bluuebunny/crossref_metadata_2025 huggingface dataset:
Streptococcal infections among children in a residential home: III. Some factors influencing susceptibility to infection
Authors: Holmes Margaret C. , Williams R. E. O. , Bloom C. V. , Hirch Ann , Lermit  , Woods Eileen
Published: May 2009

Children in a residential home whose tonsils had been removed had lower attack rates for streptococcal sore throat than tonsillectomized children. Tonsillectomy did not have a consistent effect on respiratory tract illness.

Tonsillectomy has a similar effect on the outcome of individual exposures to streptococcal infection; the difference was more marked for illness than for simple colonization.

The apparent benefit from tonsillectomy could not be attributed to the ageing of the child, and was considered real. Its magnitude did not seem, however, great enough to justify a policy of extensive tonsillectomy, particularly in view of the possible risks to the child.

A child who had been ill with infection due to one streptococcal type rarely became ill when re-exposed to the same type. In addition there was some evidence in children with tonsils of an immunity, perhaps short lived, which was clearly not type-specific.
Studies on poliomyelitis virus: III. The use of ultra-violet light as an additional means of inactivation of formalinized vaccine
Authors: Hampton J. W. F. , Polson A.
Published: May 2009

The inactivation rates of tissue-culture polio virus have been determined and these have been applied to the irradiation of formalinized vaccine, as an additional inactivation process, using a simple irradiator.

The antigenic potency of the vaccine was apparently unimpaired.

We wish to thank the late Prof. van den Ende for his keen interest and criticism; Dr H. Malherbe and his staff for carrying out many of the titrations; Dr P. D. Winter for co-operation in irradiating samples of vaccine, and Margaret Pakes for invaluable technical assistance.
The significance of the abattoir in salmonella infection in Bradford
Authors: McDonagh V. P. , Smith H. G.
Published: May 2009

1. During the years 1954–56 large number of salmonellae, comprising six sero-types and a number of Salm. typhi-murium phage types, were isolated at the Bradford abattoir.

2. Most of the cultures were derived from pigs; the animals presented no sign of clinical illness.

3. Human salmonella infections in Bradford over the same period were closely related to the abattoir findings.

4. It seems probable that individual pigs are infected on the farms and when brought to the abattoir may infect others in the lairages.

5. Limiting the duration of stay in the lairages and prevention of overcrowding may substantially reduce the proportion of animals found infected at slaughter.

We wish to express our thanks to Dr John Douglas, Medical Officer of Health, Bradford, for his interest and encouragement in this investigation and to Mr F. H. Myres, Mr J. Noble, Mr E. Root and Mr R. Butterfield of the Bradford Health Department for their enthusiastic help. Thanks are also due to Dr Joan Taylor and Dr E. S. Anderson and staffs of the Salmonella and Central Enteric Reference Laboratories, Colindale, for their assistance in typing Salmonellae, and to a number of our colleagues who have kindly read the script and offered valuable criticisms.
Studies in the epidemiology of infectious myxomatosis of rabbits: V. Changes in the innate resistance of Australian Wild rabbits exposed to myxomatosis
Authors: Marshall I. D. , Fenner Frank
Published: May 2009

Annually for 4 years groups of young Australian wild rabbits have been captured during non-epizootic periods from areas in which myxomatosis has occurred during the previous summer. The intensity of the preceding epizootic was measured by testing a sample of survivors for antibody. The captured young rabbits were raised in the laboratory until they were about 4 months old and then inoculated intradermally with small doses of the slightly attenuated myxoma virus strain Aust/Corowa/12–52/2 (KM 13), all samples of virus being derived from the same batch which has been stored at -70°C.

The results show there is a significant negative correlation between the mortality rate and the degree of exposure to myxomatosis of the forbears of the tested animals. Passive and active immunization have been excluded and this result is ascribed to increased genetic resistance.

We are greatly indebted to Mr. F. N. Ratcliffe, Officer in Charge of the Wildlife Survey Section of the Commonwealth Scientific and Industrial Organization, and to his officers, especially Messrs W. E. Poole, K. E. Myers, G. Douglas, B. V. Fennessy, H. Frith and K. Keith for their invaluable assistance in collecting rabbits and serum samples.

We have had valuable discussions with Dr W. R. Sobey, Dr P. J. Claringbold and Dr G. S. Watson on genetical and statistical aspects of the problems under study.
Another test for heterogeneity of host resistance in dilution assays
Authors: Moran P. A. P.
Published: May 2009

Suppose that λ is the average density per unit volume in a suspension of infective particles such as virus particles. To estimate λ the usual method is to make up a series of inocula of various dilutions containing expected numbers of particles …λi−1, λi, λi+1,… which are known multiples of λ. Each of these is then tested by inoculation in a host such as an egg. We consider only the case where the dilution series is twofold (λi=λ2i, say) and the same number of eggs, N, is tested at each dilution. Then if we are sure that an egg is infected if and only if the inoculum contains at least one infective particle, the probability that the egg remains sterile is Pi=exp {− λ2i}. If each particle is not certainly infective but has a probability p of infecting the egg, the probability of sterility of an egg chosen at random is exp {− λp2i} provided that p does not vary from egg to egg. It is then only possible to estimate λp from the results.
The growth of micro-organismsin vivowith particular reference to the relation between dose and latent period
Authors: Meynell G. G. , Meynell Elinor W.
Published: May 2009

The growth ofSalmonella typhimuriumin mice was studied by performing viable counts on pooled viscera and, in the case of fatally infected mice, by determining the relation between size of dose and mean death time. The results suggested that this system conformed to a general model which postulates (a) that the organisms causing the response (death in the present experiments) increasein vivoat a rate which is constant for all doses, and (b) that the response is certain to occur when their number reaches a constant figure. It follows that logarithm of dose (for doses > 1 ED50) should be linearly related to mean latent period (the interval between inoculation and response). A search of the literature showed that this relation was observed in many reported infective systems.

