An Asian patient with undiagnosed typhoid fever was admitted to a maternity hospital and delivered within 10 mm. Salmonella typhi (phage type D5) was isolated from her blood and from the faeces of her baby. Another woman in a different room of the labour suite at the same time acquired the same organism in her faeces; her brother was admitted to the Infectious Diseases Unit 5 weeks later with typhoid fever. Two babies, born over 60 h after the index case was delivered, became faecal excreters of the same strain and one of them also developed S. typhi osteitis of the hip. These two babies and their mothers were in the same ward as each other, but not that occupied by the infected mother and her baby. Nine other excreters in two of the families involved were identified. The index case and her baby were isolated immediately after delivery, and the relevant rooms in the labour suite were adequately disinfected. No evidence of undisinfected equipment used by the index case and the other infected patients was found, and no spread to staff was detected. The mode of spread remains unknown.

Household aggregation of cases, one possible characteristic of person-to-person transmitted disease, was formally tested in one epidemic of variola minor by using a pair statistic. A significant result was found for all households as well as for households grouped by the type of environment, or by the phase of the epidemic growth in time. Secondary attack rates, when related to household size (number of susceptibles) showed only a marginal trend in rural households but no trend in urban or semi-rural households.

The colonization of patients by Klebsiella and several other gram-negative bacteria was studied in a hospital urological ward over a period of six months. Before and during the survey there was no evidence of an outbreak of nosocomial infection and multi-drug resistant strains of Klebsiella were not isolated.

Klebsiella were biotyped by nine biochemical tests, which led to the detection of 66 biotypes spread uniformly throughout the survey period. This method of biotyping proved a useful epidemiological tool. The colonization rate of throats, hands, and faeces of patients increased after admission to the ward, especially when antibiotics were used. The effect of systemic antibiotics was greater than that of urinary antibiotics especially on throat and faeces carrier rates. Carrier rates for Klebsiella increased also after catheterization and operation – relationships which could well be multifactorial.

During the first two weeks after admission the proportion of antibiotic resistant strains of Klebsiella in carriers increased. The proportion of resistant strains amongst isolations from clinical infections was always greater than among strains isolated routinely from sites of carriage.

A new instrument has been designed to measure the penetration by rubbing of bacteria from cloth contaminated in the nursing of burn patients through fabrics designed for barrier garments. Most fabrics tested dry reduced the transfer of bacteria from the source cloth to about 10%, irrespective of the results of air filter tests, which agrees with mock nursing results. When the fabrics were tested against a wet surface, the transfer of bacteria rapidly reached 100% if the fabrics had a high wettability, but was slower for fabrics with a low wettability. Through closely woven waterproofed cotton, transfer was 5–25%, but increased three- to four-fold after ten launderings, in line with the water absorption. Transfer through plastic-laminated material was less than 1%. The results suggest that barrier garments should be made either of plastic or of recently waterproofed closely woven cotton at points of contact between nurse and patient where the clothes may be wetted by bacteria-containing wound secretions.

In operating theatres the air is mainly contaminated with bacteria shed from the human skin. The emission of bacteria can be prevented by wearing clothing of impervious material, while normal cotton clothing does not decrease the shedding of bacteria.

In this study shedding of viable bacteria from 20 test-persons wearing an operating theatre suit, composed of 65% polyester and 35% cotton (Diolen), was investigated in a test-chamber and compared with that when normal clothing was worn. The use of this operating-theatre suit resulted in a significant reduction (50–75%) in the number of bacteria-carrying particles in the air of the test-chamber and in an operating room when everyone present wore this suit. A combination of the suit with knee-high boots showed a further reduction in the dispersal of colony forming units.

The dispersion from female subjects wearing an operating-theatre frock was significantly higher than when wearing an operating-theatre suit.

During a 6-month period an epidemiological survey of the carriage of Klebsiella was conducted in a hospital ward where no outbreak of nosocomial infection occurred. In this endemic situation the regular sampling of several sites on patients, members of the nursing staff, and the environment, and the biotyping of Klebsiella made it possible to analyse the patterns of transmission between sites. There was abundant evidence for striking transmission of Klebsiella between the throat, hands, and faeces of patients. Transmission between patients seemed to be mainly through hands. The role of nurses' hands in transmission was not evident from this survey, probably due to the relatively long interval (a week) between samplings. Through the hands of patients, wash stands and the surrounding floor were contaminated with Klebsiella. The biotyping of Klebsiella facilitated the epidemiological analysis of the results.

