The effects of a commercial trichlorocarbanilide-containing deodorant soap and a commercial plain soap upon the cutaneous flora of individuals were compared. Using a cross-over design, 21 volunteers (10 women and 11 men) washed their forearms at least once a day with one soap for 3 weeks and then switched soaps for another 4 weeks use. By analysis of variance no significant difference in total colony counts was noted among individuals in their use of the two soaps. With the exception of individual variation, neither sequence of use, sex, nor any combination was influential. However, in 20 of 21 subjects an alteration in the composition of skin flora was observed. The deodorant soap, which in six cases increased total flora, tended to reduce or eliminate diphtheroids in 12 of 17 carriers (71%). Fewer kinds of bacteria were also noted. More Staphylococcus epidermidis was seen with the plain soap, but washing with the deodorant soap seemed to favour Acinetobacter calcoaceticus and Micrococcus luteus. The impact of this alteration and the use of total counts to measure effectiveness of deodorant soaps were brought into question.

Cold water (10° C) at ultra-high pressure (38·5–49 kg/cm2) was compared with (a) hot water (65·6–82·2° C) at low pressure (4·2–5·6 kg/cm2) and (b) hot water containing a detergent (2% (w/v) sodium silicate). Seven sites were examined in a beef abattoir and six in a bacon factory.

Three surfaces in the beef abattoir had lower residual colony counts (higher reductions) after hot water/low pressure than after cold water/high pressure. However, the differences were not significant (P > 0·05). The range of the mean log10 count/cm2 before cleaning was 4·02–5·15, and after cleaning 1·73–2·32 (hot water) and 1·9–2·85 (cold water).

On three of the remaining sites, the three methods were compared. The total differences between treatments were not significant (P > 0.05), although there was an effect of surface and an interaction between surface and treatment. The cold water produced lower residual counts on three sites in the bacon factory than the hot water (45–54°C). However, the differences were not significant on the remaining surfaces.

The patient is identified as being of prime importance for comfort standards in hospital ward areas, other ward users being expected to adjust their dress to suit the conditions necessary for patient comfort. A study to identify the optimum steady state conditions for patient comfort is then described.

Although this study raises some doubts as to the applicability of the standard thermal comfort assessment techniques to ward areas, it is felt that its results give a good indication of the steady-state conditions preferred by the patients. These were an air temperature of between 21.5° and 22° C and a relative humidity of between 30% and 70%, where the air velocity was less than 0.1 m/s and the mean radiant temperature was close to air temperature.

The decline of maternal antibodies to the fraction I antigen of Yersinia pestis was investigated in newly weaned Rattus norvegicus obtained from dams vaccinated with strain EV76(51f) of Y. pestis. IHA titre decreased by 50% each 7.3 days and CF titre declined 50% each 10.0 days in young rats. An analysis of available data indicated that maternal IHA and CF antibodies could persist to 3 months of age. Therefore, positive serologic reactions in young R. norvegicus, detected in the course of serological surveys, could be the result either of active immunization after exposure to the plague bacillus or of transient passive immunization (i.e. maternal antibody).

Mud samples collected in June 1975 from the lakes, marshes and waterways of the Camargue were examined for Clostridium botulinum. The Grand Rhône and Petit Rhone were shown to contain types B and E, but of 44 samples taken from well distributed sites on the Ile de la Carmargue, only two (4·5%) were positive and these contained type E alone. The survey indicated a much lower prevalence of Cl. botulinum than any encountered in recent surveys of inland aquatic environments elsewhere.

In 1975, 25 soil samples were collected from the London area. Of these, 20 were obtained 200–300 yards from 20 lakes that had been shown in 1974 to contain mud contaminated with one or more of types B, C, D and E of Clostridium botulinum. By means of a technique comparable with that used for the examination of mud, the 20 soil samples were found negative. The remaining 5 soil samples, obtained from sites that were not in close proximity to lakes, were also negative except for one that contained type B.

