A total of 284 Lancashire police officers each with a minimum of 5 years experience was tested for evidence of hepatitis B infection. None was hepatitis B surface antigen positive (HBsAg). Three were positive for both antibody to hepatitis B core antigen (anti-HBc) and HBsAg (anti-HBs). Five were positive for anti-HBc alone. Thus the overall prevalence was 2·8% which is within the range reported for blood donors in the UK. There was no association with working in the drug squad or custody office but there was a higher prevalence in those who had worked in the scene-of-crime's squad. However, the numbers were small, and of this group of 28 officers, 2 of the 3 with detectable hepatitis B markers were positive for anti-HBc alone. Therefore for police officers in mixed rural/urban areas of the UK, routine administration of hepatitis B vaccine is not justified although special consideration should be given to those working in selected groups. Further studies are required to ascertain whether there may be an increased risk for police officers working in conurbations.

1. Highly milled parboiled rice was found to be rich in the antineuritic vitamin B1, while roughly milled raw rice was deficient. In estimating the content of vitamin B1 the method of Chick and Roscoe was used.

2. Exact comparison was made of the vitamin B1 potency of two samples of rice, the one raw, the other parboiled, after similar degrees of milling. The vitamin value of the unmilled samples was equal, but when each was highly milled to an equal degree, as judged by weight of polishings removed in a hand rice mill, the parboiled sample retained the vitamin while the raw sample did not.

3. Polishings from parboiled rice were found to contain less vitamin B1 than those from raw rice.

4. Parboiled rice contains more P2O5 than raw rice milled to the same degree.

5. It is probable that when rice is steamed in the process of parboiling, the vitamin B1 and some of the phosphate contained in the germ and pericarp diffuse through the endosperm.

6. The P2O5 content of raw rice is a good index of vitamin B1 value, but in parboiled rice a low percentage of phosphate is compatible with the presence of the vitamin.

Thanks are due to Miss L. M. B. Patterson who kindly made the phosphate estimations recorded in the paper. I am indebted to the Director of Agriculture, British Guiana, for a number of rice samples. The rice mill used was kindly lent by Jackson and Son, 30, Mincing Lane, E.C. 3. I am grateful to Miss Chick for her continued interest in these experiments.

1. When toxic filtrates derived from coagulase-positive staphylococci including twelve food-poisoning strains, thirty pyogenic strains of human and twelve of animal origin were applied to isolated rabbit gut in vitro, two characteristic responses were obtained, associated with the α- and β-lytic titres respectively, and abolished by the corresponding antisera. They were independent of the origin of the strains.

2. A non-specific response is also described which is thought to be due to the peptone in the medium.

3. No effect that could be attributed to enterotoxin, such as was reported by Anderson (1953), was observed and it is concluded that isolated rabbit gut is unlikely to prove a useful indicator of its presence.

We are indebted to Drs Mary Barber, J. M. Talbot, F. C. O. Valentine and H. Williams Smith for strains; to Dr R. E. O. Williams for strains and bacteriophage typing; to Prof. C. E. Dolman and Messrs Burroughs Wellcome for strains and antisera; to Mr F. Crisp of the Division of Experimental Biology, National Institute for Medical Research, Medical Research Council, for rabbit gut; and Dr H. O. Schild for continued interest and practical help.

To understand the dynamics of transmission of Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) in beef calves, serum samples were obtained from calves in a beef cow-calf herd approximately every 6 weeks from birth until weaning for three consecutive years. The presence of specific anti-O157 antibodies in these serum samples was detected using a blocking ELISA assay incorporating an anti-O157 monoclonal antibody. Using seroconversion data, the basic reproduction ratio (R0) was estimated for each of the three years as well as in aggregate using both deterministic and Martingale methods. R0 for STEC O157 infection in range beef calves by deterministic methods varied from 2·9–5·6, with an average of 4·3 (95% CI 2·8–5·9). Martingale estimates of R0 ranged from 3·5–7·4, or 5·3 (95% CI 3·9–6·6), for data from all three years. Given the above estimate of R0, it is predicted that 65–86% of a herd of calves must be effectively vaccinated, or must be rendered non-susceptible through other means, to eliminate STEC O157 infection from a herd.

Thailand was a hyper-endemic country for dengue with co-circulation of four serotypes and tens of thousands of infected cases annually. Taking into consideration the large number of local dengue virus (DENV) sequences available in GenBank, Thailand was the most ideal locality to study co-evolution of DENV. Therefore, we undertook a large-scale molecular epidemiological analysis of all DENV strains isolated in Thailand. In this study, we demonstrated that DENV strains of four serotypes post-1990 grouped into distinct clades, and that specific mutations in the envelope protein were first confirmed in these clades. Compared to the DENV1, DENV2 and DENV3 clades, the DENV4 clade evolved markedly more slowly (6·4 × 10−5 substitutions/site per year). Our results also showed that the genetic diversity of the predominant genotype of each serotype tended to slightly increase over time with fluctuating changes, followed by a stationary phase after 2000. This suggests that the four DENV clades became the predominant strains due to DENV possessing improved fitness after long-term selection.

