1. Cultures of Gärtner's bacillus grown on broth do not excrete any large amount of toxin into the fluid medium.

2. Suspension in broth made from ordinary agar cultures and killed by means of heat (30 mins. at 60°C.) are fairly toxic.

3. The most toxic preparations were obtained by autolysis of the bacilli, especially in the presence of toluol.

4. Cultures grown on agar and killed by means of chloroform vapour lose their toxicity to a considerable extent.

5. Autolysis takes place best in the presence of distilled water or of normal saline.

6. Autolysed material sterilised by heat is more toxic than the filtrate obtained from the same digest.

7. Shaking the bottles during the process of autolysis increases the yield of toxic substances.

8. Gärtner toxin withstands heating to 100°C. for 30 mins.

9. Paratyphoid B. bacillus cultures on autolysis yield a filtrate quite as toxic as those from the Gärtner bacillus itself.

10. Paratyphoid toxin is also heat resistant (100° for 30 mins.).

11. A colon bacillus gave a toxin which was fatal to mice. It was not heat resistant.

12. Feeding experiments with Gärtner-infected meat, both cooked and uncooked, proved successful.

13. So far as the present experiments go the connection between virulence and toxicity does not appear to be very definite.

14. The Gärtner bacillus contains a toxin of the endotoxin type as is shown in comparing results 1 and 3. This toxin gives rise to very definite clinical symptoms of which the gluing together of the eyelids and the prolonged narcosis before death are the most notable. The post-mortem signs have much in common with those arising from other intestinal intoxications.

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.

In April, 1917, while examining some rats (probably M. decumanus) in company with Mr L. D. Cleare, Jnr., my assistant, for external and internal parasites, the lungs of a male specimen were observed to be in a highly diseased condition.

1. One hundred lepers were examined by Browning, Cruickshank and McKenzie's modification of the Wassermann reaction with positive results in 22 cases. The amount of complement deviated was in some cases exceptionally large.

2. In a control group of 110 non-leprous persons there were 11 positive reactions.

3. In only one of the lepers was there visible evidence of former venereal disease but 33 of the lepers admitted that they had suffered from syphilis or from chancres, and of these 33, 13 reacted positively, while only nine of the remaining 66 gave positive reactions.

4. In the control group, 21 admitted former syphilitic infection and, of these, eight reacted positively; among the remaining 89, who denied syphilis, there were three positive reactions.

5. There were 12 positive reactions among 44 cases of tubercular leprosy and 10 positive reactions among 56 cases of the anaesthetic type.

6. The average duration of the disease, among the 22 lepers who reacted positively, was four years and eight months, as compared with an average of three years and eight months for the 78 patients who reacted negatively; but among the latter there were many old-standing cases.

7. Seventeen of the 22 positive cases were in an advanced stage of leprosy and in some of them the disease was progressing; but among those lepers who reacted negatively there were also many advanced and progressing cases.

8. Serum from the lesions in 10 of the lepers who reacted positively was examined by dark-ground illumination, but in no case was the Treponema pallidum found.

9. The luetin test was applied to 21 lepers, with negative results in every instance; 13 of these cases gave positive and eight gave negative Wassermann reactions. The test was also applied to a control group of non-leprous persons selected because they were likely to be latent syphilitics. In this group there were 11 positive luetin reactions.

Studies on climate variables and food pathogens are either pathogen- or region-specific, necessitating a consolidated view on the subject. This study aims to systematically review all studies on the association of ambient temperature and precipitation on the incidence of gastroenteritis and bacteraemia from Salmonella, Shigella, Campylobacter, Vibrio, and Listeria species. PubMed, Ovid MEDLINE, Scopus, and Web of Science databases were searched up to 9 March 2023. We screened 3,204 articles for eligibility and included 83 studies in the review and three in the meta-analysis. Except for one study on Campylobacter, all showed a positive association between temperature and Salmonella, Shigella, Vibrio sp., and Campylobacter gastroenteritis. Similarly, most of the included studies showed that precipitation was positively associated with these conditions. These positive associations were found regardless of the effect measure chosen. The pooled incidence rate ratio (IRR) for the three studies that included bacteraemia from Campylobacter and Salmonella sp. was 1.05 (95 per cent confidence interval (95% CI): 1.03, 1.06) for extreme temperature and 1.09 (95% CI: 0.99, 1.19) for extreme precipitation. If current climate trends continue, our findings suggest these pathogens would increase patient morbidity, the need for hospitalization, and prolonged antibiotic courses.