Klebsiellas are generally typed by the method of capsular serotyping but, although this is a reliable method, it is time consuming, requires the production of a large number of antisera and is not generally available. For this reason another method for typing klebsiellas was sought.

A bacteriocin typing method involving mitomycin C induction was developed and the cultural conditions giving optimum klebecin production and the best methods of testing the sensitivity of the organisms to klebecins were determined.

Of 190 klebsiella strains screened for bacteriocinogeny, only 68 (35·8%) produced klebecin and after calculation of similarity values by computer analysis, a typing set of 15 producers was selected. This typing set allowed over 96% of klebsiella strains to be typed and tests of the reproducibility of the method and the variability of typing patterns in natural populations of klebsiella indicated that results of acceptable accuracy could be obtained, while retaining good discrimination if two or more differences were required between patterns before they were regarded as distinct.

A complete set of capsular antisera were prepared, enabling the results obtained from klebecin typing to be compared with those from serotyping. There was generally close agreement between the results from the two typing methods and greater discrimination was obtained between similar strains when the two methods were combined. Klebecin typing and serotyping revealed relationships between strains from five outbreaks of infection, and strains of the same serotype from different hospitals could frequently be distinguished by their klebecin typing patterns.

Previous investigations have shown that cross-contamination in a burn unit is mainly clothes-borne. New barrier garments have been designed and tried experimentally. The aim of the present study was to investigate the effects of different clothing routines on cross-contamination. In a long-term study, the rates and routes of colonizations with Staphylococcus aureus, Streptococcus groups A, B, C, F, and G and Pseudomonas aeruginosa were examined. The exogenous colonization rates were, with S. aureus 77%, with Streptococcus species 52% and with Ps. aeruginosa 32%. The colonization rate with Ps. aeruginosa was higher in patients with larger burns. Patients dispersed Streptococcus and Ps. aeruginosa as well as S. aureus into the air of their rooms in considerable amounts, but dispersers were not more important as sources of cross-colonization than non-dispersers. In comparison of clothing routines, there was no difference in overall colonization rates. The newly designed barrier garment that was made from apparently particle-tight material did not reduce the transfer of bacteria from patient to patient. A less rigid routine than that previously used did not increase the risk of cross-contamination. A thorough change of barrier dress after close contact nursing delayed the first exogenous S. aureus colonization from day 6 to day 14 after admission. This routine might be recommended for clinical use. Otherwise, methods must be developed for adequate selection of materials intended for barrier garments.

Seventy-three children under the age of 18 months presenting with acute gastroenteritis were given an electrolyte mixture with added sucrose or glucose in a randomized double-blind trial. The time taken to recovery in those successfully treated as out-patients was identical. However, of the 34 who received glucose, 11 (32%) required admission compared with 7 (18%) of the 39 who received sucrose. There was a wide range of osmolality of the made-up feeds, indicating inaccuracy in diluting the solutions as prescribed, but this did not in general correlate with need for admission.

Sucrose-electrolyte solution is at least as effective as a glucose-electrolyte solution for the out-patient management of acute gastroenteritis in infancy. The cheapness and easy availability of sucrose commends its use in developed and developing countries.

Sera of 197 apparently well persons were tested for residual haemagglutination-inhibiting antibodies against live Hong Kong/68, A/FM/47 and A/PR/34 strains. Sera of 62 well persons, regularly exposed to contacts with swine, were tested against an inactivated A/New Jersey/76 antigen.

Those born some time before and during a certain influenza era showed a significantly greater proportion of homologous residual titres against the subtype prevailing in that influenza era, than those born after the termination of the same era.

In each of the seven age groups tested both the percentage of positives and the geometric mean titres were usually highest against the Hong Kong strain (representing the most recent era); the next highest were those against the FM1 strain and the lowest were those against the PR8 strain (representing the most distant of these three influenza eras).

