The aim of this paper is to investigate local spatial dependency with regard to Salmonella seropositivity in data from the Danish swine salmonellosis control programme and its application in informing surveillance strategies. We applied inhomogeneous and observed-difference K-function estimation, and geo-statistical modelling to data from the Danish swine salmonellosis control programme. Slaughter-pig farm density showed large variation at both the country-wide and local level in Denmark (median 0·23, range 0·02–0·47 farms/km2). The spatial distribution of pig farms followed a random inhomogeneous Poisson process but was not aggregated. We found evidence for aggregation of Salmonella case farms over that of all farms at distances of up to 6 km and semivariogram analyses of Salmonella seropositivity revealed spatial dependency between pairs of farms up to 4 km apart. The strength of the spatial dependency was positively associated with slaughter-pig farm density. We proposed sampling more intensively those farms within a 4 km radius of farms that were identified with a high Salmonella status, and reduced sampling of farms that are within this radius of ‘Salmonella-free’ farms. Our approach has the potential to optimize sampling strategies while maintaining consumer confidence in food safety and also has potential to be used for other zoonotic disease surveillance systems.

Corynebacterium ulcerans (toxigenic C. ulcerans) produces the diphtheria toxin, which causes pharyngeal and cutaneous diphtheria-like disease in people, and this bacterium is commonly detected in dogs and cats that are reared at home. It is considered dangerous when a carrier animal becomes the source of infection in people. To investigate the carrier situation of toxigenic C. ulcerans of cats bred in Japan, bacteria were isolated from 37 cats with a primary complaint of rhinitis in 16 veterinary hospitals in Osaka. Toxigenic C. ulcerans was detected in two of the cats. By drug sensitivity testing, the detected bacterium was sensitive to all investigated drugs, except clindamycin. It appears necessary to create awareness regarding toxigenic C. ulcerans infection in pet owners because this bacterium is believed to be the causative organism for rhinitis in cats.

Influenza and respiratory syncytial virus (RSV) are common causes of respiratory tract infections and place a burden on health services each winter. Systems to describe the timing and intensity of such activity will improve the public health response and deployment of interventions to these pressures. Here we develop early warning and activity intensity thresholds for monitoring influenza and RSV using two novel data sources: general practitioner out-of-hours consultations (GP OOH) and telehealth calls (NHS 111). Moving Epidemic Method (MEM) thresholds were developed for winter 2017–2018. The NHS 111 cold/flu threshold was breached several weeks in advance of other systems. The NHS 111 RSV epidemic threshold was breached in week 41, in advance of RSV laboratory reporting. Combining the use of MEM thresholds with daily monitoring of NHS 111 and GP OOH syndromic surveillance systems provides the potential to alert to threshold breaches in real-time. An advantage of using thresholds across different health systems is the ability to capture a range of healthcare-seeking behaviour, which may reflect differences in disease severity. This study also provides a quantifiable measure of seasonal RSV activity, which contributes to our understanding of RSV activity in advance of the potential introduction of new RSV vaccines.

The efforts of the Metropolitan Asylums Board in Victorian London to isolate cases of smallpox in hospitals, and so limit its spread, set off a controversy about ‘hospital influence’, i.e. alleged escapes of the disease into the neighbourhood. When, in 1870, the Board began to gather cases of smallpox into its new intra-urban isolation hospitals, nearby householders resisted, and in 1881 their fear of aerial transmission was endorsed by a government medical inspector, W. H. Power. Not all agreed with Power, but as a result from 1885 the Board removed almost all known cases of smallpox in London to hospital ships moored in the Thames Estuary. The ships failed to provide adequate and secure accommodation, however, and so Board smallpox hospitals were erected on the adjacent Dartford marshes. After 1903, there being no more smallpox epidemics in Britain, these isolation hospitals and many similar ones outside other towns and cities were little used for their main intended purpose. Their retention for many years thereafter can be seen as an application of the precautionary principle; it bears on current contingency plans in Britain and elsewhere for dealing with serious epidemics.

We constructed a syndromic surveillance system to collect directly information on daily health conditions directly from local residents via the internet [web-based daily questionnaire for health surveillance system (WDQH SS)]. This paper considers the feasibility of the WDQH SS and its ability to detect epidemics. A verification study revealed that our system was an effective surveillance system. We then applied an improved WDQH SS as a measure against public health concerns at the G8 Hokkaido Toyako Summit meeting in 2008. While in operation at the Summit, our system reported a fever alert that was consistent with a herpangina epidemic. The highly mobile WDQH SS described in this study has three main advantages: the earlier detection of epidemics, compared to other surveillance systems; the ability to collect data even on weekends and holidays; and a rapid system set-up that can be completed within 3 days.