The interpretation of the observations on partially resistant mice (LD50= 102.5−106organisms) was not straightforward for the hypothesis of independent action (Meynell & Stocker, 1957) states that only a random fraction of the inoculum usually initiates each response. Multiplication of this fraction is considered to cause a reduction in host resistance so that other organisms survivingin vivobegan to increase in numbers and to contribute to the fatal infection. The observations showed that this could well occur as (i) the counts on all mice, whether fatally infected or not, increased exponentially for 2–3 days after inoculation; (ii) the growth curves of fatally infected mice showed exponential increase of the whole inoculum as postulated; and (iii) the length of the death time was found to be determined by the growth of the whole inoculum and not by the predicted random fraction. The viable count per fatally infected mouse at the time of death was approximately constant at 108.75organisms. There was no evidence that the course of the infection was influenced by organisms which may have been killedin vivoas the requirements of the model were satisfied by the observed behaviour of the viable organisms alone. The rate of increase of organisms in a fatally infected animal was found to be less, the greater the LD50of the host; which suggested that the degree of host resistance was determined by successive random events occurring after inoculation.

The latent period/log dose curve provides a new test of the hypothesis of independent action, since this predicts that most responses to doses equal to or less than 1 ED50are each initiated by only one inoculated organism. Hence, the latent period should become approximately constant at such doses. This was found to be so in the present experiments.

The authors are grateful to the Medical Research Council for meeting part of the expenses of this work by a grant to G. G. M. They also wish to acknowledge the help of Dr W. R. Bryan, Dr B. Mandel, Dr D. B. W. Reid and Dr G. T. Stewart who provided unpublished data.
Airborne micro-organisms: a technique for studying their survival
Authors: Harper G. J. , Hood A. M. , Morton J. D.
Published: May 2009

The concentration of viable cells in an aerosol of micro-organisms is reduced by physical loss and biological decay. To study biological decay it is necessary to distinguish between the two processes. The preferred way of doing this is to mix the test aerosol with a tracer which is subject only to physical loss: the tracer and test cells should be mixed before dissemination.

The recommended tracers for bacterial clouds are bacteria made radioactive by growing on a medium containing 32P, then killed with formaldehyde and washed. To ensure closest identity of physical behaviour it is necessary that the tracer should be of the same species as the cells under test.

We are grateful to Mr E. O. Powell for helpful comment during the preparation of this paper.
Leptospiral infection rates of wild rats in Britain
Authors: Broom J. C.
Published: May 2009

1. Microscopical examination of the kidneys of 850 Rattus norvegicus killed in various parts of England and Wales showed an infection rate of 43% with leptospires, assumed to be Leptospira icterohaemorrhagiae for reasons stated.

2. Infection rates calculated from the whole series were the same for rural, urban and sewer rats, but there were some local differences as between one area and another for both surface and sewer rats.

3. An unusual feature was the finding of a 35% infection rate among young rats.

4. In another series of 219 rats taken alive, agglutination tests and kidney cultures gave an infection rate of 43%. Kidney sections of 69 of these rats were also examined microscopically and the results of the different methods of examination were analysed.

5. A similar survey was made on R. rattus. Only 2 of 88 caught in London were positive, compared with 31 of 35 killed in other towns. An additional 98 R. rattus killed during the fumigation of ocean-going steamers were examined, and 69 were found to be infected.

I should like to record my thanks to the following members of staff at the Infestation Control Division of the Ministry of Agriculture, Fisheries and Food, Tolworth, Surbiton, Surrey, for their help in this survey: Mr C. J. Armour, Dr E. W. Bentley, Dr W. P. Crowcroft, Mr R. A. Davis, Miss Y. Larthe and Miss M. Lawrence. Also to the following Field Officers of the Ministry who supplied material for this investigation: Mr A. F. R. Brown, Mr R. J. Clark, Mr G. R. Hill, Mr A. C. Hopkins, Mr R. S. Jailler, Miss B. B. Jones, Miss M. Neve, Mrs J. C. Russell and Mr S. R. Surtees.

I wish also to acknowledge the valuable assistance received from members of my technical staff, especially Miss Joan Messum and Mr R. J. Reed.
Studies of the loss of viability of bacterial aerosols: III. Factors affecting death rates of certain non-pathogens
Authors: Ferry Ronald M. , Brown William F. , Damon Edwin B.
Published: May 2009

1. Additional quantitative studies of the survival of micro-organisms in aerosols are reported.

2. Substitution of nitrogen for oxygen in the ambient medium decreases k′2, the rate of secondary loss of viability ofM. candidus, Esch. coliandS. marcescens, by 30–50%.

