bluuebunny/crossref_metadata_2025 huggingface dataset:
A mathematical model of common-cold epidemics on Tristan da Cunha
Authors: Hammond B. J. , Tyrrell D. A. J.
Published: May 2009

Records of seven common-cold outbreaks on the island of Tristan da Cunha are compared with the corresponding time courses given by the mathematical model of Kermack & McKendrick (1927) and with an alternative model that directly involves a constant average duration of individual infection. Using computer simulation techniques the latter model is shown to be preferred and is then closely matched to the field data to obtain values for the model parameters. Consideration is then given to the intensity of epidemics predicted by the model and to the distribution of the actual epidemics relative to the theoretical epidemic threshold.
Control at hospital level of infections by methicillin-resistant staphylococci in children
Authors: Michel M. F. , Priem Catharina C.
Published: May 2009

Rapid spread of methicillin-resistant staphylococci (MeRS) in a children's hospital is described. Within 4 months of the first isolation MeRS had been isolated from infections in all clinical units. MeRS were also regularly isolated at the out-patient department. Protective isolation of one of the clinical units had no effect on the infection rate by MeRS. The use of antiseptics (Hexachlorophene and chlorhexidine) and gentamicin nose cream in children and staff members in three out of five clinical units resulted in a significant reduction of the prevalence of nose colonization by MeRS in children. In staff members a non-significant reduction of the prevalence of colonization and a significant reduction of the acquisition of MeRS was found. After a few months the infection rate decreased to zero in the units where the measures were introduced. It remained unchanged in the other units. Phage typing of two sets of strains collected at an interval of 6 months showed that the infections were mainly caused by two endemic strains of MeRS. The majority of the infections caused by MeRS was of minor importance. In 16 % of the infections a strain was isolated repeatedly and for more than 1 week. After the introduction of antiseptics a relative increase of infections by Gram-negative bacteria was observed. The significance of this phenomenon is discussed.
Salmonellosis in Botswana: I. Incidence in cattle
Authors: Miller A. S.
Published: May 2009

Clinical salmonellosis in cattle is infrequently recorded in Botswana, the majority of salmonella isolations being made from apparently healthy animals. A salmonella carrier rate of 6·7% was found in testing faeces samples from 89 apparently healthy cattle. A total of 35 salmonella serotypes were isolated from specimens of bovine origin. Salmonella dublin was isolated infrequently, possibly in part because of prophylactic vaccination.
An M-associated protein antigen (MAP) of group A streptococci
Authors: Widdowson Jean P. , Maxted W. R. , Pinney Alison M.
Published: May 2009

A streptococcal antigen that is closely associated with the M-antigen, but is not type specific can be detected by means of a complement-fixation test in extracts of M-positive, but not of M-negative, variants of group A streptococci. Purification of acid extracts results in a concomitant increase in the purity both of the type-specific M-antigen and of the M-associated protein (MAP). Antibody to MAP is present in the sera of patients who have had streptococcal infection. The highest titres are found in patients with rheumatic fever.
The Australia (hepatitis-associated) antigen amongst heroin addicts attending a London addiction clinic
Authors: Hunter J. , Carrella M. , Williams R. , Taylor Patricia E. , Zuckerman A. J.
Published: May 2009

Thirty-three of 72 heroin addicts attending a recognized clinic for drug addition had a history of jaundice, but in only five was the serum positive for hepatitis-associated antigen (HAA) when examined by immunodiffusion, immunoelectro-osmophoresis and complement fixation. Two of these were repeatedly positive over an 8–12 month follow-up period and liver biopsy showed chronic persistent hepatitis. A third later developed acute hepatitis. A study of the injection habits suggested that the present low incidence of HAA and the decrease in number of cases with jaundice was probably related to the provision of free disposable syringes by the clinic since it was opened in 1968.
Viricidal activity of open air
Authors: Benbough J. E. , Hood A. M.
Published: May 2009

Airborne Semliki Forest virus and T coliphages were inactivated at a considerably enhanced rate in open air compared with enclosed air. Open air exerts its maximum sterilizing activity on viruses contained in the smallest sized particles.
Study of an attenuated strain of feline infectious enteritis (panleucopaenia) virus I. Spread of vaccine virus from cats affected with feline respiratory disease
Authors: O'Reilly K. J.
Published: May 2009

In the course of developing a living attenuated feline infectious enteritis (panleucopaenia) vaccine, it was found that respiratory disease-infected cats newly inoculated with this vaccine spread vaccine virus to respiratory disease-infected in-contact controls. These in-contact controls were able to infect other cats with which they were placed in contact so that after five natural transmissions in this way and two oral administrations and subsequent re-isolations, reversion to virulence became evident. It is clear that before general release of a new living feline infectious enteritis vaccine, there must be satisfactory evidence that con-current infection will not affect the safety of the modified antigen.

