We assessed recent trends in hepatitis C virus (HCV) prevalence in pregnant women with HIV using data from a large national study. Based on 1240 pregnancies, we observed a 3·4-fold decline in HCV seroprevalence in pregnant women with HIV between 2001 (29·3%) and 2008 (8·6%). This decline was the net result of two components: a progressively declining HCV seroprevalence in non-African women (from 35·7% in 2001 to 16·7% in 2008), sustained by a parallel reduction in history of injecting drug use (IDU) in this population, and a significantly growing presence (from 21·2% in 2001 to 48·6% in 2008) of women of African origin, at very low risk of being HCV-infected [average HCV prevalence 1%, adjusted odds ratio (aOR) for HCV 0·09, 95% CI 0·03–0·29]. Previous IDU was the stronger determinant of HCV co-infection in pregnant women with HIV (aOR 30·9, 95% CI 18·8–51·1). The observed trend is expected to translate into a reduced number of cases of vertical HCV transmission.

Four out of fifty acute respiratory infections occurring in forty-five adult volunteers in a teaching hospital, from October 1956 to July 1957, were associated with infection by a member of the adenovirus group. In three of these adenovirus infections the clinical picture was quite distinct from that of the common cold, but not from other syndromes of unknown aetiology; in the fourth case the clinical picture was not easily distinguishable from the common cold.

It is suggested on the basis of this study that adenovirus vaccines would do little towards reducing sporadic acute respiratory infections in this type of community.

Complement-fixing and neutralizing antibody patterns to adenovirus Types 1–7, 9 and 10 were determined in paired sera from forty-four of the forty-five volunteers.

I wish to thank all the volunteers who took part in this investigation, Mrs Audrey Rae, A.I.M.L.T., for expert technical assistance, Dr Nuala Crowley and Prof. K. R. Hill, Pathology Department, Royal Free Hospital, Dr H. G. Pereira, National Institute for Medical Research, Mill Hill, and Dr F. K. Sanders, M.R.C. Virus Research Unit, London School of Hygiene, for advice and help.

Multi-locus variable number tandem repeat analysis (MLVA) is used in clinical and reference laboratories for subtyping verocytotoxin-producing Escherichia coli O157 (VTEC O157). However, as yet there is no common allelic or profile nomenclature to enable laboratories to easily compare data. In this study, we carried out an inter-laboratory comparison of an eight-loci MLVA scheme using a set of 67 isolates of VTEC O157. We found all but two isolates were identical in profile in the two laboratories, and repeat units were homogeneous in size but some were incomplete. A subset of the isolates (n = 17) were sequenced to determine the actual copy number of representative alleles, thereby enabling alleles to be named according to international consensus guidelines. This work has enabled us to realize the potential of MLVA as a portable, highly discriminatory and convenient subtyping method.

Trimethoprim resistance was seen in 14·8% of 500 strains of salmonella, 43·1% of 153 strains ofshigella and 59% of 27 strains of Escherichia coli isolated from stools of patients with diarrhoea. Strains with a high level of trimethoprim resistance (MIC of ≥ 512 μg) were subjected to conjugal transfer. Trimethoprim resistance was plasmid-mediated in all of 42 strains of shigella and 12 strains of E. coli examined. However, 2 of the 47 strains of salmonella could not transfer their trimethoprim resistance either directly or by mobilization with the transfer factors X and Δ both at 37 and 25 °C overnight incubation.

This paper describes the features of an outbreak of early syphilis in an institution for the care of adults with mental disorders. A case-note review was performed. In the period June to November 2001, 87 cases of syphilis were diagnosed [25 primary, 21 secondary and 41 early latent syphilis in 983 inmates (crude attack rate 8·9%)]. Among them 82 were heterosexual, four were homosexual or bisexual, and for one case sexual preference was not established. About half the cases were known to be promiscuous. The initial case was not identified. Penicillin therapy was administered to all cases and all known or suspected sexual contacts. Sporadic cases of syphilis have, however, continued to emerge from time to time. Institutions for patients with mental disorders are vulnerable to sexually transmitted diseases, and special strategies should be devised for their control.

