HIV-positive children are still born in Europe despite low mother-to-child transmission (MTCT) rates. We aimed to clarify the remaining barriers to the prevention of MTCT. By combining the national registers, we identified all women living with HIV delivering at least one child during 1983–2013. Of the 212 women delivering after HIV diagnosis, 46% were diagnosed during the pregnancy. In multivariate analysis, age >30 years (P = 0.001), sexual transmission (P = 0.012), living outside of the metropolitan area (P = 0.001) and Eastern European origin (P = 0.043) were risk factors for missed diagnosis before pregnancy. The proportion of immigrants increased from 18% before 1999 to 75% during 2011–2013 (P < 0.001). They were diagnosed during the pregnancy equally to natives and achieved similar, good treatment results. No MTCT occurred when the mother was diagnosed before the delivery. In addition, 12 women had delivered in 2 years prior their HIV diagnosis, most before implementation of the national screening of pregnant women. Three of these children were infected, the last one in 2000. Our data demonstrate that complete elimination of MTCT is feasible in a high-income, low-prevalence country. This requires ongoing universal screening in early pregnancy and easy access to antiretroviral therapy to all HIV-positive people.

Sheep, after infection with louping ill virus and after re-infection with the same strain of virus 19–21 months later, were bled at intervals and their sera examined for neutralizing and haemagglutinin-inhibiting antibodies. Each antibody type was measured by the constant serum/variable virus and constant virus/variable serum methods. The persistence of each type of antibody and its significance in epidemiological studies is discussed. The relationship of antibody levels in ewes and their lambs was also examined.

1. An apparently pure rabbit iso-antibody marked with 131I has been shown to adsorb specifically to a greater extent on some rabbit cells than on others. This accords with previous evidence that the same iso-antibody exhibits a higher titre with the cells which are shown here to absorb more marked antibody than with those which adsorb less.

2. Saturation of two of these red cell types by repeated application of fresh quantities of the 131I iso-antibody until no more is specifically adsorbed, suggests that the number of functional antigenic sites is six or seven times greater on the one than on the other cell.

3. There is no apparent difference in the amount of 131I iso-antibody adsorbed by any one type of rabbit cell in comparative titrations using 3·3 % MgSO4.7H2O medium instead of normal saline.

Invasive meningococcal disease (IMD) completeness of reporting has never been assessed in New York City (NYC). We conducted a capture–recapture study to assess completeness of reporting, comparing IMD reports made to the NYC Department of Health and Mental Hygiene (DOHMH) and records identified in the New York State hospital discharge database [Statewide Planning and Research Cooperative System (SPARCS)] by ICD-9 codes from 1989 to 2010. Reporting completeness estimates were calculated for the entire study period, and stratified by year, age group, clinical syndrome, and reporting system. A chart review of hospital medical records from 2008 to 2010 was conducted to validate hospital coding and to adjust completeness estimates. Overall, 2194 unique patients were identified from DOHMH (n = 1300) and SPARCS (n = 1525); 631 (29%) were present in both. Completeness of IMD reporting was 41% [95% confidence interval (CI) 40–43]. Differences in completeness were found by age, clinical syndrome, and reporting system. The chart review found 33% of hospital records from 2008 to 2010 had no documentation of IMD. Removal of those records improved completeness of reporting to 51% (95% CI 49–53). Our data showed a low concordance between what is reported to DOHMH and what is coded by hospitals as IMD. Additional guidance to clinicians on IMD reporting criteria may improve completeness of IMD reporting.

A case of typhoid fever caused by Salmonella typhi occurred in Geneva. The patient was probably infected in Mexico City. The strain isolated from this patient corresponds with the description of the Mexican S. typhi strain, since it is a degraded Vi-strain resistant to chloramphenicol, streptomycin, sulphonamides and tetracyclines. It carried an fi− transferable R factor with a CSSuT resistance pattern. It can be accepted that this case forms part of the Mexican outbreak of chloramphenicol-resistant typhoid fever which has already been observed in visitors to Mexico from England and the United States.

