A food-poisoning outbreak caused by Bacillus cereus occurred in a Finnish industrial plant in January 1975. Eighteen of the 36 persons who ate a lunch including boiled rice, meat and vegetables became ill. The disease pattern was similar to previously reported short incubation time B. cereus food-poisonings associated with cooked rice. The median incubation time was two hours, the main symptoms being nausea, abdominal pain and vomiting. Rice and certain seasonings were the contaminated raw materials. Gas chromatographic fatty acid analysis of a bacterial cell was used as a diagnostic method as well as to identify a certain strain of B. cereus.

The sheep and goat pox viruses isolated in Kenya are not host specific as in the Middle East and India. The virus strains from one species are of a similar patho-genicity for the other, and the same virus appears to occur in field outbreaks in mixed flocks. A silent infection with no skin lesions occurs in the field outbreaks.

The virus grows well in lamb testis cell cultures, it does not haemadsorb nor haemagglutinate and is ether sensitive. Most strains could not readily be adapted to grow on the chorioallantoic membrane of embryonated eggs; one isolation only was made in this way. Staining of the virus inclusions showed that they were of DNA; the virus resembled that of lumpy skin disease in many characteristics.

It was possible to cross-protect both species with virus of sheep or goat origin. A vaccine was made from tissue culture virus adsorped onto aluminium hydroxide gel and treated with formalin.

A mobile laminar cross-flow unit for surgery has been evaluated by the use of an experimental bacterial aerosol of Escherichia coli in different concentrations, generated at several different sites. A separate ventilation system, mounted underneath the table, produced an almost downward directed curtain of sterile air along both sides of the table. When the velocity of the air stream, discharged by the cross-flow unit, was adjusted at 0·50 m./sec. at 2 m. from the filter face (at the head end of the operation table), the surface of the table could be maintained free of bacterial settling, even after aerosolization of heavily concentrated suspensions of 108 bacteria/ml. at different sites outside the enclosure and underneath the table as well.

The bactericidal activity of RBA 777 has been found to vary with both the cultural and environmental test conditions against Pseudomonas aeruginosa and to a lesser extent against Staphylococcus aureus. These variations may explain certain anomalies in earlier work regarding the activity of chloroxylenol-based products. The addition of EDTA to RBA 777 has brought about an improvement in the performance against P. aeruginosa and this activity is confirmed in vivo. Previous reports have already illustrated this potential and the evaluations of the new antibacterial agent DA 136 confirms and extends these results to its performance under adverse conditions, often associated with the hospital environment.

Extracts of 3 soya bean preparations, used commercially in certain countries to replace part of the meat in popular meat products, were made by treatment with (i) sodium dodecyl sulphate, (ii) Triton-X100 or (iii) n–Butanol. Similar extracts were made from beef and pork.

All extracts were examined by electrophoretic and immunological techniques. Stained polyacrylamide gels revealed distinctive protein bands after electrophoresis. The migration rates of corresponding bands differed between beef and pork extracts. However, the migration rates of vegetable bands revealed certain similarities, but differed very greatly from those of animal origin. Characteristic fast-migrating S-bands were distinguishable only in extracts of vegetable protein. Immunodiffusion tests, using antisera produced in rabbits against each extract, revealed varying degrees of similarity between extracts of vegetable origin, but the antisera were specific for either vegetable or animal protein.

The spread of a 'cream' mutant in a wild population of house mice is reported. The hypothesis that the gene responsible for the colour, extreme chinchilla, ce, has spread because of linkage with a major gene for warfarin-resistance, is tested by a linkage backcross.

The results prove that a major gene does exist, that it is very closely linked with frizzy, fr, in chromosome 7, which in turn is linked with ce, that it is fully dominant in females at 4 months of age, and that its partial dominance in males is under the control of modifiers.

The symbol War is proposed for the gene. Its position in chromosome 7 is analagous with the position of the resistant gene, Rw2, in the rat in the analagous chromosome.

The adaptive significance of this finding is discussed, as also are reports of certain other mutants in wild populations of mice.

An area of the laboratory bench on which slide agglutinations were performed in the diagnosis of salmonella and shigella infection was examined for these organisms. Impression plates and broth-moistened swabs were used for sampling. Both techniques gave satisfactory results, but the contact plates provided positive results a day earlier than the swabs. Suitable precautions to minimize contamination of the bench surface are discussed.

A survey of the bacterial flora present at various positions in 130 male and female washrooms and toilets is reported. Several bacteria of faecal origin were found in large numbers: the areas likely to be the most important sources of cross-infection from faecal contamination are indicated. The results are used to assess priorities for disinfection.