3. The rate of primary decay (k′1) ofEsch. colidoes not appear to be affected by a similar change of atmosphere.

4. The rate of secondary decay, k′2, ofM. candidusappears to increase two-to three-fold for 10°C. increments in temperature.

5. Treatment of suspensions ofEsch. coliwith petroleum ether alone or containing lipid material increases k′1in aerosols generated from such suspensions.

6. Treatment ofMyco. phleiwith petroleum ether appears to lower resistance to subsequent sonic irradiation.

These observations are consistent with the hypothesis that differences in the physical and chemical structure of micro-organisms are reflected in constants k′1, k′2and b.

We gratefully acknowledge the effective interest of two former assistants, T. Grant Maple and Eugene Mills, as well as the careful, effective, and conscientious work of our technical assistants, Ann Barr, Nora Galins, Cynthia Hartwig, Grace C. Leigh, Elizabeth Neidhardt, Paulette Slaney and Martha Szerslip, who have at different times helped secure the data presented here. Mrs Joseph J. Ecker deserves special thanks for care in the preparation of the manuscript.
The Type Classification of Staphylococcus Aureus: a Comparison of Phage-Typing with Serological Typing
Authors: Oeding Per , Williams R. E. O.
Published: May 2009

A comparison has been made between the bacteriophage and serological methods for identifying types among coagulase-positive staphylococci. In only a few cases was one particular serotype clearly related to a particular phage-type, and in several cases single ‘types’ recognized by one method contained several different ‘types’ when tested by the second method. Nevertheless, when sets of strains isolated in the investigation of epidemics or of the nose and skin carrier state of particular individuals were tested by the two methods, consistent results were obtained: an individual combination of phage-type and serotype appeared to be stable.

The principal advantages of phage-typing are the facts that it is able to recognize more types than the serological method, and that the distinctions between the types are based on a greater number of different reactions. The advantages of the serological method are the smaller number of untypable strains and its greater technical simplicity.

Thanks are due to Miss Joan Rippon, Ph.D., for assistance in the analysis of the phage-typing results.
An Insecticide-Bait-Box Method for the Control of Sylvatic Plague Vectors
Authors: Kartman Leo
Published: May 2009

Field trials were conducted in the San Francisco Bay region to test the effectiveness of 5 and 10% DDT powder in rodent bait-boxes against fleas on native wild rodents and in the rodent nests. The principal species concerned were known flea vectors of sylvatic plague, Malaraeus telchinum and Hystrichopsylla linsdalei, and the meadow vole, Microtus californicus, an important plague reservoir. Preliminary trials with the bait-boxes showed that Microtus and other small native rodents would enter them quite readily and feed upon rolled oats. About 90 g of either 5 or 10% DDT powder, placed on the floor boards of the bait-boxes, was picked up by the rodents and resulted in effective immediate control of all flea species. Residual control of all flea species on Microtus (with the possible exception of Hystrichopsylla linsdalei) was obtained over a period of several months. Analyses of Microtus nests showed considerable amounts of DDT which had been transported to them by the rodents. All flea species in nests were effectively controlled by 5% DDT for at least 132 days after the DDT was removed from the area.

The field work was performed by Alva R. Kinney and Robert L. Martin. The fleas were identified by Harold E. Stark. The DDT analyses of rodent nests were done by the personnel of the Technical Development Laboratories, CDC, Savannah, Georgia, under the direction of J. A. Jensen.
Numerical Studies on Some Contagious Distributions
Authors: Spicer C. C. , Lipton S.
Published: May 2009

A numerical investigation of three contagious distributions characteristic of epidemic data has been made using an electronic computer.

All three show a modified threshold effect such that the proportion of a community affected tends to 100% as its size increases though there is no abrupt change of form.

We would like to thank Mr M. J. R. Healy for assistance with one of the programmes, and Miss Molly Fretton for her help with the computing.
The influence of temperature and humidity on spore formation and germination inBacillus anthracis
Authors: Davies D. G.
Published: May 2009

Experiments performed on spore formation inB. anthracis, in a wide range of closed atmospheres of chemically controlled humidity, showed that the sporing time ofB. anthracisis prolonged considerably as the humidity decreases, both at 26 and 37° C. The effect is less noticeable at the lower temperature.

Experiments performed on spore germination in the same organism showed that a temperature range of 20–44° C. permitted germination of the five strains tested. Above a temperature of 39° C. and below 30° C. germination time lengthened considerably.

Experiments performed on the influence of humidity on spore germination, both at 26 and 37° C. showed that no germination could take place at a relative humidity of 80% or below. Germination time was considerably prolonged when the humidity value fell below 100%.

This work formed part of a thesis for the degree of M.D. in Bristol University. I wish to thank Dr G. S. Wilson for his advice in preparing this paper.
An outbreak of infection with Salmonella typhimurium in a general hospital
Authors: Datta Naomi , Pridie R. B. , Anderson E. S.
Published: May 2009

An outbreak of Salmonella typhimurium infection in a large general hospital is described. The outbreak was spread over some 20 weeks and gave rise to 102 cases of enteritis and there were at least 150 symptomless excreters of the organism.

