1. A double enteric infection is defined as the simultaneous infection of an individual or group of individuals with two organisms of the enteric group. The literature of the previously recorded cases and epidemics, in which the diagnosis of double enteric infection has been established by cultural methods, is reviewed.

2. An account is given of a double enteric outbreak of seventy–six cases which occurred amongst British troops and police at Acre, Palestine, in 1948. The infection is thought to have been due to contamination of the water supply with sewage during the civil disturbances. The diagnosis was established bacteriologi–cally in seventy-four cases (93.3%);Salm. typhi was isolated in forty–three cases, Salm. paratyphi B in three, and both Salm. typhi and Salm. paratyphi B from twenty–eight cases. There were three fatal cases in the epidemic (mortality rate = 3·94%).

3. The morbidity rate from enteric fever among the infantry unit was 60%, and among the Palestine police, 17%. The possible reasons for this difference is discussed, and the conclusion drawn that it was probably due to the Palestine policemen being older men, with longer overseas service and more 'seasoned' to life in subtropical conditions.

4. Thirteen cases were treated with polymyxin B (15 mg. 4-hourly for 4-day periods); with this small dose no beneficial therapeutic effects were observed, and ten cases showed evidence of renal damage while under treatment.

5. The bacteriology, epidemiology and clinical aspects of double enteric infections are discussed. The diagnosis of a double enteric infection may be established with the greatest certainty by blood culture. Such infections are usually water-borne or milk-borne, and tend to occur when there has been a severe breach of hygiene, e.g. in the contamination of a water supply by sewage. The claim that the prognosis in instances of double enteric infection is worse than with single infections is not supported by the experiences at Acre where the three fatal cases occurred in cases infected with Salm. typhi alone.

The Charlson comorbidity index (CCI) is widely used for control of confounding from comorbidities in epidemiological studies. International Classification of Diseases (ICD)-coded diagnoses from administrative hospital databases is potentially an efficient way of deriving CCI. However, no studies have evaluated its validity in infectious disease research. We aim to compare CCI derived from administrative data and medical record review in predicting mortality in patients with infections. We conducted a cross-sectional study on 199 inpatients. Correlation analyses were used to compare comorbidity scores from ICD-coded administrative databases and medical record review. Multivariable regression models were constructed and compared for discriminatory power for 30-day in-hospital mortality. Overall agreement was fair [weighted kappa 0·33, 95% confidence interval (CI) 0·23–0·43]. Kappa coefficient ranged from 0·17 (95% CI 0·01–0·36) for myocardial infarction to 0·85 (95% CI 0·59–1·00) for connective tissue disease. Administrative data-derived CCI was predictive of CCI ⩾5 from medical record review, controlling for age, gender, resident status, ward class, clinical speciality, illness severity, and infection source (C = 0·773). Using the multivariable model comprising age, gender, resident status, ward class, clinical speciality, illness severity, and infection source to predict 30-day in-hospital mortality, administrative data-derived CCI (C = 0·729) provided a similar C statistic as medical record review (C = 0·717, P = 0·8548). In conclusion, administrative data-derived CCI can be used for assessing comorbidities and confounding control in infectious disease research.

Epidemiological research on respiratory syncytial virus (RSV) infections in children was carried out at the Virology Laboratory, University Teaching Hospital (UTH), in Lusaka, Zambia, from January–December 1996. Specimens including 736 nasal washings and 2424 throat swabs were collected from children with acute respiratory infections (ARI) and tested for RSV by enzyme immunoassay and by virus isolation. RSV was isolated in 62 (4·1%) of 1496 throat swabs collected from March to September and was detected in 99 (16·3%) of 609 nasal washings from March to November. The average RSV isolation rate was 2·6% and the average RSV detection rate was 13·5%. The highest RSV isolation (8·1%) and detection (30·5%) rates were in June 1996. RSV antibody in the 278 serum specimens collected from Zambian children, who were hospitalized in the paediatric ward, UTH, was detected using a standard neutralization test. The antibody positive rate was 60–80% in children >4 years. It is evident that RSV is one of the main causal agents of ARI in children in Zambia.