In cats infected with feline infectious enteritis there appears to be a short period, coinciding with the onset of leucopaenia, during which they are highly infectious. It seems possible that some infected animals may become immune carriers because virus has been recovered from the small intestine of two of four cats with significant antibody titres 22–24 days after exposure to infection.
Studies on type C influenza virus in the chick embryo
Authors: Jennings Roy , Freeman M. J.
Published: May 2009

The effect of varying conditions of inoculation and incubation on the growth of type C influenza virus in the allantoic cavity of the developing chick embryo were investigated. It was found that the highest yields of both virus haemagglutinin and infectious virus were obtained following the inoculation of chick embryos at 8 days with subsequent incubation at 32° C. Using the chick embryo allantoic cavity for titration of infectious virus, growth curves of allantoically propagated virus under varying inoculation and incubation conditions were determined.
Interferon induction by influenza type C
Authors: Jennings Roy
Published: May 2009

The presence of a heat-stable interferon-like inhibitor in allantoic and amniotic fluids collected from chick embryos infected with type C influenza virus was determined. This inhibitorwas characterized as an interferon and the ability of both live and ultra-violet-irradiated influenza type C virus to induce the substance was examined under various conditions.
Some consequences of the multiple infection of cell cultures by TRIC organisms
Authors: Blyth W. A. , Taverne Janice
Published: May 2009

In BHK 21 cells infected with more than one TRIC organism the inclusions coalesce so that 30 hr. after infection only one inclusion per cell remains. Six hours after infection the cells are as susceptible to further infection as uninfected cells.
An unusual plaque variant of rubella virus
Authors: Gould Janine J. , Laurence Gwenneth D. , Butler M.
Published: May 2009

In a comparative study of 24 different rubella virus strains, all but three formed small plaques in RK 13 cell cultures; of these one was the vaccine strain HPV-77, one was isolated from a congenitally infected infant, and the third was recovered from an adult who contracted severe rubella while handling this congenital strain. Whereas the plaque size of the vaccine strain was stable after further passage in cell culture, the plaque size of the other two rapidly diminished when the virus was passed in monkey kidney cells, and one of them was also reduced by passage in RK 13 cells. Cell culture passage of the typical small plaque strains did not result in altered plaque size.
Host specificities of RNA phages
Authors: Dennison Sheena , Hedges R. W.
Published: May 2009

Host ranges of members of four groups of male-specific RNA coliphages were determined by plating on hosts carrying various derepressed plasmids. An RNA phage originally isolated onPseudomonas aeruginosafailed to form plaques on any of the strains ofEscherichia coli.
Contamination of an operating theatre by Gram-negative bacteria. Examination of water supplies, cleaning methods and wound infections
Authors: Thomas Mair E. M. , Piper Elizabeth , Maurer Isobel M.
Published: May 2009

This paper describes a search for Gram-negative bacteria in an operating theatre and the steps taken to reduce the level of environmental contamination.

A high rate of infection in clean wounds prompted a bacteriological survey. Potential sources of infection found, and the measures employed are described in the hope that others may be encouraged to examine familiar equipment critically and to improve hygiene even in old premises.

The choice, design, use and care of cleaning and sterilizing equipment were open to criticism. In particular, a currently popular floor-scrubbing machine provided a breeding ground for Pseudomonas aeruginosa and was distributing it in the theatre environment.
Detection of Bordetella pertussis antibodiesin human sera by complement-fixation and immunofluorescence
Authors: Bradstreet C. M. Patricia , Tannahill Agnes J. , Edwards Joan M. B. , Benson P. F.
Published: May 2009

The complement-fixation test, as commonly used in the diagnosis of viral infections, was studied for its possible application to the diagnosis of whooping cough and the detection of antibody following pertussis vaccination. The results were compared with those obtained in parallel immunofluorescence tests. CFTs were performed on sera from 41 patients with whooping cough (Bordetella pertussis isolated), 125 vaccinated persons, and 618 controls; parallel tests by IP were made on sera from 24 cases of whooping cough, 36 vaccinated persons and 37 controls. Results of both tests correlated closely and showed that titres of diagnostic significance were seldom found in control sera. They also showed that, in patients suffering from whooping cough, antibody in a single specimen or a rise in antibody between paired sera was almost always demonstrated. Titres in general were lower in infants less than 6 months of age. IgG antibodies were involved in both tests. Although the number of sera tested was small both tests appear to be reliable as means of demonstrating the presence of antibody formed during the course of infection and after vaccination.
Bacteriuria in a Scottish island community. A comparison of chemical and cultural tests for bacteriuria applied in remote surroundings
Authors: Calvert F. R. , Hawthorne V. M. , Mann P. G. , Sandys G. H.
Published: May 2009

Four hundred and thirty-eight overtly healthy adults on Tiree were screened for bacteriuria by dip-inoculum culture and a tetrazolium reductase test.

Dip-inoculum culture affords a simple and effective means of providing a service in quantitative urine bacteriology for communities remote from a laboratory.

The pattern of bacteriuria on Tiree is much the same as in other communities surveyed. Criteria are discussed for assessing the sensitivity of the tetrazolium test in terms of quantitative urine culture.
Salmonellas on pig farms and in abattoirs
Authors: Lee J. A. , Ghosh A. C. , Mann P. G. , Tee G. H.
Published: May 2009

Salmonella infection on two pig farms and its relation to infection in pigs at slaughter was studied. On the first farm feed ingredients were mixed on the farm, and these included fish meal which was found to be contaminated with salmonellas. The feed was pumped to pigs in liquid form. There was a high salmonella isolation rate at slaughter when the contaminated fish meal was fed hi liquid feed, but it was significantly lower when no fish meal was fed to the pigs examined at slaughter. In some instances the same serotypes were found in fish meal and pig excreta on the farm and in caecal contents of the pigs at slaughter. No serotype was repeatedly isolated from any source and it appeared that the serotypes were not able to establish themselves in the pigs. It is concluded that infection found at slaughter originated on the farm where fish meal introduced and maintained infection. There was an opportunity for salmonellas to have multiplied in the liquid feed for several hours each day.

