging from 5 × 101 to <5 × 107 colour-changing units/ml. Fifty serial passes of M. pulmonis, strain JB, in mycoplasmal medium resulted in attenuation, the organisms after inoculation of TO mice not being recovered from the urine and excretion not being stimulated by treating the mice with progesterone. At autopsy, the organisms of early passage were usually but not invariably isolated from the kidneys of mice that had been urinary excretors. About half of the latter had no renal histopathological changes. The others had usually minimal renal perivascular lymphocytic infiltrates but occasionally more widespread inflammatory changes. The findings may have relevance to the spread of mycoplasmal infection within mouse colonies and suggest that an association between such infection and nephritis in other species, including man, should be sought more closely.

A total of 6593 serum samples from birds, received for diagnostic testing or surveys between 1974 and 1983, were titrated by direct complement fixation (CF) test against Chlamydia psittaciantigen. The percentage of positive reactions found was variable for domestic poultry, ranging from 1·5 in chickens to 22·2 in geese, and was highest in pigeons Columba livia (47·3) and collared doves Streptopelia decaocto (51·4). A moderate incidence was found for game birds (29·0), wild ducks (23·3) and imported birds of the order Psittaciformes (15·9). The highest titres were found in pigeons, collared doves and psittacines, confirming that infection is both frequent and active in these birds in Britain. Results of isolation of chlamydia from similar sources will be reported subsequently.

A total of 1531 diagnostic submissions from birds were examined by culture for the presence of Chlamydia psittaci between June 1976 and December 1984 by growth in NCTC 929 clone L mouse fibroblast cells, pretreated with an inhibitor of cell division, followed by direct immunofluorescence microscopy. Of these, 196 were found positive. The continued importance of psittacine birds as potential sources of infection was shown by the high number of positives (139) obtained from birds of that order. The percentage of submissions found positive was highest in parakeets (30·1) and was fairly high in psittacines as a group (16·6), but the latter figure was exceeded by the group ofcollared doves (Streptopelia decaocto) and wood pigeons (Columba palumbus) (25·0). Domestic poultry generally gave low rates, turkeys being the highest.

Both the numbers of submissions and their rates of positives increased between 1980 and 1984.

Comparing the isolation rates from the various organs sampled, the intestines gave the highest rate (20·4 per cent positive), closely followed by the other internal sites. The superficial swabbed sites (eye, nasal cavity, cloaca) gave lower rates.

The eradication of smallpox was achieved by surveillance and containment vaccination after the failure of mass immunization campaigns. The reasons for this failure are considered in this paper. Comparison of population densities in the Indian subcontinent and Africa show that in highly populated areas even an 80% vaccine coverage will still leave a density of susceptibles high enough to maintain the disease, a finding with important implications for other vaccine campaigns.

The anticoagulant rodenticide flocoumafen was tested against warfarin-resistant Norway rats (Rattus norvegicus Berk.) infesting farm buildings. Complete control was obtained in 10–21 days (mean 14·2 days) in six treatments in which baits poisoned with 0·005% flocoumafen were maintained, in surplus, until rats ceased to feed from them. A further six treatments, in which the application of poisoned bait was restricted to periodic placements of 50 g, were also completely successful in 15–30 days (mean 21·0 days). Less poisoned bait was used in the restricted flocoumafen treatments than in the unrestricted treatments but the time taken to control the rat infestations was significantly longer.

The anticoagulant rodenticide flocoumafen was evaluated against Rattus rattus and Bandicota bengalensis, In no-choice 24 h feeding tests 100% mortality occurred at 0·00125% concentration of the poison in the bait in the case of B. bengalensis and at 0·00375% in R. rattus. Feeding of 0·0025% poison bait in 1-day, no-choice and 2-day choice tests resulted in 60% and 75% mortality of R. rattus, respectively, and 100% of B. bengalensis. The differences between the consumption of plain food in the pretreatment period and of poison bait in no-choice tests were non-significant, except in one case. The rodents consumed significantly more (P < 0·01) poison bait than the plain alternative in the choice trials. Median period of survival and its 95% confidence limits of R. rattus and B. bengalensis, at the 100% mortality dose levels of the poison, were 6·3 (5·04–7·88) and 6·2 (4·92–7·81) days respectively.

In order to study the serological status of the Northern Greek population to poliovirus, 881 sera from healthy people were examined for neutralizing antibody by the micrometabolic inhibition test. The people under examination were aged from 1 day to 70 years old. Overall, of the 881 sera examined, 704 (80%) had antibodies (titre ≥ 4) to poliovirus 1, 742 (84%) had antibodies to poliovirus 2 and 715 (81%) had antibodies to poliovirus 3. Fifty-five per cent of the sera had antibodies to all three polioviruses while 3·3% had no poliovirus antibody at all. There was no statistically significant difference in the rates of seropositivity to the various poliovirus types or between males and females. However the rates of seropositivity did vary with age.