Noroviruses are a major cause of gastroenteritis. Vaccine strategies against norovirus are currently under consideration but depend on a detailed knowledge of the capsid genotypes. This study examined the incidence of norovirus outbreaks in residential aged-care facilities in Victoria, Australia over one year (2013) and documented the (capsid) norovirus genotypes associated with these outbreaks. It was found that 65·0% of 206 outbreaks tested were associated with norovirus infection, thereby showing norovirus to be the major cause of viral gastroenteritis in residential aged-care facilities. Fifteen capsid (open reading frame 2) genotypes were identified as follows: GI.2 (0·9%), GI.3 (1·8%), GI.4 (3·7%), GI.6 (0·9%), GI.7 (0·9%), GI.8 (0·9%), GII.1 (0·9%), GII.2 (0·9%), GII.3 (1·8%), GII.4 (2009-like) (0·9%), GII.4 (2012) (48·6%), GII.4 (2012-like) (16·5%), GII.4 (unknown) (9·2%), GII.5 (2·8%), GII.6 (0·9%), GII.7 (0·9%), GII.13 (6·4%) and an as yet unclassified GII genotype (0·9%). Although GII.4 was the most common norovirus capsid genotype detected, the great diversity of norovirus genotypes in the elderly indicates vaccination strategies for this demographic are not straightforward.

The results of an investigation into the incidence of canicola fever amongst owners of dogs infected with L. canicola is described.

Visits were made to forty-six households in which infected dogs lived. Altogether 137 household contacts were examined and blood samples from 99 or 72·3 % were tested for agglutination against L. canicola. All the sera proved negative.

A detailed classification of the kinds and conditions of housing and of householders is given.

Some of the difficulties in explaining the relationship between the disease in dogs and man are discussed; the results of the present survey and the experience with some reported cases of human canicola fever show that there is great variation in the risk of infection to owners and others hving in the same house with diseased dogs.

Some other source of infection common to man and dog is possible.

It is recommended that in the light of present knowledge greater attention should be paid to the preventive aspect and that more propaganda should be directed to make dog owners aware of the possibilities of infection and of the importance of observing hygienic principles when handling dogs and particularly when dealing with dejecta.

Thirty-six strains of haemorrhagic fever with renal syndrome (HFRS) virus were isolated from patients and a number of host animals in various areas in China. They were analysed by an immunofluorescence test (IFAT) using 10 monoclonal antibodies (McAbs) specific for the HFRS virus; antigenic differences among the strains have been demonstrated. The HFRS virus strainsrevealed nine different reactions with the McAbs, showing that there are at least nine different antigenic determinants including group-, type- and strain-specific. Analysis of the results shows that antigenic differences among the HFRS virus strains are mainly related to differences in the host animals.

That the human race is extremely susceptible to the ravages of measles is well known, Brownlee not being guilty of much exaggeration when he states that, in the presence of infection, the only way to avoid this disease is to have had it. MacNalty (1918) states in his report on the subject to the Local Government Board that “the disease is so universal in this country that few children escape it,” this being particularly true in reference to the poorer urban classes. Butler (1913) found as a result of the study of the statistics for the public elementary schools of Willesden that among persons who had attained the age of 15 and upwards, only 2·7 per cent. had escaped measles. Zingher states that amongst children who have not previously suffered from the disease, and who are exposed to it, between 96 and 98 per cent. will develop it.

HIV-infected individuals with high levels of IgG antibodies against human herpesvirus-8 (HHV-8) are at increased risk of developing Kaposi's sarcoma. The aim of this study was to measure the association between HHV-8 viraemia and IgG antibody responses (by immunofluorescence) in a group of 201 HIV-infected individuals attending outpatient clinics, 91 in-patients with AIDS and 87 HIV-infected patients admitted with Kaposi's sarcoma. Compared to HIV-infected outpatients, the adjusted odds ratio in relation to Kaposi's sarcoma was 15·4 (95% CI 4·4–54·2) in those with viraemia, 25·1 (95% CI 6·6–95·6) in those with a positive immunofluorescent signal and ∞ (lower exact CI 33·6) in those with a high immunofluorescent signal (all P trend <0·001). Among those without HHV-8 viraemia, 23% were IgG-positive, but only 5·5% had a high immunofluorescent signal. In those who were viraemic, 89·1% were IgG-positive, and 28·2% had a high immunofluorescent signal, suggesting viraemia is associated with high HHV-8 immunofluorescence IgG signal.