Of a total of 23,609 incidents of salmonella infection reported during the period 1968–74, 20,326 occurred in cattle, 1744 in poultry and other birds, 675 in sheep, 558 in pigs and 306 in other species of animals.

Despite the large number of serotypes isolated (153), 88% of incidents were due to only two serotypes: S. dublin (15,929 incidents of which 15,446 occurred in cattle) and S. typhimurium (4842 incidents of which 3785 occurred in cattle and 732 in birds).

S. choleraesuis was the third (314 incidents which with only 5 exceptions occurred in pigs) and S. abortusovis (243 incidents all in sheep) was the fourth most commonly isolated serotype. The following six serotypes were each recorded in more than 100 incidents: S. newport (177), S. agona (170), S. virchow (169), S. anatum (152), S. enteritidis (150) and S. montevideo (111). The other 143 serotypes accounted for only 5·8% of total incidents.

The trends of annual incidence of salmonella infection in cattle, sheep, pigs, poultry and other birds during the 17-year period 1958–74 and the distribution of the main serotypes in the individual species of animals from 1968 to 1974 are discussed.

Antibody to hepatitis B surface antigen was detected by radioimmunoprecipitation in 74 (5·5%) of 1336 staff members in a large general hospital in Edinburgh, in 14 (2·9%) of 480 volunteer blood donors in the area, and in 12 (6·1%) of 197 pregnant women attending for the first time at the ante-natal clinic in the hospital. Rates of antibody prevalence rose with age in the sample of hospital staff and in that of the blood donors, particularly among males. On the other hand, in the ante-natal patients antibody prevalence declined with age.

The rates in hospital staff were higher than those in blood donors of comparable age and sex, and high titres of antibody were more common in the staff group. However, no association was found between antibody prevalence and a history of clinical hepatitis, blood transfusion, or recognized contact with cases of hepatitis. Staff who had previously worked in an infectious disease hospital did not show increased antibody prevalence, indicating that simple isolation measures have been adequate to minimize exposure to hepatitis B.

No particular prevalence of infection was seen in physicians and surgeons, in the nursing staff, or in workers in clinical diagnostic laboratories, hospital administration or other areas. One group clearly showing increased antibody prevalence was staff currently working, or who had worked, in the Haemodialysis Unit; this correlated with the outbreak of dialysis-associated hepatitis in 1969–70. However, no evidence suggested that significant dissemination of infection had occurred to other defined groups of hospital staff. Elevated rates were also observed in a small sample of kitchen and portering staff, and in obstetric medical and nursing staff; the latter observations indicate a need for further investigation to identify unsuspected exposure to hepatitis B virus.

A provisional serotyping scheme was used to type cultures of Bacillus cereus from 84 outbreaks of food poisoning in seven countries; 283 of the 337 (84%) cultures tested were typable.

In 35 of the 61 outbreaks associated with a vomiting-type syndrome, foods, clinical specimens or both yielded H-serotype 1 only. Type 1 strains together with other serotypes were isolated in seven outbreaks. In 14 outbreaks types 3, 4, 5, 8 or a mixture of serotypes were present. Untypable strains were isolated in five outbreaks.

Two of the nine diarrhoeal-type outbreaks yielded serotype 1 only. Types 2, 6, 8, 9, 10 and a mixture of type 12 and an untypable strain appeared to be responsible for one outbreak each.

Although 16 of the 18 recognized serotypes were present among cultures of B. cereus from various routine foods, only 156 of the 400 (39%) isolates tested were typable.

Three South-Asian rodent pest species were tested for susceptibility to anticoagulant rodenticides. Wheat flour containing 0·025% warfarin, 0·0375% coumatetralyl or 0·005% difenacoum was fed to 260 Tatera indica, 140 Nesokia indica and 81 Bandicota bengalensis for 1–56 days. Tatera was about as susceptible to anticoagulants as Rattus rattus has been reported to be. Nesokia and Bandicota were extremely variable: though the majority were highly susceptible, the slopes of the dose-mortality curves were close to zero. The difenacoum diet appeared to be more toxic than the warfarin diet to all three species, but less toxic than the coumatetralyl diet to Tatera and Nesokia. All of the anticoagulants were eventually lethal to all of the animals tested.