On a second farm environmental conditions were similar, but feed was given in the form of ready-made pellets and nuts. Salmonellas were not isolated from the feed. At slaughter there was a significantly lower isolation rate than on the first farm.
Survival ofSalmonella typhiin sea-water
Authors: Nabbut Nassim H. , Kurayiyyah Fahd
Published: May 2009

The bactericidal activity of natural sea-water onS. typhiis due to the combined effect of pH, salinity, toxic ions, presence of competitor and predator marine organisms, unidentified heat-labile toxic substances and competition for the limited food supply. Sea-water subjected to filtration and autoclaving lost the major part of its bactericidal activity. It is concluded that predators and competitors contribute significantly to the rapid death ofS. typhiin raw sea-water. The addition of peptone decreases the bactericidal activity of sea-water. The fluctuations in the total number of competitors and predators in sea-water together with the fluctuations in the concentration of heavy metal ions may be affected by various factors. Such fluctuations are probably responsible for the variable bactericidal action of different sea-water samples.

Bathing in sewage-polluted sea-water carries with it a health risk in spite of the excessive dilution of pathogenic micro-organisms in the sea and the rapid self-purification process of sea-water. The natural purifying processes are incapable of coping with massive pollution problems and should not be relied on as the sole protection offered to users of sea-water.
Toxoplasma antibodies in the sera of immigrants to the United Kingdom from Asia and East Africa
Authors: Dodge J. S.
Published: May 2009

Sera from 203 Asian immigrants to the United Kingdom were examined for toxoplasma antibodies. The antibody titres were not significantly different from those found in the indigenous population although there was some indication that a higher domestic animal–human contact in Asia was associated with a higher positivity rate.
Macquarie Island: the introduction of the European rabbit flea Spilopsyllus cuniculi (Dale) as a possible vector for myxomatosis
Authors: Sobey W. E. , Adams K. M. , Johnston G. C. , Gould L. R. , Simpson K. N. G. , Keith K.
Published: May 2009

The European rabbit flea Spilopsyllus cuniculi (Dale) was first released on Macquarie Island in December 1968. The flea has survived and bred on the island and about 30% of the rabbits sampled from the original release area in January 1972 were flea-infested.
Staphylococcal infection in an intensive-care unit, and its relation to infection in the remainder of the hospital
Authors: Harris D. M.
Published: May 2009

A survey of the staphylococcal infections occurring in a general hospital over a period of four and a half years showed that multiple-resistant strains of phage type 77 were endemic in the medical and surgical wards. Strains of this phage type were uncommon among patients attending the casualty department, and those found were usually either fully sensitive to antibiotics or resistant to benzyl-penicillin only. Regular monitoring of patients admitted to the intensive-care unit showed that 58 % of staphylococcal infections in such patients were present at the time of admission to the unit. Although the wards thus constituted a significant reservoir of infection for the intensive-care unit, there was no evidence to suggest that the return of patients from the unit to the wards was responsible for the transfer of infection in the opposite direction. The possibility of reducing the numbers of multiple-resistant staphylococci in the general wards, by the screening of all new admissions for the presence of tetracycline-resistant strains, appears to be impracticable in this area.
Preservation of Staphylococcus aureus with unstable antibiotic resistance by drying
Authors: Annear D. I. , Grubb W. B.
Published: May 2009

Cultures of Staphylococcus aureus showing unstable resistance to kanamycin, streptomycin, lincomycin and penicillin have been preserved by drying. Particular attention has been paid to organisms showing linked resistance to pairs of these antibiotics. Recoveries of viable cells from the desiccates was high and the proportion of resistant and sensitive cells was maintained both during storage and during heating. The preservation of the organisms on ceramic beads stored in air over silica gel promises to be an effective and convenient method for maintaining staphylococcal desiccates during studies of unstable antibiotic resistance.
Two community outbreaks of human infection with Yersinia enterocolitica
Authors: Asakawa Yutaka , Akahane Sousuke , Kagata Naoko , Noguchi Masateru , Sakazaki Riichi , Tamura Kazumichi
Published: May 2009

Two outbreaks of human infection with Yersinia enterocolitica in Shizuoka, Japan are described. This is the first report of community outbreaks of infection with this organism in Japan, and possibly in the world. All the strains isolated in each outbreak belonged to 0 antigen group 3, biotype 4, of the species. Despite much effort, the source and mode of spread of the infection were not established.
Isolation, ultrastructure and antigenicity ofMycoplasma gallisepticummembranes
Authors: Levisohn Sharon , Razin Shmuel
Published: May 2009

The cell membrane ofMycoplasma gallisepticumwas isolated by lysing the cells with digitonin. Chemical and density-gradient analyses and electron microscopy showed the isolated membranes to be relatively free of cytoplasmic contaminants. The density of the membranes exceeded that of other mycoplasma membranes, indicating a higher protein content. Small vesicular extensions seen in the sectioned membranes were interpreted as empty blebs.