The serological involvement of donors exposed to regular contacts with swine was relatively stronger against the New Jersey antigen than the response of other serum donors shown against the other three, more recent, prototypes of influenza virus A. The oldest age groups showed significantly lower antibody response against the PR8, FM1 and Hong Kong strains (but not against the New Jersey antigen) than the next one or two of the younger age groups.

When fresh urine from LCM tolerantly infected mice was applied to small areas of excoriated skin of guinea-pigs undiluted or diluted 10−1, a high LCM infectivity developed in the local dermal tissue within 3 days and quickly spread to the lymphatic system. The skin at this site of infection became erythematous 10–12 days after infection and a few days later a rash was often seen in the hairless skin around the mammary teats. A viraemia was first detected at about 8 days after infection and persisted for at least 8 days, during which time a high infectivity titre in skin not only at the infection site but also distal to it suggested that there was a generalized active infection of the dermis. Infectivity in the tongue was simultaneously high and probably associated with erosions of the tongue tip seen a day or two later than the teat rash.

In similar experiments in hamsters and rabbits, indications were again that lightly injured dermis was a primary site of virus replication. These observations should lead to the dermal route receiving greater attention as a potential route of infection of man when exposed to infectious excretions of reservoir hosts of arena-viruses.

An open-roofed plastic isolator was built in a single patient isolation room in a burn unit. It was designed to prevent contact contamination only, as this had been shown to be the important route of cross-colonization in the unit. To exclude any possible effect on airborne transfer of bacteria, the isolator was first examined by means of an airborne particle tracer of the same size as bacteria-carrying particles. Such experiments indicated that the isolator might prevent some transfer out of but not into the isolator. This was not confirmed in simulated nursing experiments nor in a patient study, where the air counts of bacteria were practically the same inside and outside the isolator wall. Two patients only were nursed in the isolator. Both patients acquired exogenous colonizations from other patients, one with Ps. aeruginosa and the other with S. aureus. Nursing in the isolator was difficult and staff-demanding. In simulated nursing experiments, plastic aprons and gaunt-lets as the only protective measures against contact contamination gave as much protection to a mock patient as did the isolator. S. aureus were released from nurses' clothes more easily during work with the isolator than in open nursing with aprons and gauntlets. In conclusion, the isolator did not seem to be a realistic alternative to impermeable clothes such as plastic aprons as a means of preventing clothes-borne cross-contamination between burn patients.

A 14-month survey was undertaken in a diagnostic bacteriology laboratory to determine the incidence of Serratia spp. in routine clinical specimens. Gram-negative organisms with enterobacteria-like colonies were tested by a simple screening procedure. Fifty-eight strains of S. marcescens and two strains of S. liquefaciens were isolated from 59 patients. The strains were usually nonpigmented and exhibited multiple antibiotic resistance. Serotyping and determination of bacteriocine sensitivity patterns revealed that the majority of infections were sporadic, although episodes of cross-infection did occur.

S. marcescens was considered to contribute significantly to morbidity and mortality in 53% of patients and appears to be of increasing importance in hospital-acquired infections.

Live attenuated influenza vaccine containing the recombinant of A/Victoria/3/75 with A/PR/8/34 virus was administered to healthy adults in a field trial aimed at evaluating protection provided by immunization. The study was designed to measure the effect of vaccination on absenteeism from respiratory disease during a natural influenza epidemic. A total of 2115 male employees of the public transport service of Rome volunteered to participate in the trial, 1050 and 1065 receiving vaccine and placebo respectively, in a randomized blind fashion. Vaccination procedure was completed by the end of December 1976. A small-sized outbreak of influenza, due to a viral strain antigenically homologous to the vaccine, occurred during the month of February 1977. Analysis of absenteeism data, classified according to medical certificate, indicated that morbidity from respiratory disease was reduced in vaccinees compared with controls during the epidemic month; the rate of increase of morbidity compared with that of the preceding month was then three times lower in vaccinees than in controls and the difference in absenteeism between the two groups greatly exceeded the ordinary fluctuation that was observed during non-epidemic periods.