Evidence is presented to support the view that the method of spread was by cross-infection, not by contamination of food in bulk. Control measures, which ultimately brought the outbreak to an end, were instituted on this basis.

We wish to thank Dr A. J. H. Tomlinson and his staff at the Public Health Laboratory, County HallS.E. 1 for the generous assistance they gave us in examining all the specimens from the hospital staff during the outbreak. The resources of the Department of Bacteriology of the Postgraduate Medical School were at that time largely devoted to teaching and adequate investigations could not have been made without this help. Dr Tomlinson also gave us much advice both during and after the outbreak for which we are most grateful.

Dr E. S. Anderson, Director of the Central Enteric Reference Laboratory and Bureau, Colindale, London, N.W. 9, very kindly undertook the phage-typing of many of the strains of Salmonella typhimurium isolated and we wish to express our thanks to him for this and other help he gave us in the investigation of the outbreak.

Our thanks are also due to Dr Joan Taylor, Director of the Salmonella Reference Laboratory, Colindale, for her help and interest.

Discussions with Dr R. M. Fry and Dr Joan Boissard in Cambridge in connexion with their investigations of a similar outbreak were most interesting and valuable and it gives us pleasure to thank them.

We also acknowledge gratefully the help and co-operation of our colleagues at Hammersmith Hospital, especially Dr C. E. Roberts, the Medical Superintendent, and of those at the Postgraduate Medical School.
Ethylene oxide sterilization in hospital practice
Authors: Freeman M. A. R. , Barwell C. F.
Published: May 2009

A non-explosive mixture of ethylene oxide and Arcton 12 is described. This mixture is now available commercially in this country.

A sterilizing chamber and related equipment for use with this gas and a sterilizing technique are also described.

Some applications of ethylene oxide sterilization are briefly discussed.
The ventilation of operating-theatres
Authors: Lidwell O. M. , Williams R. E. O.
Published: May 2009

Measurements to assess the performance of the ventilating system have been carried out in a series of twenty six operating theatres using nitrous oxide as a gaseous tracer to simulate the movement of airborne bacterial contamination. In order to prevent local clouds of contamination derived from the activities of the operating-team persisting in the neighbourhood of the operating-site it is desirable that there should be appreciable air movement in the centre of the room. Downward displacement, ‘piston type’, ventilation systems may be an exception to this but the indications for their use are not clear. Other points discussed include the necessity for the limitation of the volume of mechanical exhaust if adequate positive pressure is to be maintained in the theatre and the need to control heat dissipation from sterilizers, autoclaves and other sources.
Some factors affecting preservability of freeze-dried bacteria
Authors: Obayashi Yoji , Ota Sunao , Arai Shiro
Published: May 2009

1. The use of sodium glutamate as a medium for freeze-drying Lact. bifidus significantly enhanced the stability of the dried product, especially the heat stability.

2. The optimal concentration of sodium glutamate, as a drying medium, was found to depend on the bacilliary concentration; the higher the concentration of the bacilliary suspension used the higher was found to be the optimal concentration of the sodium glutamate.

3. It was possible to classify various drying media according to the degree of sublimation of the product during the process of freeze-drying. Two types were observed; in the first, which included sodium glutamate and glucose, the sublimation rate diminished with the increasing concentration of the medium, whereas in the second group, which included polyvinyl pyrrolidon K 90 (PVP), soluble starch and dextran, no such diminution was observed when the concentration of the medium was increased.

4. By the combination of sodium glutamate or glucose with a medium belonging to the second group sublimation was found to be promoted.

5. The stabifity-conferring effect of sodium glutamate on dried Lact. bifidus was markedly enhanced when the glutamate was combined with a drying medium belonging to the second group. This effect is attributed to a desiccation-promoting property of the latter medium.

6. Lact. bifidus as a freeze-dried preparation showed a somewhat better survival rate when sealed in air than when sealed in vacuo. In the case of other anaerobic organisms tested there was no significant difference in the survival rates under the two methods of storage.
A comparison between the intranasal and intracerebral infection of mice with Bordetella pertussis
Authors: Standfast A. F. B. , Dolby Jean M.
Published: May 2009

1. The main differences between intracerebral and intranasal infections in mice with virulent strains of Bordetella pertussis are in: (1) the responses to small in fecting doses (< 1 LD 50); (2) the action of antisera in controlling infection; (3) the action of toxin on brain and lung; and (4) the rates of increase of the viable count. The two infections can run concurrently in the same mouse without any demonstrable interference.

2. The terminal viable count in the lung and brain is c. 108 organisms.

3. In the brain there is no sublethal infection with virulent strains; probably even single organisms can grow up to the critical level and kill the mouse. In the lung sublethal infections are found in which the count rises to a figure below the critical level and then declines.