1. The development in typhus fever blood of agglutinins for a bacillus of the colon-paratyphoid group, which was isolated in 1921 from the faeces of a typhus case is shown to be a frequent occurrence in the disease as met with in Ireland, Poland and Syria. The bacillus has preserved its agglutina-bility up to the time of writing—a period of five years. Owing to its similarity to a bacillus previously isolated by the writer and which was designated bacillus “U,” this bacillus has been named B. agglutinabilis “U2.”

2. It has been shown that bacteria preserved in alcohol even for 3 years are sensitive for use in the serological test, and that sera to which equal volumes of pure glycerine have been added retain their agglutinins for atleast 5 years.

3. Five strains of B. proteus “X 19” fermented salicin with the production of acid and gas. Ordinary Proteus strains had no action on this glucoside and neither had the anindologenes strain “Kingsbury” although belonging to the “X 19” group.

4. Strains of B. proteus “X 19” show great differences in their sensitiveness to typhus fever agglutinins.

5. Views which have been advanced to explain the Weil-Felix reaction are discussed and the conclusion is reached that to label it as an instance of paragglutination does not account for the rise and fall of the agglutinins—agglutinins which are formed not only for B. proteus “X2” and “X 19” but for certain strains of the B. pyocyaneus and colon-paratyphoid-typhoid groups.

This paper deals with a micro-organism recovered from human blood in a case of a typhoid-like infection. No evidence could be produced of either typhoid or paratyphoid bacilli being the cause. Only one germ was recovered from blood cultures on two occasions, it was strongly agglutinated by the patient's serum, suggesting that it probably produced a true infection in man. This study was undertaken because certain features of the organism may lead to a faulty diagnosis of paratyphoid. The author deems it a new species in the light of the tests he applied and refers it to the genus Proteus Hauser (emend. Amer. Comm.) under the name Pr. pseudovaleriae.

Trimethoprim resistance was examined in faecal bacteria obtained from chickens, sheep, cattle and pigs. The incidence of trimethoprim resistance in porcine strains was 17% (157/922) and, whereas 15·8% (146/922) of these bacteria were highly resistant, only 4% (37/922) of the isolates possessed trimethoprim resistance plasmids. Highly resistant porcine strains were obtained from 44% of the pig farms (41/93) but transferable trimethoprim resistance was found in isolates from 11% (10/93) of the farms. There was an association between the carriage of trimethoprim resistance plasmids and certain farms. Most of the resistance plasmids were not identical with those found in human clinical bacteria but one porcine plasmid was the same as the most ubiquitous trimethoprim resistance plasmid in Edinburgh.

1. If a mouse-population, which has been exposed to the risk of infection, be dispersed into several small groups during the pre-epidemic stage, the total mortality will be far less than if the animals be retained as a single large group. The specific mortality will be reduced to a still greater extent.

2. During the period of dispersal, the mice forming the small groups will, in most cases, have passed through an extended pre-epidemic phase of the spread of infection. In so doing they will have acquired an appreciable degree of immunity.

3. If the small groups be later re-combined into a single aggregate, further deaths will occur; but the total mortality among a group of mice, which has been dispersed and then re-accumulated, will always be less than among a similar group, which has been retained from the commencement as a single unit of population. The specific mortality will generally show a still greater reduction.

It remains for me again to express my thanks to my colleagues, Dr H. B. Weir and Dr G. S. Wilson, for their assistance in this investigation.