The prompt availability of reliable epidemiological information on emerging pandemics is crucial for public health policy-makers. Early in 2013, a possible new H1N1 epidemic notified by an intensive care unit (ICU) to GiViTI, the Italian ICU network, prompted the re-activation of the real-time monitoring system developed during the 2009–2010 pandemic. Based on data from 216 ICUs, we were able to detect and monitor an outbreak of severe H1N1 infection, and to compare the situation with previous years. The timely and correct assessment of the severity of an epidemic can be obtained by investigating ICU admissions, especially when historical comparisons can be made.

A discrimination index was applied to assess the value of biotyping and resistotyping, used alone or together, for the subspecific discrimination of Escherichia coli. The index was high when 599 strains from a wide variety of sources were examined by full biotyping with 10 tests. Although the discrimination achieved was lower when a sub-collection of 333 strains was examined, that finding probably indicated that many of the latter strains were of urinary origin and represented a limited number of uropathogenic clones. Combined biotyping and resistotyping provided a higher level of strain discrimination than either method used on its own. Results suggest that these typing methods may be used with confidence for the discrimination of strains of E. coli.

Influenza vaccine effectiveness (VE) has to be estimated anew for every season to explore vaccines’ protective effect in the population. We report VE estimates against laboratory-confirmed influenza A(H1N1)pdm09, A(H3N2) and influenza B among children aged 2–17 years, using test-negative design. Pooled data from two German federal states’ surveillance systems for acute respiratory illness from week 40/2012 to 20/2016 was used, yielding a total of 10 627 specimens. Odds ratios and 95% confidence intervals (95% CIs) for the association between laboratory-confirmed influenza and vaccination status were calculated by multivariate logistic regression adjusting for age, sex, illness onset and federal state. VE was estimated as 1-Odds Ratio. Overall adjusted VE was 33% (95% CI: 24·3–40·7). A strong variation of VE between the seasons and subtypes was observed: highest season- and subtype-specific VE of 86·2% (95% CI: 41·3–96·7) was found against A(H1N1)pdm09 in 7–17-year-olds in 2015/16. Low estimates of VE were observed against A(H3N2) in any season, e.g. 1·5% (95% CI: −39·3–30·3) in 2014/15. Estimates showed a tendency to higher VE among 7–17-year-old children, but differences were not statistically significant. Although our findings are common in studies estimating influenza VE, we discussed several explanations for observed low VE.

Little is known about long-lasting measles protective immunity when exposure to wild-type or vaccine measles virus precedes HIV infection. The results obtained suggest that measles immunity wanes and the lowest measles geometric mean titres (GMT) were significantly associated with measles vaccine-induced immunity in individuals that later developed HIV infection (86% prevalence, GMT 164 mIU/ml) compared to naturally induced immunity in HIV-infected adults (100% prevalence, GMT 340 mIU/ml, P = 0·0082) or non-HIV infected adults (100%, GMT 724 mIU/ml, P = 0·0001), and vaccine-induced immunity in non-HIV-infected adults (100%, GMT 347 mIU/ml, P = 0·017). The study was conducted in an area without wild-type virus circulation since 2000. The absence of virus circulating may alter the paradigm of lifelong immunity to measles virus after vaccination. As the proportion of HIV-infected individuals possessing only vaccine-induced immunity continues to grow, checking the status of measles immunity in this group is strongly recommended.

1. A technique is described for comparing the spermicidal powers of pessaries, using human sperms.

2. Those pessaries which do not contain cocoa-butter are more spermicidal than those that do.

3. Quinine and lactic acid pessaries, in cocoa-butter vehicles, are almost without effect upon sperms.

4. There is more than ten times as much quinine bisulphate in a quinine pessary as suffices to kill all sperms in half an hour, but the cocoa-butter prevents its action in some way which is not at present understood.

5. Semori is the most spermicidal pessary of the nine investigated. Even at one-tenth of the concentration at which it is normally used, it kills every sperm or nearly every sperm in half an hour.