4. The action of ‘intranasal’ antiserum is to reduce a lethal infection to a sublethal one in the lung but there is no effect in the brain. ‘Intracerebral’ antisera cannot act until the blood-brain barrier becomes leaky, when they are able to reduce the viable count and eventually sterilize the brain. In the lung ‘intracerebral’ sera have no action against lethal infections but can control small infections (<I LD 50). The sublethal intranasal test measures this effect but it also measures the action of ‘intranasal’ sera and so cannot be used to distinguish the two types of sera and hence the two antigens.
Infection of mice by the respiratory route with Salmonella typhimurium
Authors: Darlowa H. M. , Bale W. R. , Carter G. B.
Published: May 2009

Experiments have been described in which mice were infected by the inhalation of a mono-dispersed aerosol of Salm. typhimurium. The disease so produced was characterized by a specific primary pneumonia. The lethal dose was very much smaller than that required by ingestion, and was approximately equal to the intraperitoneal lethal dose. Possible implications have been discussed.

The authors wish to thank Mr S. Peacock for his invaluable help in the operation of the Henderson apparatus, and Messrs A. V. Lowle and C. M. R. Pitman for technical assistance. We also wish to thank Dr J. S. Paterson for supplying some of the bacterial strains, and for much advice and encouragement.
The epidemiology of the common cold II. Cross-infection and immunity
Authors: Lidwell O. M. , Williams R. E. O.
Published: May 2009

Analysis by epidemiological methods of the spread of the common cold among office workers and their families has failed to account for more than a fraction of the infections as a consequence of known exposure to infected individuals. Infections too mild to be recorded as colds, survival of the virus in the environment and its subsequent dispersal are considered as possible explanations of this.

The distribution of serial intervals between colds suffered by members of the same family indicates that the median interval between the onset of an infection and the first symptom in infection apparently arising from it as cross-infections was between 21½ and 31½ days. This is only slightly longer than the median interval, 2·4 days, observed between nasal installation and the onset of symptoms in experimental infections.

There is some epidemiological evidence that susceptibility to the common cold is reduced during the weeks following a cold.

We should like to repeat, in this the second paper in this series, our thanks to the Ministry of Pensions and National Insurance and to the Shell Petroleum Company, to those members of their staffs and to the nurses and others who helped us in this investigation.
Sodium fluoracetate and fluoracetamide as ‘direct’ poisons for the control of rats in sewers
Authors: Bentley E. W. , Hammond L. E. , Bathard A. H. , Greaves J. H.
Published: May 2009

1. Field trials suggest that 3-monthly operations against rats in sewers using either 0·25% sodium fluoracetate or 2% fluoracetamide as a direct poison are more effective than 6-monthly treatments with 2·5% zinc phosphide or 10% arsenious oxide using the pre-baiting method.

2. In six paired trials 2% fluoracetamide gave better results (an apparent 100% clearance in five instances) than 0·25% sodium fluoracetate.

3. There is no evidence, at present, that direct poisoning treatments with 2% fluoracetamide or 0·25% sodium fluoracetate are improved by the addition of mould inhibiting substances to the bait.

The work described above was made possible only by the co-operation of a large number of local authority councils and their staffs, to whom we are therefore much indebted. We wish to thank also, Mr J. D. Riley who gave considerable help during the early stages of the trials.
The effect of temperature on the growth of pox viruses in the chick embryo
Authors: Bedson H. S. , Dumbell K. R.
Published: May 2009

The ‘ceiling temperature’ of a pox virus has been defined as the maximum temperature (to the nearest 0·5° C.) of incubation at and below which that virus will grow and produce pocks on the chorioallantois of 12-day-old chick embryos, and above which no pocks appear.

Ceiling temperatures have been estimated for: alastrim (2 strains), 37·5° C.; variola major (2 strains), 3·8° C.; ectromelia (3 strains) and monkey pox (1 strain), 39°C.; cowpox (2 strains), 40°C. Five strains of vaccinia and two of rabbit pox were all capable of pock formation at 40·5° C. Above this temperature difficulty was encountered because many embryos died. But the ceiling temperature for two strains of vaccinia and one strain of rabbit pox was probably 41° C. The Utrecht strain of rabbit pox produced some lesions at 41·5° C.—the highest temperature used.

The ceiling temperatures of the viruses used were not correlated with their thermal stabilities at 55°C.in vitro. Thus vaccinia strain, Lederle-7 N, had a high ceiling temperature and a low thermal stability, while variola major had a low ceiling temperature and a high thermal stability. For this reason ceiling temperatures and thermal stability are regarded as distinct characters.

In experiments with twelve of the seventeen viruses of which the ceiling temperatures had been determined, the virulence for the chick embryo was then measured. It was found that, in general, the higher the ceiling temperature of a virus the greater was its virulence for the chick embryo.

The presentation of these results is followed by a brief discussion of their significance and potential use.
Coe (Coxsackie A21) virus, para-influenza virus and other respiratory virus infections in the R.A.F., 1958–60
Authors: McDonald J. C. , Miller D. L. , Zuckerman A. J. , Pereira Marguerite S. , Deacon Ann , Smith Robert , Woodward Thomas C.
Published: May 2009

1. In two R.A.F. recruit stations between November 1958 and March 1959, there were 2603 admissions to Sick Quarters with respiratory illness. Throat swabs from 1129, and paired sera from 1197 were tested for certain respiratory viruses.