The isolated membranes, but not the cytoplasmic fraction, elicited in chickens the production of growth-inhibiting, agglutinating and haemagglutination-inhibition antibodies toM. gallisepticumin titres resembling those obtained by injection of whole cells. The peak of the serological response varied with the serological test employed. The rapid slide-agglutination test became positive as early as 3 days after the first injection of only 50 μg. of membrane protein. The haemagglutination-inhibition antibody titre reached its peak at about 10 days after the first injection, while that of the growth-inhibiting antibodies was reached only at about 25 days. The addition of adjuvant to the membrane antigen did not improve the production of the growth-inhibiting antibodies in chickens, but it produced some improvement in rabbits. Our results support the thesis that the chief immunogens ofM. gallisepticumreside in the cell membrane of this organism.
Transfer of Staphylococcus aureus via nurses' uniforms
Authors: Hambraeus Anna
Published: May 2009

The contamination of gowns and uniforms worn in a burns unit and the transfer of patient's staphylococci by means of nurses' uniforms was investigated. The median values of staphylococci found on gowns and jackets worn during a routine nursing procedure were 3·0 × 104 and 1·4 × 103 respectively. From the results of model nursing experiments it appeared as if the fraction of staphylococci transferred from a patient's room to the air in a receiving room was 4 to 10 times less when protective gowns were worn than when no gowns were worn. The corresponding transfer directly to the model ‘patient’ was 100 times less. The protection afforded by a gown seemed mainly to be due to protection against contamination of the uniform worn underneath when nursing a burned patient. The discrepancy between the transfer of an airborne particle tracer and Staph. aurats-carrying particles earlier found in the ward could be explained by the dispersal of Staph. aureus from nurses' clothing.
The effect of preadministration ofCorynebacterium parvumon the protection afforded by heat-killed and acetone-killed vaccines against experimental mouse typhoid
Authors: Cronly-Dillon Sujatha
Published: May 2009

Mice given an intraperitoneal injection of 0.5 mg.Corynebacterium parvum(dry weight) before vaccination with heat-killed (HK) or acetone-killed (AK)Salmonella typhimuriumvaccine and later challenged intraperitoneally withS. typhimuriumstrain 1566, showed a statistically significant increase in mortality when compared with mice that had received onlyC. parvumbut no vaccine. They also showed a higher mortality rate than mice receiving only HK or AK vaccine or mice that had received no vaccine before challenge. Prior administration ofC. parvumto mice that are vaccinated with HK or AK vaccine appears to make them more susceptible to an intraperitoneal challenge withS. typhimurium. This was more apparent with HK vaccine than with AK vaccine.
Skin scales among airborne particles
Authors: Clark R. P.
Published: May 2009

The air from a house and garden in a rural area has been sampled and the size distributions of the airborne particles have been determined. The particle concentrations are shown to be generally higher indoors. Changes in the particle concentration during various activities in a small room have been shown to be greatest for particles larger than 3 μm. diameter. Stereoscan microscopic observation has shown that many of the airborne particles in rooms and some from those in outside air appear to be scales of desquamated skin. The presence of protein in many of these particles complements the microscopic observations.
Swine vesicular disease: virological studies of experimental infections produced by the England/72 virus
Authors: Burrows R. , Mann J. A. , Goodridge D.
Published: May 2009

Pigs exposed to relatively small amounts of virus by intradermal inoculation of the feet or by skin scarification developed clinical disease. Large amounts of virus were recovered from samples taken from the nose, mouth, pharynx, rectum and the prepuce or vagina during the first week of infection and smaller amounts during the second week. Virus was recovered from the faeces of most animals 16 days after infection and from one animal for 23 days. Pigs in contact with inoculated animals were killed at intervals before the appearance of clinical disease. The distribution and amounts of virus in various tissues indicated that infection had most likely gained entry through the skin or the epithelia and mucosae of the digestive tract. Some pigs acquired subclinical infections in which no virus excretion was detected and no transmission of infection to susceptible pigs took place over a period of 5 weeks.
A virological study of post-vaccinal encephalitis
Authors: Terzin A. L. , Mašlć M. , Vuković B. , Mudrić V.
Published: May 2009

In the province of Voyvodina 18 cases of post-vaccinal encephalitis have been recorded, three of which were fatal.

The estimated morbidity rate was 0·6 per 105 after revaccination, and 3·9 per 105 after primary vaccination. The virological studies described, as well as other findings referred to in this report, are consistent with the possibility of an autoimmune aetiology of the post-vaccinal encephalitis cases observed.
Recent trends in human salmonellosis in England and Wales: the epidemiology of prevalent serotypes other than Salmonella typhimurium
Authors: Lee J. A.
Published: May 2009

In the period 1960–70 meat and poultry products caused over 70% of successfully investigated outbreaks of human salmonellosis. The number of human incidents of salmonellosis declined from 1960 to 1966, but then more than doubled between 1966 and 1971. This increase was mainly due to a threefold increase of incidents of salmonella serotypes other than Salmonella typhimurium. The serotypes which increased most and contributed significantly to this trend were S. enteritidis, S. panama, S. Stanley, S. virchow, S. Agona, S. 4,12:d:- and S. indiana.

