In April 2020, Belgium experienced high numbers of fatal COVID-19 cases among nursing home (NH) residents. In response, a mass testing campaign was organised testing all NH residents and staff. We analysed the data of Flemish NHs to identify institutional factors associated with increased SARS-CoV-2 infection rates among NH residents. Cross-sectional study was conducted between 8 April and 15 May 2020. Data collected included demographics, group category (i.e. staff or resident), symptom status and test result. We retrieved additional data: number of beds and staff, type of beds (level of dependency of residents) and ownership (public, private for profit/non-profit institutions). Risk factor analysis was performed using negative binomial regression. In total, 695 NHs were included, 282 (41%) had at least one resident tested positive. Higher infection rate among residents was associated with a higher fraction of RVT beds, generally occupied by more dependent residents (incidence rate ratio (IRR) 1.97; 95% CI 1.00–3.86) and higher staff infection rate (IRR 1.89; 95% CI 1.68–2.12). No relationship was found between other investigated NH characteristics and infection rate among residents. Staff-resident interactions are key in SARS-CoV-2 transmission dynamics. Vaccination, regular staff testing, assessment of infection prevention and control strategies in all NHs are needed to face future SARS-CoV-2 epidemics in these settings.

Backyard chickens are increasingly popular, and their husbandry varies widely. How backyard chickens are housed may influence the accessibility of chicken feed and water to wild birds, and thus, the contact rates between both groups. Increased contacts have implications for pathogen transmission; for instance, Newcastle disease virus or avian influenza virus may be transmitted to and from backyard chickens from contaminated water or feed. Given this potentially increased pathogen risk to wild birds and backyard chickens, we examined which wild bird species are likely to encounter backyard chickens and their resources. We performed a supplemental feeding experiment followed by observations at three sites associated with backyard chickens in North Georgia, USA. At each site, we identified the species of wild birds that: (a) shared habitat with the chickens, (b) had a higher frequency of detection relative to other species and (c) encountered the coops. We identified 14 wild bird species that entered the coops to consume supplemental feed and were considered high-risk for pathogen transmission. Our results provide evidence that contact between wild birds and backyard chickens is frequent and more common than previously believed, which has crucial epidemiological implications for wildlife managers and backyard chicken owners.

1. Several strains of the influenza bacillus were grown under varying conditions for many months in order to ascertain whether morphology and colonial appearances could be permanently modified.

2. It was found that a modification in morphology occurred in all the strains studied.

3. Typical coccobacillary forms were changed to atypical long-curved forms.

4. The reverse change from atypical was also observed but was not so frequent, nor, when it occurred, was it so constant.

5. The change took place most readily after growth in a flask of Fildes' broth for several weeks or months at 37° C.

6. There was found to be a definite association between morphology and colonial form. The typical strains produced smooth colonies, while the atypical gave rough colonies, or colonies very much smaller than those produced by the typical.

7. When the change in morphology took place the change in colonial form occurred at the same time.

8. The biochemical characters remained on the whole unchanged.

9. One hundred and forty strains were examined for their fermentation reactions. The sugars most frequently fermented were dextrose, maltose and sucrose.

10. The atypicals were more active fermenters than the typicals.

11. 63·9 per cent. of the typicals, and 18 per cent. of the atypicals, gave a positive indol reaction.

12. Although the ability to grow on X or V alone affords an important differential criterion within this group, great care is necessary in interpreting the results obtained, especially in the case of those strains which grow on V in the absence of X. Different yeast preparations may give very different results in this respect.

13. All the strains tested were non-haemolytic.

Calculations have been carried out which suggest that as few as 6 × 104 molecules of anti-poliovirus antibody per millilitre of serum may be sufficient to prevent the clinical disease under certain epidemic conditions. Other calculations have been made involving therapy of the experimental disease in monkeys and certain factors required for successful serum therapy have been discussed.

Six of 12 men wintering at an isolated Antarctic base sequentially developed symptoms and signs of a common cold after 17 weeks of complete isolation. Examination of specimens taken from the men in relation to the outbreak has not revealed a causative agent.

