During 2012 real-time syndromic surveillance formed a key part of the daily public health surveillance for the London Olympic and Paralympic Games. It was vital that these systems were evaluated prior to the Games; in particular what types and scales of incidents could and could not be detected. Different public health scenarios were created covering a range of potential incidents that the Health Protection Agency would require syndromic surveillance to rapidly detect and monitor. For the scenarios considered it is now possible to determine what is likely to be detectable and how incidents are likely to present using the different syndromic systems. Small localized incidents involving food poisoning are most likely to be detected the next day via emergency department surveillance, while a new strain of influenza is more likely to be detected via GP or telephone helpline surveillance, several weeks after the first seed case is introduced.

The prevalence of antibodies against Lyme disease spirochaetes in serum samples from 80 forestry workers at high occupational risk of Lyme disease was surveyed by enzyme-linked immunosorbent assay (ELISA) with the OspC-I synthetic peptide. The peptide is part of the outer surface protein C (OspC) amino acid sequence located in the region conserved among Borrelia burgdorferi sensu stricto or sensu lato. Positivity for antibodies against OspC-I was observed in 25 (31·3%) of the forestry workers. Of these positive cases, 12 (15·0%) and 19 (23·8%) were positive for immunoglobulin M (IgM) and IgG antibody, respectively. Among 62 workers who were negative for IgG antibody against B. garinii or B. japonica in our previous study, 9 (14·5%) and 4 (6·5%) were positive for IgM and IgG antibody, respectively, in OspC-I ELISA. These results demonstrate for the first time that Lyme disease in forestry workers can be revealed using OspC-I ELISA. We conclude that forestry workers who show positive results for antibodies against OspC-I have very likely been exposed to Lyme disease spirochaetes, and that those who show positivity for IgM antibody against OspC-I may be in the early stage of Lyme disease.

1. Our experiments show that an intravenous injection of antigen immediately after an intravenous injection of antiserum in the guinea-pig were followed by:

(a) Acute shock and death within 5 min. The signs and post-mortem appearances were indistinguishable from acute anaphylactic shock as typically seen in the guinea-pig. Some control animals injected with antiserum only died in a way similar to those which received both antiserum and antigen. These are discussed in detail in the body of the paper.

(b) Delayed shock and death some hours later. The post-mortem appearances were those of gastro-intestinal congestion and haemorrhage resembling the changes seen in dogs dying of anaphylactic shock. Such changes were never seen in the control animals.

(c) Recovery. Practically all the animals which recovered had symptoms of respiratory embarrassment immediately following the injections of anti-serum and antigen and many had later symptoms of abdominal shock. The animals which were given an injection of antiserum only rarely had any symptoms and never abdominal symptoms.

2. It is necessary to test the antisera used by control inoculation since some antisera are toxic.

The serological characters of 66 strains of meningococci obtained from the cerebro-spinal fluid in cases of meningitis have been studied. Serological tests of a similar nature have been applied to 86 strains of Gram-negative cocci, culturally identical with meningococci, obtained from the naso-pharynx of non-contacts. The two series have been compared in respect of agglutinability, agglutinogenic capacity, and absorptive capacity with the following results:

The majority of the spinal strains can be divided into two main groups by simple agglutination tests with selected spinal sera: about 27 can be assigned to Group I and 34 to Group II, the remaining five being relatively inagglutinable or equally agglutinated by sera of both groups.

In March 2008, the Health Protection Agency in England conducted a retrospective case-control study to investigate the cause of 179 cases of the newly recognized, fully antimicrobial-sensitive Salmonella Typhimurium PT U320. Forty-three symptomatic laboratory-confirmed case-patients and 84 asymptomatic location-matched controls were interviewed by telephone about exposures in the 3 days prior to illness or interview. Multivariate logistic analysis indicated consumption of pre-packaged egg sandwiches (odds ratio 3·29, 95% confidence interval 1·19–9·09) was independently associated with illness. Eight of the 15 case-patients who consumed egg sandwiches did so from retail chain A (53·3%) whereas none of the eight controls consumed similar sandwiches (χ2=7·20, P⩽0·01). A review of the pre-packaged egg sandwich ingredients suggested this outbreak was probably caused by exposure to an ingredient common to pre-packaged sandwiches and prepared salads but we established a definitive epidemiological link with only the former. Short shelf-life, product diversity and investigation lag hinder epidemiological investigations of such popular products, providing continued challenges for food safety enforcement of freshly prepared produce.