Boiling is the most common method of household water treatment in developing countries; however, it is not always effectively practised. We conducted a randomized controlled trial among 210 households to assess the effectiveness of water pasteurization and safe-storage interventions in reducing Escherichia coli contamination of household drinking water in a water-boiling population in rural Peru. Households were randomized to receive either a safe-storage container or a safe-storage container plus water pasteurization indicator or to a control group. During a 13-week follow-up period, households that received a safe-storage container and water pasteurization indicator did not have a significantly different prevalence of stored drinking-water contamination relative to the control group [prevalence ratio (PR) 1·18, 95% confidence interval (CI) 0·92–1·52]. Similarly, receipt of a safe-storage container alone had no effect on prevalence of contamination (PR 1·02, 95% CI 0·79–1·31). Although use of water pasteurization indicators and locally available storage containers did not increase the safety of household drinking water in this study, future research could illuminate factors that facilitate the effective use of these interventions to improve water quality and reduce the risk of waterborne disease in populations that boil drinking water.

The present study attempted to analyse human papillomavirus (HPV) genotype distribution and its association with cervical cytology results in women in western China. The present retrospective analysis was performed in 1089 female outpatients with a positive HPV test result who had undergone a cervical cytology test at the gynaecological clinic, West China Second Hospital, Sichuan University, China, between January 2014 and December 2016. Of the 1089 patients with HPV infection, multiple HPV genotypes were detected in 220 patients (20.20%). Among the 1368 HPV genotypes detected, 1145 (83.70%) were high-risk subtypes. The most common genotypes were HPV-52 (18.64%), HPV-16 (16.59%), HPV-58 (13.23%), HPV-18 (6.80%), HPV-56 (5.56%) and HPV-59 (5.56%). Cervical cytology revealed abnormal cells in 430 (39.49%) patients. The most common diagnoses were atypical squamous cells of undetermined significance (ASC-US; 236 cases, 54.88%), low-grade squamous intraepithelial lesions (LSIL; 151 cases, 35.12%), high-grade squamous intraepithelial lesions (HSIL; 63 cases, 14.65%) and atypical glandular cells (AGC; 21 cases, 4.88%). HPV-66 was significantly associated (P = 0.037) with ASC; HPV-52 and HPV-56 were significantly associated with LSIL (P = 0.009 and 0.026, respectively); HPV-16 (P < 0.001), HPV-33 (P = 0.014) and HPV-58 (P = 0.003) were significantly associated with HSIL; and HPV-16 (P = 0.005) was significantly associated with AGC. HPV-16, HPV-52 and HPV-58 are associated with different diagnoses in patients with positive cervical cytological findings.

In 1972 more than 20% of boys admitted to a closed community (Junior Detention Centre) developed acute tonsillitis and group-A streptococci were isolated from more than 40% of all boys at some time during their stay of two months. The most common serotype was M-type 5, which has frequently been associated with rheumatic fever in other epidemics; four cases of rheumatic fever occurred between 1972 and 1977. Various methods were tried to eliminate the infection, but only full penicillin prophylaxis (0·25 g oral penicillin 4 times a day for 10 days) to all boys on entry appeared to be effective.

In a sample of cases of acute tonsillitis, group-A haemolytic streptococci were isolated from 31·7% by the use of dry swabs or unenriched transport medium, but with enrichment medium duplicate swabs, 77·0% yielded positive results. We question the current practice in some laboratories of reporting positive cultures only when more than ten colonies of β-haemolytic streptococci are present. In this survey viruses did not appear to be an important cause of acute tonsillitis.

High titres of streptococcal antibodies (antistreptolysin O, anti-desoxyribonuclease B and anti-M associated protein) were found, not only in cases and carriers, but in boys on entry to the centre. This supports epidemiological evidence that adolescent boys on entry to the centre. This supports epidemiological evidence that adolescent boys are particularly prone to streptococcal throat infections.

The aim of the study was to determine whether rates of hepatitis A infection are higher in people of South Asian origin compared to the general population, to look for evidence of spread to the general population, and to identify ways to improve preventive strategies. Routine laboratory reports of hepatitis A infection in England and Wales in 1992–2004 were analysed. Study participants were patients with confirmed hepatitis A infection reported to the Health Protection Agency by the diagnosing laboratory. Nam Pehchan software was used to identify patients of South Asian ethnicity. Main outcome measures were comparison of incidence of hepatitis A in South Asian and non-South Asian groups, by age and region. Rates of infection were significantly higher in the South Asian group compared to the non-South Asian group (rate ratio 2·68, 95% confidence interval 2·07–3·47). Patients in the South Asian group had a younger age distribution. Travel was an important risk factor with 85% of those of South Asian origin acquiring their infection abroad, most frequently in the Indian subcontinent, compared to less than one third of those in other groups. Health-care professionals should ensure that all travellers to high-risk countries are protected by hepatitis A vaccination. Targeted information campaigns may be indicated in regions of the United Kingdom for people in South Asian minority ethnic groups.

