Invasive fungal diseases have emerged as important causes of morbidity and mortality in haematological patients. In this study air samples were collected in two haematopoietic stem cell transplantation (HSCT) units, in which distinct air-control systems were in place. In hospital 1 no high-efficiency particulate air (HEPA) filter was available whereas in hospital 2 HSCT rooms were equipped with HEPA filters, with positive air pressure in relation to the corridor. A total of 117 samples from rooms, toilets and corridors were obtained during December 2009 to January 2011, using a six-stage Andersen sampler. In both hospitals, the concentration of potentially pathogenic fungi in the air was reduced in patients' rooms compared to corridors (P < 0·0001). Despite the presence of a HEPA filter in hospital 2, rooms in both hospitals showed similar concentrations of potentially pathogenic fungi (P = 0·714). These findings may be explained by the implementation of additional protective measures in hospital 1, emphasizing the importance of such measures in protected environments.

1. The production of soluble antigen in the chorioallantoic membranes at 6 hr. can be used to measure the infectivity of influenza virus preparations.

2. Intracellular virus is much more infective when tested by soluble antigen production at 6 hr. than when tested by conventional methods.

3. It is suggested that intracellular virus differs from extracellular because more virus particles per cell are required to initiate infection.

The author is greatly indebted to Dr L. Hoyle for his advice and encouragement throughout this work. Mr G. Field gave valuable help with the mathematics.

The purpose of this study was to apply a novel statistical method for variable selection and a model-based approach for filling data gaps in mortality rates associated with foodborne diseases using the WHO Vital Registration mortality dataset. Correlation analysis and elastic net regularization methods were applied to drop redundant variables and to select the most meaningful subset of predictors. Whenever predictor data were missing, multiple imputation was used to fill in plausible values. Cluster analysis was applied to identify similar groups of countries based on the values of the predictors. Finally, a Bayesian hierarchical regression model was fit to the final dataset for predicting mortality rates. From 113 potential predictors, 32 were retained after correlation analysis. Out of these 32 predictors, eight with non-zero coefficients were selected using the elastic net regularization method. Based on the values of these variables, four clusters of countries were identified. The uncertainty of predictions was large for countries within clusters lacking mortality rates, and it was low for a cluster that had mortality rate information. Our results demonstrated that, using Bayesian hierarchical regression models, a data-driven clustering of countries and a meaningful subset of predictors can be used to fill data gaps in foodborne disease mortality.

During the thirteen years which have elapsed since the publication of my researches upon the bactericidal properties of the blood and other fluids of the body, a large amount of most valuable knowledge has been acquired regarding the blood both in health and disease. Through the work of many investigators the complicated subject of immunity is gradually being solved, and we are beginning to understand the way in which the body combats or is protected against the inroads of disease. We have learnt of the existence of specific antitoxic, agglutinative, haemolytic, bactericidal and cellulicidal properties in the blood-serum, etc., as also of a number of neutralizing bodies to these. The quite recent discovery of specific precipitins, which act upon various bacterial products, milks, peptone, egg-albumin, and upon human blood and its derivates, has opened a wide field for investigation, which cannot fail to ultimately yield results of the greatest importance. We have to thank bacteriological investigation for the greater part of the advances which have been made, although a considerable portion properly belongs in the domain of physiology.

