Between 1969 and 1984, 6564 non-typhoid salmonella strains were isolated at the Liverpool Public Health Laboratory of which 194 (3·0%) were from extraintestinal sites. Blood (34%) and urine (32%) isolates accounted for twothirds of these, with the remainder being recovered from pus and inflammatory tissue (23%), bone (5%), cerebrospinal fluid (5%) and sputum (3%). Certain serotypes tended to cause more invasive disease than others, i.e. Salmonella choleraesuis, S. dublin, S. london, S. virchow and S. panama: this association for S. london has not previously been described. The spectrum of disease caused by non-typhoid strains was broad. This survey confirms the importance of nontyphoid salmonellas as occasional causes of invasive disease and local sepsis outside the gastrointestinal tract.

Serological typing was used as an epidemiological tool in the investigation of 524 outbreakes of Clostridium perfringens food poisoning in the United Kingdom and 37 outbreaks in other countries.

Five thousand five hundred and fifty-four (77%) of 7245 strains of C. perfringens association 561 outbreaks were typable with the 75 Food Hygiene Laboratory antisera; in 354 (63%) of these outbreaks were typable with the 75 Food Hygiene Laboratory antisera; in 354 (63%) of these outbreaks a specific serotype was established as being responsible for the outbreak.

An assessment is made of the ability of two additional sets of antisera, prepared against 34 American and 34 Japanese strains of C. perfringens, to increase the number of strains which can be typed. The extent of cross-reaction between the three sets of antisera was determined and the results are discussed in relation to the source and history of the type strains.

The investigation recorded in the present paper was undertaken as a corollary to the clinical trials with a new antityphoid serum, the results of which were recently published (Felix, 1935). Its object was to enquire into:

(i) the occurrence of Vi antigen in strains of B. typhosus freshly isolated from cases of typhoid fever;

(ii) the occurrence of Vi antibody in the blood serum of typhoid patients and convalescents.

To date there has been no satisfactory explanation of the worldwide excess of tuberculosis (TB) notifications among adult males. We investigated the epidemiological basis for sex differences in TB notifications in high-burden countries using available group-level data. Multiple linear regression analysis was used to explore the ecological relationship between smoking and sex differences in TB notifications among high-burden countries. Cigarette consumption was a significant predictor of the sex ratio of TB notifications, and explained 33% of the variance in the sex ratio of TB notifications. Our findings suggest that smoking is an important modifiable factor which has a significant impact on the global epidemiology of TB, and emphasize the importance of tobacco control in countries with a high incidence of TB. This analysis provides support for the interpretation of sex differences in worldwide TB notification rates as indicative of true differences in the epidemiology of TB between males and females.

Between 1966 and 1991, melioidosis, a disease caused by Pseudomonas pseudomallei that is mostly confined to tropical regions, occurred in farm animals and a farmer in temperate south-west Western Australia. Using an Escherichia coli probe containing a ribosomal RNA operon, P. pseudomallei DNA from isolates from 8 animals, a soil sample and the human case showed an identical ribotype on Southern blotting. The ribotype was different from the 3 commonest ribotypes seen in tropical Australia. This molecular typing supports the theory of clonal introduction of P. pseudomallei into a non-endemic region, with environmental contamination, local dissemination and persistence over 25 years. As melioidosis is often fatal in humans, such persistence in a temperate region is cause for concern.

Mycobacteria from lymph node biopsies of patients with cervical lymphadenitis reporting for tuberculosis treatment in Matany and Moroto Hospitals in the transhumant areas of Karamoja, Uganda were isolated and characterized. The AccuProbe® culture identification kits for Mycobacterium tuberculosis complex (MTC), M. avium complex (MAC) and M. avium were used to identify the isolates. Spoligotyping, IS901 PCR and IS1311 and IS1245 restriction fragment length polymorphism (RFLP) were used to characterize the isolates. Of the 43 biopsies, ten M. avium, seven M. tuberculosis, three M. bovis, and two M. intracellulare were isolated. Two isolates could not be identified with AccuProbe® and from 19 samples no mycobacteria could be isolated. Three isolates with the Beijing spoligotype were identified from the seven M. tuberculosis isolates. The spoligopatterns of the M. bovis isolates had previously been detected in cattle in Uganda. Isolation of members of the MAC group reflects the complex interaction between the transhumant communities, water sources and their cattle. None of the M. avium isolates harboured IS901, and all showed several bands on IS1311 and IS1245 RFLP, in accordance with M. avium subsp. hominissuis. Composite dendrograms of IS1311 and IS1245 RFLP showed that the isolates were similar and identical patterns were found. The isolation of M. bovis confirms the human infection with zoonotic mycobacteria in areas where consumption of raw milk and meat is routine. Isolation of environmental mycobacteria also confirms their increasing role in human disease and the occupational risk of infection in the transhumant ecosystem in the absence of safe drinking water and environmental contamination.

