1. The incidence of salmonellosis in cattle in England and Wales has been investigated.

2. S. dublin and S. typhi-murium were much the commonest serotypes encountered.

3. The frequency of both serotypes was highest in the last quarter of the year, which is the period of maximum calvings. The high incidence of calf infection in this quarter is probably related to calf sales and movement.

4. In the previous investigations (Reports, 1959a, 1961), these serotypes were isolated only infrequently from the raw materials of animal feedingstuffs and from complete animal foods.

5. The distribution of phage-types of S. typhi-murium in cattle was compared with that in man and in animal feedingstuffs. Six phage-types were common both in cattle and in man. These types were: 1a (2), 1 var. 5 (U9), 1a var. 1 (3an), 1 (1), 1a (U57) and 2 (12). Three of the types found in feedingstuffs were common in both human and bovine infections. These types were: 1a (2), 1a (U57)and 2 (12).

6. In a study of ten incidents of salmonellosis in cattle, it was shown that the same phage-type or serotype was commonly found in man in other farm animals and occasionally in feedingstuffs.

7. It is clear that salmonellosis is spread into different regions of the country by calf movement.

8. The importance is endorsed of conditions of travel and lairage, and of the holding time at abattoirs, in the promotion of cross-infection with salmonellae.

9. Measures are outlined for the reduction of salmonellosis in cattle and of its transfer to man.

The carriage of Trichophyton mentagrophytes (Robin) Blanchard by symptomfree laboratory mice has been described by La Touche (1957), Dolan, Kligman, Kobylinski & Motsavage (1958) and Mackenzie (1961). It may often be only the development of infections in the animal handlers which draws attention to the carriage of the fungus by the mice. These ringworm infections in man may take the form of a rapidly developing eczematous and vesicular lesion and the mouse carrier constitutes a significant hazard to the laboratory animal worker.

A study was made of the ‘latent’ viral flora of simian tonsils. This was followed by isolation of viruses from two batches of sick monkeys whose illness is described. Simian viruses 15, 17 and 32 were isolated from nose and throat swabs obtained from the sick monkeys. A connexion between human and simian adenoviruses is suggested.

1. Long-established infection of a mouse colony with Eperthyrozoon coccoides was eliminated by regular insecticidal treatments designed to reduce infestation with lice and fleas.

2. Undesirable consequences of E. coccoides infection upon mice used as experimental animals are noted and an easy routine for exclusion of this parasite from mouse colonies is suggested.

1. The bacteriology of the pus from 79 cases of tropical pyomyositis has been studied. In 74 cases Staphylococcus aureus was isolated in pure culture.

2. Phage typing showed that 60% of the pyomyositis strains belonged to phage Group II as compared with 22% for miscellaneous hospital infections and 21% for nasal carrier strains.

3. A high proportion of the Group II strains from pyomyositis were found to be penicillin resistant and it is thought that this is unlikely to be due to the use of penicillin therapeutically but is probably a natural characteristic of the strains.

4. Other suggested aetiological factors in pyomyositis such as leptospirosis and syphilis have been investigated but no association has been found.

5. The phage types of staphylococci found in Uganda have been compared with those reported from England and Australia and found not to be strikingly different.

A serological study of cytomegalovirus infection in London shows it to be prevalent. Under 5 years of age only 4% of children have antibodies, but this increases to 15% by 10 years of age and 21% by 15 years. The maximum incidence of 54% is reached by 25–35 years, and this is maintained in the older age groups of the population. In two mixed day schools the incidence of infection was significantly lower than in a boarding school, suggesting that close prolonged contact is required for spread of infection.

Different strains of cytomegalovirus possess common group-specific complement-fixing antigens.

It is suggested that clinical disease caused by cytomegaloviruses is more frequent and more varied than previously believed, although diagnosis may be difficult without virological help.

Sera from most of the Tristan da Cunha community were tested for toxoplasma antibody. In a comparison with sera from ‘normal’ inhabitants of South Wales there was a significantly higher incidence of dye tests positive at 1/16 or more in the Tristan community at all age groups. The incidence of retinitis was also found to be much higher than in Britain. It appears unlikely that toxoplasmosis caused any cases of mental defect or abortion on the Island.

Guinea-pigs given two doses of 2–25 Lf of fluid tetanus toxoid at 28 days interval had very satisfactory antitoxin titres 10 days after the second dose of toxoid (g.m. 28–2 units/ml.). Similar groups of animals given 150 units of horse tetanus antitoxin simultaneously with the first dose of toxoid responded very badly (g.m. < 0·016).