The British genera of blowflies, if the term be restricted to members of the Muscid subfamily Calliphorinae, are Calliphora with the two species erythrocephala Mg. and Vomitoria L., Lucilia, with several species, of which the commonest in the Manchester area are caesar L. and simulatrix Pand., and Protocalliphora, withe two species azurea. Fln. and groenlandica Ztt., of which the later alone concern us.

Evaluation of antimalarial efficacy is difficult because recurrent parasitaemia can be due to recrudescence or re-infection. PCR is used to differentiate between recrudescences and re-infections by comparing parasite allelic variants before and after treatment. However, PCR-corrected results are susceptible to misclassification: false positives, due to re-infection by the same variant present in the patient before treatment; and false negatives, due to variants that are present but too infrequent to be detected in the pre-treatment PCR, but are then detectable post-treatment. This paper aimed to explore factors affecting the probability of false positives and proposes a Monte Carlo uncertainty analysis to account for both types of misclassification. Higher levels of transmission intensity, increased multiplicity of infection, and limited allelic variation resulted in more false recrudescences. The uncertainty analysis exploits characteristics of study data to minimize bias in the estimate of efficacy and can be applied to areas of different transmission intensity.

Cryptosporidium hominis is one of the most prevalent protozoan parasites to infect humans where transmission is via the consumption of infective oocysts. This study describes sporadic cases in addition to the molecular diversity of outbreak cases in Scotland using the glycoprotein-60 subtyping tool. From a total of 187 C. hominis isolates, 65 were subjected to further molecular analysis and 46 were found to be the common IbA10G2 subtype. Unusual subtypes included four isolates belonging to the Ia family (IaA14R3, n = 12; IaA14R2, n = 1; IaA9G3, n = 1; IaA25R3, n = 2), two from the Id family (IdA24, n = 1; IdA17, n = 1) and one belonging to the Ie family, namely IeA11G3T3. These data contribute significantly to our knowledge and understanding of the molecular diversity of C. hominis isolates from outbreak investigations involving Scottish residents which will be beneficial for the management of future outbreaks.

This study compares the frequency and severity of influenza A/H1N1pdm09 (A/H1), influenza A/H3N2 (A/H3) and other respiratory virus infections in hospitalised patients. Data from 17 332 adult hospitalised patients admitted to Sir Charles Gairdner Hospital, Perth, Western Australia, with a respiratory illness between 2012 and 2015 were linked with data containing reverse transcription polymerase chain reaction results for respiratory viruses including A/H1, A/H3, influenza B, human metapneumovirus, respiratory syncytial virus and parainfluenza. Of these, 1753 (10.1%) had test results. Multivariable regression analyses were conducted to compare the viruses for clinical outcomes including ICU admission, ventilation, pneumonia, length of stay and death. Patients with A/H1 were more likely to experience severe outcomes such as ICU admission (OR 2.5, 95% CI 1.2–5.5, P = 0.016), pneumonia (OR 3.0, 95% CI 1.6–5.7, P < 0.001) and lower risk of discharge from hospital (indicating longer lengths of hospitalisation; HR 0.64 95% CI 0.47–0.88, P = 0.005), than patients with A/H3. Patients with a non-influenza respiratory virus were less likely to experience severe clinical outcomes than patients with A/H1, however, had similar likelihood when compared to patients with A/H3. Patients hospitalised with A/H1 had higher odds of severe outcomes than patients with A/H3 or other respiratory viruses. Knowledge of circulating influenza strains is important for healthcare preparedness.

Pulsed field gel electrophoresis (PFGE) of the genomic DNA of Moraxella catarrhalis was done in 172 strains isolated from sputum of patients with respiratory infections in Nagasaki (130 strains), Europe (14 strains), Thailand (6 strains), Uganda (3 strains), Bangladesh (5 strains) and Kuwait (14 strains). Restriction endonuclease with SmaI generated 4–16 DNA fragments ranging from 1000 kb to 24·25 kb and was classified into 31 major groups. It was found that there were wide variations of DNA restriction patterns of strains isolated from the same and different geographical areas. DNA restriction patterns of strains isolated in Nagasaki during the last 12 years showed dynamic changes of the predominant strains in each time period. We conclude from this study that PFGE is a suitable method to document interstrain variation in M. catarrhalis.

Skin and soft tissue infections (SSTIs) due to Staphylococcus aureus have become increasingly common in the outpatient setting; however, risk factors for differentiating methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) SSTIs are needed to better inform antibiotic treatment decisions. We performed a case-case-control study within 14 primary-care clinics in South Texas from 2007 to 2015. Overall, 325 patients [S. aureus SSTI cases (case group 1, n = 175); MRSA SSTI cases (case group 2, n = 115); MSSA SSTI cases (case group 3, n = 60); uninfected control group (control, n = 150)] were evaluated. Each case group was compared to the control group, and then qualitatively contrasted to identify unique risk factors associated with S. aureus, MRSA, and MSSA SSTIs. Overall, prior SSTIs [adjusted odds ratio (aOR) 7·60, 95% confidence interval (CI) 3·31–17·45], male gender (aOR 1·74, 95% CI 1·06–2·85), and absence of healthcare occupation status (aOR 0·14, 95% CI 0·03–0·68) were independently associated with S. aureus SSTIs. The only unique risk factor for community-associated (CA)-MRSA SSTIs was a high body weight (⩾110 kg) (aOR 2·03, 95% CI 1·01–4·09).