In Rajahmundry town in India, 234 community cases of jaundice were interviewed for risk factors of viral hepatitis B and tested for markers of hepatitis A–E. About 41% and 1·7% of them were positive for anti-HBc and anti-HCV respectively. Of 83 cases who were tested within 3 months of onset of jaundice, 5 (6%), 11 (13·3%), 1 (1·2%), 5 (6%) and 16 (19·3%) were found to have acute viral hepatitis A–E, respectively. The aetiology of the remaining 60% (50/83) of cases of jaundice could not be established. Thirty-one percent (26/83) were already positive for anti-HBc before they developed jaundice. History of therapeutic injections before the onset of jaundice was significantly higher in cases of hepatitis B (P = 0·01) or B–D (P = 0·04) than in cases of hepatitis A and E together. Other potential risk factors of hepatitis B transmission were equally prevalent in two groups. Subsequent studies showed that the majority of injections given were unnecessary (74%, 95% CI 66–82%) and were administered by both qualified and unqualified doctors.

This work was undertaken for the purpose of determining the occurrence and specificity of bacterial precipitins in infections caused by the Staphylococcus aureus. The differences in antigenic properties of various strains of orange and white staphylococci employed in the preparation of the filtered antigens and the importance of the presence of peptone in this connection led to numerous experimental observations which had not been anticipated. The presence of strong S. aureus precipitins in the blood of an adult suffering from very acute serum sickness following an injection of anti-diphtheritic serum led to an investigation of the blood of patients suffering from serum sickness, the results of which are fully recorded here. The investigation of the blood of normal rabbits revealed the fact that in some of these animals staphylococcal precipitins were present, which led to unexpected difficulties in the study of precipitins in the actively immunised animal.

It is now almost universally recognised that a test for disinfectants which is to yield results of direct practical significance must include appropriate “organic matter” in the test mixture. Some types of disinfectant, notably those which act by liberating chlorine or oxygen, are greatly reduced in activity by the addition of only small quantities of any extraneous material with which these elements can combine. Other disinfectants are more resistant to this influence; they are capable of efficient action in the presence of excreta and dirt of other kinds if used in adequate concentration. What this concentration should be under such unfavourable conditions it is necessary to determine, since the degree of interference is not the same for all disinfectants even in the same class, and no constant relationship exists between efficiency under these conditions and that displayed in a medium of distilled water as determined by the Rideal-Walker test. Numerous efforts have been made in the past to introduce tests employing adequate amounts of complex organic matter; few of these have achieved permanence and none popularity. The following short survey of past work is concerned only with what may be termed “excremental” disinfectants; the testing of surgical disinfectants, which may reasonably be held to demand different methods, is outside the scope of this paper.

The aim of the study was to describe the epidemiology and determinants of anti-hepatitis A seroprevalence in 2- to 19-year-olds in the USA for 2007–2008. This study was conducted in a sample of 2621 individuals aged 2–19 years in the USA using data from National Health and Nutrition Examination Survey (NHANES) 2007–2008. The overall seroprevalence of anti- hepatitis A virus (HAV) in this population was 39% (95% confidence interval 32·6–45·3). HAV seroprevalence was higher in Mexican Americans than other ethnic groups, in younger persons, and in those who reported previous vaccination compared to those who did not. We concluded that anti-hepatitis A seroprevalence rates are increasing in younger individuals in the USA, indicating a shift of seroprevalence over time due to vaccination status. Findings are consistent with a persistent influx of infection through international travel and migration and highlight the need to discern hepatitis A infection from vaccination status when assessing the effectiveness of vaccination using seroprevalence data.

An investigation into the classification of strains of Shigella sonneiby the method of phage-typing (using unadapted bacteriophages) is described.

829 strains, obtained during 3 years from twelve regions in England (including Monmouthshire) were examined by a standard technique. There were fifty-two outbreaks (involving 587 strains) from which two or more strains were isolated.

Results confirmed the finding by Hammarström in Sweden that such classification was possible, strains falling into twenty phage-types of which thirteen were found more than once. All strains were typable, 74% belonging to the same type. In forty-seven outbreaks the phage-type was uniform, the commonest type occurring in thirty-eight of these. In five outbreaks the phage-type was not uniform.

It is concluded that this method of phage-typing, because of evidence of type instability and because the majority of strains belong to the same phage-type, has little practical value as a routine procedure in the control of Sonne dysentery in this country.