To determine the burden and distribution of acute gastrointestinal illness (AGI) in the population, a cross-sectional, monthly face-to-face survey of 10 959 residents was conducted in Jiangsu province between July 2010 and June 2011. The adjusted monthly prevalence was 4·7% with 0·63 AGI episodes/person per year. The prevalence was the highest in children aged <5 years and lowest in persons aged ⩾65 years. A bimodal seasonal distribution was observed with peaks in summer and winter. Regional difference of AGI prevalence was substantial [lowest 0·5% in Taicang, highest 15·1% in Xinqu (Wuxi prefecture)]. Healthcare was sought by 38·4% of the ill respondents. The use of antibiotics was reported by 65·2% of the ill respondents and 38·9% took antidiarrhoeals. In the multivariable model, gender, education, season, sentinel site and travel were significant risk factors of being a case of AGI. These results highlight the substantial burden of AGI and the risk factors associated with AGI in Jiangsu province, China.

1. 1614 strains of Corynebacterium diphtheriae have been typed and analysed and some anomalous varieties described.

2. The various types have been considered in their relation to case severity.

3. Some comments are offered on the colonial and biochemical characteristics of the various types of C. diphtheriae

4. and on the serology of the strains found in Glasgow.

5. Two gravis-like strains Types IV and VI have been observed and correlated with clinical findings, and their cultural and biochemical characteristics described.

6. Attempt has been made to confirm alleged change in fermentative characteristics by growth in serum broth, with negative results.

1. In two R.A.F. recruit stations between November 1958 and March 1959, there were 2603 admissions to Sick Quarters with respiratory illness. Throat swabs from 1129, and paired sera from 1197 were tested for certain respiratory viruses.

2. From the serological results it was estimated that 19% of the admissions were associated with influenza A infection, 7% with influenza B, 26% with adenovirus, 1% with para-influenza Type 1, 1% with para-influenza Type 3 and 8% with Coe virus, but as 21% of the identified infections were multiple the proportion of illness associated with one or more of these infections was only 50%. Thirty-four per cent of the Coe virus infections and 56% of the para-influenza virus infections were multiple.

3. Virus isolation test results led to a similar estimate of the frequency of adenovirus infection (23%) but to a lower estimate for Coe virus (3%) and for the para-influenza viruses, no systematic attempt was made to isolate influenza viruses. Reasons are given for thinking that most of the admissions associated with Coe virus infection in 1958, but few of those in 1959, were caused by this agent. The proportion of illnesses attributable to viruses of the para-influenza group was probably about 1%.

4. The main symptoms associated with Coe virus infection were upper respiratory. Hoarseness was rather more prominent than in other infections but the height and duration of fever and the frequency of febrile symptoms were less. The few illnesses associated with para-influenza virus infection had no obvious distinguishing features.

1960 survey

1. Blood specimens were taken from 205 recruits on their arrival at a recruit camp in January 1960 and immediately before their departure in March; 764 men in ten operational stations were bled in January and a sample of 260 were bled again in March.

2. The respiratory illness admission rate was 25% in the recruits and 4% in the trained men; 49% of the recruits showed a rise in antibody to one or more respiratory virus antigens compared with 2% in the other group. The high rate of infection in recruits was mainly due to adenovirus (36%) and Coe virus (20%).

3. It was estimated that about a third of the adenovirus infections and an eighth of the Coe virus infections were responsible for illness requiring admission. There was no indication that either infection caused any appreciable number of less severe illnesses not requiring admission.

4. Evidence from this survey and the earlier one suggests that the presence of neutralizing antibody to Coe virus does not prevent infection, though it appears to lower the probability of illness.

More than 12800 clinical isolates from 115373 in-patient specimens obtained at the Sir Charles Gairdner Hospital, Perth, Western Australia, were identified and analysed statistically for relationships with usage of three generations of cephalosporins over the 5-year period from July 1984 to June 1989. A positive relationship between cephalosporin usage and significantly increasing isolation rates for those species capable of producing chromosomal β-lactamases was observed. Simultaneously, a small increase in the isolation frequency of non-chromosomal β-lactamase-producing strains was noted and no correlation with cephalosporin usage was demonstrated. The trend toward predomination in the hospital environment of strains possessing substantial cephalosporin resistance has implications for future antimicrobial policy, choice of empiric therapy and the predictive value of standard antimicrobial susceptibility tests.

