The distribution of phage types among 221 human strains of Salmonella paratyphi A in Indonesia was studied. Approximately 50% were phage type 5, a rare type elsewhere in the world. Most other isolates were the cosmopolitan phage type 1. The ratio of phage type 1–5 was compared for two cities on Java, Jakarta and Yogyakarta. The ratios were significantly different, phage type 5 predominating in Jakarta. The ratio of phage types among 10 S. paratyphi A strains isolated from Jakarta river water was similar to that found in Jakarta patients.

A test is described for assessing the effect of hypochlorites in reducing the bacterial load on soiled napkins during storage, between removal from the infant and the laundering.

The outbreak of typhoid fever in Aberdeen during 1964 (Walker, 1965) presented an opportunity to study the antibody titres of typhoid fever patients and of TAB immunized individuals to obtain further knowledge concerning the behaviour of these titres with the passage of time.

This paper gives an abbreviated version of part of a research programme which followed the Aberdeen typhoid outbreak of 1964.

The antibody titres of patients were followed up for a period of 2 years after discharge from hospital and the findings have been compared with those in TAB immunized healthy individuals. The following points emerged:

(1) The value of the Widal test as an aid to diagnosis was limited;

(2) the flagellar antibody titre in patients' sera provided a more reliable aid towards diagnosis than did the somatic antibody titre;

(3) the response of immunized and non-immunized patients to the somatic antigens was poor and often delayed well into the period following discharge from hospital;

(4) titres of 1/40 and over for Vi agglutinins were present in immunized and non-immunized patients for at least 12 months after discharge without their being S. typhi excretors;

(5) Vi agglutinin titres as high as 1/40 were present in TAB immunized healthy individuals and also in members of the general public;

(6) the presence of S. typhi septicaemia need not result in a high antibody titre; (7) patients who relapse, may do so without enhancement of previous antibody titres and may relapse even in the presence of earlier appreciable titres.

In a previous paper (Brodie, 1977) the value of the Widal test in the diagnosis of typhoid fever was shown to be limited. Evaluation of possible alternative tests showed that:

(1) the sensitivity of the anti-human globulin (Coombs') test appeared greater than that of the agglutination test but the length of time (48 h) before results were available rendered it of little value in rapid diagnosis;

(2) the complement fixation test offered no particular help towards diagnosis;

(3) immunized and non-immunized typhoid fever patients developed fimbrial antibodies, as also did immunized healthy individuals. In this latter group, however, those immunized with alcoholized TAB vaccine had higher antibody titres to fimbrial antigen than those immunized with heat-killed phenolized vaccine.

Groups of student volunteers were immunized with one of five different inactivated influenza virus vaccines. The concentration of virus in the various vaccines differed by both the international unitage test and by the concentration of haemagglutinin, as measured by the single radial diffusion test; the results of the two methods of standardization showed no correlation. The serum HI response to immunization was variable; volunteers given A/England/72 showed a 16·6-fold increase in homologous serum antibody titre whilst volunteers given A/Hong Kong/68 vaccine showed a 4·2-fold increase. The variable response of volunteers to immunization could not be explained by the varied concentration of virus in the vaccines, as measured by either test, the titres of serum HI antibody present before immunization, or a combination of these two factors.

The ability to infect volunteers with WRL 105 virus 4 weeks after immunization with heterologous, inactivated virus vaccine was directly related to the degree of cross-reactivity between the haemagglutinins of this vaccine virus and WRL 105 virus. Thus, the greatest number of infections by the challenge virus were seen in volunteers given A/Hong Kong/68 vaccine, less were observed in volunteers given A/England/72 vaccine, and least were found in groups given A/Port Chalmers/73 or A/Scotland/74 vaccine. However, compared with the incidence of infection in volunteers given B/Hong Kong/73 vaccine, all the heterologous influenza A vaccine gave some immunity to challenge infection.

Bacteriologically proved cases of salmonellosis presenting at the University Hospital have increased nearly threefold since 1957. The most striking change has been a considerable increase in the incidence of Salmonella heidelberg and Salmonella derby in the last 5 years, probably resulting from hospital acquired infection.

About 80 cases of typhoid fever are reported each year in Jamaica. There has been little change in the prevalence of different phage types of Salmonella typhi since 1961. Paratyphoid fever is rare.

Standardized antimicrobial disk-sensitivity testing was performed on selected surviving salmonella strains since 1964. S. typhi has remained fully sensitive to all the agents tested except streptomycin. Other salmonellas, however have shown a significant increase in antimicrobial resistance since 1970. Most of this increase was due to multiple resistance in S. heidelberg and S. derby, and the survival and dissemination of these strains in the hospital environment may be related to antibiotic usage.

