Of thirty-six babies delivered at home 72% acquired Staph. aureus in their noses and throats within their first fortnight of life. The carrier rate among the twenty-eight who were subsequently followed was 65% during the first fortnight period. Only 18% acquired penicillin-resistant strains, in contrast to the previously observed hospital-born group, 97% of whom acquired strains resistant to penicillin. Phage typing demonstrated that the home-born babies who acquired Staph. aureus during their first fortnight carried the same strains throughout the 15–25 week observation period. As in the hospital-born babies, many of them tended to lose the strains from the nose while retaining them in the throat. Strains having phage patterns of Groups I and II were most common among the home-delivered babies, whereas among the hospital-born babies Groups I, III, or untypable strains were most frequent. There was no evidence that the penicillin sensitive strains acquired from the home are carried for shorter periods than the penicillin-resistant strains of the hospital. Babies failing to acquire Staph. aureus within the first fortnight tended either to acquire it in the throat alone, or to remain non-carriers. It is suggested that babies who do not become carriers within the first two months of life are unlikely to do so later.

I owe thanks to many people: to the late Prof. Sir Alexander Fleming for generously extending the laboratory facilities of The Wright-Fleming Institute; to Prof. Robert Cruickshank for patient guidance and invaluable suggestions; to Dr R. E. O. Williams for providing materials and laboratory space for the phage typing, and to Dr Joan E. Rippon for instruction in the phage typing technique; to Dr Agnes H. W. Smythe for the co-operation of the Marylebone and Lisson Grove Child Welfare Centres, and to Mrs Eastham and Miss MacGilley who took the swabs there; to Dr W. Howard Hughes, Dr W. G. Booth, and Dr K. Hart for arranging co-operation of the Ealing Public Health Department; to the Ealing midwives who collected the swabs from the domiciliary-delivered babies; to members of the Wright-Fleming Institute technical staff.

Also, I am grateful to the following organizations for personal grants while conducting the study: The United States Educational Commission in the United Kingdom for a Fulbright Scholarship, 1951–53; The University of California for a grant from the Student Aid Fund; Sigma Delta Epsilon for a Fellowship Award.

The objective of this study was to assess the impact of a possible unmeasured confounding variable in a previously published association between the effects of household water supply and positive results for hepatitis A serology. This was estimated using a path of integration between two methods of sensitivity analysis, called Rosenbaum's method and Greenland's external adjustment. The association between household water supply and positive results for hepatitis A (outcome) serology was insensitive to confounding unless the odds ratio for the association between the confounder and the outcome was ⩾4. The integration of the two sensitivity analysis methods presented proved useful when assessing the effects of a potential unmeasured confounder.

A modified haemagglutination inhibition test for rubella antibodies, using standardized freeze-dried reagents, was developed and compared with haemagglutination inhibition tests using fresh erythrocytes. This comparison was made in collaboration with six European laboratories. A total of 4205 serum samples were tested. The results show that:

(1) Sensitivity and reliability of the modified test are good;

(2) the modified test can be performed in glass tubes as well as in polystyrene microtitration plates.

Since 2015, the number of hepatitis B virus (HBV) cases increased substantially in Germany. In 2015, a more sensitive HBV case definition was introduced. This coincided with an asylum seeker influx with differing screening strategies. Information on the asylum seeker status has been collected since 09/2015. We investigated this increase to interpret HBV notification data in Germany. We compared HBV surveillance data from 2010–2013 (baseline) with 2015–2016, excluding 2014 due to beginning of asylum seeker influx. We estimated the excess above the mean case number (baseline) using Poisson regression and compared asylum seeker cases and the excess of cases with the unknown asylum seeker status. HBV cases increased from 1855 (mean baseline) to 3873 (2015) and 3466 (2016) with 1903 asylum seeker cases and 1099 excess-cases with the unknown asylum seeker status in 2015–2016. Cases only fulfilling the changed case definition increased from 60% (1119) in baseline to 81% (P < 0.01) in 2015–2016; 69% of asylum seeker cases and 61% of excess-cases were males <40 years compared to 27% (baseline) (P < 0.01). Changed case definition increased the number of cases in official statistics substantially. Demographic and geographical distributions suggest that screening of asylum seekers increased the case numbers even to a higher extent than surveillance data indicates.