Investigations using a liquid-phase blocking sandwich enzyme-linked immunosorbent assay (ELISA) for the measurement of antibodies against foot-and-mouth disease virus (FMDV) in sera from sheep and from cattle are reported, and results compared with those obtained by virus neutralization (VN) tests.

Serum antibody titres in sheep after primary vaccination and in cattle challenged with a natural aerosol after vaccination were similar by ELISA and VN. However, the antibody levels detected in sera of cattle during early infection and of vaccinated cattle after intradermolingual challenge were clearly greater by ELISA than by VN.

The ELISA titres in cattle sera following synthetic peptide vaccination indicated some relationship to protection and were clearly different from those recorded by VN. On the other hand, the antibody levels following conventional vaccination showed that ELISA and VN titres in cattle sera were related to protection. Although there was a good agreement between the ELISA antibody titre and protection for the four vaccines used, by VN the titre which afforded protection varied depending on the vaccine used.

The ELISA was considered therefore to be more reliable than the VN and may prove useful for evaluating the immunological response of animals following infection and following vaccination.

The type strains of Bact. coli, described by Bray (1945), Giles & Sangster (1948), Giles et al. (1949), Taylor et al. (1949), Smith (1949) and Rogers (1951b), because of their very intimate association with epidemic infantile gastro-enteritis, have been used as indicator organisms to show that the method of cross-infection of epidemic gastro-enteritis is very like that of the cross-infection of burns.

It has been shown how a cubicle becomes widely contaminated within 18 hr. and that type strains of Bact. coli will remain viable in dust for at least 27 days. Communal articles used throughout a ward are blamed for the inter-cubicle spread in a divided ward.

The intimate association of the α- and β-types of Bact. coli with outbreaks of gastro-enteritis is demonstrated, and figures are given to show how these outbreaks prolong the patient's stay in hospital and waste valuable hospital space.

Between 1992 and 1999, 93 cases of blastomycosis, including 25 laboratory confirmed cases, were identified in Missouri (annual incidence, 0·2/100000 population). Mississippi County in southeastern Missouri had the highest incidence (12/100000) with a much higher rate among blacks than whites in this county (43·2/100000). The mortality rate, 44% was also higher among blacks. To determine risk factors for endemic blastomycosis, a case-control study was conducted among southeastern Missouri residents. Independent risk factors for blastomycosis were black race and a prior history of pneumonia. No environmental exposures or socioeconomic factors were significantly associated with increased risk. The increased risk among blacks may possibly be related to genetic factors, but further studies are needed to clarify this. However, heightened awareness of the disease and a better understanding of the risk factors are important and may lead to earlier diagnosis and start of treatment, possibly improving outcome.

Mice were immunized by three intraperitoneal and one intravenous injection of rubella haemagglutinin. Splenocytes from these mice were fused with the cells of a syngeneic myeloma cell line, and following culture for various periods of time, single-cell clones were derived by the technique of limiting dilution.

A total of 139 clones were derived from 13 parent hybrid cultures. To date, four of these cloned cultures have been propagated as ascitic tumours in mice. The preparation of IgG from ascitic fluid and labelling of this antibody with 125I is described. Results indicate that the use of labelled monoclonal antibodies as indicator reagents in solid-phase IgM antibody capture assays for the detection of rubella-specific IgM results in enhanced performance of these tests.

1. The specific mortality rates for males, females and the total population for England and Wales, for Scotland and for Sweden, have been fitted to a formula ƒ (t, θ) = α. (t—θ) βθ where ƒ (t, θ) is the specific mortality rate at a time t for age θ, β0 is a function depending solely on the age θ, and α (t —θ)depends only on the time of birth (t — θ). The results are in substantial agreement with those obtained by less refined methods in the previous paper. The probable errors of the values found for à and for β have been calculated.

2. It is shown that the β0 curves for the Scottish and the English males are approximately represented by the Makeham-Gompertz formula A+Becθ, where A, B and c have suitable values. The other β0 curves do not appear to conform exactly to a formula of this type.

3. With the help of the representation of β0 by the Makeham-Gompertz expression the effect of variation of α on the survival curves, the death curves, and the expectation of life has been determined. It is shown that with the range of values of α experienced in Britain during the last 50 years, the most marked effect is most likely to be experienced in the future between the ages of 65 and 85, a very considerable increase of people of these ages being likely provided that the relationship exhibited by the statistics up to the present date is maintained in the future.

Though the Makeham-Gompertz formula does not hold in the case of the English and Scottish females, nor for the Swedish statistics, these approximate sufficiently closely to the values for the English and Scottish males, to allow of the conclusion deduced in the latter case being extended to the former.