A Canadian outbreak investigation was initiated in January 2022 after a cluster of cases of Shiga-toxin-producing Escherichia coli (STEC) O157 was identified through whole genome sequencing (WGS). Exposure information was collected through case interviews. Traceback investigations were conducted, and samples from case homes, retail, and the manufacturer were tested for STEC O157. Fourteen cases were identified in two provinces in Western Canada, with isolates related by 0–5 whole genome multi-locus sequence typing allele differences. Symptom onset dates ranged from 11 December 2021 to 7 January 2022. The median age of cases was 29.5 (range 0–61); 64% were female. No hospitalisations or deaths were reported. Of 11 cases with information available on fermented vegetable exposures, 91% (10/11) reported consuming Kimchi Brand A during their exposure period. The traceback investigation identified Manufacturer A in Western Canada as the producer. One open and one closed sample of Kimchi Brand A tested positive for STEC O157, with isolates considered genetically related by WGS to the outbreak strain. Napa cabbage within the kimchi product was hypothesised as the most likely source of contamination. This paper summarises the investigation into this STEC O157 outbreak associated with kimchi, the first reported outside of East Asia.

During October 2021, the County of San Diego Health and Human Services Agency identified five cases of shigellosis among persons experiencing homelessness (PEH). We conducted an outbreak investigation and developed interventions to respond to shigellosis outbreaks among PEH. Confirmed cases occurred among PEH with stool-cultured Shigella sonnei; probable cases were among PEH with Shigella-positive culture-independent diagnostic testing. Patients were interviewed to determine infectious sources and risk factors. Fifty-three patients were identified (47 confirmed, 6 probable); 34 (64%) were hospitalised. None died. No point source was identified. Patients reported inadequate access to clean water and sanitation facilities, including public restrooms closed because of the COVID-19 pandemic. After implementing interventions, including handwashing stations, more frequent public restroom cleaning, sanitation kit distribution, and isolation housing for ill persons, S. sonnei cases decreased to preoutbreak frequencies. Improving public sanitation access was associated with decreased cases and should be considered to prevent outbreaks among PEH.

The impact of influenza and pneumonia on individuals in clinical risk groups in England has not previously been well characterized. Using nationally representative linked databases (Clinical Practice Research Database (CPRD), Hospital Episode Statistics (HES) and Office for National Statistics (ONS)), we conducted a retrospective cohort study among adults (≥ 18 years) during the 2010/2011–2019/2020 influenza seasons to estimate the incidence of influenza- and pneumonia-diagnosed medical events (general practitioner (GP) diagnoses, hospitalisations and deaths), stratified by age and risk conditions. The study population included a seasonal average of 7.2 million individuals; approximately 32% had ≥1 risk condition, 42% of whom received seasonal influenza vaccines. Medical event incidence rates increased with age, with ~1% of adults aged ≥75 years hospitalized for influenza/pneumonia annually. Among individuals with vs. without risk conditions, GP diagnoses occurred 2–5-fold more frequently and hospitalisations were 7–10-fold more common. Among those with obesity, respiratory, kidney or cardiovascular disorders, hospitalisation were 5–40-fold more common than in individuals with no risk conditions. Though these findings likely underestimate the full burden of influenza, they emphasize the concentration of disease burden in specific age and risk groups and support existing recommendations for influenza vaccination.

The association between time to positivity (TTP) of blood culture and the clinical prognosis of patients with Klebsiella pneumoniae bloodstream infection (BSI) remains unclear. A retrospective study of 148 inpatients with BSI caused by K. pneumoniae was performed at Shanghai Tongji Hospital, China, from October 2016–2020. The total in-hospital fatality rate was 32%. The median TTP was 11.0 (7.7–16.1) h and the optimal cutoff for prediction of in-hospital mortality was 9.4 h according to the ROC curve. Early TTP (<9.4 h) was a risk factor for in-hospital mortality by univariate analysis (OR = 2.5, 95% CI 1.2–5.0, P = 0.01), but not by multivariate analysis (OR = 2.7, 95% CI 1.0–7.4, P = 0.06). Old age, serum creatinine, white blood cells, and C-reactive protein values were risk factors for in-hospital mortality by multivariate analysis. Early TTP was not a risk factor for septic shock (OR = 1.8, 95% CI 0.6–5.1, P = 0.27) or ICU admission (OR = 1.0, 95% CI 1.0–1.0, P = 0.32). In conclusion, the in-hospital fatality rate of patients with K. pneumoniae BSI was relatively high and associated with an early TTP of blood cultures. However, no increased risk of mortality, septic shock or ICU admission was evident in early TTP patients.