Towards the end of May, 1923, we received information of two fatal cases of bubonic plague in man, one near Yakoshih (a village on the Chinese Eastern Railway, 168 miles east of Manchouli), and the other at Haranor (in Transbaikalia, 52 miles west of Manchouli); both victims were Russians who had hunted tarbagans and afterwards developed axillary buboes.

Replication of vaccinia and monkeypox viruses was impeded in the presence of 5-bromodeoxyuridine (BUdR) in RL-33 cells derived from rabbit lung tissue. The different degree of inhibition was found among strains of those viruses, in which it was evident that five strains (CV-1, Lister, IHD, Dairen-I and Ikeda) of vaccinia viruses resulted in more reduced yields of infectious virus than four strains (Sen-19, Orang Utan, Copenhagen and Sierra Leone) of monkeypox viruses. There was also strain variation in BUdR sensitivity within vaccinia viruses but not in the case of monkeypox viruses.

In a warfarin-resistant population of wild mice reared in the laboratory, a dominant gene for adiposity, Ad, was found to segregate. The onset of obesity is at 4–6 months, and adipose mice suffer from hyperinsulinaemia; the sexes differ in penetrance, males having greater penetrance then females. Linkage backcrosses show the gene to be situated on chromosome 7 with about 25% recombination with the closely linked warfarin-resistance genes War, and frizzy, fr. The finding of adipose in two other wild populations also carrying War is discussed as an ecological and physiological problem.

Influenza surveillance enables systematic collection of data on spatially and demographically heterogeneous epidemics. Different data collection mechanisms record different aspects of the underlying epidemic with varying bias and noise. We aimed to characterize key differences in weekly incidence data from three influenza surveillance systems in Melbourne, Australia, from 2009 to 2012: laboratory-confirmed influenza notified to the Victorian Department of Health, influenza-like illness (ILI) reported through the Victorian General Practice Sentinel Surveillance scheme, and ILI cases presenting to the Melbourne Medical Deputising Service. Using nonlinear regression, we found that after adjusting for the effects of geographical region and age group, characteristics of the epidemic curve (including season length, timing of peak incidence and constant baseline activity) varied across the systems. We conclude that unmeasured factors endogenous to each surveillance system cause differences in the disease patterns recorded. Future research, particularly data synthesis studies, could benefit from accounting for these differences.

This study aims to investigate the human immunodeficiency virus (HIV) transmission rate in HIV serodiscordant couples, in addition to the relevant influencing factors. From January 1999 to August 2016, patients with HIV/AIDS (index cases) along with their fixed partners were registered and monitored to determine the rate of HIV transmission between couples, as well as relevant influencing factors. A total of 231 HIV-positive couples were investigated, of these, 45-negative (19.48%) partners were infected with HIV via sexual transmission prior to diagnosis of the first case detected in couples. After diagnosis, the transmission rate between spouses was 0.39 per 100 person-years (2/507.7), and the cumulative transmission rate was 1.08% (2/186), which was significantly lower than the transmission rate before diagnosis (χ2 = 35.714, P < 0.001). Among the 119 HIV/AIDS patients who received antiretroviral therapy (ART), the transmission rate was 0 (0/119), whereas the transmission rate was 2.99% (2/67) in HIV/AIDS patients who did not receive ART. In addition, HIV transmission rate in serodiscordant couples was high prior to diagnosis of the index case. However, following diagnosis, the transmission rate was reduced, and the risk of transmission in the index case with antiviral treatment was null. Therefore, a prompt intervention in HIV discordant couples with ART of index case is vital to reduce the risk of HIV transmission.

In summer 2004, an outbreak caused by Salmonella enterica serovar Enteritidis phage type 13 (S. Enteritidis PT13) was recorded in the Czech Republic. As well being a relatively rare phage type the strain was also ampicillin resistant. Outbreak (n=39) and pre-outbreak isolates (n=13) were characterized by pulsed-field gel electrophoresis (PFGE), β-lactamase gene polymerase chain reaction and plasmid profile. The majority of outbreak isolates (n=37) were identical in XbaI PFGE profile, and two other outbreak isolates each differed from this profile by one or two fragments respectively. The pre-outbreak isolates were uniform in PFGE profile but distinct from the outbreak strain. Ampicillin resistance was confirmed to be encoded by the blaTEM gene located on the TnA transposon. This gene was readily transferable to a S. Enteritidis recipient strain and was associated with the transfer of a 200-kb plasmid. Our results indicate that all S. Enteritidis PT13 tested from 2004 belonged to a single outbreak strain which prior to 2004 had not been recognized in the Czech Republic.