2. From the serological results it was estimated that 19% of the admissions were associated with influenza A infection, 7% with influenza B, 26% with adenovirus, 1% with para-influenza Type 1, 1% with para-influenza Type 3 and 8% with Coe virus, but as 21% of the identified infections were multiple the proportion of illness associated with one or more of these infections was only 50%. Thirty-four per cent of the Coe virus infections and 56% of the para-influenza virus infections were multiple.

3. Virus isolation test results led to a similar estimate of the frequency of adenovirus infection (23%) but to a lower estimate for Coe virus (3%) and for the para-influenza viruses, no systematic attempt was made to isolate influenza viruses. Reasons are given for thinking that most of the admissions associated with Coe virus infection in 1958, but few of those in 1959, were caused by this agent. The proportion of illnesses attributable to viruses of the para-influenza group was probably about 1%.

4. The main symptoms associated with Coe virus infection were upper respiratory. Hoarseness was rather more prominent than in other infections but the height and duration of fever and the frequency of febrile symptoms were less. The few illnesses associated with para-influenza virus infection had no obvious distinguishing features.

1960 survey

1. Blood specimens were taken from 205 recruits on their arrival at a recruit camp in January 1960 and immediately before their departure in March; 764 men in ten operational stations were bled in January and a sample of 260 were bled again in March.

2. The respiratory illness admission rate was 25% in the recruits and 4% in the trained men; 49% of the recruits showed a rise in antibody to one or more respiratory virus antigens compared with 2% in the other group. The high rate of infection in recruits was mainly due to adenovirus (36%) and Coe virus (20%).

3. It was estimated that about a third of the adenovirus infections and an eighth of the Coe virus infections were responsible for illness requiring admission. There was no indication that either infection caused any appreciable number of less severe illnesses not requiring admission.

4. Evidence from this survey and the earlier one suggests that the presence of neutralizing antibody to Coe virus does not prevent infection, though it appears to lower the probability of illness.
On the recognition and therapy of Simian woolsorter's disease
Authors: Gochenour W. S. , Sawyer W. D. , Henderson J. E. , Gleiser C. A. , Kuehne R. W. , Tigertt W. D.
Published: May 2009

1. A model of anthrax infection in rhesus monkeys closely simulating human inhalation anthrax has been employed to study the course of the illness and methods of recognition and therapy.

2. Roentgenographic evidence of mediastinitis was detected early in the illness and served as a suitable indication for starting treatment.

3. Therapy with either penicillin or tetracycline appeared efficacious when started at the time chest roentgenograms first evidenced disease.

4. Isolation of penicillin-resistant B. anthracis from an animal dying during treatment with penicillin is reported.
The use of acetylethyleneimine in the production of inactivated foot-and-mouth disease vaccines
Authors: Brown F. , Hyslop N. St G. , Crick Joan , Morrow A. W.
Published: May 2009

Suspensions of FMD virus treated with 0·05% formalin at 26° C. for periods up to 144 hr. remained infective for cattle, although the infectivity could not be detected in the presence of aluminium hydroxide. Infectivity was detected in similar virus suspensions which had been treated with 0·05% AEI at 37° C. for 8 hr. but not in suspensions treated for 12 hr.

Vaccines prepared from these suspensions were antigenically potent and serum neutralization tests demonstrated the development and regression of serum antibody. The AEI vaccines were at least as potent as the corresponding formalin vaccines.
The use of ceiling temperature and reactivation in the isolation of pox virus hybrids
Authors: Dumbell K. R. , Bedson H. S.
Published: May 2009

A simple method for the isolation of pox virus hybrids on the C.A.M. has been described. One parental virus was used as a heat-inactivated suspension. The other parent was used in the active state, but at a temperature higher than its ceiling temperature. Under these conditions the inactive parent was reactivated so that pocks resulted only from the cells infected with both parental viruses. Many of these pocks were unlike those of either parent. Such lesions were found to contain a high proportion of hybrids. In these experiments, alastrim was crossed with rabbit pox and variola major with cowpox.

The term ‘heat-tethered’ has been used to describe virus whose intracellular cycle of development has been arrested by incubation at too high a temperature. Heat-tethered virus has interesting properties and two of these have been described. When the temperature is lowered, heat-tethered virus will start to grow again. Its reactivating potential has been mentioned above. A more detailed account of the properties of heat-tethered virus is being prepared.
Hybrids derived from the viruses of alastrim and rabbit pox
Authors: Bedson H. S. , Dumbell K. R.
Published: May 2009

The characters of seven clones of virus derived from mixed infections with alastrim and rabbit pox have been described. One clone was shown to behave as rabbit pox in respect of all its markers. The other six were found to be distinct new types of virus, each having a different combination of the parental characters. The reasons for accepting these viruses as hybrids have been discussed. An analysis of the pairwise crosses between individual markers suggested that each of the nine markers was capable of segregating independently.
The serological differentiation ofMycoplasmastrains (pleuropneumonia-like organisms) from various sources
Authors: Lemcke Ruth M.
Published: May 2009

A complement fixation test with rabbit antisera was used to differentiate 82 cultures ofMycoplasmafrom man, mammalian cell cultures, laboratory rats and mice, cattle, goats, poultry, embryonated eggs and sewage.