Although Malta is historically linked with the zoonosis brucellosis, there had not been a case of the disease in either the human or livestock population for several years. However, in July 2013 a case of human brucellosis was identified on the island. To determine whether this recent case originated in Malta, four isolates from this case were subjected to molecular analysis. Molecular profiles generated using multilocus sequence analysis and multilocus variable number tandem repeat for the recent human case isolates and 11 Brucella melitensis strains of known Maltese origin were compared with others held on in-house and global databases. While the 11 isolates of Maltese origin formed a distinct cluster, the recent human isolation was not associated with these strains but instead clustered with isolates originating from the Horn of Africa. These data was congruent with epidemiological trace-back showed that the individual had travelled to Malta from Eritrea. This work highlights the potential of using molecular typing data to aid in epidemiological trace-back of Brucella isolations and assist in monitoring of the effectiveness of brucellosis control schemes.

Matching individuals reported to a sentinel surveillance scheme for hepatitis C between 2000 and 2005 to individuals with a hospital episode for hepatitis C-related liver disease in the same hospitals, we estimated that the number of cases of hepatitis C-related end-stage liver disease in these English hospitals was 42% (597/419) higher than Hospital Episode Statistics (HES) would indicate. Further, matching records of hepatitis C-related deaths in HES to death certificates, we estimated that, between 2000 and 2005, the true number of deaths from hepatitis C-related end-stage liver disease was between 185% (353/124) and 257% (378/106) higher than the number recorded in routine mortality statistics. We provide estimates of under-recording that can be used to modify existing models of disease burden due to hepatitis C and provide a simple approach to improve the monitoring of trends in severe hepatitis C-related morbidity over time.

Masturbation is a common sexual practice in men, and saliva is often used as a lubricant during masturbation by men who have sex with men. However, the role of saliva use during masturbation in the transmission of chlamydia is still unclear. We developed population-level, susceptible-infected-susceptible compartmental models to explore the role of saliva use during masturbation on the transmission of chlamydia at multiple anatomical sites. In this study, we simulated both solo masturbation and mutual masturbation. Our baseline model did not include masturbation but included transmission routes (anal sex, oral-penile sex, rimming, kissing and sequential sexual practices) we have previously validated (model 1). We added masturbation to model 1 to develop the second model (model 2). We calibrated the model to five clinical datasets separately to assess the effects of masturbation on the prevalence of site-specific infection. The inclusion of masturbation (model 2) significantly worsened the ability of the models to replicate the prevalence of C. trachomatis. Using model 2 and the five data sets, we estimated that saliva use during masturbation was responsible for between 3.9% [95% confidence interval (CI) 2.0–6.8] and 6.2% (95% CI 3.8–10.5) of incident chlamydia cases at all sites. Our models suggest that saliva use during masturbation is unlikely to play a major role in chlamydia transmission between men, and even if it does have a role, about one in seven cases of urethral chlamydia might arise from masturbation.

Organ cultures prepared from 15 different organs obtained from 43 fetuses were consistently found to support the growth of rubella virus, irrespective of the gestational age of the fetus or the strain of rubella virus inoculated. Although rubella virus replicated in fetal lenses, adult lenses did not support the growth of rubella virus. Organs obtained from four fetuses between 8 and 17 weeks gestational age produced similar titres of an inhibitor which had the characteristics of interferon. The use of Trowell T8 medium and incubation in a mixture of 5% CO2 in oxygen provided the most suitable conditions for the maintenance of most organ cultures. Under these circumstances it was possible to obtain adequate histological preparations from these organs, but light microscopy studies revealed no significant differences in sections of rubella inoculated and control organ cultures.

Guinea-pigs immunized with alum-precipitated diphtheria toxoid (APT) become hypersensitive to diphtheria toxin and toxid. This hypersensitivity is probably due to a mixture of immediate (Arthus-type) reactions and delayed (tuberculin-type) reactions, the former increasing as the level of circulating precipitating antitoxin rose and tending to mask the latter. In a hyperimmune guinea-pig the residual damage following the intradermal injection of toxin is due, at least in part, to hypersensitivity to toxin; toxicity probably contributes relatively little to the extent of the lesion in animals with a high titre of antitoxin.

The technical difficulties of proving the presence of a delayed allergic reaction in animals with an early allergic reaction are discussed.

I am grateful to Dr C. G. Pope, who has been closely associated with this work, not only for providing highly purified materials, but also for his advice.

