An autoradiographic method to trace the dissemination in water of radioactive bacteria is reported. It has been tested for accuracy and sensitivity and a field trial has been performed. The method appears suitable for practical use and permits the study of environmental effects on the spreading bacteria.

Hepatitis B virus (HBV) can be eliminated by effective universal vaccination. In Belgium, a free-of-charge HBV vaccination programme in infants with catch-up in adolescents was introduced in 1999. To evaluate the effects in <20-year-olds, seroprotection (anti-HBs >11 mIU/ml, according to the assay) and markers of infection (anti-HBc, HBsAg) were assessed in 2443 residual sera collected 7–8 years after implementation of the programme. The maximal prevalence of a solely anti-HBs seroprotective (‘vaccinated’) serostatus was 82·9% at age 1 year and 60·5% at age 13 years. A clear increase was found in age cohorts targeted by the campaign after a similar serosurvey conducted 4 years earlier. The prevalence of HBV infection remained unchanged at a low level (1·8% in 2006) similar to pre-vaccination data (1993–1994). We conclude that universal HBV vaccination has achieved overall high levels of vaccine-induced immunity, despite regional variations, which may give rise to pockets of susceptible young adults in the future.

Europe is in the midst of a COVID-19 epidemic and a number of non-pharmaceutical public health and social measures have been implemented, in order to contain the transmission of severe acute respiratory syndrome coronavirus 2. These measures are fundamental elements of the public health approach to controlling transmission but have proven not to be sufficiently effective. Therefore, the European Centre for Disease Prevention and Control has conducted an assessment of research gaps that can help inform policy decisions regarding the COVID-19 response. We have identified research gaps in the area of non-pharmaceutical measures, physical distancing, contact tracing, transmission, communication, mental health, seasonality and environment/climate, surveillance and behavioural aspects of COVID-19. This prioritisation exercise is a step towards the global efforts of developing a coherent research road map in coping with the current epidemic but also developing preparedness measures for the next unexpected epidemic.

To better understand the epidemiology of colonization of vancomycin-resistant enterococci (VRE), we performed an 8-year retrospective study of all hospitalized patients with recurrent VRE colonization after they were documented as being clear of VRE and compared the primary colonization isolates and recolonization isolates by pulsed-field gel electrophoresis and Tn1546 typing. Review of the medical records of all patients showed that of the 15 patients with recurrent colonization, six continued to be hospitalized on the same floor. Five were discharged home and then readmitted. Four were moved to another floor. Patients who remained on the same floor were recolonized with a strain that was indistinguishable from the original colonizing strain. Patients who were moved or were discharged had de novo VRE colonization with strains distinct from the original colonizing strain.

Modified Moore's swabs, placed in sewers for 5 days, were used to concentrate salmonellas from sewage. Duplicate cultures of swab strips in selenite broth were incubated at 41 and 37°C. respectively. Salmonella organisms were recovered consistently from the swabs when the enrichment broths were incubated at 41°C., However, when equal portions of the same swabs were incubated at 37°C., only 22% of them yielded Salmonella organisms. These results indicate an advantage in incubating the selenite broths at 41°C. rather than 37°C. in attempting to isolate salmonellas from sewage.

One hundred and fifty faecal samples were examined for salmonellas by culture in selenite broths incubated at 41 and 37°C. Twelve (8%) samples were positive at 41°C. compared to only 10 (6·7%) positive samples at 37°C. This difference is not statistically significant to indicate an advantage of the elevated-temperature of incubation over the conventional temperature in attempting to isolate salmonellas from human faeces. Moreover, results of the recovery rates of S. paratyphi B, S. typhi, and S. typhimurium indicate that an incubation temperature of 37°C. is more appropriate for recovering salmonellas from artificially infected faecal samples than an incubation temperature of 41°C. This stresses the inability of laboratory studies to mimic conditions in nature.