There is a paucity of evidence about the prevalence and risk factors for symptomatic infection among children. This study aimed to describe the prevalence of symptomatic coronavirus disease 2019 (COVID-19) and its risk factors in children and adolescents aged 0–18 years in Qatar. We conducted a cross-sectional study of all children aged 0–18 years diagnosed with COVID-19 using polymerase chain reaction in Qatar during the period 1st March to 31st July 2020. A generalised linear model with a binomial family and identity link was used to assess the association between selected factors and the prevalence of symptomatic infection. A total of 11 445 children with a median age of 8 years (interquartile range (IQR) 3–13 years) were included in this study. The prevalence of symptomatic COVID-19 was 36.6% (95% confidence interval (CI) 35.7–37.5), and it was similar between children aged <5 years (37.8%), 5–9 years (34.3%) and 10 + years (37.3%). The most frequently reported symptoms among the symptomatic group were fever (73.5%), cough (34.8%), headache (23.2%) and sore throat (23.2%). Fever (82.8%) was more common in symptomatic children aged <5 years, while cough (38.7%) was more prevalent in those aged 10 years or older, compared to other age groups. Variables associated with an increased risk of symptomatic infection were; contact with confirmed cases (RD 0.21; 95% CI 0.20–0.23; P = 0.001), having visited a health care facility (RD 0.54; 95% CI 0.45–0.62; P = 0.001), and children aged under 5 years (RD 0.05; 95% CI 0.02–0.07; P = 0.001) or aged 10 years or older (RD 0.04; 95% CI 0.02–0.06; P = 0.001). A third of the children with COVID-19 were symptomatic with a higher proportion of fever in very young children and a higher proportion of cough in those between 10 and 18 years of age.

Oral pretreatment of mice with either a mixture of kanamycin and erythromycin or metronidazole to modify the gut microflora greatly enhanced the faecal excretion of Fusobacterium necrophorum biovar A given by mouth. This lends support to the suggestion that disturbance of the gastrointestinal microflora in animals such as cattle, which often carry the organism in the rumen, may lead to intestinal multiplication and faecal excretion, thereby providing a source of infection that may lead to necrobacillosis of the body surface.

Relationship of genetic polymorphisms in cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and interleukin-18 (IL-18) with susceptibility to viral hepatitis was already investigated by many association studies. The aim of this study was to more comprehensively analyse associations between genetic polymorphisms in CTLA-4/IL-18 and viral hepatitis by combing the results of all relevant association studies. We searched Pubmed, Embase, Web of Science and CNKI for eligible studies. We used Review Manager to combine the results of eligible studies. Thirty-seven studies were finally included in this meta-analysis. Combined results demonstrated that CTLA-4 rs231775 (recessive comparison: OR 1.31, 95% CI 1.11–1.55), IL-18 rs1946518 (dominant comparison: OR 0.82, 95% CI 0.75–0.90; recessive comparison: OR 1.29, 95% CI 1.11–1.50; allele comparison: OR 0.76, 95% CI 0.68–0.86) and IL-18 rs187238 (dominant comparison: OR 1.25, 95% CI 1.03–1.52; allele comparison: OR 1.20, 95% CI 1.05–1.37) polymorphisms were all significantly associated with viral hepatitis in the general population. Further subgroup analyses revealed that CTLA-4 rs231775, IL-18 rs1946518 and IL-18 rs187238 polymorphisms were significantly associated with susceptibility to hepatitis B virus (HBV), especially among East Asians. Moreover, CTLA-4 rs5742909, IL-18 rs1946518 and IL-18 rs187238 polymorphisms were also significantly associated with susceptibility to hepatitis C virus (HCV), especially among South Asians. So to conclude, this meta-analysis demonstrated that CTLA-4 rs231775, IL-18 rs1946518 and IL-18 rs187238 polymorphisms may confer susceptibility to HBV in East Asians, while CTLA-4 rs5742909, IL-18 rs1946518 and IL-18 rs187238 polymorphisms may confer susceptibility to HCV in South Asians.

A cohort of 214 drug addicts with serum hepatitis and a cohort of 193 hepatitis patients without drug addiction were examined in respect of death rates, causes of death and a number of risk factors for reduced survival. The death rate was significantly higher among the drug addicts than among non-addicts. The annual mortality rate was 1·5% in the drug addict group and 0·7% in the non-addict group. The highest relative risk of death was 860 for female drug addicts in age group 15–24 compared to females of the same age in the general population. The most prevalent cause of death in the drug addict group was drug overdose (53%), whereas in the other group 66% died from various somatic diseases. Hepatitis or complications of viral hepatitis played no role as cause of death among the drug addicts, and infections as a whole were also responsible for very few deaths. For male drug addicts, imprisonment before admission and leaving hospital without the doctors' permission were risk factors for early death.