Clothes-borne transmission is an important way of spread of infection from patient to patient which is not interrupted by common cotton gowns. New barrier garments were designed from spun-bonded olefin that, in particle penetration tests, was 100 times better as a filter than cotton cloth. Three designs, a gown, a loose coverall and a close coverall, were compared with each other and with conventional cotton gowns in experimental exercise and nursing procedures. Staphylococcus aureus from burned patients were used as markers. The close coverall was 4–7 times better than the loose coverall or gown in preventing the soiling of clothes worn underneath it, but appeared to permit substantially more transfer from garments underneath it to a mock ‘patient’ and to the air than did the looser garments. A cotton gown reduced the soiling of clothes underneath it by more than 10 times and the contamination of a mock patient by more than 30 times as compared with no barrier garment. The close coverall further diminished the contamination of clothes but not the transfer to the patient. The possible mechanisms for the discrepancy between particle transmission tests and experimental procedures are discussed.

A galactose epimeraseless (gal E) mutant of Salmonella typhimurium was investigated in mice and calves for its suitability as a live vaccine. In mice, a very highly significant difference in the mortality rates was observed when vaccinated and non-vaccinated animals were challenged with virulent strains of S. typhimurium and S. dublin.

In calves, doses of 106 and above of gal E mutant injected subcutaneously provided highly significant protection both in terms of mortality and prevalence of symptoms when calves were challenged orally with S. typhimurium. However, there appeared to be a relation between the vaccine and the presence of renal lesions and before gal E mutants can be recommended, further work is necessary to determine the pathogenesis of these lesions.

Milk chocolate mass containing salmonellas was prepared by mixing artificially contaminated milk powder with the other ingredients at a temperature of about 40 °C. From this mass bars were made. Two series were prepared, with S. eastbourne and S. typhimurium respectively. The number of surviving salmonellas was counted after various periods of storage, up to 19 months. S. eastbourne was reduced in numbers during 19 months from an initial count of ca. 3 × 104 to ca. 3 × 102 per 100 g of chocolate. S. typhimurium died off more rapidly, and was not detectable in about 55 g after 15 months, in spite of an initial count of ca. 105 per 100g.

In these experiments the salmonellas in the milk powder had had to survive the spraying procedure and the adverse conditions in the dried powder. This may be the reason why S. eastbourne showed a distinctly better survival on storage than the same serotype showed in previous experiments in which the organism was added as a broth culture to the chocolate mix. With S. typhimurium, however, such a difference was hardly detectable.

Possible explanations of these results are discussed.

Ferrets immunized with an H3N2 recombinant of A/PR/8/34 and A/Scotland/ 840f74 (RIT 4025 vaccine strain) were almost completely protected against a challenge with the homologous strain A/Scotland/ 840/ 74. The protection was lower but highly significant when the challenge was performed with the heterologous A/Victoria/3f75 wild strain. The protection afforded by the vaccine strain was measured by three indicators: absence of temperature rise, absence or reduction of virus shedding and absence or reduction of nasal protein increase when compared with uninoculated controls.

Heterotypic immunity in this animal model was not significant when these three indicators were measured after a challenge inoculation performed 5 weeks after immunization.

The faecal survival of Salmonella typhimurium orally administered to restrained American cockroaches maintained on an antibiotic diet was investigated. Significant reductions in median numbers of total aerobic faecal microorganisms were noted in insects fed antibiotics daily, and when Salmonella was introduced to this modified micro-environment, it persisted for 44 days in all specimens. Multiplication of the pathogen was also observed in these insects, with numbers often exceeding 103 times that of the initial input. This differs significantly from our previous results showing that the pathogen is unable to multiply in conventional cockroaches. Attempts to restore the normal flora by feeding a faecal suspension from untreated cockroaches resulted in a decrease in numbers of Salmonella excreted, but did not result in their elimination. Carcasses of infected cockroaches retained viable Salmonella for at least 60 days post mortem, or 104 days after the infective meal.

The diagnosis of abortion in cattle caused by Salmonella dublin depends upon the isolation of the organism from either the products of conception, uterine discharges, vaginal mucus or milk together with serological evidence of active infection. S. dublin may be isolated when an active or a latent carrier cow aborts but in these cases an active infection will not be demonstrable. The retrospective identification of a case of S. dublin abortion may prove difficult as excretion of the organism is usually transient and the serum agglutinating antibodies frequently fall to low titres soon after the abortion.

Myxomatosis on the Western Plains is an enzootic disease in contrast with the epizootic pattern which is general in eastern Australia. The most unusual aspects are the presence of significant numbers of diseased rabbits throughout the winter and the continuously low percentage of rabbits with antibodies to myxoma virus.

Climatic and topographic conditions are unsuited to the production of the high densities of mosquitoes necessary for widespread epizootics. Under these conditions the effects of less efficient methods of myxomatosis transmission are apparent. The unusual epidemiology of myxomatosis has resulted in selection for virulence of the virus similar to that which has occurred under summer epizootic conditions. All field strains are now in the mid range of virulence.