Human milk has a bacteriostatic effect on Escherichia coli in vitro. The milks of 40 mothers were tested for this effect against E. coli isolated from their stools, from those of their own babies, and from those of babies not breast-fed. The milks had a direct bacteriostatic effect, not dependent on complement, on some but not all the strains of E. coli. Breast-fed babies receiving supplementary bottle feeds were colonized with milk-resistant strains, whereas bottle-fed babies and, surprisingly, babies completely breast-fed were colonized equally with milk-sensitive and milk-resistant strains, as were the mothers. These results suggest that the bacteriostatic effect of human milk, demonstrable in vitro does sometimes operate in vivo.

The antibacterial activity of human milk is not influenced by the O, H or K antigens of E. coli and is effective against other Gram-negative organisms, e.g. Salmonella, Klebsiella, Proteus.

The faeces of nine subjects eating mainly at home were collected at regular intervals over periods ranging from 2–5 months. Although a large number of serotypes of E. coli were isolated, the variety per subject was lower than is usually found. In most subjects only a limited number of serotypes persisted over most of the periods of study while many serotypes were only isolated on single occasions.

A study of the kinetics of inactivation of foot-and-mouth disease virus type SAT 2 strains revealed that in most cases the rate of neutralization was not rectilinear. Deviations from first-order kinetics observed represented biphasic or parabolic and stepwise reactions. The initial rate was rapid and showed no lag phase or shoulder. The effects of deviations from linearity could be minimized by dilution of antiserum to a suitable extent. Treatment of virus–antibody mixtures with anti-species globulin resulted in enhancement of the rate of neutralization of homologous and heterologous reactions without significantly altering the relation between the two. This treatment also considerably reduced the amount of the persistent fraction. In attempt to disaggregate virus it was observed that sodium dodecyl sulphate inhibited neutralization of virus by specific antiserum.

Salmonella johannesburg (1, 40: b: e, n, x), a previously rare salmonella serotype, has established itself rapidly as an important and highly prevalent cause of gastroenteritis among children. The clinical features of the infection are usually mild but chronic. It has been suggested that S. johannesburg was introduced into Hong Kong through imported foods but no common vehicle could be traced as the source of infection. A thorough investigation of one paediatric ward in a general hospital revealed that non-infected patients admitted to the ward usually acquired S. johannesburg infection within 3–7 days, with or without symptoms. Thus hospital cross-infection could be a significant factor in contributing to its rapid spread in the community. Furthermore, the rapidity with which S. johannesburg spread was facilitated by (a) its tendency to produce a chronic infection, (b) its multiple resistance to antibiotics, and (c) the higher infectivity of S. johannesburg over other salmonellas endemic in this locality. These factors combined with the overcrowded conditions in many of the hospitals in Hong Kong facilitated the occurrence of hospital infection, which in its turn contributed to the spread of the infection in the local community.

A survey was carried out between June 1970 and December 1971 in which gall bladders from cattle either slaughtered for food consumption or disposed of through knackeries were cultured for salmonellas. Salmonella dublin was isolated from 28 of 1617 gall-bladders of adult cattle killed in the slaughterhouse at Carmarthen, and from 23 of 197 gall-bladders obtained from adult cattle sent to a knackery at Abergwili, near Carmarthen. The results are compared with a similar survey carried out in 1947 and 1948.

Between June and November 1971 gall-bladders and uteri were also obtained from a slaughterhouse in Newcastle Emlyn, North Carmarthenshire, and a knackery in Tanygroes, South Cardiganshire. S. dublin was cultured from two gall-bladders but from none of the uteri of the 161 slaughterhouse cases. Seven of the 46 cows from the knackery yielded S. dublin on culture: 2 in the gall-bladder only, 3 in the uterus only and 2 in both gall bladder and uterus.