6. Even if the foam-producing substances are omitted, semori remains effective.

7. The minute quinine urea hydrochloride pessary is nearly as effective as semori, but the absence of foam-producing substances in this pessary limits its usefulness.

8. Speton relies for its spermicidal power wholly upon its foam-producing substances. Its supposedly active substance, sodium dichlorylsulphamidbenzoate, is without effect upon sperms.

In May 1996, the Georgia Division of Public Health was notified about a cluster of persons with Salmonella Enteritidis (SE) infections in Waycross, Georgia. A matched pair case-control study to determine risk factors for illness found a statistically significant association of SE infection with a history of having eaten at Restaurant A during the 5 days before onset of illness (relative risk = 13 [95% confidence interval (CI)=3–62, P<0·01]). In a second case-control study, to determine specific food exposures, consumption of a deep-fried Mexican dish (chile relleno) (4 of 21 cases vs. 0 of 26 controls, odds ratio undefined, 95% CI>1·46, P=0·034) was found to be significantly associated with SE infection. An environmental investigation found evidence of suboptimal food storage and cooking temperatures at Restaurant A; cross contamination of foods may have contributed to the low attributable risk identified for chile rellenos. Five of 37 Restaurant A food and environment specimens yielded SE strains. All five positive specimens were from chiles rellenos. Of the seven outbreak-associated strains (six patient isolates and one food isolate from Restaurant A) for which phage typing was conducted, all were phage type 34. A FDA traceback investigation through Restaurant A's single-egg supplier identified the potential source as three interrelated farms in South Carolina. Environmental culture from one of these farms yielded SE phage type 34. As a result of this outbreak, FDA helped institute a statewide egg quality-assurance programme in South Carolina to minimize SE contamination of eggs.

Toxigenic Clostridium difficile (C. difficile) carriers represent an important source in the transmission of C. difficile infection (CDI) during hospitalisation, but its prevalence and mode in patients with hepatic cirrhosis are not well established. We investigated longitudinal changes in carriage rates and strain types of toxigenic C. difficile from admission to discharge among hepatic cirrhosis patients. Toxigenic C. difficile was detected in 104 (19.8%) of 526 hepatic cirrhosis patients on admission, and the carriage status changed in a portion of patients during hospitalisation. Approximately 56% (58/104) of patients lost the colonisation during their hospital stay. Among the remaining 48 patients who remained positive for toxigenic C. difficile, the numbers of patients who were positive at one, two, three and four isolations were 10 (55.6%), three (16.7%), two (11.1%) and three (16.7%), respectively. Twenty-eight patients retained a particular monophyletic strain at multiple isolations. The genotype most frequently identified was the same as that frequently identified in symptomatic CDI patients. A total of 25% (26/104) of patients were diagnosed with CDI during their hospital stay. Conclusions: Colonisation with toxigenic C. difficile strains occurs frequently in cirrhosis patients and is a risk factor for CDI.

Influenza B virus reinfection in Japanese children was studied epidemi-ologically during 1979–91 and virologically during 1985–91. During this investigation, there were four epidemics caused by influenza B viruses, each of which accompanied antigenic drift. Between the epidemics in 1987/88 and 1989/90, the viruses changed drastically, both genetically and antigenically. The minimum rate of reinfection with influenza B virus during the whole period was 3–25% depending on the influenza seasons. The antigens of primary and reinfection strains of influenza B virus isolated from 18 children during 1985–90, which covered three epidemic periods, were studied by haemagglutination inhibition tests. The results showed that the viruses isolated in the 1984/85 and 1987/88 influenza seasons, which belonged to the same lineage, were antigenically close, and reinfection occurred with these viruses. The results of amino-acid analysis of the HA1 polypeptide of these viruses corresponded with those of antigenic analysis. There were no specific amino-acid changes shared by the primary infection and reinfection influenza B viruses; the patients were infected with the viruses epidemic at that time.