A survey was conducted in seven hospitals to assess the risk of cross-infection with the highly infectious air-borne diseases, varicella-zoster and measles, in isolation wards of different design. Existing wards and isolation techniques were found to afford a high degree of protection, but there was considerable variation in the incidence of cross-infection related to ward structure, ward practice and the availability of trained staff. Recommendations are made for the design of new isolation wards and for safe practice.

In the present study rubella HI antibodies were determined in cases of congenital malformation and bad obstetric history to determine the role of rubella in such cases in India, as it has been reported to be rare in Japan in contrast to Western countries. The incidence of antibodies was statistically significant in cases of congenital eye, c.n.s., visceral and miscellaneous malformations and cases of spontaneous abortion and still-birth compared with controls of matching age groups. This is further supported by the demonstration of IgM antibodies in seven cases of congenital malformations and ten cases of spontaneous abortion. Our findings show that congenital rubella is not rare in India.

This work is concerned with the cleaning and disinfection by heat of stainless-steel and polypropylene bedpans, which had been soiled with either a biological contaminant, human serum albumin (HSA) labelled with technetium-99m 99m(Tc), or a bacteriological contaminant, streptococcus faecalis mixed with Tc-labelled HSA. Results of cleaning and disinfection achieved with a Test Machine and those achieved by procedures adopted in eight different wards of a general hospital are reported. Bedpan washers installed in wards were found to be less efficient than the Test Machine, at least partly because of inadequate maintenance. Stainless-steel and polypropylene bedpans gave essentially the same results.

This paper gives an abbreviated account of part of a research programme which followed the Aberdeen typhoid outbreak of 1964. Chloramphenicol, the main antibiotic used in treatment, was shown to have a minimum inhibitory concentration (MIC) of between 5 and 2.5 μg./ml. for the S. typhi phage type 34 of the outbreak. The MIC for methacycline was between 2.5 and 2 μg./ml. Whereas the deep and shallow broth techniques used gave similar results with these antibiotics, the MIC for ampicillin, and also cephaloridine, was less in the deep than in the shallow broths.

Serum assays in patients given ampicillin or cephaloridine yielded abnormally high concentrations of both antibiotics when S. typhi phage type 34 was the test organism whereas, with other test organisms, the concentrations were within expectation. These abnormally high values fell within expected values when the sera under investigation had first been heated to 56° C. for 30 min. before assay against the S. typhi of the outbreak.

The findings with ampicillin suggested that dosages given were satisfactory. With cephaloridine the concentrations found in patients' sera seemed to show that twice daily doses of 0.5 g. fell short of adequacy.

Experiments were carried out to assess the reduction rate of two salmonella strains (S. eastbourne and S. typhimurium) in chocolate bars. After artificial contamination of chocolate, after ‘conching’, with about 106S. eastbourne/g. this organism was still recovered after 9 months storage. The strain of S. typhimurium was less resistant. Both serotypes died off more rapidly in bitter chocolate than in milk chocolate.

After contamination with a smaller dose (about 103/g.) with these two serotypes, similar differences were observed.

The report investigates the variation in results noticed when testing iodophor disinfectants in the presence of a 5% (w/v) yeast suspension.

It was found that these variations were not related to individual iodophor formulations but bore a direct relationship with the storage time of the prepared yeast suspension.

A range of new Tubercul ns prepared from extracts of living organisms belonging to 12 mycobacterial species has been used to assess the effect of BCG immunization and contact with environmental mycobacteria on Ugandan adults. A total of 2,456 tests were carried out on 562 people, 86% of whom came from three areas selected for special study. These areas were chosen on the basis of occurrence of leprosy and M. ulcerans infection and on data concerning the distribution of environmental mycobacteria. It was found that the effect of BCG was small compared with that previously observed amongst Kenyan schoolchildren, but that the effect of geographical origin was considerable. There was some correlation between the percentages of reactivity to the reagents and the frequency of mycobacteria in the environment.

As part of the bacteriological quality control programme of the Public Health Laboratory Service, we were asked to investigate the possibility of providing simulated water samples for distribution to the laboratories. For this purpose it was necessary to find some means whereby suspensions of coliform organisms and Escherichia coli could be kept relatively stable in number at room temperature for a period of 7–10 days. This, it was finally found, was best achieved by adding selected strains of the organisms to improved formate lactose glutamate medium (Gray, 1964) without the lactose but with added boric acid to a final concentration of 1·8%.

The procedures adopted in the successful quality control programme are described.

An account is given of some human diseases which affect one sex more than the other.