Twenty-three pre- and post-treatment isolates of Helicobacter pylori from the antral mucosa of eight patients with dyspepsia and gastritis were compared using 1-D SDS PAGE of proteins. The protein patterns were highly reproducible and were used as the basis for two numerical analyses. The first, based on the total protein patterns, showed that a number of the strains did not cluster with their respective patient set. This was thought to be due to differences in both mobility and intensity of proteins in the major band region. The second analysis, based on partial patterns, excluding the major band region (51–68 kDa), divided the clinical isolates into clearly defined groups corresponding to the patient sets. Although there was a degree of heterogeneity with respect to protein pattern between the pre- and post-treatment isolates of some patients, there was nonetheless clear evidence that each patient was harbouring strains of only a single type. These results suggested that patients were not being reinfected with a different strain but that there was recrudescence of the pre-treatment strain. Protein ‘fingerprints’ provided a precise and reproducible means of strain differentiation, and revealed that in each patient the same strain persisted after drug therapy even though there was marked patient-to-patient strain variation.

Recent epidemiological data suggest a link between the consumption of bovine offal products and Shiga toxin-producing Escherichia coli (STEC) infection in Japan. This study thus examined the prevalence of STEC in various types of these foods. PCR screened 229 bovine offal products for the presence of Shiga toxin (stx) gene. Thirty-eight (16·6%) samples were stx positive, of which eight were positive for rfbEO157 and three were positive for wzyO26. Four O157 and one O26 STEC isolates were finally obtained from small-intestine and omasum products. Notably, homogenates of bovine intestinal products significantly reduced the extent of growth of O157 in the enrichment process compared to homogenates of beef carcass. As co-incubation of O157 with background microbiota complex from bovine intestinal products in buffered peptone water, in the absence of meat samples, tended to reduce the extent of growth of O157, we reasoned that certain microbiota present in offal products played a role. In support of this, inoculation of generic E. coli from bovine intestinal products into the homogenates significantly reduced the extent of growth of O157 in the homogenates of bovine intestinal and loin-beef products, and this effect was markedly increased when these homogenates were heat-treated prior to inoculation. Together, this report provides first evidence of the prevalence of STEC in a variety of bovine offal products in Japan. The prevalence data herein may be useful for risk assessment of those products as a potential source of human STEC infection beyond the epidemiological background. The growth characteristic of STEC O157 in offal products also indicates the importance of being aware when to test these food products.

41·7 per cent. of the rats in the Oxford district were found to carry Leptospira icterohaemorrhagiae in their kidneys. The percentage infection increases until the animals are mature, reaching a maximum of 56 per cent. among one class of the population, but is less among the oldest rats. There is evidence that the organism is acquired comparatively early in life, and that immunity is obtained after a long period of infection.

Much work has already been done in connection with the differentiation of true diphtheria bacilli from diphthomorphic organisms. Some observers have maintained that all disease producing strains could be distinguished from non-pathogenic types by their sugar reactions. Others have laid much stress on some particular forms of virulence test. More recently serological classification has been attempted in order to help to solve this problem.

With regard to sugar reactions Graham-Smith (1908) found that certain strains produced acid in media containing saccharose, while Hine (1913), on the other hand, maintained that no true diphtheria bacillus could ferment this sugar. Eagleton and Baxter (1922) have shown that diphtheria bacilli, virulent and non-virulent, ferment glucose but do not produce any change in saccharose. Jordan and his collaborators (1922) have found that virulent and non-virulent bacilli fermented glucose and maltose and produced no change in saccharose and that their action on dextrin was variable.