Neutralizing antibody responses to conventional rabies post-exposure regimens of human diploid cell strain vaccine (HDCSV) and the new purified Vero cell rabies vaccine (PVRV) were compared in 58 healthy Thai veterinary students. The geometric mean titres (GMTs) of the group given HDCSV were slightly higher than those given PVRV, but on day 28 the peak GMTs of the two groups were statistically similar. The early antibody response to PVRV was unaffected by the addition of passive immunization, whereas the level of HDCSV response was reduced on day 14, so that there was no difference on that day between the GMTs of the two vaccine groups given HRIG. However, by day 91 the GMT of those given PVRV and HRIG was lower than in those given HDCSV alone or with HRIG. The appearance of antibody was less rapid than was observed in previous studies using multiple-site intradermal vaccination. Side effects were trivial. Our results confirm the promise of this new, potentially more economical tissue culture vaccine, but they suggest that the regimen could be improved.

Four thousand and one hospital staff were screened for hepatitis B virus (HBV) markers in a vaccination programme in Hong Kong. The seropositivity rate for HBsAg, anti-HBs and anti-HBc were significantly higher in the 3160 existing hospital staff than in 841 new recruits. Of the subjects negative for HBV markers, 605 were randomized to receive three doses of either 10 or 20 μg of the Merck Institute vaccine (HB-VAX). Compared with the 20 μg dose, vaccination with the 10 μg dose results in equal immunogenicity and efficacy at the completion of the three injections but induced a slower response rate and lower anti-HBs titres with the first two doses. The commonest side-effect of local soreness was less with the 10 μg dose. We conclude that (1) hospital staff working in high endemic areas should be vaccinated on recruitment and (2) the 10 μg dose of HB-VAX can replace the recommended 20 μg dose for adults, being cheaper and as efficacious.

Four groups of sows were inoculated, either once or twice, with O1BFS 1860 foot and mouth disease oil-emulsion vaccine during pregnancy and samples of serum. for analysis, were collected at intervals for > 300 days.

The pregnant sows responded well to vaccination regardless of their state of gestation. Single vaccination produced protective levels of antibody (> 1·53 log10SN50) in 3 out of 4 sows while double vaccination produced protective levels in all 6 sows tested. Anti-FMD IgM antibodies could be detected for 40–60 days after vaccination or revaccination. Anti-FMD IgG antibodies appeared within 10 days of vaccination and persisted, in each sow, for the duration of the study. The anti-FMD IgA response observed was less easy to characterize due to significant animal to animal variation. Although there was no evidence of a fall in the neutralizing antibody titres over one year post vaccination the anti-FMD IgG antibody population did show signs of a change in its heterogenity and avidity.

Fifty volunteers, treated with an inactivated trivalent influenza vaccine containing A/Bangkok/1/79 (H3N2), A/Brazil/11/78 (H1N1) and B/Singapore/222/79 virus, were subdivided according to the estimated first exposure to influenza in their lifetime (priming) and the presence of antibodies against the vaccine components in the pre-vaccination sera. The isotypic antibody response (IgG, IgA, IgM) was determined by means of an antibody capture haemadsorption immunosorbent technique. For all three vaccine components, previously seropositive subjects produced antibodies of the IgG- and IgA-class more frequently than previously seronegative persons. Subjects primed to one of the influenza A subtypes showed more IgG and IgA responses in comparison with those unprimed (prime-effect). In contrast, IgM antibodies occurred in only 19 and 11% of primed, but in 59 and 54% of unprimed subjects, for A (H3N2) and A (HlNl), respectively. The incidence of IgM titre rises was not influenced by the prevaccination state. However, the mean magnitude of anti-A(H1N1)-IgM titre rises was greater in those previously seronegative. The concepts of primary and reinfection and of ‘original antigenic sin’ are discussed, and it is suggested that age and, if possible, serological state prior to antigen-exposure should be taken into account when studying isotypic antibody responses after influenza infection or vaccination.

Enzyme immunoassays (ELISA) have been developed for the detection of BK virus IgG- and IgM-antibodies. Specific IgG is detected by an antigen-coated solid phase test; IgM by an antibody capture method.

These methods have been used to study the age-distribution of BK virus antibodies in Troms county in Northern Norway. The serum panels tested were: (a) 60 sera from paediatric patients aged 0–1 year; (b) 220 sera from healthy persons aged 1–82 years; (c) 74 sera from healthy blood donors; (d) 107 sera from healthy pregnant women.

The age-distribution of BKV-IgG antibodies showed that primary infections took place predominantly between the ages of 1 and 6 years, and that there were no sex differences, either in the age-specific prevalence or in the level of BKV-IgG.

We found no significant differences in the prevalence of BKV-IgM antibodies in healthy children and adults and pregnant women. BKV-IgM was detected in 26 of the 461 sera tested (5·6%).