1. Data obtained by the disinfection at 51° C. of standard cultures of Bact. coli at pH values ranging from 2·8 to 8·8 have been used for the calculation of the concentration exponents of hydrogen and hydroxyl ions. The times taken to reach various degrees of mortality from 50 to 99·99 % have been taken as measures of the activities of the ions.

2. The formula Cn×t = constant proved satisfactory for describing the data for all the mortality levels and at all the pH values tested except pH 2·8, 6·25, 6·4 and 7·0. In these instances the cultures exhibited heightened sensitivity, though the results at all, except pH 2·8, could be included when the 99·.99 % mortality times were used. The exponents increased sharply at pH values below 3·9.

3. The values of the concentration exponents varied similarly under both acid and alkaline conditions, according to the mortality level chosen. The largest value was obtained from the 90 % mortality times, there being a decrease when both higher and lower levels were employed. The changes were greater under acid conditions, when the values ranged from 0·60 to 0·25, compared with 0·60–0·47 for the alkaline reactions.

4. The mean of the pH values for maximal survival at the various mortality levels, derived from the regressions of log mortality time on pH, was ·51, but this was close to a point of greater susceptibility. Experimentally, maximal survival occurred at pH 6·65, which is very near to the neutral point of water at 51° C.

5. It is concluded that within the pH range 6·25–7.0 the hydrogen and hydroxyl ions were relatively inactive, the effects observed being due to other factors possibly including the action of undissociated water molecules.

The authors acknowledge with thanks the receipt of a grant from Messrs I.C.I. (Pharmaceuticals) Ltd. towards the expenses of this investigation.

Restriction digest fragments of DNA from 46 clinical isolates identified as Corynebacterium group D2, were separated by electrophoresis, Southern blotted onto nylon membranes and hybridized to a ribosomal RNA gene probe. The resulting band patterns were subjected to unweighed pair-group cluster analysis. Representative strains from the main clusters were compared with similarly prepared band patterns from type strains of human Corynebacterium species.

The results indicate that strains identified as Corynebacterium group D2 represent a unique taxon and that computer-assisted analysis of rRNA gene restriction fragment polymorphism (ribotyping) could be a useful technique in epidemiological studies of these bacteria.

We evaluated all fatal neonatal sepsis and pneumonia cases occurring in Alaska during 1992–2000. Risk factors were evaluated using a database of all births occurring during the study period. Of 32 cases, group B streptococcus (GBS) was isolated from 21% (all <7 days of age), Candida spp. from 19% (all >7 days of age), non-GBS Gram-positive bacteria from 50% (53% <7 days of age), and Gram-negative infections from 38% (58% <7 days of age). Infants born at <37 weeks gestation accounted for 72% of cases and had an increased risk of GBS [rate ratio (RR) 9·1, 95% confidence interval (CI) 2·0–41] and non-GBS (RR 40, 95% CI 16–101) disease. Neonatal sepsis mortality has become an outcome concentrated among pre-term infants. Aetiologies include GBS during the early neonatal period, Candida spp. during the late neonatal period, and other bacteria during both periods.

The quantitative theory for the interaction between antigen and antibody presented in the previous paper has been compared with some experimental precipitin reactions published in the literature. These reactions include Type VIII pneumococcus polysaccharide-homologous (horse) antibody, egg albumin-(rabbit) anti-egg albumin and diphtheria toxin-(horse) antitoxin.

1. The general course of the experimental precipitation curves (total amount of precipitate, amounts of precipitated antigen and antibody) corresponded well to the theoretical type curves. Hence it may be concluded that the precipitates may be composed of mixtures of compounds of the types AG, A2G, A3G, …, ANG in accordance with the law of mass action. In the cases with ‘inhibition zones’, however, AG, or ANG, or both (and perhaps several more compounds) retain the same solubility as the free antigen (G) and free antibody (A).

2. With regard to the location of the ‘equivalence zones’, experiment and theory also showed a satisfactory agreement.

3. A hypothesis on the velocity of flocculation in the precipitin reaction is presented and compared with some recent results. The relation between the immunological concepts ‘equivalence (neutral) point’, ‘optimum point’ and ‘maximum precipitation point’ is also discussed.