Interference by passive antitoxin occurred even when the antitoxin was given as late as 4 days after the first dose of toxoid.

Interference by passively administered antitoxin was minimal when aluminium hydroxide-adsorbed toxoid was used. It was necessary to increase the dose of antitoxin from 150 to 2400 units before significant interference occurred.

The route of administration of antitoxin did not significantly affect the results except when the antitoxin was given intravenously.

When guinea-pigs were immunized and bled at regular intervals it was found that with both fluid and aluminium hydroxide-adsorbed preparations, titratable antitoxin was present on the 14th day. The increase in titre thereafter was more rapid with the adsorbed preparation, but after a second dose of toxoid there was no significant difference in titre.

Passively administered antitoxin virtually abolished the active response to fluid toxoid, but with aluminium hydroxide-adsorbed preparations the primary response was not abolished but reduced and delayed and there was much individual variation.

Horse serum-sensitive guinea-pigs given adsorbed toxoid with simultaneous passive horse antitoxin gave a better primary response to the toxoid than did unsensitive animals.

The effectiveness of adsorbed tetanus toxoid in the simultaneous immunization procedure was directly related to the concentration of aluminium hydroxide or phosphate used: this concentration was critical and amounts below a certain level were ineffective. Calcium phosphate used as an adsorbent was unsatisfactory in this way, although it was an excellent adsorbent.

Investigation of the adsorbent characteristics of aluminium hydroxide and phosphate and of calcium phosphate, showed that the calcium salt on a molar basis was the most effective and that aluminium phosphate was the least effective.

Elution of toxoid from centrifuged precipitates of the three types of adsorbent showed that only 5% of toxoid was removed from the aluminium hydroxide, 13–18% from the calcium phosphate and 31–33% from the aluminium phosphate preparation when incubated with normal serum at 37° C.

Aluminium hydroxide adsorption in vitro interfered with the ability of antitoxin to combine with toxoid and to a lesser extent calcium phosphate had the same effect; aluminium phosphate, however, did not appear to interfere at all in this way

Histological observations on the tissue response to aluminium phosphate and calcium phosphate indicated that the typical alum granuloma produced by aluminium phosphate was not produced by the calcium salt.

Of 918 severely subnormal patients in mental deficiency hospitals in Lincolnshire 917 were tested by the toxoplasmin skin tests, forty-nine out of 265 patients were dye tested because of a positive skin test or other indication. All patients in another group of 655 subnormals were dye tested, and comparison of these results with those of groups from the normal population showed that in children there was an excess of about 20% of dye-test positivity among the subnormals—a figure identical with that found by Thalhammer in Vienna.

The excess of positives became progressively less with increasing age and by middle age the incidence was the same in subnormals as among blood donors in the county. It is suggested that this indicates that patients in hospital are exposed to a lower risk of acquiring infection and that the higher incidence among adult males than among adult female defectives is due to the fact that more of them go out to work, many of them on farms. This factor could also explain the lower incidence of positivity in adult mongols and epileptics who are less commonly employable.

Possible explanations of the higher incidence among subnormal than among control children are discussed. Although it is tempting to assume that it indicates that some may be cases of congenital toxoplasmosis, the lack of gradient between child mongols, child epileptics and other subnormal children does not support this hypothesis. The numbers of mongol and epileptic children were too small to give statistically significant results. It is possible that the home environments of severely subnormal children exposed them to a higher risk of infection than did the homes of the control children and that the observed excess of dye and skin-test positivity may be due to increased incidence of acquired infection before their admission to hospital.

It was found that there was reasonable concordance between the dye test at a titre of 1/8 and skin sensitivity reactions exceeding 7 mm. in diameter, but poor agreement if 10 mm. was taken as the criterion of positivity.

Despite the lesser sensitivity of the skin test, the pattern of the results was the same as that observed in the dye-test survey, and the value of the skin-test for epidemiological surveys was confirmed.

Photoinactivation of vaccinia virus sensitized by methylene blue had parameters similar to those observed with other viruses. Thus inactivation proceeded exponentially to completion, was irreversible, independent of temperature and the intensity of illumination. Inactivation was dependent on the dose of illumination and the concentrations of both methylene blue and hydrogen ions. The effects of pH appeared to be primarily concerned with the tenacity of dye-virus binding. Inactivation was inhibited by small amounts of nucleic acid but not by their bases or pentoses. Inactivation was only affected by the presence of extraneous protein in relatively high concentration: it was not affected by the enzymes catalase or peroxidase. Attempts to obtain direct chemical evidence of the participation of viral nucleic acid in photoinactivation were unsuccessful.