White pock variants of cowpox virus give papular lesions on intradermal inoculation of rabbits, without the necrosis and haemorrhage that are produced by wild type cowpox viruses. Rondle & Dumbell (1962) have shown that white pock variants of cowpox virus fail to produce a specific, precipitating antigen which they called ‘d’ substance. In this paper it is shown that ‘d’ is demonstrable in soluble antigen preparations of rabbitpox virus and of neurovirulent strains of vaccinia virus but not in soluble antigens of variola viruses. Two series of recombinant viruses prepared by Dumbell & Bedson (1964) from variola and cowpox and from variola and rabbitpox viruses were tested for the production of ‘d’ substance. These results were compared with the previously recorded effects of these recombinants when inoculated intradermally in rabbits. It is concluded that functional genes determining the production of ‘d’ and of rabbit skin pathogenicity are closely linked on the pox virus genome, but that there is insufficient evidence to say that the two functions are interdependent.

The flora of both faeces and small bowel lumen was studied in children with gastroenteritis from London, England, and Kingston, Jamaica.

Clinical and laboratory differences between these two groups are described.

All bacterial groups in the faeces were greatly altered during gastroenteritis and this particularly affected anaerobic organisms. These changes generally reverted rapidly to normal after the illness.

The small bowel flora was also altered during gastroenteritis; there was a tendency for a wider range of organisms including anaerobes to be isolated from the children in Jamaica than from those in England.

During July 1991, a single laboratory reported an increased number of an unusual salmonella isolate. An outbreak control team was convened. A case was defined as an individual with diarrhoea from whose faecal sample Salmonella hadar was isolated after 1 July 1991. By 30 July, 90 isolates had been identified and 57 persons interviewed including 39 primary cases. Interviews failed to identify any common features among the cases. A review of the laboratory procedures revealed that the selenite enrichment medium was inoculated using the spoon from the stool collection kit after it was used to emulsify the faecal sample with saline for microscopy. Salmonella hadar was isolated from this saline. Once this practice was stopped, no further isolates of S. hadar were made. This pseudo-outbreak is a powerful reminder to verify the existence of an outbreak, especially when epidemiological data are inconsistent.

Statistical methods are described in detail for the calculating and comparing of cross-infection rates. In addition the use of these rates has been extended to study the influence of age and of different virus types on susceptibility to cross-infection in children's wards.

Ledingham and Penfold have shown that during the lag-phase of growth of B. coli in a nutrient medium the time and bacilli are connected by an equation of the form Xn=K log Y where n and k are constants (the initial seeding = 1). It has been pointed out in this communication that there is a relationship between n and k, and that the above equation can be put in the form

The advantage of this new equation is that K remains of the same value throughout the whole series of experiments.

In the case investigated by Ledingham and Penfold the constant of unrestricted growth is approximately equal to 2K.

The equation can also be put in the form

where Z is the “constant” of growth at a time X. By suitably adjusting n and a this equation can be made to represent not only the lag-phase of growth but also the logarithmic phase, and the special phase of retarded growth when the X − Y curve is rectilinear. When cell-death occurs the bacteria usually perish at such a rate that the X − Y curve is logarithmic; the general equation therefore also covers this case.

The following investigation was undertaken at the request of the War Office Committee on Antityphoid Inoculation, to ascertain the nature and degree of the changes that occur in the blood after inoculation, and to determine the extent to which these changes are influenced by differences in the dosage of the vaccine.

Sensitive surveillance systems are crucial for effective control of infectious disease outbreaks, and regional surveillance could provide valuable data to supplement global systems, improve sensitivity and timeliness of reporting, or capture otherwise undetected outbreaks. In New Zealand (NZ), there are no endemic arboviral diseases in humans, and the majority of dengue cases are imported from neighbouring Pacific Islands where comprehensive surveillance systems are under development. From 1997 to 2009, 679 cases of dengue were reported in NZ (74·2% acquired from the Pacific Islands), and the patterns of reported incidence of dengue acquired from different islands closely reflected local reported incidence in those areas. NZ is therefore in a unique position to provide early alerts on dengue outbreaks in the Pacific Islands. Such a strategy would reduce disease burden in both the Pacific Islands and NZ, and provide a model for transnational collaboration in disease surveillance with regional as well as global benefits.