Identification of covariates associated with disease is a key part of epidemiological research. Yet, while adjustment for imperfect diagnostic accuracy is well established when estimating disease prevalence, similar adjustment when estimating covariate effects is far less common, although of important practical relevance due to the sensitivity of such analyses to misclassification error. Case-study data exploring evidence for seasonal differences in Salmonella prevalence using serological testing is presented, in addition simulated data with known properties are analysed. It is demonstrated that: (i) adjusting for misclassification error in models comprising continuous covariates can have a very substantial impact on the resulting conclusions which can then be drawn from any analyses; and (ii) incorporating prior knowledge through Bayesian estimation can provide potentially more informative assessments of covariates while removing the assumption of perfect diagnostic accuracy. The method presented is widely applicable and easily generalized to many types of epidemiological studies.

A description is given of the topography, type of farming carried out, and the living conditions of the agricultural community of a district in South Wales where a survey was made of the infection rate of rats with Leptospira icterohaemorrhagiae.

Leptospires were seen in stained sections of the kidneys of eighty-two of the 357 rats examined (23%). With a single exception, all the infected rats were adult, but no difference in sex-incidence was found.

Weil's disease occurs in this area, but no cases in man or cattle had been reported from this particular locality. Blood samples taken from six persons living on two heavily infested farms contained no anti-leptospiral agglutinins.

To describe the consequences of medical care interruptions (MCIs) we selected patients with at least two medical encounters between January 2006 and June 2013 in the Dat'AIDS cohort. Patients with any time interval >15 months between two visits were defined as having a MCI, as opposed to uninterrupted follow-up (UFU). Patients’ characteristics at the time of HIV diagnosis and at the censoring date were compared between groups. Cox proportional hazards models were built to assess the role of interruptions on survival (total and AIDS-free). Of 11 116 patients, 824 had at least one MCI. These patients were younger at the time of HIV diagnosis (30 vs. 33 years, P < 0·0001). MCI was less frequent in men having sex with men vs. heterosexual patients [odds ratio (OR) 0·81, 95% confidence interval (CI) 0·69–0·96)], and a centre effect was described. MCI was independently associated with AIDS (OR 2·54, 95% CI 2·10–3·09) and death (OR 2·65, 95% CI 1·94–3·61). At the censoring date, 52·2% of patients with at least one MCI had viral load below detection vs. 85·3% of the UFU group (P < 0·0001). In conclusion, MCIs were associated with patients’ survival and with the proportion of viral loads below detection in our cohort, compromising individual and collective treatment benefits.

At the beginning of the war, the London County Counoil issued a report by Sir Frederick Menzies, their late School Medical Officer, on the average heights and weights of London elementary school children in 1938. The report is based on the measurements of about 100,000 children, and is probably the most important contribution to the anthropometry of childhood that has appeared in this country for many years.

The numerous additions to the group of Streptothrices which have been recently made, and the close resemblance which the majority of these newly described forms bear to one another, render it by no means an easy task to assure oneself that a freshly isolated member of this group is one that has not previously been met with and described. A curious fact also, which soon strikes anyone who investigates the literature relating to this group of micro-organisms, is that in very few of these has the particular form described by one author been met with by another. While great interest to the bacteriologist naturally attaches to any new species, whatever its source, the group of those which are pathogenic in their action on man, on animals, or on both, are, ipso facto, of more general importance. To this last category belongs the new member of the group which we have isolated from a fatal case of lung disease and pericarditis in man.

We sought to examine the factors associated with bacteraemia and their outcome in children with pneumonia and severe acute malnutrition (SAM). All SAM children of either sex, aged 0–59 months, admitted to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh with radiologically confirmed pneumonia from April 2011 to July 2012 were enrolled (n = 405). Comparison was made between pneumonic SAM children with (cases = 18), and without (controls = 387) bacteraemia. The death rate was significantly higher in cases than controls (28% vs. 8%, P < 0·01). In logistic regression analysis, after adjusting for potential confounders, the SAM children with pneumonia and bacteraemia more often had a history of lack of bacillus Calmette-Guérin (BCG) vaccination (odds ratio 7·39, 95% confidence interval 1·67–32·73, P < 0·01). The results indicate the importance of continuation of BCG vaccination which may provide benefit beyond its primary purpose.