Potential underestimation of the health system burden of pertussis was investigated by linking administrative datasets including pertussis notifications, hospitalizations and emergency department (ED) presentations for 1 304 876 children aged <15 years in NSW, Australia. From 2005 to 2008, 3006 children had a pertussis notification, 455 were hospitalized and 644 had an ED presentation with a coded diagnosis of pertussis. Linking hospital and ED records with pertussis notifications identified 140 hospitalizations and 735 ED presentations which occurred ±7 days from notification but did not have a diagnosis of pertussis recorded. These additional events were more likely to have a diagnosis of bronchiolitis, upper respiratory infection and cough compared to all other admissions and presentations. Including these additional events significantly increased the proportion of notified cases that were hospitalized or visited EDs, particularly for those aged 5 to <15 years. Linked administrative data allowed more comprehensive estimation of the health system burden of pertussis.

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.

The present communication deals with an analysis and comparison of the principal physical measurements, physical characters and relative bodily proportions in groups of boys and girls at corresponding ages who were under treatment for asthma and rheumatism respectively in the special clinics established at the Sick Children's Hospital, Great Ormond Street, and of other groups of boys and girls of similar ages with no history of asthma or rheumatism and no obvious serious impairment of general health who were attending the Outdoor Department of the hospital for treatment of trivial ailments. The last-mentioned series of boys and girls have been assumed to represent the normal hospital population and have been referred to throughout as the normal groups. The object of the investigation was to determine if there was any real evidence that the asthmatic and rheumatic children differed from one another or from the normal children in general physical type or build. The inquiry has been restricted to children in the age period 6–12 years, and these have been taken in two-yearly age groups in order to provide more adequate numbers of observations for comparison. In all, the characters of approximately 1212 children have been dealt with. Of these, 368, 236 boys and 132 girls; 459, 189 boys and 270 girls; and 385, 195 boys and 190 girls, were considered to be asthmatic, rheumatic and normal respectively. A study of the frequency distributions, mean values and variabilities of the characters compared at the corresponding ages in the three groups of boys and girls seems to provide a reasonable basis for the following conclusions:

1. The corresponding averages of practically all the absolute physical measurements brought under review are in such close agreement in the contrasted groups of asthmatic and rheumatic children that the data provide no evidence of any real difference in the general dimensions of children with the respective diseases. Though the average antero-posterior diameter of the chest is probably greater in the asthmatic than the rheumatic children, no emphasis can be laid on this feature as it may be, in part, the result of the disease.

2. Though at some ages the mean dimensions of a few characters in the asthmatic and rheumatic groups do differ from the corresponding averages in the normal series, the differences are not sufficiently consistent at the different ages and in the two sexes to indicate any real divergence from the normal.

3. A comparison of the relative proportions of the body as expressed by the percentage ratios or indices, stem length/stature, body length/stature, biacromial diameter/body length, bicristal diameter/biacromial diameter and length of arm/length of leg, at corresponding ages in the asthmatic and rheumatic children does not provide any definite evidence that children suffering from these two diseases differ from one another in morphological type.

4. Though occasionally, at one or more ages, one or more of the indices used to express the relative proportions of the body may appear to differ in mean value from the normal averages at the corresponding ages the differences are not sufficiently consistent in regard to age and sex to suggest any real divergence from the normal.

5. Comparison of the frequency distributions of hair colour shows that the asthmatic children do not really differ from the rheumatic children in respect of pigmentation. The rheumatic children do not differ from the normal, but both the asthmatic boys and girls show a relatively greater excess of the blonde haired type and a greater deficiency in the dark haired as compared with the normal than might be expected to occur as a chance variation.

6. With regard to distribution of eye colour, the asthmatic boys do not differ from the rheumatic boys, but the asthmatic girls appear to have a relative defect in brown eyes and a relative excess in blue eyes as compared with the rheumatic group; neither in boys nor girls with asthma or rheumatism can the distribution of eye colour be said to differ significantly from the normal on the data available.

7. There is no definite evidence that the proportions of relatively long and slender and short and thick-set types, as appraised by general inspection, amongst asthmatics differ from the normal.

8. There is no evidence in the data for boys or girls that the distribution of grades of posture differs significantly in either the asthmatic or rheumatic groups from the normal, though in girls with rheumatism the habitual posture appears to be relatively worse than in those with asthma.

9. Both in regard to form of face, as expressed by the upper and total facial indices, and form of head, as represented by the cephalic index, the groups of asthmatic and rheumatic children do not differ significantly from one another or from the normal.

10. The differences in the three groups of children, the asthmatic, the rheumatic and the normal, in respect of the aggregate of physical characters brought under review are relatively so slight that they cannot be considered to support the view that asthmatic and rheumatic children really differ on the average from one another or from the general population of children from which they are drawn in bodily conformation or physical type, though they may possibly, indeed probably, differ in other constitutional traits.