The prevalence of antibody to measles virus in 759 children aged 11–18 years attending a secondary school in Cumbria was measured using a salivary IgG antibody capture assay. Serum IgG antibody levels were measured using a plaque reduction neutralization assay in subjects whose saliva was antibody negative. Vaccination histories were obtained from the child health computer and general practice records. A total of 662 pupils (87 % of those tested) had detectable measles-specific IgG in saliva. Of the remaining 97, 82 provided blood samples and 29 had serum neutralizing antibody levels above 200 mlU/ml. After adjusting for non-participation rates, the proportion considered non-immune (no IgG in saliva and ≤ 200 mlU/ml in serum) was 9 % overall, ranging from 6 % in vaccinated children to 20 % in unvaccinated children. Measles-mumps-rubella vaccine was given to 50 children of whom 38 provided post-vaccination serum and 32 saliva samples. Thirty (79 %) had a fourfold or greater rise in serum neutralizing antibody and 28 (88 %) developed IgG antibody in saliva. Half of the children considered non-immune by antibody testing would have been overlooked in a selective vaccination programme targeted at those without a history of prior vaccination. A programme targeted at all school children should substantially reduce the proportion non-immune since a primary or booster response was achieved in three quarters of previously vaccinated children with low antibody levels and in all unvaccinated children. While it is feasible to screen a school-sized population for immunity to measles relatively quickly using a salivary IgG assay, a simple inexpensive field assay would need to be developed before salivary screening and selective vaccination could substitute for universal vaccination of populations at risk of measles outbreaks. The salivary IgG assay provided a sensitive measure of a booster response to vaccination.

A large serosurvey was carried out in Luxembourg in 2000–2001, to determine the population immunity against a number of vaccine-preventable infections including diphtheria and pertussis. Immunity to diphtheria and pertussis was assessed using an in-house neutralization assay and a commercial ELISA test respectively. Mean pertussis antibody activity decreased from 4 to 8 years of age, reflecting the effects of waning of vaccine-induced immunity. Mean pertussis antibody activity increased during adolescence due to infection in previously vaccinated individuals and levelled out after approximately 20 years of age. For adults >25 years age, a statistically significant 30% difference in mean antibody activity between men and women was observed. The proportion of seronegatives for diphtheria among children and adolescents aged <20 years was 2·5% reflecting the high vaccination coverage. The proportion seronegative for diphtheria tended to increase with age such that 42% of individuals aged >40 years were seronegative. Our study supports the recently introduced acellular pertussis vaccine booster at 6 years to reduce pertussis transmission in school-aged children and adolescents.

An epidemic of epidemic hepatitis occurred in the district of a rural Central School in Yates and Ontario Counties of Central New York. The epidemic comprised 176 cases of which 135 were jaundiced, and extended from September 1949 to May 1950, with most cases in March 1950.

No common source could be demonstrated and the transmission was believed to be due to human contact alone.

The overall morbidity rate was about 5%, attack rate among school children 22%, and among the adults and pre-school family contacts of infected school children the attack rate was 18%, with no significant age difference in attack rate.

Differences in attack rate in the various school grades were explained by higher number of siblings of children in certain grades.

Household attack rates among non-school persons were related to number of sick school children, family size, and hygienic standard of the home. The first of these factors seemed most important.

More jaundiced cases occurred in families where the exposure was heaviest.

After one passage of influenza A2/Singapore/l/57 virus in mice treated with 150 mg./kg./day of aminoadamantane, a partially drug-resistant strain of virus was detected in 1 of 12 mice. The isolation rate of aminoadamantane-resistant viruses increased to 8 after three passages in drug-treated mice. Some virus strains showed a 500-fold increase in resistance to aminoadamantane and to the structurally related compounds α-methyl-1-adamantane methylamine and 2-adamantanamine sulphate. No aminoadamantane-resistant viruses were detected after passage of influenza four times in mice treated with lower (15 or 1·5 mg./kg./day) concentrations of aminoadamantane. Aminoadamantane had no detectable effect on the development of lung lesions in mice infected with the drug-resistant influenza strain, whereas lung lesions were reduced in aminoadamantane treated mice infected with a control strain of influenza A2/Singapore virus. No differences were detected in the buoyant density in caesium chloride, morphology or serology between control and aminoadamantane-resistant strains of virus. These drug-resistant influenza viruses may be useful for detailed studies of the mode of action of aminoadamantane.