The prognostic factor for in-hospital mortality in tuberculosis (TB) patients requiring intensive care unit (ICU) care remains unclear. Therefore, a retrospective study was conducted aiming to estimate the in-hospital mortality rate and the risk factors for mortality in a high-burden setting. All patients with culture-confirmed TB that were admitted to the ICU of the hospital between March 2012 and April 2019 were identified retrospectively. Data, such as demographic characteristics, comorbidities, laboratory measures and mortality, were obtained from medical records. The Cox proportional hazards regression model was used to identify prognostic factors that influence in-hospital mortality. A total of 82 ICU patients with confirmed TB were included in the analysis, and 22 deaths were observed during the hospital stay, 21 patients died in the ICU. In the multivariable model adjusted for sex and age, the levels of serum albumin and white blood cell (WBC) count were significantly associated with mortality in TB patients requiring ICU care (all P < 0.01), the hazard ratios were 0.8 (95% confidence interval (CI): 0.7–0.9) per 1 g/l and 1.1 (95% CI: 1.0–1.2) per 1 × 109/l, respectively. In conclusion, in-hospital mortality remains high in TB patients requiring ICU care. Low serum albumin level and high WBC count significantly impact the risk of mortality in these TB patients in China.

Our study aimed to investigate the epidemiology of extrapulmonary tuberculosis (EPTB) and analyse the epidemiological characteristics of EPTB patients with or without pulmonary tuberculosis (PTB). EPTB cases admitted in our hospital from January 2015 to December 2020 were included. Uni- and multi-variable logistic regression analysis was carried out to identify risk factors and prognostic factors of concomitant EPTB and PTB or exclusively EPTB. A total of 3488 EPTB patients were reviewed, including 2086 patients with concurrent PTB and EPTB, and 1402 patients with exclusively EPTB. Logistic regression analysis showed that age >60 years (OR = 1.674, 95% CI = 1.438–1.949, P < 0.001) and female (OR = 1.325, 95% CI = 1.155–1.520, P < 0.001) were risk factors of exclusively EPTB, while co-morbidities (OR = 0.676, 95% CI = 0.492–0.929, P = 0.016) and severe symptoms (OR = 0.613, 95% CI = 0.405–0.929, P = 0.021) were risk factors for concurrence of EPTB and PTB. Age >60 years was an independent prognostic factor in EPTB patients with or without PTB (HR = 11.059, 95%CI = 5.097–23.999, P < 0.001; HR = 23.994, 95%CI = 3.093–186.151, P = 0.0020). Female gender was an independent prognostic factor in patients with concurrent PTB and EPTB (HR = 23.994, 95%CI = 3.093–186.151, P = 0.002). Our study disclosed the differential epidemiological characteristics of EPTB patients with or without PTB in China.

Phthisis (pulmonary tuberculosis) is distinguished from nearly all other infectious diseases by its protracted duration and by the prolonged disability which it imposes upon enormous numbers of the total working population. It is further distinguished by the complexity of the influences which are regarded as affecting its spread or capable of controlling its prevalence. It is therefore of the first importance that the relative values of measures for controlling phthisis should be closely studied, and that special attention should be given to those which promise the greatest yield for a given expenditure. In particular it is important to be aware of any which can be set to work without the delay and expense involved in creating a new service. The present paper is intended as a contribution to this study. The facts collected in it and others of a similar kind deserve more extended investigation than it has been possible for me to give them in the intervals of official work. They are put forward here without any illusions as to the inevitable shortcomings of their presentation but with a conviction that from the economic standpoint they are of fundamental importance in the prevention of phthisis.

(1) A collection of S. typhi-murium strains, isolated during 11 months, in or near Manchester, was examined for the presence of symbiotic bacteriophage. In all, 177 strains derived from eighty-three incidents were investigated.

2. The different phages, or combinations of phage, allowed these strains to be divided into eleven varieties. Three hitherto undescribed types of phage were discovered.

3. With two minor exceptions, all groups of strains isolated from associated cases of infection carried the same type of phage, so that the ‘typing’ was in agreement with epidemiological expectations. In the two exceptions, the relationship of the cases was not intimate, and infection from different sources was an obvious possibility.

4. It is concluded that this is a reliable method of typing. It is probably applicable to other groups of bacteria. Its value would be enhanced by the discovery of a simpler method than filtration for sterilizing the lysato without damaging the phage.

Massive use of antibiotics has led to increased bacterial resistance to these drugs, making infections more difficult to treat. Few studies have assessed the overall antimicrobial resistance (AMR) burden, and there is a paucity of comprehensive data to inform health policies. This study aims to assess the overall annual incident number of hospitalised patients with AMR infection in France, using the National Hospital Discharge database. All incident hospitalisations with acute infections in 2016 were extracted. Infections which could be linked with an infecting microorganism were first analysed. Then, an extrapolation of bacterial species and resistance status was performed, according to age class, gender and infection site to estimate the total number of AMR cases. Resistant bacteria caused 139 105 (95% CI 127 920–150 289) infections, resulting in a 12.3% (95% CI 11.3–13.2) resistance rate. ESBL-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus were the most common resistant bacteria (>50%), causing respectively 49 692 (95% CI 47 223–52 142) and 19 493 (95% CI 15 237–23 747) infections. Although assumptions are needed to provide national estimates, information from PMSI is comprehensive, covering all acute bacterial infections and a wide variety of microorganisms.

