The relative susceptibility of the LLC-MK2 cell line and primary rhesus monkey kidney cultures to thirty-eight prototype strains of human enteroviruses is described; of these strains only ECHO types 16, 18, 21 and 23 failed to cause CPE in the continuous cell line. The efficiency of the two tissues for the isolation of enteroviruses from faecal extracts is compared. The results show that the LLC-MK2 cell line is very satisfactory for the isolation of Coxsackie B and polioviruses, but not so useful for the isolation of ECHO viruses. The identification of enteroviruses by neutralization tests in LLC-MK2 cells is successful.

Samples of lesions containing viable myxoma virus were collected from 222 infected wild rabbits captured in 80 counties of Britain during October–November 1962. They were dispatched by air to Australia and passaged once in domestic rabbits before being tested for their virulence by the intradermal inoculation of groups of six laboratory rabbits with small doses of virus.

The results showed that a wide range of viruses of differing properties now coexist in Britain. Their virulence ranges from very high (99 % lethal) to low (about 50 %), but the majority of strains fall into the grade III virulence group, with estimated case mortality rates varying between 70 and 95%. The viruses also produce disease of varying symptomatology, skin lesions being very prominent, raised or flat. There was no obvious association between lesion type and virulence.

Tests made on the wild rabbits from which the samples were obtained, and on Inoculated domestic rabbits, showed that virulence could not be predicted by gel-diffusion tests.

The findings are described of a combined clinical, bacteriological and virological study which included all children admitted to the City Hospital, Edinburgh, with acute respiratory infection and whooping cough during the winters 1961–62 and 1962–63. During the first winter 131 cases aged 0–12 years and in the second winter 133 aged 0–6 years were examined. The respiratory illnesses were divisible into upper respiratory tract infection, bronchitis, pneumonia, and whooping cough; many of the cases of whooping cough had respiratory complications with bronchitis or pneumonia.

Paired sera, a throat swab and a faecal specimen were taken from each child and investigated vircdogically. Over both winters the highest total virus isolation rate was found in the group suffering from upper respiratory disease. Approximately two-thirds of the total number of patients from whom virus was isolated and from whom both acute and convalescent sera were available gave a serological response to the homologous virus; the highest proportion of these patients occurred in the pneumonia and URTI groups. The groups of viruses associated with a fourfold or greater rise in antibodies occurred in the following proportions of the cases: myxovirus 9 %; adeno virus 7 %; entero virus 4 %; herpes simplex 3 %.

Bacterial pathogens were isolated from 37 % of patients in 1961–62 and from 49 % in 1962–63, Staph. pyogenes being the most common pathogen. Isolation of pneumococci was facilitated during the second year by the examination of a nasal swab. Pre-admission chemotherapy did not significantly alter the bacterial isolation rates. Agglutination studies were carried out on forty clinical cases of whooping cough admitted during the two winters and thirty-two showed significant stable titres to Bordetella pertussis; only 9 (18 %) of these cases gave a history of prophylactic immunization.

A third of the patients had neither bacterial nor viral pathogens.

The findings in this survey illustrate the need for further intensive virological and bacteriological studies of acute respiratory infections in early childhood.

A method is given for obtaining the approximate standard error of the anti-serum (or antigen) maxima titre in the complement fixation test when the maxima line is determined by only two points; the same formulae may be used to obtain a conservative estimate of the standard error when more than two points are available. If the degree of lysis in each reaction mixture can be scored more finely than into the three simple states of ‘no lysis’, ‘partial lysis’ and ‘complete lysis’, then more accurate estimates can be obtained. A method is also given for estimating the concentration of one antiserum (or antigen) relative to that of another when they react homologously.

1. The susceptibility of sheep to infection with Langat virus has been studied. No viraemia or symptoms were detected in sheep inoculated either subcutaneously or intracerebrally.

2. Only those sheep inoculated intracerebrally with 106·0–108·0 mouse IC LD 50 of virus developed significant quantities of neutralizing antibody.

3. Two-thirds of sheep vaccinated with varying doses of Langat virus withstood subcutaneous challenge of louping-ill virus followed by intracerebral starch. All the intracerebrally vaccinated sheep survived this form of challenge but no sheep, whether vaccinated subcutaneously or intracerebrally, withstood intracerebral challenge of louping ill.

4. In a field trial, three of ten hoggs vaccinated with Langat virus and exposed to natural louping ill infection at Camlarg and Dalcairnie died of the disease compared with all eight of the non-vaccinated hoggs. At Knockgray, there was no louping ill infection, but 93% of the hoggs from this hirsel developed louping ill antibody after transfer to Camlarg.

5. Monkeys infected intracerebrally, subcutaneously or orally with Langat virus showed a low titre viraemia without clinical symptoms or histological changes in the brain and developed high titres of antibody. Vaccinated monkeys challenged with either Central European tick-borne encephalitis or Kyasanur Forest disease viruses remained healthy compared with control monkeys which showed evidence of disease.

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.

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.

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.

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. 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.

An antibiotic substance biologically resembling penicillin G was produced by the growth of Trichophyton mentagrophytes var. erinacei, T. mentagrophytes var. granulare and T. mentagrophytes var. interdigitale in Sabouraud's dextrose broth. An antibiotic concentration equivalent to 7 units/ml. penicillin G could be produced by var. erinacei when grown in a suitable nutrient medium. Epidermophyton floccosum also produced a substance which inhibited the growth of the Oxford staphylococcus. However, this substance was not completely inactivated by penicillinase. No in vitro antibiotic production could be demonstrated with T. rubrum, T. concentricum, T. terrestre or Microsporum canis.

Penicillin production could be demonstrated in rabbit skin infected with T. ment-agrophytes var. erinacei. Pathogenic staphylococci falling on a var. erinacei guinea-pig lesion increased rapidly in the ringworm tissue. The inhibiting concentration of penicillin G for such staphylococci was shown to increase from 5·0 µg./ml. to above 20·0 µg./ml. as the ringworm progressed.

The presence of T. mentagrophytes var. erinacei in a high percentage of hedgehogs is considered the main reason why the skin is the primary site of staphylococcal multiplication in hedgehogs and why most of the Staphylococcias aureus strains recoverable from these animals are penicillin resistant.

Control of houseflies by modern insecticides is becoming unreliable owing to emergence of resistant strains, so that some older measures deserve reconsideration. Exclusion of mosquitoes by gauze has been studied experimentally but not, apparently, of houseflies.

Some simple tests show that a suitable gauze to exclude houseflies (and larger insects) would be 10 mesh 32 s.w.g. with an aperture 2·17 mm. square. This compares with a gauze recommended for excluding mosquitoes, 18 mesh and 32 s.w.g. with an aperture 1·16 mm. square.

The advantages of the wider gauze for flies are admission of more light and air and lower cost. Some simple experiments on the relative air resistance of mosquito ind fly gauze were made by a method involving retardation of a pendulum by a gauze circle. The results suggest that the obstruction to ventilation is roughly proportional to the percentage obstruction (as with light) which was 20 % for the fly gauze and 36 % with the mosquito gauze.