Biochemical and serological investigations were made upon Bact. coli O 55 B 5 strains isolated from infants with diarrhoea and vomiting. On the basis of their reactions with six fermentable substances and of their H antigen types, the strains could be differentiated into three sero-fermentative types, I, II and III, which comprised, respectively, those having H6, H2 and H7 antigens.

We wish to acknowledge our thanks and indebtedness to the following: the Chairman and Members of the Tottenham Group Hospital Management Committee, and Dr T. H. C. Benians, Dr W. I. Leslie and Dr R. Swyer, for facilities for research in the laboratory and wards of St Ann's General Hospital; Mr L. G. C. Maslen for most valuable advice and assistance; the entire laboratory staff for their willing and efficient help.

Infants' stools were examined for the presence of Clostridium difficile and its cytotoxin in a study performed over a one-year period on a special care baby unit. Overall, 21% of infants were colonized, but the organism was only recovered in a seven-month period during which its weekly prevalence in the group varied from zero to 44%, with a distinct clustering of colonized infants being observed. Tests for the presence of cytotoxin in the stools and in supernatants of broth that had been inoculated with each isolate were negative. The factors predisposing to colonization were a prolonged stay in the unit, low birth weight, younger gestational age and being nursed in an incubator. The organism was recovered only once from an environmental screen.

An antibiogram, used in conjunction with toxin production, was helpful in distinguishing these isolates from a collection obtained from other units in the hospital. We conclude that Cl. difficile was acquired by nosocomial spread although we did not establish the precise mechanism involved.

The detection of para-cresol by gas–liquid chromatography was found to be specific but insufficiently sensitive as a screening test for the organism's presence in the stools. It could only be demonstrated in infants whose birth-weights were less than 2500 g, and no association was observed between the type of feed and para-cresol presence in stools.

Health risks in the effluents of seven swine abattoirs and of seven poultry abattoirs were evaluated with regard to environment degradation and to dissemination of pathogenic microorganisms during the rainy and dry seasons. Supply-water samples from affluents and effluents of the treatment systems at different sites within the abattoir processing system were analysed. Similarly, water samples from the three recipient sites (emission point, 100 m upstream, 100 m downstream) were also analysed. Temperature, free residual chlorine (FRC), total coliform bacteria, Escherichia coli, enterococci, identification and serotyping of salmonellae were assessed. Scalding is the most significant stage in the slaughtering chain (P<0·05) when temperature is taken into account. Temperatures at effluents and at the sampled sites in the water bodies accorded to state and federal legislation standards. Supply waters did not meet the standards for FRC and microbial count standards according to the Ministry of Health and within limits imposed by the Industrial and Sanitary Inspection Regulations for Animal Products. Feather plucking and evisceration in poultry slaughter and the cleansing of carcasses and facilities in poultry and swine slaughtering had the highest contamination impact. The three loci at the water bodies were above the microbiological standards for classes II and III sites, in conformity with Law 8468 of the state of São Paulo, Brazil and Conama. Salmonella was found at several sites during slaughter, at both types of abattoirs, including in the effluent treatment system. This showed that these sites were the dissemination sources of the microorganism.

The dip-slide, consisting of a glass microscope slide coated with nutrient medium and inoculated by dipping in freshly voided urine, provides a simple measure of the bacterial concentration in fresh urine. This is a useful supplement to the usual microscopy and culture of urine in the diagnosis of urinary tract infections in general practice, when specimens cannot be delivered to a laboratory within several hours of collection, particularly when urine specimens have to travel by post. Dip-slides are also useful as the sole test in screening for symptomless bacteriuria.

The following enteropathogens were isolated from the faeces of 769 (10·2%) of 7,545 patients of whom 5,704 had diarrhoea or abdominal pain, attending a teaching hospital in Hong Kong during one year: salmonellae 458 (6·1%); Vibrio parahaemolyticus 125 (1·7%); campylobacters 108 (1·4%); shigellae 83 (1·1%); others 19 (0·3 %). Further identification of the campylobacter isolates showed that 63 (58%) were Campylobacter jejuni biotype 1, 44 (41%) were C. coli and only one was C. jejuni biotype 2. Seventy-five (69%) of the 108 campylobacters were isolated from children under two years of age, mostly during the second year of life. Faecal specimens from 1,841 children under the age of two years without gastrointestinal symptoms yielded almost the same percentages of salmonellae, campylobacters and shigellae as children with diarrhoea.