Experiments in the quality control of water samples are being conducted in the Public Health Laboratory Service and the water industry in the United Kingdom. The number of distributions which have been made is 7 and 92 laboratories are now participating. The methods used for preparing and distributing samples are described. Some participating laboratories use the multiple tube method and some use membrane filtration to assess the presence of coliforms and Escherichia coli. The results are, therefore, a mixture of estimated numbers and direct colony counts.

Three hundred and seventy-six patients attending their general practitioner with cutaneous warts at five health centres in Northern Ireland were screened for human papilloma virus (HPV) types 1 and 2 IgM antibody using an indirect immunofluorescence test. Eighty-eight (23·4%) patients were positive for HPV type 1 IgM and 156 (41·5%) for HPV type 2 IgM. HPV 1 IgM antibody was significantly more likely to be associated with plantar warts than warts elsewhere (P 0·0001). HPV 2 IgM was present in 45 (34·1%) patients with plantar warts and 99 (45·6%) patients with warts at other sites (P=0·1). Evidence of multiple infection by HPV types 1 and 2 was demonstrated by the finding of HPV 1 and 2 IgM antibodies in the sera of 16 (4·3%). HPV 4 was found in only 1 out of 30 biopsies and HPV 4 IgM was undetectable in 50 randomly chosen sera.

The Isle of Ely is the northern half of the geographical County of Cambridge-shire and forms in itself a separate administrative county. It is the heart of the fen country, and its population is one which long retained a degree of isolation and independence tending to preserve in its members certain mental, and perhaps physical characters peculiar to themselves. It is interesting to recall that from this neighbourhood came Boadicea, Queen of the Iceni, and Hereward the Wake, who proved such stubborn enemies to the conquerors of their country.

Influenza activity was studied in the Rome population from 1956 to 1976 by analysis of mortality from respiratory causes and from all causes. During cold weather months, type A influenza virus was associated, as a rule, with epidemic excess deaths at two year intervals while type B virus was prevalent twice during epidemic excess mortality periods. Excess absenteeism from work and virus isolation data were also compared with epidemic excess mortality during four consecutive years. The evidence obtained indicated that influenza virus isolation alone does not represent a reliable index of epidemic influenza activity in this population. The proportion of deaths attributed to respiratory causes consistently increased in every epidemic, the most pronounced increases occurring during large epidemics. The break-down by age of deaths from respiratory causes in the course of two epidemic periods showed that the percentage distribution of deaths was essentially the same as in non-epidemic periods. This evidence indicates that the same factors influencing the age-related distribution of mortality from respiratory causes during non-epidemic periods, probably affect the fatal outcome of influenza during epidemics.

The course of mortality has undergone some remarkable changes since the early part of the last century, the period for which official statistics are available. The variations in the death-rates are emphasised when the rates of various countries are compared, and the cause of the difference in the trend of mortality between various countries has been the source of much speculation. The most striking contrast between the course of mortality in two countries is, probably, that discussed by Prof. Greenwood (1924) in his paper, “The vital statistics of Sweden and England” (J. Roy. Stat. Soc. 87, Part 4). He made a comparison between the two countries for the ages 10–50 for two periods. The first period covered the years 1838–54 for England and Wales and 1841–50 for Sweden, the second period was 1901–10 for both countries. The probability of dying for males during the first period was greater in England and Wales between the ages 10–35 than in Sweden. The greatest difference occurred at age 19, when the value for England and Wales was 151·2 per cent, of the Swedish figure. From age 36 the male mortality in Sweden was in excess of that for England and Wales. The female mortality was greater in England and Wales for every age 10–50. In the second period the mortality at adolescence in England and Wales had made such an improvement that it was less than that of Sweden, the probability of dying for males in England and Wales being less than that of Sweden for the ages 10–31. The England and Wales value at age 19 was now only 59·8 per cent, of that of Sweden. From age 32 the male mortality in Sweden was less than that of England and Wales. The female rate for England and Wales was below that of Sweden for the ages 10–36 and above for 37–50. The mortality of 1901–10, of both countries, had shown considerable improvement on that of the earlier period. This decline in mortality has been general and has been shown in the experience of most countries.

1. A food store infested with house-mice (Mus musculus L.) was treated with boxes containing 1% warfarin dust surrounding a solution containing 0·005% sodium warfarin and 5% sugar. The boxes were placed around the bases of the stacks, in the air-lanes between stacks and at eaves height at the gable ends of the store.

2. Census baitings with counted numbers of wheat grains showed that the mouse population was reduced by about 95% after 5 weeks of the poison treatment and by almost 100% after 20 weeks.

