Chlamydia trachomatis (CT) infections remain highly prevalent. CT reinfection occurs frequently within months after treatment, likely contributing to sustaining the high CT infection prevalence. Sparse studies have suggested CT reinfection is associated with a lower organism load, but it is unclear whether CT load at the time of treatment influences CT reinfection risk. In this study, women presenting for treatment of a positive CT screening test were enrolled, treated and returned for 3- and 6-month follow-up visits. CT organism loads were quantified at each visit. We evaluated for an association of CT bacterial load at initial infection with reinfection risk and investigated factors influencing the CT load at baseline and follow-up in those with CT reinfection. We found no association of initial CT load with reinfection risk. We found a significant decrease in the median log10 CT load from baseline to follow-up in those with reinfection (5.6 CT/ml vs. 4.5 CT/ml; P = 0.015). Upon stratification of reinfected subjects based upon presence or absence of a history of CT infections prior to their infection at the baseline visit, we found a significant decline in the CT load from baseline to follow-up (5.7 CT/ml vs. 4.3 CT/ml; P = 0.021) exclusively in patients with a history of CT infections prior to our study. Our findings suggest repeated CT infections may lead to possible development of partial immunity against CT.

Cell surface hydrophobicity, haemagglutination pattern and adherence to HeLa cells were examined in 230 strains of Escherichia coli collected from women (n = 61 strains) and children (n = 65 strains) with non-obstructive acute pyelonephritis and in 104 faecal control strains of E. coli from healthy adults (n = 71 strains) and children (n = 33 strains). Pyelonephritogenic E. coli strains showed a significantly increased incidence of hydrophobic properties (90%) and mannose resistant haemagglutination (MRHA) of human erythrocytes (83%) than faecal control strains (64 and 23% respectively, P < 0·001 in both cases). Mannose sensitive haemagglutination (MSHA) was observed in 48% of the pyelonephritogenic E. coli strains and in 50% of the faecal control strains (NS). The incidence of adherence to HeLa cells was low both in pyelonephritogenic and faecal control strains, 6 and 7% respectively (NS). The bacterial phenotypes MRHA + MSHA + and MRHA + MSHA− appeared significantly more often in pyelonephritogenic E. coli strains (35 and 48% respectively) than in faecal control strains (5 and 17% respectively, P < 0·001 in both cases). The phenotype MRHA − MSHA + occurred significantly more often in control strains (45%) than in pyelonephritogenic strains (13%, P < 0·001). Eighty-three per cent of the pyelonephritogenic E. coli strains expressing hydrophobic properties showed MRHA and 50% of the hydrophobic strains showed MSHA. There were no significant correlations between cell surface hydrophobic properties and haemagglutination pattern or adherence to HeLa cells in pyelonephritogenic E. coli strains nor in faecal control strains.

Between 1968 and 1975, well over 3000 samples of pig faeces and 407 samples of pig mesenteric glands were examined for salmonellas. A very wide range of serotypes was isolated. The material from this survey was used to evaluate certain aspects of salmonella isolations. The factors studied were: selective motility enrichment, size of inoculum of faeces, comparison of drain swab with animal sample and comparison of selenite F broth with Muller–Kauffmann tetrathionate broth. The conclusions drawn from these investigations allowed an efficient routine to be developed during the survey.

In 1975, 25 soil samples were collected from the London area. Of these, 20 were obtained 200–300 yards from 20 lakes that had been shown in 1974 to contain mud contaminated with one or more of types B, C, D and E of Clostridium botulinum. By means of a technique comparable with that used for the examination of mud, the 20 soil samples were found negative. The remaining 5 soil samples, obtained from sites that were not in close proximity to lakes, were also negative except for one that contained type B.

A retrospective analysis of levels of antibody to hepatitis B surface antigen in 1419 health care workers was carried out to compare the efficacy of intramuscular and intradermal administration of plasma derived and recombinant hepatitis B vaccines. No significant difference was detected between the response to intradermal and intramuscular plasma derived vaccine. However of those who received intramuscular recombinant vaccine 81.6%, 13.8% and 4.7% were good (> 100 miu/ml). low (10–99 miu/ml) and non-responders (< 10 miu/ml) respectively. compared with 51.1%, 29.8% and 19.2% of the intradermal group (P > 0.0001). Low dose intradermal administration of recombinant vaccine did not produce satisfactory levels of antibody to hepatitis B surface antigen.