Strong evidence exists that these serotypes have a path of infection from animal feedingstuffs to the pig and poultry animal reservoirs to pork and poultry foods to man. Cattle appear to be a less important source than pigs and poultry and this may be because the nature and content of their feed is different.

The importance of the control of the pig and poultry reservoirs of salmonella infections is stressed and a significant role of animal feedingstuffs in the maintenance of these reservoirs strongly suggested.
Selective elimination of Enterobacteriaceae species from the digestive tract in mice and monkeys
Authors: van der Waaij D. , Berghuis-de Vries J. M.
Published: May 2009

In mice and in monkeys, ‘selective’ elimination of Enterobacteriaceae species from the digestive tract of animals with a sensitive flora was accomplished by oral treatment with nalidixic acid (1 mg./g. body weight in mice and 0·4 mg./g. body weight in monkeys). During treatment, the concentration of enterococci (and also of Candida albicans in the monkey) remained unaltered. This indicates that the fraction of the anaerobic microflora which is responsible for the colonization resistance of the digestive tract is not affected by the treatment. An important consequence seems to be, that elimination of yeast and fungi with fungistatic drugs can be started at the same time as elimination of Enterobacteriaceae is attempted.
Virus isolations from patients in general practice, 1961–71
Authors: Higgins P. G.
Published: May 2009

During the period 1961–71 of 1785 viruses isolated from patients in the general population 503 (28%) were rhinoviruses, 465 (26%) influenza viruses, 248 (14%) enteroviruses, 234 (13%) herpes simplex virus, 132 (7%) parainfluenza viruses, 129 (7%) adenoviruses and 49 (3%) respiratory syncytial virus. Also isolated were 18 strains of mumps virus, 7 coronaviruses and 295 streptococci of groups A, C or G.

Fluctuations were observed in the frequency with which respiratory syncytial virus, parainfluenza virus type 2, and the adenoviruses were isolated over the 10-year period.

Influenza viruses types A and B, parainfluenza viruses types 1 and 2, respiratory syncytial virus, adenoviruses types 3, 4, 6, 7 and 21, and many enteroviruses were all associated with outbreaks.

Infections with influenza viruses A and B and parainfluenza viruses types 1 and 2 came during the winter, whereas those with parainfluenza virus type 3, enteroviruses, and rhinoviruses were more frequently seen in the summer and early autumn.
Interactions of TRIC agents with macrophages: effects on lysosomal enzymes of the cell
Authors: Taverne Janice , Blyth W. A. , Ballard R. C.
Published: May 2009

Two changes were observed in the acid phosphatase of macrophages that had ingested infective TRIC organisms: the proportion of extralysosomal enzyme rose, while the total amount in the cells fell. Both effects were directly related to the number of organisms ingested and increased with time. When macrophages were inoculated with more than 50 organisms per cell, changes were obvious within a few hours; with 2–10 organisms per cell changes were detectable only after 18 hr. or more. Enzyme appeared in the culture medium as the amount in the cells decreased. Ingestion of organisms killed by heat or treated with antibody did not induce such changes. In infected BHK-21 cells, no changes in acid phosphatase were detected at any stage of the developmental cycle of the organism.
The growth of salmonellas on cooked cured pork
Authors: Akman M. , Park R. W. A.
Published: May 2009

With the use of streptomycin-resistant mutants to facilitate recovery, 5 strains of 4 species ofSalmonellawere shown to grow rapidly at 22° C. on low salt ham even from an inoculum of 10–20 organisms.S. pullorumdid not grow well. All 6 strains ofSalmonellasurvived but did not grow on ‘high salt ham’. We conclude that cooked ham containing approximately 2·8 g. NaCl/100 g. H2O once infected is more likely to give rise to food poisoning than is ham with the higher salt content traditionally used.
Determination of the colonization resistance of the digestive tract of individual mice
Authors: van der Waaij D. , Berghuis J. M.
Published: May 2009

It has been shown that it is possible to investigate the colonization resistance in individual mice by determining the concentration of a certain contaminant (S.R.-E. coli) in the faeces during the first 4 days after contamination. Experimental contamination is contra-indicated in many cases such as in individuals with decreased resistance to infection. Particularly in this group, the value of the colonization resistance should be determined. It appeared to be possible to determine the colonization resistance in such individuals by quantitative biotyping of the Enterobacteriaceae species in the faeces on several consecutive days.
A study of foot-and-mouth disease virus strains by complement fixation: II. A comparison of tube and microplate tests for the differentiation of strains
Authors: Forman A. J.
Published: May 2009

Several foot-and-mouth disease virus strains were examined by complement-fixation tests in microplates and in tubes. It was established that the two systems are comparable, although greater reproducibility is obtained with tube tests. While microplate tests are a satisfactory method for the differentiation of strains, tube tests provide a more precise method for the identification of small antigenic differences.
On the use of contour maps in the analysis of spread of communicable disease
Authors: Splaine Michael , Lintott Alan P. , Angulo Juan J.
Published: May 2009