Understanding local perceptions of disease causation could help public health officials improve strategies to prevent bloody diarrhoea. A cross-sectional survey was conducted in Dhaka, Bangladesh to elicit community beliefs about the causes of and prevention strategies for bloody diarrhoea. Between March and June 2003, we interviewed 541 randomly selected respondents. Overall, 507 (93%) respondents perceived that a vaccine could prevent bloody diarrhoea. If a vaccine provided lifetime protection, 445 (83%) respondents stated that they would opt to get the vaccine and would pay a median of $0·05 (range U.S.$0·01–0·15) for it, equivalent to <1% of their median weekly income. There was almost universal perception that an effective vaccine to prevent bloody diarrhoea was highly beneficial and acceptable. While respondents valued a vaccine for prevention of bloody diarrhoea, they were only willing to pay minimally for it. Therefore, achieving a high rate of Shigella vaccine coverage may require subsidy of vaccine purchase.

Human monkeypox (mpox) virus is a viral zoonosis that belongs to the Orthopoxvirus genus of the Poxviridae family, which presents with similar symptoms as those seen in human smallpox patients. Mpox is an increasing concern globally, with over 80,000 cases in non-endemic countries as of December 2022. In this review, we provide a brief history and ecology of mpox, its basic virology, and the key differences in mpox viral fitness traits before and after 2022. We summarize and critique current knowledge from epidemiological mathematical models, within-host models, and between-host transmission models using the One Health approach, where we distinguish between models that focus on immunity from vaccination, geography, climatic variables, as well as animal models. We report various epidemiological parameters, such as the reproduction number, R0, in a condensed format to facilitate comparison between studies. We focus on how mathematical modelling studies have led to novel mechanistic insight into mpox transmission and pathogenesis. As mpox is predicted to lead to further infection peaks in many historically non-endemic countries, mathematical modelling studies of mpox can provide rapid actionable insights into viral dynamics to guide public health measures and mitigation strategies.

The number of reported cases with Legionnaires' disease (LD) is increasing in Belgium. Previous studies have investigated the associations between LD incidence and meteorological factors, but the Belgian data remained unexplored. We investigated data collected between 2011 and 2019. Daily exposure data on temperature, relative humidity, precipitation and wind speed was obtained from the Royal Meteorological Institute for 29 weather stations. Case data were collected from the national reference centre and through mandatory notification. Daily case and exposure data were aggregated by province. We conducted a time-stratified case-crossover study. The ‘at risk’ period was defined as 10 to 2 days prior to disease onset. The corresponding days in the other study years were selected as referents. We fitted separate conditional Poisson models for each day in the ‘at risk’ period and a distributed lag non-linear model (DLNM) which fitted all data in one model. LD incidence showed a yearly peak in August and September. A total of 614 cases were included. Given seasonality, a sequence of precipitation, followed by high relative humidity and low wind speed showed a statistically significant association with the number of cases 6 to 4 days later. We discussed the advantages of DLNM in this context.

The incidence of heat-resistant Cl. welchii in selected classes of a rural population has been investigated. The carrier rate for the general population was low (l·5–6·0%), but persons associated with communal feeding and poor hygienic conditions were shown to have a much higher carrier rate (15·1–25%).

Sex and season had little effect on the incidence of the organism, but among aboriginals the carriage was significantly affected by age. This was probably due to eating habits of the different age groups. The carriage appears to be transient; no persons were shown to be permanent carriers of one strain of heat-resistant Cl. welchii.

Our objectives were to assess the prevalence of anti-hepatitis A (HAV) antibodies in Spanish travellers to developing countries and to carry out a cost analysis to allow the comparison of two vaccination strategies. Adult subjects were selected from among travellers to developing countries. Information was obtained on age, sex, destination, previous vaccination against HAV and having received immunoglobulin. Blood specimens were obtained for anti-HAV antibody determination. A total of 485 travellers were studied. The prevalence of anti-HAV antibody was 30·5% (95% CI 26–35). Antibody prevalence was inversely correlated with age: 9·8% in 18–25 years of age, rising to 75·4% in those 41–55 years of age. Cost analysis determined that the critical value of prevalence for vaccination with HAV vaccine was 37·5%. It was concluded that the youngest Spanish travellers lack anti-HAV antibodies. Vaccination without screening in those [les ] 35 years of age and screening before vaccination for those > 35 years, are the preferred alternatives.