Neisseria meningitidis is the main cause of bacterial meningitis and sepsis in the UK, and can potentially be lethal or cause long-term sequelae. Bexsero® (4CMenB) is a new multi-component vaccine approved by the European Commission for use in individuals aged ⩾2 months. A theoretical transmission model was constructed to assess the long-term effectiveness of Bexsero compared to standard care. The model was populated with UK-specific demographic data and calibrated to ensure that the transmission dynamics of meningococcal disease in the UK were adequately simulated. The model showed the best strategy to be a routine vaccination programme at ages 2, 3, 4, 12 months and 14 years combined with a 5-year catch-up programme in toddlers aged 12–24 months and adolescents aged 15–18 years. This would lead to a 94% reduction in meningococcal cases or 150 000 cases and 15 000 deaths over a 100-year time-frame.

Estimating the lengths-of-stay (LoS) of hospitalised COVID-19 patients is key for predicting the hospital beds’ demand and planning mitigation strategies, as overwhelming the healthcare systems has critical consequences for disease mortality. However, accurately mapping the time-to-event of hospital outcomes, such as the LoS in the intensive care unit (ICU), requires understanding patient trajectories while adjusting for covariates and observation bias, such as incomplete data. Standard methods, such as the Kaplan-Meier estimator, require prior assumptions that are untenable given current knowledge. Using real-time surveillance data from the first weeks of the COVID-19 epidemic in Galicia (Spain), we aimed to model the time-to-event and event probabilities of patients’ hospitalised, without parametric priors and adjusting for individual covariates. We applied a non-parametric mixture cure model and compared its performance in estimating hospital ward (HW)/ICU LoS to the performances of commonly used methods to estimate survival. We showed that the proposed model outperformed standard approaches, providing more accurate ICU and HW LoS estimates. Finally, we applied our model estimates to simulate COVID-19 hospital demand using a Monte Carlo algorithm. We provided evidence that adjusting for sex, generally overlooked in prediction models, together with age is key for accurately forecasting HW and ICU occupancy, as well as discharge or death outcomes.

Wells (1937) discovered that field voles in this country are subject to an epizootic disease due to an acid-fast bacillus. The natural disease in the vole is characterized by the deposition of a cheesy substance in the areolar tissue spaces and the formation in the organs, the lungs particularly, of lesions which have a close resemblance to those of tuberculosis.

As part of the bacteriological quality control programme of the Public Health Laboratory Service, we were asked to investigate the possibility of providing simulated water samples for distribution to the laboratories. For this purpose it was necessary to find some means whereby suspensions of coliform organisms and Escherichia coli could be kept relatively stable in number at room temperature for a period of 7–10 days. This, it was finally found, was best achieved by adding selected strains of the organisms to improved formate lactose glutamate medium (Gray, 1964) without the lactose but with added boric acid to a final concentration of 1·8%.

The procedures adopted in the successful quality control programme are described.

Subcutaneous inoculations: Two strains of human origin were tested, one was of eugonic human type from the sputum of an English case of pulmonary tuberculosis; the other was of dysgonic human type obtained by Dr J. A. Young from a native in Nigeria. Both strains produced typical general tuberculosis in the hamster, the lesions on the whole showing less caseation than those set up by bovine bacilli (vide 1939).

The vole strain of bacillus gave rise to generalized disease resembling tuberculosis. The duration of life of the animal was, however, prolonged and though the bacilli were abundant in the lesions there was no necrosis or caseation. Similar results in two hamsters were reported in 1939.

The avian bacillus was the least pathogenic of the four types. Of the three hamsters inoculated only one (H. 17, dose 5·0 mg.) showed macroscopic foci in the liver and spleen; as these were not seen microscopically in sections it is doubtful if they were due to the action of tubercle bacilli. It is unfortunate that the specimens of Hamster 17, which died in my absence from the laboratory, were badly fixed; a smear preparation of the spleen was not made. In the others tubercle bacilli were found in the organs, but were not numerous. The peculiar result after 5·0 mg. of avian bacilli—enormous multiplication of bacilli in spleen, liver and a local gland without macroscopic tuberculous lesions—described in the first paper was not reproduced.