In autumn 1978 an epidemic of respiratory disease resembling allergic alveolitis occurred in a small Finnish community. The disease was caused by repeated exposures to tap water aerosol. The raw water of the community and the sand filters of the purification system were heavily contaminated with mesophilic actinomycetes. Fourteen different strains of actinomycetes were isolated. Exposed persons with and without symptoms as well as unexposed control persons were tested for antibodies against five of these actinomycetes and against Enterobacter agglomerans. Both the exposed and the control persons had antibodies to actinomycetes but the exposed persons had antibodies against more actinomycete strains than the control persons. Precipitating antibodies against E. agglomerans were also found in control persons as well as in patients. There was a significant difference between the patients and the exposed healthy persons in bacterial agglutination tests with flagellar antigen of one E. agglomerans strain. However, the role of mesophilic actinomycetes and E. agglomerans in the aetiology of the disease could not be firmly established.

We estimated prevalence and incidence of liver condition outcomes, and costs to the health service of diagnosed hepatitis B virus (HBV) in Tayside, UK. HBV patients were identified from electronic virology data between 1989 and 2003. The health resource costs of HBV for surface antigen-positive (HBsAg+) patients and HBV (HBsAg+ or immune, i.e. recovered) patients were calculated. A total of 633 patients had HBV (275 HBsAg+), and were more likely to be male (62% vs. 48%), older (mean age 42·6 vs. 39·2 years) and deprived than the general population. The prevalence of immune individuals increased steadily. Post-HBV diagnosis, 24% of immune and 13% of HBsAg+ patients were diagnosed with a liver condition. The median cost per immune patient (£3023) was greater than per HBsAg+ patient (£1498) (P = 0·02). While increasing prevalence of immune HBV patients highlights an increase in screening and treatment, the costs associated with this group are high.

1. Avian tubercle bacilli were grown in hanging-drop cultures in embryo extract prepared as for tissue culture, but diluted to 25–5% of its usual concentration.

2. Microscopic branching colonies of pseudomycelia developed in the surface film of the hanging drops during the first few days of incubation, after which growth declined.

3. The development of these colonies was studied on the warm stage and proceeds as follows:

(a) The original rods elongate into filaments.

(b) The filaments multiply by ordinary fission and also by forming fine, pin-like terminal sprouts which grow into independent bacilli.

(c) After division the daughter filaments usually remain in contact at the site of fission; their terminal growth continues at an angle to the former cleavage plane and the colony thus acquires its characteristic branching structure.

(d) The colony enlarges and ramification becomes increasingly complex until about the fifth day of incubation when growth declines. The bacilli remain filamentous.

4. When transferred to embryo extract of normal concentration the pseudomycelial colonies revert to the ‘standard’ type of development characteristic of the more concentrated medium, i.e. they pass through a phase of filamentous proliferation followed by disintegration of the filaments into short discrete rods.

5. The development of a pseudo-mycelium is compared with the three common types of growth previously seen in more concentrated embryo extract.

6. The results of this investigation shed light on the controversial question of whether the ‘mycelial’ form of the tubercle bacillus is a single individual formed by ‘true’ lateral budding or a composite structure produced by the terminal, angular growth of coherent but independent bacilli. Our observations on the living organisms have shown that under appropriate experimental conditions both these forms may develop.

Drinking water has long been supposed to play an important part in the causation of endemic goitre. Estimations by v. Fellenberg (1923, 1924) in Switzerland and by Mcclendon and Hathaway (1924) in the United States have shown that, in these countries, drinking water in goitre areas contains less iodine than in goitre-free areas. The iodine content of several waters has been estimated at this Institute. The results show that in this country there is no correlation between presence of goitre and a low iodine content in drinking water. It is true that the lowest figure (Swindon) is for water from a goitre area, but the next one (Aberdeen) is not. The figures for Cumberland and Derbyshire, both goitre areas, are not low.