The co-ordinates of the dwellings where cases of variola minor (alastrim) occurred during a small epidemic were used in a worked example of contour mapping of disease spread. The contoured variable was the date of onset, relative to an arbitrary base date, of the case introducing the disease into each of twenty-two households. Three contour maps prepared with slightly different computer programmes or dates exhibited similar concentric loops whose centres were close to the first infected household. The average rate of spread of the disease was estimated by regression of the number of days to onset of the first case in the household on the average distance from an arbitrary origin to the relevant contour line. The calculated average rate of spread was 1.22 metres per day. An additional map was contoured using the cumulative number of cases as the contoured variable, relative to the onset of the example epidemic.
Introduction of a cross-infection rate in children's wards and its application to respiratory virus infections
Authors: Weightman Doris , Downham M. A. P. S. , Gardner P. S.
Published: May 2009

Statistical methods are described in detail for the calculating and comparing of cross-infection rates. In addition the use of these rates has been extended to study the influence of age and of different virus types on susceptibility to cross-infection in children's wards.
Epidemiology of human brucellosis in Isfahan, Iran
Authors: Sabbaghian H. , Nadim A.
Published: May 2009

Studies on brucellosis were carried out to elucidate the epidemiology of the disease in Isfahan province, where Brucella melitensis is highly prevalent in animals and man. A positive milk ring test of 32% and 23% was found in unvaccinated goats and sheep respectively. Card and tube agglutination tests showed an infection rate of about 12% in sheep and goats and 42% in cattle. B. melitensis was isolated from 8% of 677 samples of fresh cheese examined.

Of 1526 clinically suspected human cases, 476 showed laboratory evidence of brucellosis. Of these patients, 291 cases were from urban and 185 cases from rural areas. Cases from urban and rural areas were seen principally in the younger age groups. The median age of infection was 19·7 in urban and 15·7 in rural patients respectively. The infection was encountered mainly from April to August. This correlates with animal parturition and the greatest amount of sheep and goat milk production, which is introduced to the local market as fresh cheese. Raw dairy product consumption is the most probable way of Brucella transmission in urban patients. In rural areas, both dairy product consumption and contact with animals are sources of infection.
Enterotoxin production by strains ofStaphylococcus aureusisolated from foods and human beings
Authors: Wieneke Antonnette A.
Published: May 2009

Enterotoxin production by strains ofStaphylococcus aureusisolated from routine samples of foods and from human beings was investigated. Twenty-one to 26% of 112 strains isolated from raw meat, sausages and poultry and 32–36% of 183 strains isolated from cooked foods, e.g. meat, chicken and frozen seafoods, produced enterotoxins A, B, C, D or E.Staph. aureusisolated from raw meat and chicken less frequently produced enterotoxins A, B, C or E and more frequently enterotoxin D, than those from cooked meat and seafoods. Of the 113 strains isolated from cheese and raw milk 6–11% produced enterotoxin and most of these produced enterotoxin D. Only a few strains isolated from foods produced enterotoxin E. Results of enterotoxin tests onStaph. aureusfrom human beings resembled those on strains from cooked foods.
Respiratory and humoral immune response to aerosol and intramuscular pertussis vaccine
Authors: Thomas Gerald
Published: May 2009

Animal experiments have shown that respiratory administration of pertussis antigen induces a protective immune response. In this study pertussis antibody in human respiratory secretions was measured and the response to aerosol and intramuscular pertussis immunization investigated. Substantial increases in this antibody occurred after aerosol immunization but no changes were found in serum antibody. The reverse was observed after intramuscular immunization. Severe side effects are frequently seen after intramuscular pertussis vaccine in adults but not with aerosol immunization. The latter method may be of value for paediatric medical and nursing personnel exposed to the risk of pertussis infection.
In vivotransfer of R factors betweenEscherichia colistrains inoculated into the rumen of sheep
Authors: Smith M. G.
Published: May 2009

Substantial transfer of R factors occurredin vivo, under certain conditions, in the rumen of adult sheep in the absence of any antibiotic treatment. A starvation period of 24–48 hr. was required to produce the conditions necessary, when even quite low inocula (ca. 103cells) of donor and recipientE. colicould grow within the rumen and reach a population density sufficient for transfer to take place. The results indicate that under the same conditions R factors may be transferred between organisms in the lower intestinal tract also. Without the starvation period, the inoculation of even massive numbers (1010cells) of the same organisms resulted in almost no detectable transfer.

Some of the experimental animals on which a starvation period was imposed became carriers of either the inoculated recipientE. coli, or of R factor bearing coliforms, and these formed 1–10% of the total coliform population of the faeces for at least 6 weeks.
Numerical analysis of the characteristics ofCorynebacterium diphtheriaestrains isolated in Victoria from 1962 to 1971
Authors: Gibson L. F.
Published: May 2009

A study of the incidence of diphtheria in the State of Victoria, Australia, was carried out. Numerical analysis of the characteristics of 264 strains ofCorynebacterium diphtheriaeisolated between 1962 and 1971 placed them into 18 varieties plus six strains which were unique in their combination of reactions to the characteristics examined. During the 10-year period, some varieties appeared inter mittently and were recognized by certain defining characteristics but exhibited a gradual change in their antigenic structure. In contrast, when the outbreaks were examined over shorter periods of time, a number of varieties and single strains were found which differed greatly from each other yet possessed the same major serotype antigen. These findings are discussed in terms of a 'one-parent' concept in which the varieties and single strains represent phases of a common ancestor.