Seventeen serotypes were distinguished, 5 from man, 1 from mammalian cell cultures, 4 from rats and mice, 4 from cattle and goats, 2 from poultry and one saprophytic. Most of these corresponded to recognized species ofMycoplasma, but 1 of human origin (represented by 1 strain, Navel), and 1 from tissue cultures (5 strains), may represent new species. R38, one of the serotypes from rats, could be distinguished from the speciesM. arthritidis, but is probably an antigenic variant rather than a distinct species. Two species hitherto recognized as distinct,M. arthritidisandM. hominis type2, could not be distinguished and appear to constitute a single species. These findings illustrate the necessity, from the viewpoint of taxonomy, of comparing mycoplasma strains by serological methods.

The serotypes of human and animal origin were largely host-specific. Exceptions were the inclusion ofM. arthritidisfrom rats andM. hominis type2 from man in a single serotype, the finding of a bovine organism among the strains isolated from goats and of a saprophytic strain in a rat.

In relation to the aetiology of disease in man and animals, the isolation of an endogenousMycoplasmafrom embryonated eggs used to passage infective material illustrates the importance of identifying these organisms serologically. The demonstration of mixed mycoplasma infections in lesions in two rats shows the necessity of adequately purifying all cultures ofMycoplasmabefore examination.

I would like to thank those workers mentioned in Table 1 who kindly provided the cultures which they isolated. In addition I wish to thank the following who sent cultures: Prof. A. C. Ruys and Dr D. Herderscheê (Amsterdam) for G2, Prof. H. E. Morton (Philadelphia) for Campo and 07, Dr D. G. ff. Edward (Beckenham) for Campo (PG27),M. bovigenitalium(PG11),M. iners, andM. gallinarum, Dr R. G. Wittler for H606 and Miss A. G. Newnham for A36, TU, PSU4 and TC727.

My thanks are also due to Dr L. H. Collier of this Institute, Dr G. W. Csonka (London), Prof. A. E. Macdonald (Aberdeen), Dr J. Payne (Edmonton, Alberta), Mr A. A. Tuffrey (Carshalton) and Dr D. Weisinger (Basle) who provided material from which PPLO were isolated. I gratefully acknowledge all the information so generously supplied by these workers about the strains or material provided.

I am indebted to Miss A. G. Newnham for carrying out an agglutination test on the avian strains.

Part of this work was carried out by the author under the author aegis of the Medical Research Council Working Party on Non-Specific Urethritis with the aid of a grant from the U.S. Public Health Service.
Neomycin-resistantStaphylococcus aureusin a burns unit
Authors: Lowbury E. J. L. , Babb J. R. , Brown Vivien I. , Collins B. J.
Published: May 2009

Early in 1963 neomycin-resistantStaph. aureusappeared in the burns of patients in a burns unit; after a period of 7 weeks three-quarters of the strains ofStaph. aureusisolated from patients in the unit were resistant to neomycin, and after 22 weeks almost half of the patients in the burns wards were carrying the organism on their burns. When treatment with neomycin and kanamycin was stopped in the Burns Unit, neomycin-resistant strains gradually diminished in numbers and were no longer found in the ward after 6 months.

The neomycin-resistant staphylococci appeared during controlled trials of local neomycin and systemic kanamycin, and were much more frequently isolated from the burns of patients treated with these antibiotics than from patients in the control series.

During the previous 9 years local neomycin application had been used on many patients; though all staphylococci were tested for sensitivity to neomycin for a considerable part of this time, no resistant staphylococci were found.

All the neomycin-resistant staphylococci showed a pattern of inhibition by phages 6, 47, 54 and 77, and many also by phages 7, 53, 75 and 75B at 1000 R.T.D. No neomycin-sensitive staphylococci with this phage pattern were found at the time when resistant strains first appeared (though two such strains were found later); it seemed likely, therefore, that the resistant strain was introduced from outside the hospital. Preliminary tests of habituation to neomycin of sensitive strains with the phage inhibition pattern are described.

Back mutation to sensitivity was not found in tests on neomycin-resistant staphylococci.
An outbreak of Salmonella typhi-murium food poisoning
Authors: Jackson Thomas F. M. , Smyth D. A.
Published: May 2009

1. An outbreak of food poisoning due to Salmonella typhi-murium phage-type la is described.

2. Bread and (or) bakery confectionery eaten by all but two of the victims, had originated from a particular bakery firm.

3. S. typhi-murium phage-type 1a was found in the stools of an apprentice baker, a female packer of cakes and bread, and in three female counter-hands. The apprentice baker was responsible for the preparation and decoration of the confectionery which was distributed to the branch-shops and other establishments throughout the area.

4. S. typhi-murium was not found in any of the raw materials used at the bakehouse.

5. The cases which arose at a residential school for cripples gave a ratio of six cases to eight symptomless excretors.

6. Seven weeks after the start of the outbreak the last of the infected food-handlers was considered to be free from infection and fit to return to work.

Twelve weeks later the last member of the public was declared to be negative.