The success of childhood vaccination against hepatitis B relies on persistence of immunity into adolescence and adulthood. In 2000, two hexavalent vaccines with a hepatitis B component (Hexavac®, Infanrix hexa®) were introduced in Germany. Hexavac was withdrawn in 2005 amidst concerns about its long-term hepatitis B protection. We compared hepatitis B surface antibody (anti-HBs) levels in children fully vaccinated with Hexavac or Infanrix hexa (n=477) in a secondary data analysis of a large cross-sectional health survey in Germany. On average 2·4 years after vaccination, 25·3% of Hexavac vaccinees had anti-HBs levels <10 mIU/ml (95% CI 19·0–32·8) compared to 4·7% of Infanrix hexa vaccinees (95% CI 2·4–8·9). These findings suggest that short-term hepatitis B immunogenicity in Hexavac vaccinees may also be weaker. Further studies are warranted to assess whether Hexavac vaccinees should be re-vaccinated or receive a booster vaccination before these birth cohorts reach adolescence.

This study investigates whether a child's risk of rotavirus diarrhoea is associated with season of birth in England and Wales, countries where rotavirus infections are highly seasonal. Poisson regression models were fitted to weekly counts of laboratory-confirmed rotavirus infections from children aged <5 years born between 1998 and 2007. In the first year of life, the risk of a laboratory-confirmed rotavirus infection was significantly higher for children born in summer compared with winter [relative risk (RR) 2·13, 95% confidence interval (CI) 2·07–2·19]. In the second to fifth years of life, the pattern reversed (second year of life: RR 0·73, 95% CI 0·71–0·75). The cumulative risk up to age 5 years remained significantly higher for children born in summer compared with winter due to the increased risk for summer births during their first year of life. Maternal immunity and age-specific levels of exposure to rotavirus could explain our findings.

An epidemiological study of hepatitis A and enteroviruses was conducted in a military diving training school, by evaluating the viral contamination of water using an ultrafiltration concentration technique, and assessing seroconversion and the presence of virus in stool specimens obtained from 109 divers and 48 controls. Three of 29 water specimens were positive for enterovirus by cell culture and 9 by molecular hybridization. There was little or no risk of virus infection during the training course (49 h exposure) because there was no significant difference between divers and controls for both viral isolation and seroconversion. However, a higher percentage of coxsackievirus B4 and B5 seropositive divers suggests that these were more exposed during previous water training. No hepatitis A virus (HAV) detection and no seroconversion to HAV was observed. The rate of HAV seropositive subjects was 17% in this 24·5-year-old population

Salmonella enterica serotype Enteritidis isolates of phage types (PTs) PT1, PT4, PT13a and PT22 derived from sporadic cases and outbreaks of food poisoning in Japan during 1994 and 1995 were analysed by pulsed-field gel electrophoresis (PFGE). While PT1 strains from 5 different outbreaks showed 14 PFGE patterns, 5 PFGE patterns were observed among PT4 isolates from 5 different outbreaks and 6 independent isolates from imported chicken. Interestingly, 8 out of 9 PT4 strains associated with foreign travel to Southeast Asia were indistinguishable in PFGE pattern from 5 independent isolates of imported chicken from England. Although both PT13a and PT22 were first reported in Japan in 1994, PT22 showed various PFGE patterns compared to PT13a which had the same pattern within an outbreak, unlike PT1. These results could indicate that multiple clonal lines of PT1 and PT22 had already spread while relatively fewer clonal lines of PT4 and PT13a might exist in Japan.

The coronavirus 2019 (COVID-19) outbreak in China rapidly spread throughout the world, becoming a threatening pandemic with unprecedented consequences. Mobile technologies have led to a revolution in health and their applicability in the context of COVID-19 is promising. In this commentary, we provide an overview of the role that mobile technologies play in the COVID-19 pandemic context and discuss the main issues associated. Four main domains stood out: health communication, prevention, support and research. Strengthening local surveillance systems, geographic contact tracing, support for clinical practice and data collection of real-time longitudinal data at the population level are some of the main advantages of the applications reported so far. The potential conflict to data privacy urges for discussion on their use in a responsible manner. Along with fair regulation and close monitoring of data collection and process, data anonymisation must be a standard and personal data must be deleted after its usage. Preparation is key for effective containment of a public health crisis and learning lessons on the role of mobile technologies is useful for future challenges in global health. It is noteworthy that their use must be driven by an equitable and inclusive orientation, and mostly integrated into an articulated policy to respond to the crisis.