Salmonellae, shigellae and vibrios were isolated most often in the hot late summer months (August to October), but, contrary to the pattern in Europe and North America, both C. jejuni and C. coli were most prevalent in the coolest months of the year (January to March). The reasons for this ‘reversed’ trend are unknown.

An increase in the number of human isolates of Salmonella virchow phage type (PT) 26 in England and Wales during 1994 was investigated. A national case control study was conducted which included 88 cases and 182 controls. The cases were mostly young adults (median age 26) and 13 (15%) were admitted to hospital. Acquisition of S. virchow PT 26 was associated with the consumption of any chicken (OR 2·5, CI 1·1–5·8), of chicken curry from restaurants and take aways (OR 2·9, CI 1·4–6·1), and of some other diverse types of pre-prepared chicken (OR 3·8, CI 1·9–7·6). Halal chicken was associated (P = 0·006) with illness in a subset. There were negative associations with contact with animals (OR 0·47, CI 0·23–0·95) and with the consumption of chicken cooked whole (OR 0·37, CI 0·21–0·66). The increase in S. virchow PT 26 may be due to changing epizoology and may be an indicator of what will become the dominant salmonella strain in poultry in future years. The increasing incidence of S. virchow PT 26 is of particular concern because of its association with more invasive disease in humans.

Geographically widespread outbreaks involving commonly isolated organisms and where the vehicles of infection are commonly eaten foodstuffs pose particular difficulties at a technical and organizational level.

An outbreak of Salmonella typhimurium infection, affecting 39 people, spread over a wide area in North West England and North Wales in April and May 1991, was detected thanks to the practice of sending specimens to the national reference laboratory where phage typing and characterizing of antibiotic resistance patterns enabled the identification of a cluster of distinctive isolates (S. typhimurium DT193 resistant to sulphonamides, trimethoprim and furazolidone). An investigation, involving twenty environmental health departments in addition to health authorities and the Public Health Laboratory Service, showed an association between the illness and eating loose sliced cooked ham (P = 0.004). Detailed tracing of the chain of supply of the ham showed this to be particularly cooked ham originating from a single small local producer (P = 0.00003). Further investigation of that producer revealed that a batch of ham distributed on one day in early April was undercooked due to a malfunction in cooking equipment.

Tuberculous meningitis (TBM) is a severe complication of tuberculosis and occurs mainly during early childhood. The incidence rate of TBM varies with season, and serum vitamin D levels, which are dependent on sunlight, might play a role. We studied the association between TBM incidence rate and hours of sunshine in Cape Town, South Africa and found a significant association between the incidence rate of TBM and hours of sunshine 3 months earlier (incidence rate ratio per 100 sunshine hours 0·69, 95% confidence interval 0·54–0·88, P = 0·002). The association supports the hypothesis that vitamin D might play a role in the pathophysiology of TBM. Further prospective studies in which vitamin D status is measured are necessary to determine causality.

Cytomegalovirus (CMV) seroprevalence was determined in 9343 first-time New Zealand blood donors between 2003 and 2006. Of 39 960 current seropositive donors the proportion testing seropositive more than 12 months previously was calculated. Overall, seroprevalence declined from 66·1% [95% confidence interval (CI) 64·1–68·1] in 2003 to 60·6% (95% CI 58·5–62·6) in 2006. Nevertheless, these rates are significantly higher than the 47% overall seroprevalence found in a 1988 study. Seroprevalence was higher in females than males and in older than in younger age groups in all four years examined. Ethnicity appeared to be related to seroprevalence with the highest rates found in Pacific Islanders (93·2%) and the lowest in Caucasians (54·8%). At least 38 242/39 960 (95·7%) seropositive donors were found to have seroconverted more than 12 months previously. Recent evidence suggests that such ‘remote’ seroconverters may pose a much lower risk of transfusion-transmitted CMV infection than recently infected seroconverting, but seronegative, blood donors.