4. It is strongly emphasised that the validity of all the predictions depends upon a hypothesis of extrapolation which, however attractive in the light of the figures so far available, might not be fulfilled under certain contingencies.

Outbreaks of enteric illness in long-term care facilities (LTCFs) were reviewed to identify preventative recommendations. Systematic review methodology identified outbreak reports of gastrointestinal illness in LTCFs either published or that occurred from January 1997 to June 2007. The inclusion criteria captured 75 outbreaks; 23 (31%) associated with bacterial agents and 52 (69%) with viral agents. Transmission was mainly foodborne (52%) for those of bacterial origin and person-to-person (71%) for viral outbreaks. Norovirus infection was associated with 58% of hospitalizations. Sixty deaths were reported, about half from Salmonella infections. Recommendations for foodborne outbreaks emphasized appropriate sourcing and preparation of eggs, staff training, and temperature control during food preparation. Recommendations from outbreaks transmitted person-to-person centred on controlling residents' movements, effective environmental cleaning and disinfection, cancelling social events and restricting visitors, excluding ill staff, encouraging effective hand hygiene, and preventing cross-contamination through gloving and gowning. In none of the 75 published outbreak reports were the suggested recommendations evaluated for effectiveness in controlling the outbreak. Applied research of this type could greatly help in the acceptance of prevention and control strategies.

Aichi virus has been proposed as a novel causative agent of acute gastroenteritis. In addition to several Asian countries, South America and Africa, Aichi virus has also recently been found in Europe. Our objective was to study the causative role of Aichi virus in children with acute gastroenteritis in Finland. We analysed 595 stool specimens from infants in an efficacy trial of rotavirus vaccine and 468 stool specimens from children in a hospital-based epidemiological and aetiological study of acute gastroenteritis. The screening was done by nested reverse transcription–polymerase chain reaction amplifying a 519-bp segment and a 223-bp segment in the 3CD junction region of non-structural proteins. Aichi virus was detected in five stool samples (0·5%), of which four were co-infections with other gastroenteritis viruses. Two Aichi virus genotypes, A and B, were found. Aichi virus appears to be rare in children with acute gastroenteritis in Finland.

Streptococcus pyogenes (or Group A Streptococcus, GAS) is a Gram-positive human pathogen responsible for a diverse array of superficial, invasive and immune-related diseases. GAS infections have historically been diseases of poverty and overcrowding, and remain a significant problem in the developing world and in disadvantaged populations within developed countries. With improved living conditions and access to antibiotics, the rates of GAS diseases in developed societies have gradually declined during the 20th century. However, genetic changes in circulating GAS strains and/or changes in host susceptibility to infection can lead to dramatic increases in the rates of specific diseases. No situations exemplify this more than the global upsurge of invasive GAS disease that originated in the 1980s and the regional increases in scarlet fever in north-east Asia and the UK. In each case, increased disease rates have been associated with the emergence of new GAS strains with increased disease-causing capability. Global surveillance for new GAS strains with increased virulence is important and determining why certain populations suddenly become susceptible to circulating strains remains a research priority. Here, we overview the changing epidemiology of GAS infections and the genetic alterations that accompany the emergence of GAS strains with increased capacity to cause disease.

Acute respiratory infections (ARI) are the leading cause of death worldwide in children aged <5 years, and understanding contributing factors to their seasonality is important for targeting and implementing prevention strategies. In tropical climates, ARI typically peak during the pre-rainy and rainy seasons. One hypothesis is that rainfall leads to more time spent indoors, thus increasing exposure to other people and in turn increasing the risk of ARI. A case-crossover study design in 718 Bangladeshi children aged <5 years was used to evaluate this hypothesis. During a 3-month period with variable rainfall, rainfall was associated with ARI [odds ratio (OR) 2·97, 95% confidence interval (CI) 1·87–4·70]; some evidence of an increased strength of association as household crowding increased was found (⩾3 people/room, OR 3·31, 95% CI 2·03–5·38), but there was a lack of association in some of the most crowded households (⩾5 to <6 people/room, OR 1·55, 95% CI 0·54–4·47). These findings suggest that rainfall may be increasing exposure to crowded conditions, thus leading to an increased risk of ARI, but that additional factors not captured by this analysis may also play a role.

Campylobacter are zoonotic pathogens commonly associated with gastroenteritis. To assess the relevance of Campylobacter in Vietnam, an economically transitioning country in SE Asia, we conducted a survey of 343 pig and poultry farms in the Mekong delta, a region characterized by mixed species farming with limited biosecurity. The animal-level prevalence of Campylobacter was 31·9%, 23·9% and 53·7% for chickens, ducks and pigs, respectively. C. jejuni was predominant in all three host species, with the highest prevalence in pigs in high-density production areas. Campylobacter isolates demonstrated high levels of antimicrobial resistance (21% and 100% resistance against ciprofloxacin and erythromycin, respectively). Multilocus sequence type genotyping showed a high level of genetic diversity within C. jejuni, and predicted C. coli inter-species transmission. We suggest that on-going intensification of animal production systems, limited biosecurity, and increased urbanization in Vietnam is likely to result in Campylobacter becoming an increasingly significant cause of human diarrhoeal infections in coming years.