An age–sex relationship has been noted among British patients with acquired toxoplasmic lymphadenopathy. This is compared with the findings of other European workers.

A possible explanation is offered taking all these diseases into consideration together with some of the experimental work done in animals and some of the variations in immunological responses by man.

A plastic, mechanically ventilated source isolator with filters in the air effluent was designed to enable infected patients to be nursed and treated in a general ward or to be transported without risk to staff or other contacts.

Two models of isolator were developed. Their potential value was tested by the challenge of heavy dispersal, inside the isolator, of bacteria (a) from patients with burns, during the change of dressings, (b) from contaminated bedding during simulated bed-making, and (c) from the dispersal of a suspension of Bacillus subtilis var. globigii.

Sampling of air by slit samplers outside the isolator and, in comparable control patients, from the air of the room in which dressings were changed, showed consistently lower counts of bacteria and of Staph. aureus during dressings when the isolator was used; on removal of the isolator canopy there was, in some experiments, a considerable increase in airborne bacteria, due to residual bacteria in the isolator or to the re-dispersal of bacteria which settled on the patient and his bedding during the dressing.

Simultaneous sampling with slit samplers inside and outside the isolator during and after bed-making or dispersal of B. subtilis var. globigii showed an almost complete protection of the air outside the isolator against contamination by bacteria released inside the isolator.

A seroepidemiological survey of a sample – roughly representative by age and sex – of 2744 persons of the Greater Athens area revealed that hepatitis B virus (HBV) infections are highly endemic in Greece. Hepatitis B surface antigen (HBsAg) was detected in 72 (2·6 %) of them. The subtype was identified in 70 of the 72 carriers, and 69 were ay; the other was ad. Determinant w was present in all 61 that were capable of being typed further, and a23y(w) was twice as common as a11y(w). Antibody to HBsAg (anti-HBs) was found in 514 (18·7%) persons. The prevalence of the HBsAg rose rapidly with age, reaching peak values (5·3%) at 20–29 years, while anti-HBs reached its highest value (42·1%) in older age groups (50–59 years). The frequency of HBsAg was significantly higher in males (3·4%) than in females (1·5%). The percentage of infected persons who become chronic HBsAg carriers (12·3%) was found higher than in other developed populations. It was also found higher in children (25%) than in adults (5·5%) and in males (14·6%) than in females (8·1%). These data indicate that HBV infection in early life is a major risk factor in the development of HBsAg carriers and support the hypothesis that males are more likely to become HBsAg carriers than females.

The effect of operating clothing on the dispersal of bacterial particles from the wearers was studied in a dispersal chamber. A comparison was made of six gowns as well as four types of trousers. The gowns were of three basic types, namely a conventional cotton type, disposable types made of non-woven fabric and those of the total-body exhaust system (Charnley type). The dispersal chamber could simulate conditions as expected both in down-flow unidirectional ultra-clean systems and in a conventional turbulent plenum-ventilated system. It was found that the disposable gowns would reduce the dispersal rate by about 30% in the simulated conventionally ventilated system and about 65% in the laminar flow system. The total-body exhaust system (Charnley) would reduce the count by 10-fold in the conventional ventilated system and by 66-fold in the laminar-flow system.

The poor performance of the gowns in conventionally ventilated systems was caused by the dispersal of bacterial particles from underneath the gown (about 80%). This was not reduced by the disposable gown and only partially by the Charnley type. This small drop would be further decreased in a conventionally ventilated operating-room as only scrubbed staff would wear the gown. In order to overcome this poor performance in conventionally ventilated operating-rooms impervious trousers would be required. Four types were studied and it was demonstrated that those made either from Ventile or non-woven fabric would reduce the bacterial dispersion fourfold.

As these tests had been carried out in an artificial environment checks were carried out in the unidirectional-flow operating-room during total-hip arthroplasty. This was done by comparing conventional cotton gowns with non-woven gowns and total-body exhaust gowns. The results showed good correlation between the operating room and the chamber with the non-woven fabric gown but the total-body exhaust system did not perform as well in the operating room (12-fold compared to 66-fold) the difference being possibly due to the contribution from the patient. However, as this comparison was that which would be most open to influence from other variables confidence could be placed on the chamber test results.

Values were also obtained for the total number of bacterial particles dispersed by persons during a standard exercise wearing different clothing. This count was dependent on the clothing worn but a median count of between 1000 and 1500 peatorial particlos/min. would be expected when conventional clothing was worn, with a range of between 300 and 19,000. This count could be reduced to about 100/min. if a total-body exhaust suit was worn (range 30–400).