Recombination experiments strongly indicated the involvement of viral protein in photoinactivation. Immunogenicity was not impaired since good responses of neutralizing antibody were obtained in rabbits immunized with vaccines photoinactivated over a wide range of exposure times.

Twenty-five grade cattle were infected subcutaneously with 1040 to 104·6 TCD 50 of a highly-attenuated strain of rinderpest virus which is used as a vaccine. No clinical reaction was observed but the proliferation of virus was studied in twenty-two tissues harvested at daily intervals from the first to the 10th days after inoculation. Serum samples collected at the same times were examined for rinderpest-neutralizing antibody.

There was an ‘eclipse’ phase of 3 days during which no infectivity could be demonstrated in any tissue. On the 4th day virus had generalized, as shown by its detection in lymphoid tissues which were not associated with the site of inoculation; occasional animals showed evidence of viral proliferation in the local muscle and subcutaneous tissue. A considerable growth of virus, with peak titres between 104·0 and 105·0 TDC50/g., was demonstrated in the prescapular, pharyngeal and mesenteric lymph nodes, also in the palatal tonsils and Peyer's patches of the ileum. Highest titres (105·4 TCD50/g.) were recorded in the prescapular haemo-lymph nodes, but less virus (up to 103·4 TCD50/g.) appeared in the spleen.

A low-level viraemia was detected in eight of the thirteen cattle killed on the 5th to 8th days inclusive. Minimal quantities of virus were found on two occasions each in the bone marrow and lung. No virus was recovered from the mucosae of the base of the tongue, abomasum, ileum, caecum and colon; liver, heart, kidney and brain tissue also failed to support its multiplication.

Neutralizing antibody was present in all cattle by the 10th day after inoculation, its appearance being associated with the abrupt decline in virus titres, which was usually demonstrable on the 8th day.

The behaviour of the attenuated virus was compared with that of virulent strains, and it was concluded that its lack of pathogenicity was due primarily to its failure to proliferate in the mucosae of the gastro-intestinal and respiratory tracts. Vaccine virus was, in fact, exclusively ‘lymphotropic’, a characteristic which may account for the solid, lasting immunity it confers and for the considerable antibody response it provokes in inoculated cattle. Inability to spread by contact amongst susceptible cattle may be a result of the absence of virus in mucosae or parenchymatous organs and hence in excretions.

Inactivated vaccinia virus vaccines were prepared from purified virus inactivated by either formalin, hydroxylamine or heat. The immunogenicity of these vaccines was assessed in rabbits by measurement of virus neutralizing antibody following each of two inoculations. It was concluded that inactivated vaccinia virus stimulates the production of neutralizing antibody and that the most important single factor in this immunogenicity is the concentration of virus in the vaccine. Vaccines prepared from virus suspensions containing 107 to 108 pfu/ml. before inactivation give variable antibody responses.

By means of the fluorescent antibody method and of acridine orange staining experimental infection with adenovirus type 14 has been investigated in KB and MK cell cultures. Intracellular changes could be shown to precede the appearance of the cytopathic effect.

Thus, progressive stages in the development of adenovirus at this level could be separated both by the demonstration of the specific antigen and by the appearance of an altered DNA.

Both methods have proved to be equally useful for the detection of virus multiplication and of the histochemical changes induced in the cells.

No significant differences have been found to exist with respect to the cell line used.

The possible risks of infection associated with the practice of licking envelopes, stamps and labels were investigated. Although pathogenic bacteria and viruses were not isolated from sample envelopes obtained from various sources, the gums used in manufacture were found to exert a protective effect against death from desiccation on the bacteria and viruses which had been introduced into them. Staph. aureus and Salm. paratyphi B remained viable for several months in dried films of two out of four gums tested. An echovirus could be recovered from similar films for up to 30 days, and an adenovirus for up to 10 days.

Bacterial multiplication occurred in the gum used for the manufacture of postage stamps. The comparison is drawn between the possible consequences of minimal contamination of this gum and of cans of corned beef in the light of recent studies.

1. A description is given of the outbreak of typhoid fever in Zermatt in 1963.

2. There were 437 cases and three deaths, a case fatality rate of 0·7%.

3. Information from 260 tourists established that the initiation of infection was explosive and allowed the period of infection to be determined.

4. The mean incubation period of various tourist fractions was probably between 16 and 18 days but was found to be significantly longer (20–21 days) for hotel employees.