3. The field trial suggests that the combined use of rodenticidal dust and poison solution baiting points is a useful additional method of controlling M. musculus and is most effectively employed against mice living in warm, dry environments.

Thanks are expressed to our colleague Mr E. W. Powell, who co-operated in this work.

The establishment of Aedes albopictus in southern France, a recognized competent vector for several arboviruses, represents a new threat for the local transmission and spread of what were until recently considered as tropical diseases. A preparedness and response plan, based on vigilance of both clinicians and laboratories, has introduced significant changes in guidelines and behaviour regarding patients’ care specifically during the activity period of mosquitoes. In the present study, we report the results of a 1-year activity in arboviral infection diagnosis. A total of 141 patients were included in this retrospective study. The number of suspected imported and autochthonous cases was 69 and 72, respectively. A diagnosis of arboviral infection was confirmed for 15 (21·7%) suspected imported cases, with identification of 13 dengue viruses, one chikungunya virus and one Zika virus. No autochthonous cases were detected. This report illustrates the increase in requests for arboviral infection diagnosis and confirms the challenge with identifying autochthonous arboviral infection cases in many unspecific febrile syndromes.

One of the major difficulties in determining the cleanliness of blankets for use in hospital wards is the estimation of bacterial contamination remaining on the blanket after washing. Present procedures are either cumbersome or not readily reproducible. Procedures for measuring bacterial contamination on fabrics may be based on dispersion of the bacteria as an aqueous or as an airborne cloud. As aerial sampling has the advantages that it may be rapid and simple and can be used to sample blankets which have been washed with a bactericide the possibilities of this principle were investigated. A simple method has been developed (Blowers & Wallace, 1955) in which the blanket is scraped manually by the edge of an agar plate so that the bacterial dust is thrown on to the exposed agar surface, but this procedure is difficult to control. There are wide differences in surface properties of blankets, and consequently in the amount of fibrous material shaved off by the Petri dishes. Puck, Robertson, Wise, Loosli & Lemon (1946) worked on the principle of hitting an area of taut blanket and sampling the aerial cloud so formed, but as their apparatus was not convenient for routine sampling in wards an improved version has been developed.

We utilized de-identified data to evaluate increases in four outcomes during influenza outbreak periods (IOPs) including: hospitalization, intensive care unit admission, mechanical ventilation or death for adults aged 18 years or older with medically attended acute respiratory illnesses (MAARI) admitted to any of Maryland's 50 acute-care hospitals over 12 years. Weekly numbers of positive influenza tests in the Maryland area were obtained from the US Center for Disease Control and Prevention interactive website. The fewest consecutive weeks around the peak week containing at least 85% of the positive tests defined the IOP. Weekly counts of individual study outcomes were positively correlated with regional weekly counts of positive influenza tests during all the IOPs over 12 years. Also, rate ratios comparing daily occurrences of each study outcome between the IOP and non-IOP were significantly elevated. These results confirm conclusions of previous studies that influenza outbreaks are clearly associated with deaths and increased use of advanced medical resources by patients with MAARI. These data analyses suggest that increased efforts to develop more effective influenza vaccines and therapeutics should be a priority.

In this paper we report the distribution of Salmonella Typhi isolates in Italy and their resistance patterns to antibiotics. The data were collected by the Italian SALM–NET surveillance system in a pilot retrospective study of the period 1980–96. Data on drug-resistance were available for 82 isolates out of 176 S. Typhi isolated in Italy. Of these 82 isolates, 32 (39%) were resistant or intermediate to 1 or more antibiotics. Eight isolates were resistant and 7 intermediate to streptomycin; 4 isolates were resistant to ampicillin alone or in association with other antibiotics; only 2 strains (1 isolated in Lombardia in 1993 and the other 1 in Lazio in 1994) were resistant to chloramphenicol, and 2 (isolated in Sardegna and Piemonte in 1995 and 1996, respectively) showed intermediate resistance to chloramphenicol. The strains showing resistance to 3 or more antibiotics were very scarce: 1 (with 5 complete resistances) was isolated in Lazio in 1994, and another 1 (with complete resistance to 10 antibiotics and intermediate resistance to 2 antibiotics) was isolated in Molise in 1988. In conclusion, besides the routine activities to control typhoid fever, an accurate and continuous surveillance is necessary in order to quickly identify multidrug-resistant (MDR) S. Typhi strains and prevent their spread, even though their level, in our country, is still quite low.