Vaccination has reduced the disease burden of vaccine-preventable diseases. However, the extent to which seasonal cycles of immunity could influence vaccine-induced immunity is not well understood. A national cross-sectional serosurveillance study performed in the Netherlands (Pienter-2) yielded data to investigate whether season of vaccination was associated with antibody responses induced by DT-IPV (diphtheria, tetanus and poliomyelitis), MMR (measles, mumps and rubella) and meningococcus C (MenC) vaccines in children. In total, 434 children met the inclusion criteria to study DT-IPV immunity, 811 for MMR and 311 for MenC. Differences in log(antibody levels) by season of vaccination were investigated with linear multivariable regression analyses. Seroconversion rates varied according to season of vaccination for rubella (90% of autumn-vaccinated children vs. 99% of winter-vaccinated had concentrations above cut-off levels). Summer-vaccinated boys showed a slower decline of tetanus antibodies (6% per month), in comparison with winter-vaccinated boys. In conclusion, season of vaccination showed little association with immunological protection. However, a number of associations were seen with a P-value of about 0.03; and adding data from a just-completed nationwide serological study might add more power to the current study. Further immunological and longitudinal investigations could help understand the mechanisms of seasonal influence in vaccine-induced responses.

We report the development of a regression model to predict the prevalence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) antibodies on a population level based on self-reported symptoms. We assessed participant-reported symptoms in the past 12 weeks, as well as the presence of SARS-CoV-2 antibodies during a study conducted in April 2020 in Ischgl, Austria. We conducted multivariate binary logistic regression to predict seroprevalence in the sample. Participants (n = 451) were on average 47.4 years old (s.d. 16.8) and 52.5% female. SARS-CoV-2 antibodies were found in n = 197 (43.7%) participants. In the multivariate analysis, three significant predictors were included and the odds ratios (OR) for the most predictive categories were cough (OR 3.34, CI 1.70–6.58), gustatory/olfactory alterations (OR 13.78, CI 5.90–32.17) and limb pain (OR 2.55, CI 1.20–6.50). The area under the receiver operating characteristic curve was 0.773 (95% CI 0.727–0.820). Our regression model may be used to estimate the seroprevalence on a population level and a web application is being developed to facilitate the use of the model.

Adult cockroaches were found to survive up to 22 weeks when provided with 1% Formalin (0·4% formaldehyde) in lieu of drinking water. Given 4% Formalin or 2% glutaraldehyde they survived up to 41 days. During the experiments eggs were laid and hatched and the offspring continued to grow. Combined with surface disinfection, this may hold out a simple method of rendering adult cockroaches gnotobiotic or even axenic.

Mass gatherings (MG) present a number of challenges to public health authorities and governments across the world with sporting events, tournaments, music festivals, religious gatherings and all other MG having historically posed a risk to the spread and amplification of a range of infectious diseases. Transmission of gastrointestinal, respiratory, waterborne and sexually transmitted infectious diseases pose a particular risk: all have been linked to MG events [1–4]. Infection risk often depends on the nature of the mass gathering, and on the profile and behaviour of its participants. The interaction between environmental, psychological, biological and social factors plays a vital part. The risk of outbreaks particularly as a result of respiratory transmission remains high at MG, with the majority of outbreaks over the last two decades resulting from a variety of respiratory and vaccine preventable pathogens [5–7]. Concerns about the spread of infectious diseases at MG are often focussed on crowding, lack of sanitation and the mixing of population groups from different places. Sporting events, which have in recent decades become more complex and international in nature, pose a challenge to the control of communicable disease transmission [8]. Despite this, large scale outbreaks at sporting events have been rare in recent decades, particularly since the rise of more robust public health planning, prevention, risk assessment and improved health infrastructures in host countries [9].

In extensive cohort studies, the ascertainment of covariate information on all individuals can be challenging. In hospital epidemiology, an additional issue is often the time-dependency of the exposure of interest. We revisit and compare two sampling designs constructed for rare time-dependent exposures and possibly common outcomes – the nested exposure case-control design and exposure density sampling. Both designs enable efficient hazard ratio estimation by sampling all exposed individuals but only a small fraction of the unexposed ones. Moreover, they account for time-dependent exposure to avoid immortal time bias. We evaluate and compare their performance using data of patients hospitalised in the neuro-intensive care unit at the Burdenko Neurosurgery Institute in Moscow, Russia. Three different types of hospital-acquired infections with different prevalence are considered. Additionally, inflation factors, a primary performance measure, are discussed. We enhance both designs to allow for a competitive analysis of combined and competing endpoints compared to the full cohort approach while substantially reducing the amount of necessary information. Nonetheless, exposure density sampling outperforms the nested exposure case-control design concerning efficiency and accuracy in most considered settings.