The recovery of virulence by means of reversion of a live streptomycin-dependent (Sm D) Salmonella typhimurium vaccine was studied in CD–I Swiss mice. Initially, a one–step Sm D mutant was obtained from a virulent streptomycin-sensitive (Sm S) S. typhimurium strain. Afterwards, two pools of streptomycin-independent (Sm I) revertants were prepared from the Sm D strain. The virulence of the Sm D strain and of the Sm I revertants was tested intraperitoneally. In the virulence testing the original suspension of the Sm I revertants, as well as their 1st and 10th passages on plain medium, medium + 50 μg. streptomycin/ml, and medium + 1000 μg. streptomycin/ml, were used. The results show that the Sm D mutant was avirulent, its avirulence being due to an intrinsic, genetic quality. The Sm I revertants, compared to the original Sm S strain, also displayed a lack of virulence. However, afterwards, the Sm I revertants behaved quite differently, according to their subsequent passages. Indeed, there was an increase in virulence after passages on plain medium, whereas after similar passages on medium containing the drug, the virulence not only failed to increase, but disappeared almost completely. Moreover, the passages on medium containing 1000 μg. streptomycin/ml, induced a return to the status of drug–dependence. The danger of recovery of virulence by means of revertants is evaluated.

A rubella outbreak involving 1900 cases was recorded in the Federation of Bosnia and Herzegovina between mid-December 2009 and the end of May 2010. Sera from 389 suspected rubella cases were examined for the presence of rubella-specific IgM and IgG antibodies. A total of 32 throat swabs from suspected rubella cases were tested by RT–PCR and were used to attempt virus isolation. Most patients (945/1900, 49·73%) had never received rubella vaccination or had an unknown vaccination status (563/1900, 29·63%). About 45% (178/389) of suspected rubella patients were IgM positive. From 13 of the throat swabs a virus isolate and E1 gene sequences attributed to genotype 2B were obtained. The rubella outbreak was due to failure to vaccinate during the war period (1992–1995) and emphasizes the need for additional vaccination opportunities.

1. During the pre-epidemic stage of the spread of bacterial infection among mice, single deaths, or small groups of deaths, due to the specific infection being studied, are found to occur at considerable intervals before the rise of the main epidemic wave, and to afford a warning that such a wave is at hand.

2. In many cases there may be observed, during the same period, an increase in the daily mortality from all causes.

I should wish to express my thanks to Dr Major Greenwood for the interest he has shown in this investigation, and for much useful information with regard to epidemiological records. I am again greatly mdebted to my co-workers, Dr H. B. Weir and Dr G. S. Wilson, for their assistance in these experiments.

The epidemiology of surgical site infections (SSIs) in surgical programmes in sub-Saharan Africa is inadequately described. We reviewed deep and organ-space SSIs occurring within a trauma project that had a high-quality microbiology partnership and active follow-up. Included patients underwent orthopaedic surgery in Teme Hospital (Port Harcourt, Nigeria) for trauma and subsequently developed a SSI requiring debridement and microbiological sampling. Data were collected from structured chart reviews and programmatic databases for 103 patients with suspected SSI [79% male, median age 30 years, interquartile range (IQR) 24–37]. SSIs were commonly detected post-discharge with 58% presenting >28 days after surgery. The most common pathogens were: Staphylococcus aureus (34%), Pseudomonas aeruginosa (16%) and Enterobacter cloacae (11%). Thirty-three (32%) of infections were caused by a multidrug-resistant (MDR) pathogen, including 15 patients with methicillin-resistant S. aureus. Antibiotics were initiated empirically for 43% of patients and after culture and sensitivity report in 32%. The median number of additional surgeries performed in patients with SSI was 5 (IQR 2–6), one patient died (1%), and amputation was performed or recommended in three patients. Our findings suggest the need for active long-term monitoring of SSIs, particularly those associated with MDR organisms, resulting in increased costs for readmission surgery and treatment with late-generation antibiotics.