Thanks are expressed to Dr Joan Taylor of the Salmonella Reference Laboratory for her advice and assistance in the preparation of this paper, and to the staffs of the Public Health Laboratory and Public Health Department, Edmonton, N. 9, for their help and co-operation during the investigation.
Serological evidence for the susceptibility of the hippopotamus (Hippopotamus amphibiusLinnaeus) to natural infection with rinderpest virus
Authors: Plowrigh W. , Laws R. M. , Rampton C. S.
Published: May 2009

A survey of rinderpest-neutralizing antibody was carried out on the sera of 315 hippopotamuses which were shot in the Queen Elizabeth Park, Uganda. No serological positives were found in animals aged 11 years or less but about 4% were detected in the age class 13–25 years. In the 28–41 years age class the proportion of positives rose to about 36%. All except one of the positive sera were titrated, the figures obtained being comparable to those in other recently infected species of wild ungulates.

It was concluded that the heat-stable antibody in hippopotamuses resulted from inapparent infections with rinderpest virus during epizootics which passed through the areas of Lake George and Lake Albert in the years 1920/21, 1931/33 and 1944/45. No record was available of clinically recognizable rinderpest in the hippopotamus population but deaths due to other causes were mentioned briefly.

Comment was made on the stability of rinderpest-neutralizing antibody over periods of about 30 years.

One of us (R. M. L) is grateful to the Nuffield Foundation for financial support. Thanks are due to Drs S. S. Stone and W. P. Heuschele (Agricultural Research Service, United States Department of Agriculture) for their assistance in organizing the collection of serum samples.

This paper is published by permission of Mr H. R. Binns, C.M.G., O.B.E., Director, E.A.V.R.O.
The relationship of a type of Mycoplasma isolated from tissue cultures to a new human oral Mycoplasma
Authors: Lemcke Ruth M.
Published: May 2009

A previously unidentified type of Mycoplasma found as a contaminant in tissue cultures and in a culture of Eaton agent, is identical with a newly recognized human oral type.

I am indebted to Drs Herdersheê and Chanock for sending me their cultures and relevant information.
The isolation of an unclassified virus from an outbreak of infantile diarrhoea
Authors: Murphy A. M.
Published: May 2009

A virus was isolated from fifteen of nineteen children living in an infants' home during an outbreak of diarrhoea. The virus possesses many of the characteristics of the enterovirus group but is serologically distinct from any of the accepted members of this group. It is non-pathogenic for unweaned mice, non-cytopathic in tissue cultures of monkey kidney, but is rapidly cytopathic for tissue-cultured cells of human origin. It is serologically similar to virus Hu 659 isolated by Abrahams in the United States (personal communication).

I should like to thank the Director-General of Public Health and State Psychiatric Services, New South Wales, for permission to publish.
The epidemiology of leptospirosis in North Queensland: II. Further observations on the hosts in the Mossman district
Authors: Battey Yvonne M. , Smith D. J. W. , Barrow G. J.
Published: May 2009

Investigations in the Mossman districts of North Queensland showed the maintaining hosts of leptospiral serotypemedanensisto bePerameles nasutaandIsoodon macrourusin canefields, secondary woodland and rain forest.Rattus sordidus conatusis the maintaining host ofgrippotyphosain canefields. The host range of six serotypes was extended by the cultural studies.

We would like to express our thanks to Dr G. Alberts, superintendent of Mossman District Hospital, for his co-operation, and also to Miss H. MacDonald and Mr A. Wood for technical assistance.
Polyvinyl-pyrrolidone-iodine: an assessment of antibacterial activity
Authors: Saggers B. A. , Stewart G. T.
Published: May 2009

Polyvinyl-pyrrolidone-iodine complex (PVP-I) was shown to have a rapid disinfectant activityin vitroagainst vegetative bacteria and fungi and against vegetativeTrichomonas. The presence of organic matter had a slight delaying effect on the killing time. Bacterial spores survived in PVP-I for 17 hr. and fungal spores for 1½ hr. Used as an agent for pre-operative preparation of the skin, PVP-I was more efficient than others tested, rendering the skin surface sterile even when heavily contaminated, and keeping it so for 1 hr. None of the staining characteristics of iodine were noted since PVP-I was easily removed by water. Two individuals, known to be iodine sensitive, developed mild iodism after application of PVP-I.

The authors are indebted to the staff of the hospital for their co-operation; and to Berk Pharmaceuticals Limited for supplies of PVP-I, manufactured by them as Betadine (Povidone-iodine B.P.).
Distribution of heat-resistant Clostridium welchii in a rural area of Australia
Authors: Sutton Ross G. A.
Published: May 2009

The incidence of heat-resistant Cl. welchii in selected classes of a rural population has been investigated. The carrier rate for the general population was low (l·5–6·0%), but persons associated with communal feeding and poor hygienic conditions were shown to have a much higher carrier rate (15·1–25%).

Sex and season had little effect on the incidence of the organism, but among aboriginals the carriage was significantly affected by age. This was probably due to eating habits of the different age groups. The carriage appears to be transient; no persons were shown to be permanent carriers of one strain of heat-resistant Cl. welchii.
The nature of the opaque colony variation in group A streptococci
Authors: McCarty Maclyn
Published: May 2009

Opaque colonies of group A streptococci, detected on clear agar plates with obliquely transmitted light, are composed of extremely long chains of cocci. The mucopeptide layer of the cell-wall is involved in the formation of enhanced intercellular bridges. It is suggested that this exaggerated chaining results in an altered growth pattern which gives the appearance of granular opacity to surface colonies.