A stratified and randomly-selected population sample was identified in 1990 in order to study the seroprevalence of nephropathia epidemica (haemorrhagic fever with renal syndrome) in Northern Sweden. Sera from 1538 subjects (750 men, 788 women), 25—64 years of age, were analysed for the presence of Puumala virus (PUV) specific-IgG by the indirect immunofluorescence antibody test. Specific IgG was detected in sera from 83 subjects (5·4%). Men and women had similar seroprevalence rates. The highest seroprevalences were found in subjects 55 years or older (8·0%) and among farmers and forestry workers (15·9%). The geographic distribution of seropositive individuals was uneven and there were significantly more seropositive persons in rural than in urban areas (P < 0·05).

In a setting where potable water is contaminated with Legionella pneumophila serogroup 1, we performed two case control studies. The first case control study consisted of 17 cases of nosocomial Legionnaires' disease (LD) and 33 control (the patients who were admitted to the ward where the case was admitted immediately before and after the case) subjects. Cases had a higher mortality rate 65% vs 12% (P < 0.004); were more likely to have received assisted ventilation (P < 0.00001); to have nasogastric tubes (P < 0.0004) and to be receiving corticosteroids or other immunosuppressive therapy (P < 0.0001). Based on the results of this study, sterile water was used to flush nasogastric tubes and to dilute nasogastric feeds. Only 3 cases of nosocomial LD occurred during the next year compared with 12 the previous year (P < 0.0001). Nine cases subsequently occurred and formed the basis for the second case-control study. Eighteen control subjects were those patients admitted to the same unit where the case developed LD, immediately before and after the case. The mortality rate for the cases was 89% vs 6% for controls (P < 0.00003). The only other significant difference was that cases were more likely to be receiving corticosteroids or other immunosuppressive therapy 89% vs 39% ( < 0.01). We hypothesized that microaspiration of contaminated potable water by immunocompromised patients was a risk factor for nosocomial Legionnaires' disease. From 17 March 1989 onwards such patients were given only sterile potable water. Only two cases of nosocomial LD occurred from June 1989 to September 1990 and both occurred on units where the sterile water policy was not in effect. We conclude that aspiration of contaminated potable water is a possible route for acquisition of nosocomial LD in our hospital and that provision of sterile potable water to high risk patients (those who are receiving corticosteroids or other immunosuppressive drugs; organ transplant recipients or hospitalized in an intensive care unit) should be mandatory.

A new scheme for phagetyping campylobacters has been evaluated using strains isolated from five outbreaks. The phagetyping results have been compared with the results of Penner serotyping, Lior serotyping and Preston biotyping. Phagetyping recognized the causative strains in all of the incidents and also differentiated these strains from animal and environmental strains isolated during these investigations. In some outbreaks phagetyping proved to be more discriminatory than serotyping or biotyping, e.g. strains of Penner serotype 2, and serogroup 4, 13, 16, 50 were subdivided by this method. Phagetyping is to be recommended for typing strains from outbreaks and although the results indicate that it may be used alone we advocate that it should be used in conjunction with one of the established typing methods.

The aim of this study was to investigate the burden of disease associated with gastroenteric viruses (rotavirus, norovirus, sapovirus, astrovirus and enteric adenovirus) using structured surveillance of children aged <6 years in the community. Faecal samples were collected between 2000 and 2003 from 685 children with symptoms of gastroenteritis. The children comprised three groups; 223 in the structured surveillance cohort, 203 in a community cohort and 259 in a cohort of hospitalized children. All samples were tested for the presence of viral pathogens using molecular methods. Questionnaires were sent to the parents/carers of the children recruited to the structured surveillance cohort in order to collect data that would allow an estimation of the severity of illness by means of the Vesikari score, and of the cost associated with gastrointestinal disease in this age group. A viral aetiological agent was detected in 53·5% of samples tested. Rotavirus was the most common pathogen found in all three cohorts followed by norovirus and enteric adenoviruses. Multiple viruses were found in 8% of the samples, and commonly involved rotavirus and any other virus. G1P[8] was the most commonly detected rotavirus strain and there was no significant difference in the distribution of rotavirus genotypes among the three cohorts. Analysis of the questionnaires indicated that rotavirus infections were likely to be more severe than any other virus infection, and children from whom a viral pathogen was identified were more likely to require rehydration therapy.