The aerosol survivals in air and nitrogen of radiation sensitive and resistant mutants of Escherichia coli B have been determined with logarithmic and resting phase bacteria. No consistent correlation was found between radiation sensitivity and aerosol sensitivity in the strains tested. Hence, the phenotypes Fil Her Exr, which determine sensitivity to radiation, do not influence aerosol survival, i.e. these known mechanisms which repair radiation-induced damage do not operate in aerosol stressed E. coli. In all cases the survival in air was less than that in nitrogen particularly so for E. coli Bs-1. The effect is explained in terms of a toxic action of oxygen. Comparison of survival of log and resting phase bacteria show that log phase cells are less aerosol stable than are resting phase cells. The ability to synthesize DNA in bacteria collected from the aerosol was less than in control unstressed bacteria, and this effect was independent of the presence of oxygen. Reduced ability to synthesize DNA could have been caused by reduced metabolic activity. It is shown that two different death mechanisms occur simultaneously in aerosols at low relative humidity. One mechanism is oxygen dependent and the other oxygen independent. The former was not through a decrease in metabolic activity, whereas the latter could be.

A total of 256 sera collected from three species of domesticated equidae in four different Spanish provinces were examined 1–4 months after the administration of attenuated monovalent African horse sickness virus (AHSV) serotype 4 vaccine. Approximately 10% of the sera were negative by ELISA, virus neutralization, agar gel immuno-diffusion and complement fixation tests. Similar negative reactions were recorded with sera from two ponies after experimental primary vaccination. The rapid rise in antibodies in sera from these two ponies, after a second dose of vaccine, suggested they would probably have been immune to challenge. It is therefore suggested that the apparent absence of antibodies against AHSV in some animals after primary vaccination may not necessarily indicate a total lack of protection.

Samples were collected at two abattoirs from four sites on pig carcasses as they were being placed in a chiller. Bacteriological examination showed that no single sampling site could be used to assess the microbiological status of pig carcass surfaces. Sampling from multiple sites on a carcass may be required to assess the degree of contamination by different bacteria. It is suggested that the hygiene of slaughtering and dressing of pig carcasses at an abattoir cannot be assessed on a single visit and that a number of visits are necessary to establish a hygiene pattern.

While studying the infection of Trypanosoma dimorphon in mice at the Pasteur Institute some five months ago, I noticed in one of the fresh blood preparations made from a brown mouse (A) infected with the trypanosomes, a small and very active spirochaete. At first I was of the opinion that its presence in the blood was due to contamination from the skin, but, as it was constantly present and was constantly present and was found in blood taken from any part of the body, it was evident that it was parasitic in the blood.

Leprosy still represents a serious health problem in a number of countries, including Brazil. Although leprosy has been associated with poverty for a long time, it is still difficult to accurately define this relationship. Here, we evaluated in an endemic municipality the progress from 1995 to 2015 of epidemiological indicators to establish if there were any strong associations between social indicators and the occurrence of leprosy. An ecological study was conducted using the SINAN database (Brazilian leprosy-national notifiable diseases information system) in combination with georeferencing of leprosy cases. The georeferencing used the ArcGis programme and occurrence of cases was evaluated in relation to the Health Vulnerability Index (HVI), an indicator that categorises socio-economic and sanitation factors. The data identified a marked decrease in the overall prevalence of leprosy, a reduction in the new case-detection rate and a reduction in the number of cases with grade 2 disabilities (albeit with transient peaks in 2007 and 2015). Logistic regression analysis showed association of detection rates with elevated HVI. Thus, while the epidemiological indicators point to the elimination of leprosy, there is evidence of hidden cases and an association between higher rates of leprosy detection and greater social vulnerability remain.

Mathematical modelling is an important tool for understanding the dynamics of the spread of infectious diseases, which could be the result of a natural outbreak or of the intentional release of pathogenic biological agents. Decision makers and policymakers responsible for strategies to contain disease, prevent epidemics and fight possible bioterrorism attacks, need accurate computational tools, based on mathematical modelling, for preventing or even managing these complex situations. In this article, we tested the validity, and demonstrate the reliability, of an open-source software, the Spatio-Temporal Epidemiological Modeler (STEM), designed to help scientists and public health officials to evaluate and create models of emerging infectious diseases, analysing three real cases of Ebola haemorrhagic fever (EHF) outbreaks: Uganda (2000), Gabon (2001) and Guinea (2014). We discuss the cases analysed through the simulation results obtained with STEM in order to demonstrate the capability of this software in helping decision makers plan interventions in case of biological emergencies.