Work on the serological classification of these organisms has also shown some considerable variation. Havens (1920) isolated 206 strains of diphtheria bacilli. These represented cultures from acute cases, release cultures and cultures from healthy carriers. He found that these 206 strains could be divided into two serological groups, one group containing 169 strains, the other 37. There was no evidence of any cross agglutination. Durand (1920) isolated 255 strains of typical diptheria bacilli and after excluding those strains which would not form stable suspensions divided them into five groups, A. B. C. D. and E. containing 16, 8, 25, 61 and 40 strains respectively. Eighty-seven strains were found to be inagglutinable by these five sera but nevertheless could absorb agglutinins from such sera. His final figures for the five groups of bacilli are 18, 8, 31, 76 and 51. Durand and Guerin (1921) in a further paper showed that small isolated outbreaks were always due to the same type of bacillus. They also found that healthy carriers gave the same type of bacillus as was found in the cases arising from these sources of infection. Bell (1922) isolated 133 strains of B. diphtheriae indifferently collected from cases and carriers. He was able to agglutinate 80 per cent. of these strains by three monovalent sera. Group I contained 17 strains, Group II 8 strains, Group III 80 strains.

In view of the results which have just been described it has appeared important to investigate further a considerable number of strains as encountered in routine work, not only as regards the serological characteristics of the organisms but also in regard to their morphology, their biochemical reactions, and their virulence for guinea-pigs.

The pH-stability of three strains of rinderpest virus, propagated in tissue cultures, was investigated at 4°C. in veronal-acetate buffers (Michaelis) of pH 3·0–10·7.

An attenuated laboratory strain, in its 95th culture passage (RBOK), showed maximal stability in the pH range 7·2–8·0, the half-life being about 3·7 days. It was relatively stable from pH 4·0 to 10·2, the half-life at the extremes of this range being over 2 hr. At pH 3·0 the infectivity declined very rapidly, the half-life period being 24·0 sec.

One virulent strain (RGK/1) showed a significantly lower resistance than strain RBOK at pH 3/0, probably also at pH 5·0. The inactivation rates for these two strains were, however, not greatly different at pH 10·7. The other virulent strain (RBT/1) was even less stable than RGK/1 at pH 4·0 or 5·0 but of a comparable stability at pH 9·0 and 10·2.

These findings are discussed in comparison with published data on the related viruses of measles and canine distemper. The importance of strain differences in studies of this kind is stressed.

We are grateful to Mr C. S. Rampton, A.I.M.L.T., and Mr L. W. Rowe, F.I.M.L.T., for help in the preparation of the diagrams. This paper is published with the permission of Mr H. R. Binns, C.M.G., O.B.E., Director, E.A.V.R.O.

Antibiotic resistance plasmids from organisms that had caused serious epidemics, including those responsible for epidemics of chloramphenicol-resistant typhoid fever and dysentery in Central America, were transferred to a strain of Salmonella typhimurium and of Salmonella gallinarum. The virulence and infectivity of these R+ forms were then compared with the R− parent forms in orally inoculated chickens.

None of the R+ forms were more virulent than their R− parent forms. The mortality rates they produced were either the same as or less than that of their R− parent forms. The mortality rates were not increased by feeding the chickens on diets containing antibiotics against which the plasmids provided resistance.

The removal of the plasmids from some R+ forms of decreased virulence was not accompanied by any alteration in virulence, indicating that they were less virulent mutants of the parent strain that had conjugated preferentially. In other cases their virulence was increased, indicating that the very possession of the plasmid was involved in their decreased virulence. Of four forms of the S. gallinarum strain harbouring the plasmid that had been incriminated in the Central American dysentery outbreak, one was as virulent as the parent R− form and the other three were less virulent. Preferential conjugation by an avirulent mutant was responsible for the lack of virulence of one of them but the very possession of the plasmid appeared responsible for the decreased virulence of the other two. The decreased virulence of de-repressed F+ and I+ forms of the S. typhimurium strain was increased to that of repressed F+ form and of the parent form by plasmid removal.

Organisms of the R+ forms of the S. typhimurium strain were not excreted in larger amounts or for longer periods of time by infected chickens than organisms of the R− parent form were. Neither did organisms of the R+ forms of this strain or the S. gallinarum strain spread more rapidly or more extensively from infected chickens to in-contact chickens than organisms of the R− parent forms did. When antibiotics against which the infecting R+ organisms provided resistance were included in the diet of these chickens the R+ organisms were usually excreted in greater amounts, for longer periods of time and spread more rapidly and more extensively from the infected chickens to the in-contact chickens.