We studied the spatial trend of norovirus (NoV) epidemics using sentinel gastroenteritis surveillance data for patients aged <15 years (n = 140) in the Tokyo area for the 2006–2007 to 2008–2009 seasons utilizing the kriging method of geographical information system (GIS). This is the first study of the spreading pattern of NoV epidemics using sentinel surveillance data. Correlations of sentinel cases between the seasons and with demographic data were examined to identify the trend and related factors. A similar pattern of diffusion was observed over the seasons, and its mean correlation between seasons was significantly high. A higher number of cases were found in the peripheral area, which surrounds the most populated central area, and showed a correlation with the ratio of the children population (r = 0·321, P < 0·01) and the ratio of residents in larger families (r = 0·263, P < 0·01). While NoV susceptibility remained, the results suggest a transmission route in the local community as a possible epidemic factor. Prevention with focus on the peripheral area is desirable.

Measles is a notifiable disease, but not everyone infected seeks care, nor is every consultation reported. We estimated the completeness of reporting during a measles outbreak in The Netherlands in 2013–2014. Children below 15 years of age in a low vaccination coverage community (n = 3422) received a questionnaire to identify measles cases. Cases found in the survey were matched with the register of notifiable diseases to estimate the completeness of reporting. Second, completeness of reporting was assessed by comparing the number of susceptible individuals prior to the outbreak with the number of reported cases in the surveyed community and on a national level.

We found 307 (15%) self-identified measles cases among 2077 returned questionnaires (61%), of which 27 could be matched to a case reported to the national register; completeness of reporting was 8.8%. Based on the number of susceptible individuals and number of reported cases in the surveyed community and on national level, the completeness of reporting was estimated to be 9.1% and 8.6%, respectively. Estimating the completeness of reporting gave almost identical estimates, which lends support to the credibility and validity of both approaches. The size of the 2013–2014 outbreak approximated 31 400 measles infections.

The survey of Vibrio cholerae O1 in marine area was carried out in the Port of Osaka, Japan in 1987–2001, and 51 V. cholerae O1 strains were isolated. All strains were identified to be of El Tor biotype, Ogawa serotype and classic Ubon Kappa-phage type, and were cholera toxin (CT)-negative and CT gene-negative. In order to clarify certain ecological aspects of V. cholerae O1 in the marine environment of the temperate zone, we performed molecular analysis of the isolated strains using pulsed-field gel electrophoresis (PFGE) with NotI and SfiI restriction enzymes. We found the indistinguishable strains by DNA analysis using PFGE with strains passed for 1 year, and also found the closely related strains with that passed for 3 and 12 years. Those results indicated that V. cholerae O1 can survive over one winter at least, and that it survives in marine water for a long time by undergoing continuous mutation.

The seasonality of canine births was investigated using records from the Kennel Club and the breeding centre for the Guide Dogs for the Blind Association. In these populations a distinct seasonal pattern was found with a greater number of puppies being born in the summer months than the winter. The hypothesis that the greater number of puppies acquired as pets during the summer months may Contribute to the seasonal rise in human campylobacter cases, seen at this time, is discussed.

The technique of radial haemolysis (SRH) was used to assess the response to infection with different strains of influenza B virus, to determine the persistence of antibody following such infection and to examine sera from boys entering school at age 11 years. The technique detected 95 % of infections and in primary infection the antibody response was mainly to the infecting strain. Re-infections resulted in a broad response, both to the homotypic strain and to strains more distantly related. Antibody to the homotypic strain persisted for at least 3 years but in some individuals the reaction with heterotypic strains tended to become weaker – resulting in zones of incomplete lysis – or was lost. Examination of the sera collected on entry to the school showed that about 60 % of the boys bled before B/Hong Kong became widespread in the United Kingdom had antibody to strains representative of those isolated in the 1960s and few boys had antibody to B/Hong Kong. After 1974 antibody to B/Hong Kong and later strains became more common while antibody to earlier strains was less frequently detected. The significance of the results as an estimate of past experience is discussed.

A pleomorphic, Gram-negative organism, apparently the cause of purulent meningitis, is described. Reasons for regarding it as a Neisseria are adduced.

Serological studies on cows recovered from natural cowpox indicated that Haemagglutinin-Inhibiting (HAI) antibody persisted for at least 27 weeks, and Virus Neutralizing (VN) antibody persisted for at least 98 weeks.