5. The evidence favours a waterborne outbreak. Studies of the water supply showed that the catchment area and the surface streams and their water were liable to contamination.

6. One particular stream, the Zmuttbach, constituted a greater danger than the remainder.

7. The water purification at the treatment station was inadequate; in particular the holding time for chlorination was too short, and the required concentration of 0·2 p.p.m. was not reached consistently. In addition, there were periods during which completely unchlorinated water reached the general supply.

8. It was discovered, some months after the epidemic, that there was leakage of sewage, probably of long standing, into the chlorination tank. This seems to be the most likely source of the water contamination.

9. The typhoid excretor responsible for the outbreak was not discovered.

Two events concerned with echo virus 14 infection were reported.

The first, which occurred in Sendai in 1962, was that the intestinal infection with the attenuated poliovirus 1 vaccine was possibly suppressed by naturally occurring infection with echovirus 14. Echovirus 14 was isolated 10 days after the vaccine feeding in six out of nine cases, but poliovirus in only two cases. Six of the vaccinated babies did not exhibit antibody response to the poliovirus 1, while a significant rise of antibody titre against echovirus 14 was seen in as many as eight babies 7 weeks after the vaccination.

The second was a small outbreak of aseptic meningitis due to echovirus 14 in Aomori in 1963. During August to October, echovirus 14 was isolated from the faeces of seven patients with aseptic meningitis. The virus was also isolated from the CSF in one case. The antibody titre against echovirus 14 was detected in all the patients from whom the virus was isolated. In addition, echovirus 14 antibody was detected in four out of fourteen patients with aseptic meningitis from whom no virus was recovered. The onset of serologically positive patients was limited to the months of August to October.

1. Residual populations of wild house mice (Mus musculus L.) were trapped alive in premises where poison treatments with 0·025% warfarin bait had been reported to be ineffective.

2. In the laboratory the individually caged mice were fed 0·025% warfarin in a sugar/oil/coarse oatmeal base. In toxicity tests lasting 10 and 21 days, the total mortality was low and the rate of death slow compared with mice drawn from habitats not treated with warfarin.

3. It is suggested that tolerance to warfarin in M. musculus either is polygenically based or is controlled by a single major gene influenced by modifiers and that these hard-to-kill populations have arisen through selection during successive control treatments.

The Antarctic provides unusually simplified conditions for the study of the persistence and exchange of micro-organisms of the upper respiratory tract. The work reported here was done while the author was in the Falkland Islands Dependencies Survey and the United States Antarctic Research Program.

Staph, aureus and Staph, albus persisted in the noses, and a-haemolytic streptococci in the throats of men throughout long periods of isolation and semi-isolation in Antarctica.

On the whole, men kept their own strains (phage types) of Staph, aureus despite living in very close contact with each other.

Persistent carriers of Staph, aureus (90% or more positive swabs per individual) continued to carry this organism for as long as 2 years in Antarctica. Data from men at Wilkes and Hallett IGY Stations indicated that there was a decrease in the intermittent and occasional carrier rates, resulting in a much lower total carrier rate after 12 months Antarctic isolation.

Evidence is presented to suggest that β-haemolytic streptococci had disappeared from throats after 12 months of isolation. It is thought that the absence of upper respiratory infections in these communities is due to absence of the bacterial or viral agents.

There is an urgent need for further work on the carriage of micro-organisms in the present unique epidemiological conditions of the Antarctic, and for better laboratory facilities there.

1. Strains of Staphylococcus aureus were obtained from the nostrils of twenty-three of fifty-eight hedgehogs; the skin of thirty-eight of fifty-six hedgehogs; the paws of thirty-six of fifty-seven hedgehogs and the anus of six of eleven hedgehogs.

2. Of 118 strains, 106 (90%) were typable with human staphylophages. Seventeen were phage group I, three phage group II, twenty-five phage group III, sixty-one were typable but unclassifiable into groups, and twelve were untypable.

3. Male hedgehogs were more heavily infected than females, while all ages of hedgehogs appeared equally susceptible to infection.

4. Of the 124 coagulase positive strains obtained, 107 (86·3%) were resistant to penicillin. Resistance to other antibiotics—chloramphenicol, streptomycin, tetracycline, erythromycin, celbenin—was not encountered.

5. Thirty-three (83%) of forty strains produced β-lysin.

6. Mites (Caparinia tripilis) and fungi (Trichophyton mentagrophytes var. erinacei) did not appear to directly influence the carriage of Staphylococcus aureus on the hedgehog skin.