Skin scales may be attracted onto the surface of administration set connector needles before insertion into infusion containers. Viable microorganisms associated with skin scales may therefore gain access to the infusion by this route. A technique is described for creating an environment of airborne skin scales. This environment is used to examine the attraction of skin scales onto the surface of administration set connector needles and three other materials. After exposure, skin scales are found adhering to the surface of each material examined. The attraction of skin scales onto administration set connector needles is dependent on the time of exposure to the environment. Results suggest that intravenous infusions can be contaminated by this route when the infusion and administration set is assembled.

A technique is presented for the titration of the virus of foot-and-mouth disease in culture in surviving epithelial tissue from the tongues of cattle. The cultures are incubated in cups on Perspex plates, and the detection of virus multiplication is by a complement-fixation test made on the culture in each cup.

On the basis of comparative titrations in culture and in cattle, the method has been found to be as sensitive for the detection of virus as the titration by intradermal inoculation of the tongue of cattle. The method can also be applied in the detection of antibody in neutralization tests.

We wish to record our thanks to Messrs E. Scoates and P. Mitchell for their technical assistance, and to Messrs H. M. Smith, R. H. Compton and R. L. Jackson for their part in the design and fabrication of various bottle rotators, plate shakers, Perspex lids and the inoculating box.

There seems to be considerable evidence in favour of the view that the immediate cause of this acute infective fever is an organism in the form of a streptococcus although there does not yet appear to be unanimity as to the specific characteristics of the latter. With regard to the secondary or indirect or predisposing causes of the complaint, the agencies which influence favourably the development and activity of the organism and consequently the prevalence of the disease, there has been a definite tendency in recent years not only to abandon the hitherto prevailing opinion on the influence of certain meteorological factors, namely, that increase in the amount of rainfall and decrease in the temperature are generally associated with increased incidence of the disease but even to assert that the action of these factors is the reverse of this.

Aquatic wild birds are often carriers of low-pathogenic avian influenza viruses (LPAIVs). If H5 and H7 LPAIVs are transmitted to poultry and have the opportunity to circulate, a highly pathogenic AIV may arise. Contact with aquatic wild birds is one of the most important ways in which these LPAIVs can be introduced into poultry flocks. In this study, the transmissibility of a duck-originated H5 LPAIV between ducks and chickens was analysed in a series of animal experiments, using different transmission routes. Results indicate that the outcome of virus intake by chickens exposed to infectious ducks depends on the way the virus is presented. Faecally contaminated drinking water proved to be the most efficient route by which the virus can be transmitted to chickens. The results from this study also suggest that some duck-originated H5 LPAIVs may be introduced to poultry but do not have the potential to become established in poultry populations.

When mice were injected intracerebrally with doses of Bordetella pertussis vaccine greater than 5 ImD50 and challenged intracerebrally 14 days later with virulent B. pertussis there was an immediate reduction in the numbers of organisms. An analysis of this in vivo bactericidal effect has shown that large doses of an unrelated vaccine, Salmonella typhosa, equivalent in cell mass to about 50 ImD 50 of B. pertussis vaccine can achieve this effect, so for such doses the effect must be partly non-specific. This action is not maintained and so is not ultimately protective. Local immunoglobulin was also demonstrable 14 days after 300 ImD 50 of B. pertussis vaccine but following smaller doses of 10–20 ImD 50 it could not be found until after the mice had been infected and the blood–brain barrier impaired.

A similar immediate reduction in the numbers of infecting organisms inoculated 1 day after vaccination has been shown to follow very small, non-protective doses of vaccines unrelated to B. pertussis and to be achieved with lipopolysaccharide and endotoxin isolated from B. pertussis. Brains were not sterilized and only in mice receiving protective B. pertussis vaccine was the lowering of infection maintained beyond 2 days and the brains eventually sterilized.

The antibody passively protecting mice against intracerebral infection was found in the 19 S and 11 S globulin fractions of the serum of once-vaccinated mice and in the 11 S and 7 S fractions of the serum of rabbits and ascitic fluid of mice receiving repeated doses of vaccine. The IgM probably eliminated infections by immediate sterilization but had to be present locally to do so since it was unable to pass from the circulation into the brain, and was therefore inactive when injected intraperitoneally. The IgA and IgG were not so restricted and both the 11 S and 7 S globulins were capable of exerting an immediate suppressive effect on infecting organisms. The 7 S globulin was also capable of a maintained or delayed suppressive effect.