This study investigated an outbreak in a kindergarten in Wuyi County of acute gastroenteritis concerning a large number of students and teachers. We performed a case-control study, and collected information on the layout of the school, symptoms, onset time of all cases and vomiting sites. A total of 62 individuals fit the definition of probable cases; among these, there were 19 cases of laboratory-confirmed norovirus infection. Nausea and vomiting were the most common symptoms in the outbreak. Seven student norovirus patients vomited in the school. The odds ratio (OR) of norovirus illness was 15.75 times higher among teachers who handled or interacted with student vomitus without respiratory protection than compared to those without this type of exposure (OR 15.75, 95% CI 1.75–141.40). Nine samples were successfully genotyped; eight samples were norovirus GII.2[P16], one sample was norovirus GII.4 Sydney[P16]. This study revealed that improper handling of vomitus is a risk factor of norovirus infection. Therefore, more attention should be given to train school staff in knowledge of disinfection.

In an effort to provide guidelines for standardizing aeration times for plastics sterilized with ethylene oxide, an Aeration Index has been developed. Based on the rate of diffusion of ethylene oxide in selected polymers, the Index provides an indication of the aeration time at ambient temperature (23°C) for the ethylene oxide concentration in freshly sterilized plastics to drop to 50 parts/106.

In recent decades, the invasive Aedes albopictus vector has spread across Europe and is responsible for numerous outbreaks of autochthonous arboviral disease. The aim of this study was to identify epidemiological and sociological risk factors related to individual levels of exposure to Aedes albopictus bites. A multidisciplinary survey was conducted with volunteer blood donors living in areas either colonised or not by Aedes albopictus in mainland France. Individual levels of exposure were evaluated by measuring the IgG level specific to Aedes albopictus saliva. The most striking risk factors concerned the localisation and characteristics of the dwelling. Individuals living in areas colonised prior to 2009 or recently colonised (between 2010 and 2012) had higher anti-salivary gland extract IgG levels compared with those who were living in areas not yet colonised by Ae. albopictus. The type of dwelling did not seem to impact the level of exposure to Aedes bites. People living in apartments had a higher anti-salivary gland extract IgG level than those living in individual houses but the difference was not statistically significant. Interestingly, the presence of air conditioning or window nets was associated with a noticeable reduction in bite intensity.

Laboratory-based case confirmation is an integral part of measles surveillance programmes; however, logistical constraints can delay response. Use of RDTs during initial patient contact could enhance surveillance by real-time case confirmation and accelerating public health response. Here, we evaluate performance of a novel measles IgM RDT and assess accuracy of visual interpretation using a representative collection of 125 sera from the Brazilian measles surveillance programme. RDT results were interpreted visually by a panel of six independent observers, the consensus of three observers and by relative reflectance measurements using an ESEQuant Reader. Compared to the Siemens anti-measles IgM EIA, sensitivity and specificity of the RDT were 94.9% (74/78, 87.4–98.6%) and 95.7% (45/47, 85.5-99.5%) for consensus visual results, and 93.6% (73/78, 85.7–97.9%) and 95.7% (45/47, 85.5-99.5%), for ESEQuant measurement, respectively. Observer agreement, determined by comparison between individuals and visual consensus results, and between individuals and ESEQuant measurements, achieved average kappa scores of 0.97 and 0.93 respectively. The RDT has the sensitivity and specificity required of a field-based test for measles diagnosis, and high kappa scores indicate this can be accomplished accurately by visual interpretation alone. Detailed studies are needed to establish its role within the global measles control programme.