Feeding: The four different types of bacilli were given by the mouth to six hamsters, the dose in each instance being 10 mg. of culture. Two of the hamsters, one fed with a potato culture of the vole strain, the other with a human strain, escaped infection. The remaining four hamsters, each fed with one of the four types of bacilli, developed disease, the severity of which in each instance was in harmony with that following subcutaneous inoculation of the type.

Transfer of shigella R–plasmids in vivo has seldom been demonstrated. Strains of Shigella dysenteriae type 1 and Shigella flexneri type 5b were isolated from a Bulgarian traveller who visited Vietnam and developed dysentery, which was treated with trimethoprim/sulfamethoxazole (TMP/SMZ) for a short time. Both species of shigellae are unusual in Bulgaria where strains of S. sonnei predominate. Both shigella strains were multiresistant to the same antimicrobial agents. Each strain contained a 48–kilobase plasmid that conferred the entire resistance phenotype to a susceptible Escherichia coli. Restriction endonuclease patterns of plasmid DNA from the respective strains were identical. Transmissible plasmids of the same resistance phenotypes and restriction patterns were isolated from the patient's colonic E. coli. Transconjugants hybridized to a dihydrofolate reductase type I–DNA probe. These studies support the hypothesis that R–plasmid transfer may occur between non-pathogenic, faecal strains and pathogenic shigellae, a process that may have been facilitated by inadequate treatment with TMP/SMZ at the onset of the illness.

We studied the evolution, genotypes, and the molecular clock of dengue virus serotype 1 (DENV-1), between 2001 and 2014 in Guangzhou, China. The analysis of the envelope (E) gene sequences of 67 DENV-1 strains isolated in Guangzhou, together with 58 representative sequences downloaded from NCBI, have shown shifts in viral genotypes. The genotype changed several times, from genotype I to IV in 2002, from IV to I in 2005, and from I to V in 2014. These genotype shifts may be the cause of DENV outbreaks. The diversity of genotypes and clades demonstrates a high risk of future outbreaks in Guangzhou. The mean rate of virus nucleotide substitution in Guangzhou was determined to be 7·77 × 10−4 per site per year, which represents a medium substitution rate compared to two other countries. Our research can point to different ancestors of the isolated strains, which may further reveal the different origins and transmission of DENV-1 strains in Guangzhou.

1. One per cent of samples of farm milk were found to contain pathogenic varieties of Bacterium coli of the O groups associated with infantile gastroenteritis.

2. Unheated cows' milk is a dangerous food for babies.

3. Summer diarrhoea was probably, for the most part, milk-borne infection by special O groups of Bact. coli.

4. Thirteen per cent of chickens on farms were found to be excreting Bact. coli of the O groups associated with infantile gastro-enteritis but only a few of the strains possessed H antigens of varieties known to have an association with human disease.

5. Possible reservoirs of infection cannot be adequately searched for until a selective method is devised to aid the separation of pathogenic O groups of Bact. coli from the non-pathogenic.

Workplaces are one of the most important regular meeting places in society. The aim of this study was to use simulation experiments to examine the impact of different workplace cultures on influenza dissemination during pandemics. The impact is investigated by experiments with defined social-mixing patterns at workplaces using semi-virtual models based on authentic sociodemographic and geographical data from a North European community (population 136 000). A simulated pandemic outbreak was found to affect 33% of the total population in the community with the reference academic-creative workplace culture; virus transmission at the workplace accounted for 10·6% of the cases. A model with a prevailing industrial-administrative workplace culture generated 11% lower incidence than the reference model, while the model with a self-employed workplace culture (also corresponding to a hypothetical scenario with all workplaces closed) produced 20% fewer cases. The model representing an academic-creative workplace culture with restricted workplace interaction generated 12% lower cumulative incidence compared to the reference model. The results display important theoretical associations between workplace social-mixing cultures and community-level incidence rates during influenza pandemics. Social interaction patterns at workplaces should be taken into consideration when analysing virus transmission patterns during influenza pandemics.

In Spain hepatitis A is a compulsory notifiable disease and individual cases are reported to the national epidemiological surveillance network. Incidence rates show variations in different regions. The aim of this study was to analyse the space–time pattern of hepatitis A risk at municipal level in Spain and at global and local levels during the period 1997–2007. At global level we used two estimates of risk: the standardized incidence ratio (SIR) and the posterior probability that the smoothed relative risk is >1 (PP). At local level we used the scan statistic method to analyse the space–time clusters. The SIR and significant PP (>0·8) showed the highest risk concentrated in areas of the Mediterranean coast. The most likely cluster gave a relative risk of 53·530. These spatial statistics methodologies can be complementary tools in the epidemiological surveillance of infectious diseases.