Pork was cured by (a) the Wiltshire method and (b) a hygienic sweet cure process. Representative samples of both bacons were inoculated at ‘low’ density (103 organisms/g.) and ‘high’ density (106 organisms/g.) with a toxin-producing strain of Staphylococcus aureus, ‘High’ and ‘low’ density samples of both bacons were each stored at 5° C. for 42 days and 15° C. for 21 days.

Results indicated that the test organism at high inoculum density grew slowly in both bacons at 5° C. The organism survived at 5° C. in both ‘low density’ bacons. At 15° C. the test organism grew; growth being more pronounced in the ‘hygienic’ than in Wiltshire bacon.

Four hundred and sixty admissions for whooping cough to three hospitals between 1974–9 were reviewed. Many children had a long illness. More than half of them had severe or moderately severe coughing spasms and a quarter had pronounced feeding difficulties. The incidence of clinical pneumonia and convulsions was low and there were no deaths. The disease continues to be much more severe in infancy. There was some evidence that the disease declined in severity over the period studied. A number of factors including increased use of erythromycin may have contributed to this change.

From 24 January 2020 to 18 May 2020, Chaoshan took measures to limit the spread of coronavirus disease 2019 (COVID-19), such as restricting public gatherings, wearing masks and suspending classes. We explored the effects of these measures on the pathogen spectrum of paediatric respiratory tract infections in Chaoshan. Pharyngeal swab samples were collected from 4075 children hospitalised for respiratory tract infection before (May–December 2019) and after (January–August 2020) the COVID-19 outbreak. We used liquid chip technology to analyse 14 respiratory pathogens. The data were used to explore between-group differences, age-related differences and seasonal variations in respiratory pathogens. The number of cases in the outbreak group (1222) was 42.8% of that in the pre-outbreak group (2853). Virus-detection rates were similar in the outbreak (48.3%, 590/1222) and pre-outbreak groups (51.5%, 1468/2853; χ2 = 3.446, P = 0.065), while the bacteria-detection rate was significantly lower in the outbreak group (26.2%, 320/1222) than in the pre-outbreak group (44.1%, 1258/2853; χ2 = 115.621, P < 0.05). With increasing age, the proportions of respiratory syncytial virus (RSV) and cytomegalovirus (CMV) infections decreased, while those of Mycoplasma pneumoniae and adenovirus infections increased. Streptococcus pneumoniae, CMV and rhinovirus infections peaked in autumn and winter, while RSV infections peaked in summer and winter. We found that the proportion of virus-only detection decreased with age, while the proportion of bacteria-only detection increased with age (Table 2). Anti-COVID-19 measures significantly reduced the number of paediatric hospitalisations for respiratory tract infections, significantly altered the pathogen spectrum of such infections and decreased the overall detection rates of 14 common respiratory pathogens. The proportion of bacterial, but not viral, infections decreased.

Mixing matrices quantify how people with similar or different characteristics make contact with each other, creating potential for disease transmission. Little empirical data on mixing patterns among persons who inject drugs (PWID) are available to inform models of blood-borne disease such as HIV and hepatitis C virus. Egocentric drug network data provided by PWID in Baltimore, Maryland between 2005 and 2007 were used to characterise drug equipment-sharing patterns according to age, race and gender. Black PWID and PWID who were single (i.e. no stable sexual partner) self-reported larger equipment-sharing networks than their white and non-single counterparts. We also found evidence of assortative mixing according to age, gender and race, though to a slightly lesser degree in the case of gender. Highly assortative mixing according to race and gender highlights the existence of demographically isolated clusters, for whom generalised treatment interventions may have limited benefits unless targeted directly. These findings provide novel insights into mixing patterns of PWID for which little empirical data are available. The age-specific assortativity we observed is also significant in light of its role as a key driver of transmission for other pathogens such as influenza and tuberculosis.