Multiple cases of atypical scrapie in the same holding and co-existence with classical scrapie have been reported in Great Britain. A two-stage simulation tool was developed by combining a sampling algorithm and a hierarchical Bayesian model to simulate the number of positive cases of atypical scrapie from: (i) random sampling and (ii) using the actual sampled population in Great Britain, being the output probability of detection of flocks with one and more cases. Cluster analysis was conducted to assess the level of geographical over- and under-sampling over the years. The probability of detecting at least two cases of atypical scrapie in the same holding is much lower in simulated random data than in simulated actual data for all scenarios. Sampling bias in the selection of sheep for testing led to multiple sampling from fewer but larger holdings, Scotland, and areas of Wales were under-sampled and the South-West and East of England oversampled. The pattern of atypical scrapie cases observed is unlikely to be explained by a multi-case event epidemiologically linked. The co-existence of classical and atypical scrapie is a rare event with 19 holdings detected in GB and does not suggest an epidemiological link between the two types of disease.

Household contacts of an index case of invasive meningococcal disease (IMD) are at increased risk of acquiring disease. In revising WHO guidance on IMD in sub-Saharan Africa, a systematic review was undertaken to assess the effect of chemoprophylaxis and of vaccination in preventing subsequent cases of IMD in household contacts following an index case. A literature search for systematic reviews identified a single suitable review on chemoprophylaxis in 2004 (three studies meta-analysed). A search for primary research papers published since 2004 on chemoprophylaxis and without a date limit on vaccination was therefore undertaken. There were 2381 studies identified of which two additional studies met the inclusion criteria. The summary risk ratio for chemoprophylaxis vs. no chemoprophylaxis (four studies) in the 30-day period after a case was 0·16 [95% confidence interval (CI) 0·04-0·64, P = 0·008]; the number needed to treat to prevent one subsequent case was 200 (95% CI 111-1000). A single quasi-randomized trial assessed the role of vaccination. The risk ratio for vaccination vs. no vaccination at 30 days was 0·11 (95% CI 0·01–2·07, P = 0·14). The results support the use of chemoprophylaxis to prevent subsequent cases of IMD in household contacts of a case. Conclusions about the use of vaccination could not be drawn.

Recently, the antibacterial properties of oestrogen and progestogen were discovered. The aim of this study was to find the cross-sectional association between oral contraceptive use and Helicobacter pylori seroprevalence. Data were obtained from the US National Health and Nutrition Examination Survey (NHANES). The H. pylori immunoglobulin G (IgG) enzyme-linked immunosorbent assays were used to categorise participants as seropositive or seronegative. The study population included 799 female participants who had information on H. pylori seroprevalence and all other covariates and had not been taking any medications (except oral contraceptives). The bivariate Rao–Scott chi-square test indicated a significant association between H. pylori seroprevalence and contraceptive use (P < 0.01). The variables of race, education, poverty income ratio, smoking, and blood lead and cadmium levels were also significantly associated with H. pylori seroprevalence (P < 0.01). Multiple logistic regression analysis of the age-adjusted model revealed that contraceptive users are 65% less likely of being H. pylori seropositive as compared to non-contraceptive users (odds ratio (OR): 0.35, 95% confidence interval (CI): 0.18–0.68). This association is stronger with the final multivariate model (OR: 0.46, 95% CI: 0.23–0.89). Conclusions: This finding reveals the potential protective effect of oral contraceptives against H. pylori infection and serves as a foundation study for further investigations.

In August 2011, we investigated an outbreak of Escherichia coli O157 in Plymouth, England, utilizing a case-control study and food traceback. Nine cases, eight laboratory-confirmed with E. coli O157 phage type 21/28 verocytotoxin 2 and one epidemiologically linked, had onsets from 30 July 2011 to 15 August 2011. We compared cases (n = 8) with controls (n = 28) of similar age and sex (median age 61 vs. 55 years, females 75% vs. 61%). Cases were 58 times more likely to have eaten crab (88% vs. 11%; odds ratio 58, 95% confidence interval 4-2700). Eight cases consumed crab sourced from the same supplier who was not registered with the local authority. This outbreak pointed to crab as a possible vehicle of E. coli O157 infection. We ensured the withdrawal of crab meat sourced from unregistered suppliers from food venues by 25 August 2011. We also emphasized the importance of only using registered suppliers to the food venues. Since then no further associated cases have been reported.