The method of path analysis is described in detail. Application of this analytical technique in the interpretation of causal relationships in complex biological systems is demonstrated using data from an epidemiological study of echinococcosis in New Zealand. The results identified the major causal pathways determining Echinococcus granulosus prevalence in dogs, based on multiple regression analysis of a linear causal model constructed from prior biological and epidemiological knowledge. Only ethnic and sheep husbandry variables had important direct effects on prevalence in the North Island of New Zealand, with some climatic factors (maximum temperature and relative humidity) and soil porosity acting indirectly through animal husbandry practices. It is suggested that path analysis, by permitting interaction between epidemiological theory and statistical analysis, provides a valuable additional tool to epidemiologists for the study of causal relationships among variables in multivariate systems.

A total of 259 clinical isolates of nonrepetitive non-typhi salmonellae (NTS) were examined for antibiotic resistance patterns and plasmid content. The antibiotics used were amoxicillin-clavulanic acid (AMC), ampicillin (AM), aztreonam (ATM), carbenicillin (CB), cefixime (CFM), cefotaxime (CTX), cefoxitin (FOX), ceftazidime (CAZ), ceftriaxone (CRO), chloramphenicol (C), ciprofloxacin (CIP), gentamicin (GM), imipenem (IPM), ofloxacin (OFX), tetracycline (TE), trimethoprim-sulfomethoxazole (SXT). Multi-drug resistant (MDR) strains comprised 19·3% of the total isolates (50/259) and almost all were S. typhimurium (49/50). Fifteen different patterns of resistance was observed, AM/CB/C/AMC/TE and AM/CB/C/AMC/SXT/GM/CTX/CRO/CAZ/CFM/ATM being the most frequent patterns. Twenty-eight out of 50 multiresistant isolates were found to contain at least one plasmid (mean five) and the size of the plasmids ranged between 1·7 and 158 kb. Plasmid profiles of multi-resistant NTS strains were heterogenous as 21 different profiles were detected in a total of 28 plasmid-bearing isolates. No direct correlation was established between antibiotic resistance patterns and plasmid profiles.

A survey conducted in 1980, 9 years after the banning of the use of tetracyclines as feed additives in the U.K., indicated that table chickens and pigs were still a large reservoir of tetracycline-resistant Escherichia coli; the incidence of transferable tetracycline resistance was greater in chicken E. coli strains (68%) than in pig E. coli strains (20%). Large amounts of sulphonamide-resistant and of furazolidone-resistant E. coli were found in the faeces of chickens; E. coli resistant to both sulphonamides and streptomycin were common in the faeces of chickens and pigs. E. coli with transferable or mobilizable trimethoprim resistance were present in the faeces of most pigs and in the faeces of 10 % of chickens.

Vaccination remains a mainstay of companion animal population health. However, how vaccine use at a population level complies with existing guidelines is unknown. Here we use electronic health records to describe vaccination in dogs, cats and rabbits attending a large sentinel network of UK veterinary practices. In total, 77.9% (95% CI: 77.6–78.1) of animals had recorded vaccinations. The percentage of animals with recorded vaccinations was higher in dogs, neutered animals, in insured dogs and cats and in purebred dogs. Vaccination rates varied in different regions of Great Britain in all species. Dogs and cats belonging to owners living in less deprived areas of England and Scotland were more likely to be recorded as vaccinated. In the vaccinated population, cats received more core vaccines per year of life (0.86) than dogs (0.75), with feline leukaemia vaccines almost as frequent as core vaccines. In dogs, leptospira vaccines were more frequent than core vaccines. This descriptive study suggests a substantial proportion of animals are not benefiting from vaccine protection. For the first time, we identify potential factors associated with variations in recorded vaccination frequency, providing a critical baseline against which to monitor future changes in companion animal vaccination and evidence to inform future targeted health interventions.

1. A review has been made of literature on the ecology of different types of coliform bacteria. The main object of the review has been to consider whether there is evidence to support the view that Bact. aerogenes and the intermediate types live normally on plants or in the soil and not in the intestines of man and other animals.

2. There is ample evidence that Bact. coli is by far the most common type of coliform in normal human faeces. On the other hand, there is evidence that Bact. aerogenes or intermediate types are usually present in faeces, may sometimes be present in greater numbers than Bact. coli, and on rare occasions may be the only type present. Both quantitatively and qualitatively the coliform flora of the faeces of an individual person may vary from day to day. There is insufficient evidence on the numbers of Bact. aerogenes and intermediate types in faeces to justify any more definite statement, but limited data suggest that such types may be absent or may be present in numbers of the order of a million per gram.