By inspection and analysis of the characteristics of the strains, certain associations were apparent. For instance, a correlation was found between the antigenic structure of the organism and the colonial appearance on tellurite blood agar. Similarly, correlation was observed between bacteriophage type, diphthericin type and biochemical activity in that a strain which was highly active in one of the properties was also very active in the other two.
Studies on the 1967–68 foot and mouth disease epidemic: incubation period and herd serial interval
Authors: Hugh-Jones M. E. , Tinline R. R.
Published: May 2009

The incubation period during this epidemic was studied using both a spectral analysis-cum-filtering method and analysis of case histories. Using spectral analysis, the modal herd serial interval was estimated to be 8–10 days based on the record of the daily number of outbreaks and an adjusted cattle series. The case histories tended to confirm these estimates but indicated that the serial interval varied considerably between species. The filtering method revealed that the herd serial interval apparently changed during the epidemic. For the first 4 weeks the interval was 8 days, while in the latter stages it was about 2 weeks.
Age-specific incidence of neutralization antibodies of Herpes simplex virus
Authors: Terzin Alexander L. , Mašic` Milan G.
Published: May 2009

Sera of 1255 individuals from Novi Sad, varying in age from <1 month to 69 years, have been tested for neutralization antibodies to Herpes simplex virus type 1.

The eight newborns tested and 97% of the 507 adults were positive, with titres ranging from 1/4 to 1/256. The titres in newborns were significantly lower than the titres in adults.

After birth the maternal antibodies declined rapidly and 94% of infants at the age of >6 months and <2 years were negative.

After the first year infants in Novi Sad start to acquire herpes-neutralizing antibodies actively, reaching a 50% incidence of positives between the 2nd and 3rd year of age.

Age-specific incidence rates of herpes positives found in Novi Sad have been compared with those reported from Edinburgh, Freiburg i. Br. and Louisiana. Possible influences of several circumstances upon the incidence rate of positives detected by the neutralization test are discussed.
Pathogenesis of foot-and-mouth disease: clearance of the virus from the circulation of cattle and goats during experimental viraemia
Authors: Sutmoller P. , McVicar J. W.
Published: May 2009

Viraemia is an important aspect of the pathogenesis of infectious diseases, but the mechanisms of entry and removal of virus from the vascular system particularly in natural hosts are poorly understood. The results of this study showed that the clearance of foot and mouth disease virus (FMDV) from the circulation of cattle and goats followed the general rules for the clearance of inert particulate materials and other viruses from the circulation. High doses of infused FMDV were cleared less efficiently than low doses, probably as a result of a depletion of the reticulo-endothelial system by the higher doses. FMDV was cleared from the circulation of cattle at a considerably slower rate than from the circulation of goats, but in both species significant individual variation in clearance was observed. These results could explain individual as well as species variations relative to the onset and duration of viraemia.
Counts on viableBacteroides fragilis:a modification of the microdroplet technique
Authors: Kelly M. J.
Published: May 2009

A modification of Sharpe's microdroplet counting technique is presented which permits viable counting ofBacteroides fragilis. Lysed horse blood was added to 0·1 ml soy digest agar droplets and 2% was found to be the optimal concentration which combined adequate intradroplet colony size with acceptable visibility on the counting screen of the Colworth Droplette machine.
Myxomatosis: the occurrence ofSpilopsyllus cuniculi(Dale) larvae on dead rabbit kittens
Authors: Shepherd Rosamond C. H.
Published: May 2009

Spilopsyllus cuniculilarvae were found actively feeding on dead rabbit kittens left in nest boxes for up to 12 days.
A study of the surface and somatic antigens ofBacteroides fragilis
Authors: Elhag K. M. , Tabaqchali Soad
Published: May 2009

Antisera against live cultures of 20 strains ofBacteroides fragilisproduced in rabbits agglutinated homologous whole-cell as well as O-antigen suspensions with several cross-reactions. Pure specific antisera were produced by absorbing cross-reacting antigens. O-antisera reacted against O-antigens but failed to do so against most whole-cell suspensions, suggesting the presence of surface structures which might have blocked the reactions. The titres of the whole-cell antisera were not significantly higher than those of O-antisera, but the reactions were more definite and easier to read.