Eight-hundred and one patients amongst 1912 referred for skin testing because of suspected allergies were found suffering from asthma due to the house-dust mite or from grass pollenosis. They were analysed in terms of sex, age of referral and age of onset of symptoms. Amongst children referred below the age of 10 with house-dust mite asthma the ratio of males to females was 3:1; with grass pollenosis 2–1:1, as expected. The sex ratio gradually became reversed with increasing age of referral, females overtaking males in the third decade. Female–male ratios increased to a mean of 1–8:1 in the fourth and fifth decades. Reliable ages of onset of symptoms were obtained in 388 males and 323 females. Of these, 280 males and 162 females experienced their first symptoms before the age of 10 whereas 96 males and 148 females first developed symptoms between 10 and 29 years of age. The remaining 12 males and 13 females showed their first symptoms after the age of 29.

The fluorescent antibody technique was used for the identification of specific cytomegalovirus IgM in the sera of twenty-four of 1065 unmarried pregnant women. Seventeen of them were followed to term and five infected infants were identified. Two other infants had CMV IgM in neonatal serum samples but virus excretion was not demonstrated. The congenital infection rate in this study was 5·3 per 1000 births by virus excretion and 7·9 per 1000 if cases with specific IgM are included; from previous studies a rate of 8·8 per 1000 was expected. The reasons for the lack of relationship between specific IgM in the mothers' serum and infected babies is discussed.

The use of a single-radial-haemolysis technique for the detection of antibody to rubella virus is described. The single-radial-haemolysis test was compared with the standard HI methods for the detection of antibody to rubella virus. A close correlation between the two methods was observed in a survey of over two thousand serum samples and the study indicated that single-radial-haemolysis was highly satisfactory as an assay method for IgG antibodies to rubella virus. It was found that the immuno-globulins active in SRH tests sedimented in the 7S range in sucrose rate gradients and were presumably immunoglobulins of the IgG class, but 19S iinmunoglobulins did not produce haemolysis.

During an 8-week period all specimens of stool passed by six nurses were examined for the presence of Escherichia coli and all isolations of this organism were serotyped. During the middle 4 weeks of the period the nurses ate a sterile diet. A smaller number of serotypes was isolated during the period of sterile diet than during the period when normal food was eaten. This finding supports the view that normal food is a source of strains of E. coli present in the bowel. Some new serotypes of E. coli did appear during the period of sterile diet. The possible sources of these are discussed.

An epidemic of acute haemorrhagic conjunctivitis (AHC) recurred at Lucknow during July to September 1975, after a gap of 4 years. Out of the 35 cases investigated thoroughly, 20 Entero-70-like cytopathogenic agents were isolated from the conjunctiva which were neutralized by antisera against AHC virus J670/71 of Japan. Seroconversion was seen in 7 out of 11 paired sera from patients. Serological study was also done on 100 sera after 1975 epidemic. There were no neutralizing antibodies in the pre-epidemic period, while 18% of sera after the first epidemic and 32% after the second epidemic showed antibodies. The incidence of antibodies was highest (43%) in children aged below 10 years. Of the children born after the first epidemic, 44% had antibodies. Thus our findings show that the AHC virus appeared for the first time at Lucknow in 1971 and the almost complete absence of disease in children, and its mildness during second epidemic, may be due to immunity.

The mechanism causing viable Francisella tularensis to lose virulence in aerosols has been investigated. Fully virulent organisms were found to be encapsulated and avirulent organisms from aged aerosols, decapsulated. Capsules were also removed by suspension of F. tularensis in hypertonic sodium chloride. The resulting naked, but viable, organisms were predominantly avirulent for guinea-pigs challenged intraperitoneally. Capsular material and cell walls were found to contain large amounts of lipid, about 50 and 70% (w/w) respectively, and to differ in lipid and sugar composition. Isolated capsular material was not found to contain a lethal toxin for mice or guinea-pigs, or to induce an immunological response in these animals to fully virulent F. tularensis.

Three hundred and fifty-seven sera selected at random from hospital patients of all ages were examined for rotavirus antibodies using indirect immunofluorescence (FA) and complement fixation tests (CFT). Three hundred and fourteen of these were also tested for neutralizing antibodies to human rotavirus. Sera from patients admitted with a diagnosis of acute gastroenteritis were excluded from this survey.

FA antibodies were found in newborn infants but fell to undetectable titres at 3 months. The highest titres were found in children between the ages of one and three years. In older age groups, the modal titre fell gradually with increasing age until, in sera from those above 70 years of age, FA antibodies were almost undetectable. The same pattern was observed with neutralizing antibodies. A high modal titre of CF antibodies was only found in sera from those aged one to three years.