Lymphocytes from fully protected once-vaccinated mice, transferred 2–3 weeks after intraperitoneal vaccination, were able to confer some protection when injected intraperitoneally or intracerebrally into recipient mice infected 2 weeks after transfer. Homologous, non-concentrated antiserum from once-vaccinated mice, injected intraperitoneally 1 hr. before infection sometimes augmented the transferred immunity, whereas alone it was inactive.

Like the skin and its appendages, the teeth, nails and hair, so also other tissues of ectodermal origin are here shown to be affected by fluorine. The action of fluorine consists in lowering the level of the calcium in the blood and tissues. The epithelia of the mouth and the salivary glands, of the nasopharynx, the conjunctivae and the lachrymal glands may be affected. Signs and symptoms are thus produced which are closely similar to those usually attributed primarily to infection. It is suggested that an infection accompanying chronic fluorine poisoning is of a secondary nature, and that it is brought about by the loss of calcium in the body.

Coronavirus disease 2019 (COVID-19) has had a tremendous impact in China and abroad since its onset in December 2019 and poses a major threat to human health. Healthcare workers (HCWs) are at the forefront of the response to outbreaks. This study reviewed literature data and found that HCWs were at high risk of infection during the COVID-19 pandemic, especially at the early stage of the epidemic, and many factors greatly affected their occupational safety. Although SARS-CoV-2 transmission was controlled in China, the Chinese experience can help protect HCWs from COVID-19 and other respiratory diseases.

Healthcare workers (HCWs) reporting no history of varicella frequently receive varicella vaccination (vOka) if they test varicella-zoster virus (VZV) immunoglobulin G (IgG) negative. In this study, the utilities of VZV-IgG time-resolved fluorescence immunoassay (VZV-TRFIA) and a commercial VZV-IgG purified glycoprotein enzyme immunoassay (gpEIA) currently used in England for confirming VZV immunity have been compared to the fluorescent-antibody-to-membrane-antigen assay (FAMA). A total of 110 HCWs received two doses of vOka vaccine spaced 6 weeks apart and sera collected pre-vaccination (n = 100), at 6 weeks post-completion of vaccination (n = 86) and at 12–18 months follow-up (n = 73) were analysed. Pre-vaccination, by FAMA, 61·0% sera were VZV IgG negative, and compared to FAMA the sensitivities of VZV-TRFIA and gpEIA were 74·4% [95% confidence interval (CI) 57·9–87·0] and 46·2% (95% CI 30·1–62·8), respectively. Post-completion of vaccination the seroconversion rate by FAMA was 93·7% compared to rates of 95·8% and 70·8% determined by VZV-TRFIA and gpEIA, respectively. At 12–18 months follow-up seropositivity rates by FAMA, VZV-TRFIA and gpEIA were 78·1%, 74·0% and 47·9%, respectively. Compared to FAMA the sensitivities of VZV-TRFIA and gpEIA for measuring VZV IgG following vaccination were 96·4% (95% CI 91·7–98·8) and 74·6% (95% CI 66·5–81·6), respectively. Using both FAMA and VZV-TRFIA to identify healthy adult VZV susceptibles and measure seroconversion showed that vOka vaccination of HCWs is highly immunogenic.

Neonatal listeriosis is rare and detecting more than one case together would be unlikely without a causal link. Thirty-five instances of neonatal listeriosis where cross-infection occurred in the UK and Ireland were reviewed together with 29 other similar episodes reported elsewhere. All instances comprised an infant who was ill at or within one day of delivery and who had direct or indirect contact with a second infant, or in the minority, two or more infants, who then usually developed meningitis 6 to 12 days later. In most instances, the infants were nursed on the same day in obstetric units or new-born nurseries and consequently, staff and equipment were common: hence, the likely route of transmission was via direct or indirect neonate to neonate contact. In one instance, a stethoscope was used on both infants nursed in different parts of the same hospital. In a further incident, the mother of the early-onset infant cuddled a baby from an adjacent bed who developed meningitis 12 days later. The largest outbreak occurred in Costa Rica where nine neonatal listeriosis cases resulted after bathing in mineral-oil shortly after birth which had been contaminated from the early-onset index case.