This system may prove useful in serological studies ofB. fragilis.
Differential inhibitory effects of 5-bromodeoxyuridine on vaccinia and monkeypox viruses
Authors: Yoshii T. , Kono R.
Published: May 2009

Replication of vaccinia and monkeypox viruses was impeded in the presence of 5-bromodeoxyuridine (BUdR) in RL-33 cells derived from rabbit lung tissue. The different degree of inhibition was found among strains of those viruses, in which it was evident that five strains (CV-1, Lister, IHD, Dairen-I and Ikeda) of vaccinia viruses resulted in more reduced yields of infectious virus than four strains (Sen-19, Orang Utan, Copenhagen and Sierra Leone) of monkeypox viruses. There was also strain variation in BUdR sensitivity within vaccinia viruses but not in the case of monkeypox viruses.
Myxomatosis in the Mallee region of Victoria, Australia
Authors: Shepherd Rosamond C. H. , Edmonds J. W. , Nolan I. F. , Gocs A.
Published: May 2009

Sharp reductions in the wild rabbit (Oryctolagus cuniculus (L.)) population in the Mallee are associated with annual myxomatosis epizootics. The extent to which the population reductionsare the direct result of the epizootics varies with time of epizootic occurrence. All grazing animals in the Mallee are under nutritional stress each summer and autumn. When the epizootic occurs during the early summer heavy losses occur in a previously healthy population. Similar losses which occur in the late summer and autumn are the result of a nutritional stress – epizootic complex. The end result in each case is a population reduction of about 80%.

This reduction occurs in a population which is the most resistant to myxomatosis known in Victoria and in association with epizooties caused by field strains of myxoma virus of moderate virulence only.

The earlier summer epizootics are of considerable economic importance because they sharply reduce the pressure on the limited food available for other grazing animals.
Stool viruses in babies in Glasgow: 2. Investigation of normal newborns in hospital
Authors: Madeley C. R. , Cosgrove B. P. , Bell E. J.
Published: May 2009

The stools of 37 newborn babies born in hospital were examined for the presence of virus. An extract of every stool passed by each baby was examined in the electron microscope and inoculated into cell cultures. The babies were delivered in four separate maternity units (A–D). All the babies from units A and C (9 babies) were found to be excreting rotavirus though none showed any evidence of diarrhoea. Two of the babies also excreted astrovirus. Subsequently unit A was closed for cleaning and, on reopening with more restrictions on visitors, a further 19 babies were examined. No virus was found in any of their stools, nor was virus observed in the stools of babies from units B and D, where visiting was also more restricted. Visiting restrictions in these units excluded older siblings of the babies. No virus was cultured from any stools in this study.
Contaminated roof-collected rainwater as a possible cause of an outbreak of salmonellosis
Authors: Koplan J. P. , Deen R. Doug , Swanston W. H. , Tota B.
Published: May 2009

Roof-collected rainwater is a common water source in subtropical regions and has not been associated with human illness. In Trinidad, the West Indies, a church group, attending a rural camp, developed gastrointestinal illness, caused by Salmonella arechevalata. This rare serotype was isolated from stool specimens of campers, foods eaten at the camp, and a water tap, which was supplied by a storage tank of roof-collected rainwater. The surface of the roof, used as water catchment, was covered with bird faeces. It is postulated that rainwater, falling on the roof, washed off animal excrement which contained S. arechevalata and led to the outbreak of salmonellosis through camper ingestion of contaminated food and water.
The safety of the Trexler isolator as judged by some physical and biological criteria: a report of experimental work at two centres
Authors: Hutchinson J. G. P. , Gray J. , Flewett T. H. , Emond R. T. D. , Evans Brandon , Trexler P. C.
Published: May 2009

We have assessed the effectiveness of flexible-film negative-pressure isolators by physical and biological means. We have found that they afford a high degree of containment and therefore also of safety to hospital staff. We offer some recommendations on the operation of these isolators to ensure the optimum degree of protection.
The derivation of a minimum immune titre of rubella haemagglutination-inhibition (HI) antibody. A Public Health Laboratory Service collaborative survey
Authors: Patricia Bradstreet C. M. , Kirkwood B. , Pattison J. R. , Tobin J. O'H.
Published: May 2009

Ten laboratories collaborated in a study of minimum immune titre (MIT) of rubella haemagglutination-inhibiting (HI) antibody with one laboratory acting as a reference laboratory to provide a uniform basis for comparison of the HI results. The international unitage equivalent to the MIT used by the ten laboratories was found to vary from 24 to 98 units. Testing of the sera by immunofluorescence and by HI after flotation centrifugation indicated that residual non-specific inhibitors may interfere with HI antibody testing to an extent equivalent to 12–15 units. An acceptable MIT would therefore be equivalent to 24–48 units of rubella HI antibody. The single radial haemolysis (SRH) results on the sera indicate that this is a sensitive and specific test for rubella antibody.
Myxomatosis: changes in the epidemiology of myxomatosis coincident with the establishment of the European rabbit flea Spilopsyllus cuniculi (Dale) in the Mallee Region of Victoria
Authors: Shepherd Rosamond C. H. , Edmonds J. W.
Published: May 2009

Outbreaks of myxomatosis during the winter or spring have coincided with the establishment of the European rabbit flea in the Mallee region. The severity of these outbreaks has varied from causing complete suppression of the normal spring increase in rabbit numbers to being completely ineffective in a year in which late spring rains allowed rabbit breeding to extend into the early summer.

In 1973 and 1974 effective spring myxomatosis caused heavy mortality in kittens before they emerged from the warrens. The age of the population increased as the result of few young rabbits coming into the population and of the lessened stress on old rabbits in a low summer-autumn population. This effect was reversed in the late-breeding year, 1976, when flea numbers were apparently too low to maintain a spring outbreak and rabbit numbers increased rapidly.