Norovirus (NoV) infections occur very frequently yet are rarely diagnosed. In Denmark, NoV infections are not under surveillance. We aimed to collect and describe existing laboratory-based NoV data. National NoV laboratory data were collected for 2011–2018, including information on patient identification number, age and sex, requesting physician, analysis date and result. We defined positive patient-episodes by using a 30-day time window and performed descriptive and time series analysis. Diagnostic methods used were assessed through a survey. We identified 15 809 patient-episodes (11%) out of 142 648 tested patients with an increasing trend, 9366 in 2011 vs. 32 260 in 2018. This corresponded with a gradual introduction of polymerase chain reaction analysis in laboratories. The highest positivity rate was in patients aged <5 years (15%) or >85 years (17%). There was a large difference in test performance over five Danish geographical regions and a marked seasonal variation with peaks from December to February. This is the first analysis of national NoV laboratory data in Denmark. A future laboratory-based surveillance system may benefit public health measures by describing trend, burden and severity of seasons and possibly pinpoint hospital outbreaks.

Polluted water from a stream caused three cases of infection with Salm. paratyphi B belonging to two phage-types. These phage-types and two others were isolated from the water.

One woman, aged 81, with a history of enteric fever 20 years previously was discovered to be a prolific carrier of at least three of these phage-types, and to be the source of the pollution.

We are greatly indebted to Mr G. K. Anderson, County Sanitary Inspector, Midlothian, and to his staff for the large volume of field work they carried out; to Dr E. S. Anderson and Dr A. Bernstein, Central Enteric Reference Laboratory and Bureau, Colindale, London for the phage-typing on which this survey is based; and to Mr James Sutherland, F.I.M.L.T., for his enthusiastic technical assistance.

We assessed if there has been a decline in the median number of reported lifetime sexual partners in Kenya following the AIDS epidemic. The Wilcoxon rank-sum test was used to compare the median and interquartile range (IQR) of the number of lifetime sexual partners for men aged 20–54 years in the 1993 and 2008 Kenyan Demographic Health Surveys. The median number of sexual partners in 1993 increased rapidly to 10 partners reported at age 30 years then plateaued at this level. In 2008, the median number of sexual partners plateaued at around half the value of the 1993 plateau. The median number of lifetime sexual partners for men aged 20–54 years declined from 10 (IQR 4-20) in 1993 to 3 (IQR 2-7) in 2008 (P < 0·001). This decline could be due to a combination of the effects of AIDS mortality and a misreporting bias.

After the winter of 2021/2022, the coronavirus disease 2019 (COVID-19) pandemic had reached a phase where a considerable number of people in Germany have been either infected with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, vaccinated or both, the full extent of which was difficult to estimate, however, because infection counts suffer from under-reporting, and the overlap between the vaccinated and recovered subpopulations is unknown. Yet, reliable estimates regarding population-wide susceptibility were of considerable interest: Since both previous infection and vaccination reduce the risk of severe disease, a low share of immunologically naïve individuals lowers the probability of further severe outbreaks, given that emerging variants do not escape the acquired susceptibility reduction. Here, we estimate the share of immunologically naïve individuals by age group for each of the sixteen German federal states by integrating an infectious-disease model based on weekly incidences of SARS-CoV-2 infections in the national surveillance system and vaccine uptake, as well as assumptions regarding under-ascertainment. We estimate a median share of 5.6% of individuals in the German population have neither been in contact with vaccine nor any variant up to 31 May 2022 (quartile range [2.5%–8.5%]). For the adult population at higher risk of severe disease, this figure is reduced to 3.8% [1.6%–5.9%] for ages 18–59 and 2.1% [1.0%–3.4%] for ages 60 and above. However, estimates vary between German states mostly due to heterogeneous vaccine uptake. Excluding Omicron infections from the analysis, 16.3% [14.1%–17.9%] of the population in Germany, across all ages, are estimated to be immunologically naïve, highlighting the large impact the first two Omicron waves had until the beginning of summer in 2022. The method developed here might be useful for similar estimations in other countries or future outbreaks of other infectious diseases.