3. When fresh faeces are stored there is first a multiplication of such bacteria as will grow on ordinary laboratory media, including the coliform types. The rate of multiplication, as with the flora of soil, water, and milk, increases with an increase in the incubation temperature to 37° C, but the period of multiplication becomes shorter. In the literature consulted no evidence can be found to show which groups are prominent in the multiplication. Results are in agreement that on further storage the ratio of the numbers of Bact. coli to those of Bact. aerogenes and intermediates decreases, the typical Bact. coli flora dying off more rapidly than other conform types. The rapidity of decrease appears to depend partially at least upon the temperature of the environment, and the decrease may be accelerated by intense sunlight.

4. In urine from patients suffering from genito-urinary infections the dominant types of coliform are usually either Bact. aerogenes or intermediates. No data on the number of such organisms in urine have been obtained from the works consulted.

5. There is no-evidence that coliform bacteria multiply on fresh grasses or grains. Few quantitative data on this question have been found. In some of the older work it is doubtful whether a large proportion of the cultures isolated were actually coliform bacteria or whether they were species of other genera capable of fermenting lactose at 30° C. but not at 37° C. In the decomposition of grasses and legumes during ensilage, a process involving a considerable increase in temperature, it would appear that multiplication of conform bacteria may take place and counts may for a time equal those found in fresh faeces. No indication has been found that this multiplication is confined to Bact. aerogenes or intermediates.

6. Most workers who have studied the coliform bacteria in soil have ignored the quantitative aspects and no counts at intervals over long periods of coliform bacteria in any undisturbed soil appear to have been made. No evidence of any multiplication of coliform bacteria in soil has been found. Results, however, are in agreement that where pollution of the soil by animal excreta has taken place, the heavier the pollution the greater is the number of coliform bacteria; soils relatively free from human or other animal pollution either contain no coliform bacteria or only small numbers. It is generally agreed that the ratio of the numbers of Bact. coli to those of Bact. aerogenes and intermediates decreases with the increase of time which has elapsed since pollution of the soil. This change is similar to that which occurs in faeces during storage.

7. There is insufficient evidence to justify the definite statement often made that Bact. aerogenes and intermediates are normal inhabitants of soils, grasses, and grains.

Norovirus is the leading cause of acute gastroenteritis in the USA. Although secondary household transmission of norovirus is frequently reported in outbreaks, little is known about specific risk factors for susceptibility and infectiousness in the household. Three norovirus outbreaks were investigated and data were collected on individuals exposed in the primary outbreak setting and their household members. Potential individual- and household-level risk factors for susceptibility and infectiousness were assessed using univariate and multivariate generalised linear mixed models. In the univariate models, the secondary attack rate (SAR) was significantly higher when living in a household with two or more primary cases (incidence rate ratio (IRR) = 2·1; 95% confidence interval (CI) 1·37–3·29), more than one primary case with vomiting (IRR = 1·9; CI 1·11–3·37), and at least one primary case with diarrhoea (IRR = 3·0; CI 1·46–6·01). After controlling for other risk factors in the multivariate models, the SAR was significantly higher among those living in a household with two or more primary cases (adjusted IRR = 2·0; CI 1·17–3·47) and at least one primary case with diarrhoea (adjusted IRR = 2·8; CI 1·35–5·93). These findings underscore the importance of maintaining proper hygiene and isolating ill household members to prevent norovirus transmission in the household.

Enzyme immunoassays (EIA) for IgG and IgM antibodies against influenza A and B virus are described. One hundred and seven subjects with a clinical diagnosis of acute respiratory infection (influenza, bronchitis or pneumonia) were selected for this study during two epidemics of influenza A which occurred in Finland in 1983 and 1985. Paired sera and nasopharyngeal secretions were obtained from all subjects. The sera were tested for influenza A and B antibodies by IgG and IgM EIAs and by complement fixation tests. The nasopharyngeal secretions were tested by an indirect EIA for influenza A and B antigens.

The IgG EIA was found to be better than complement fixation for the diagnosis of influenza A infections: only 22% of the significant increases detected by this test were also positive by complement fixation. The additional contribution of the IgM EIA to the number of positives was minimal.

It was also found that testing a single 1/1000 dilution of serum for influenza A and 1/100 dilution for influenza B in the IgG EIA gave as many positives as the conventional method of testing several dilutions.