The influence of treatment with increasing oral doses of three absorbable antibiotics on the colonization resistance of the digestive tract was investigated in mice. Mice treated with ampicillin or epicillin in any of the applied doses had a strongly decreased colonization resistance as demonstrated by ‘bacterial over-growth’ after contamination with resistant strains of Escherichia coli. After a treatment period of 2 weeks, Streptococcus faecalis became resistant in a number of animals. Oral treatment with cephradine on the other hand had no obvious influence on the endogenous flora of the mice, nor was the colonization resistance decreased.

The model was based on grasping a fabric-covered bottle contaminated with a strain of Staphylococcus saprophyticus, then grasping a sterile fabric-covered bottle and counting the organisms transferred. When the donor fabric was moist 10% of the available cells passed onto the hands, but this fell to 0·05% when the inoculum dried. Transfer from wet hands to the fabric amounted to 85%, but in the complete model only 0·06% of the available cells were transferred. The model was used to assess simple methods of degerming the hands. Washing the hands reduced transfer by 95%, while washing in 70% alcohol reduced transfer by 99·99%. Lesser procedures investigated included applying 0·2 ml of 80% ethanol to the hands, which reduced transfer by 93%.

The results of experiments to investigate antibody to ‘virus infection associated’ (VIA) antigen in cattle repeatedly vaccinated with formalin- or acetylethyleneimine- (AEI) inactivated foot-and-mouth disease (FMD) vaccines under laboratory conditions are reported. Results are also presented from some vaccinated animals subsequently exposed to FMD infection.

Antibody against VIA was not detected before and after the first vaccination with formalin or AEI-inactivated vaccine but did develop in all animals after the second formalin vaccination and persisted throughout the experiment. After the second AEI vaccination, 4 of 12 animals developed antibody which persisted for at least 37 days. This transient response in some cattle was repeated after successive vaccinations but, in general, more animals responded as the number of vaccinations increased.

After exposure to infection, a transient VIA antibody response was occasionally observed in immune AEI-vaccinated animals. Some immune repeatedly AEI-vaccinated cattle did not develop detectable VIA antibody after challenge despite the persistence of virus in oesophageal–pharyngeal (O/P) fluid.

The presence of antibody to VIA antigen is not conclusive proof that vaccinated animals have been exposed to infection and field data must be interpreted with caution.

In recent years, mycoplasma taxonomists have found that numerous mycoplasma strains from goats are serologically indistinguishable from Mycoplasma mycoides subsp. mycoides, the causative agent of contagious bovine pleuropneumonia (CBPP), by routinely used tests, e.g. the metabolism-and growth-inhibition tests. As a result, such organisms are now openly referred to as M. mycoides subsp. mycoides.

Seven of these so-called M. mycoides subsp. mycoides strains from goats were compared with two strains of M. mycoides subsp. mycoides from CBPP, and with one strain of M. mycoides subsp. capri, by means of two in-vivo tests, namely, (1) a test of the ability of each strain, injected intraperitoneally into mice, to produce mycoplasmaemia, and (2) a cross-protection test in mice. Of the seven strains, only one (‘O goat’) was indistinguishable from genuine M. mycoides subsp. mycoides; it also had small colonies resembling those of genuine M. mycoides subsp. mycoides. The other six were easily distinguished from genuine M. mycoides subsp. mycoides, and they produced large colonies. These six strains and others like them should no longer be given a name that fails to distinguish them from the causative agent of CBPP.

Cross-protection tests showed that the seven goat strains referred to above differed from M. mycoides subsp. capri.

The specimens here described enlarge our knowledge of the bills of health of the Order of St John issued from Malta, an aspect of public health that had hitherto remained unexplored. These lone survivors from a vanished by-way of Maltese medical history formed, in their age, an integral part of the daily social, commercial and sanitary pattern of life in Malta. The earliest met so far, and described in the present series, dates from 1713; two belong to 1766 and another dates from 1794. A further bill, issued in 1782, has been published elsewhere. The chance preservation of these documents in unlikely places, as here indicated, makes it probable that additional ones may eventually come to light.

Brucella abortus infection in the bitch, associated with an aborted bovine fetus, is described. Clinical signs were absent, but the organism was isolated from many sites in the body, including the urine, after death. The response of the dog to B. abortus infection and its possible role as a vector of the disease is discussed.