To investigate whether single nucleotide polymorphisms (SNPs) in Toll-like receptors (TLRs) 3 and 9 affect the susceptibility of hepatitis B virus (HBV) intrauterine transmission, we genotyped 399 neonates for TLR3 (c.1377C/T) [rs3775290] and TLR9 (G2848A) [rs352140] using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). A femoral venous blood sample was obtained from these subjects. Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were measured using chemiluminescence immunoassay kits and hepatitis B virus DNA (HBV DNA) levels were determined by fluorescence quantitative PCR assay. Our results showed that when adjusting for maternal HBeAg, maternal HBV DNA and mode of delivery, allele ‘T’ for SNP c.1377C/T was significantly associated with HBV intrauterine transmission susceptibility [adjusted OR (aOR) 0·55, 95% confidence interval (CI) 0·34–0·91, P = 0·020] and the TT genotype decreased the risk of HBV intrauterine transmission (aOR 0·28, 95% CI 0·09–0·91, P = 0·033). Allele ‘A’ for SNP G2848A was significantly associated with HBV intrauterine transmission susceptibility (aOR 0·62, 95% CI 0·39–1·00, P = 0·048) and the GA genotype protected neonates from HBV intrauterine transmission (aOR 0·45, 95% CI 0·22–0·93, P = 0·031). The TLR3 (c.1377C/T) and TLR9 (G2848A) polymorphisms may be relevant for HBV intrauterine transmission susceptibility, although the reduction in risk to HBV intrauterine transmission is modest and the biological mechanism of the observed association merits further investigation.

Sixteen foot-and-mouth disease virus (FMDV) strains of type SAT 1 were compared in complement-fixation tests. With the test used, the range of antigenic variation within a type appeared to be greater than previously described. The concept of a sub-type group within which all strains are more closely related to each other than to any strain outside the group was not supported. Considering the group of strains studied, it is suggested that the classification of strains is best achieved by nominating a reference strain for each sub-type. Others are classified as related strains in one or more sub-type groups according to their relationships with the reference strains.

The aims of this study were to identify Staphylococcus aureus nasal colonization prevalence, behavioural risk factors, and to determine staphylococcal protein A (spa) types in community-based injection drug users (IDUs). Nasal swabs were collected and methicillin susceptibility testing and spa/SCCmec typing were performed on S. aureus isolates. Generalized estimating equations were used to report adjusted odds ratios and 95% confidence intervals. Of the 440 participants, 24·1% were colonized and 5·7% had methicillin-resistant S. aureus (MRSA). Colonization was associated with age, employment/marital status, and the presence of scabs but not with sexually transmitted disease co-infection, HIV status, antibiotic use, hospitalization, or drug treatment programme participation. The USA300 MRSA clone spa types were most common, but 15/49 spa types were new to one of the international databases. Community-based IDUs appear to have different risk factors compared to IDUs from clinical studies. In addition, the number of newly identified spa types indicates a diverse, understudied population.

In Hong Kong, universal varicella vaccination started in July 2014. Before this, children could receive varicella vaccine via the private market. We analysed the epidemiology of varicella and zoster before universal vaccination. We estimated varicella vaccination coverage through surveys in preschool children. We estimated the burden of varicella and zoster with varicella notifications from 1999/00 to 2013/14, Accident and Emergency Department (A&E) attendance and inpatient admissions to public hospitals from 2004/05 to 2013/14. We fitted a catalytic model to serological data on antibodies against varicella-zoster virus to estimate the force of infection. We found that varicella vaccination coverage gradually increased to about 50% before programme inception. In children younger than 5 years, the annual rate of varicella notifications, varicella admission and zoster A&E attendance generally declined. The annual notification, A&E attendance and hospitalisation rate of varicella and zoster generally increased for individuals between 10 and 59 years old. Varicella serology indicated an age shift during the study period towards a higher proportion of infections in slightly older individuals, but the change was most notable before vaccine licensure. In conclusion, we observed a shift in the burden of varicella to slightly older age groups with a corresponding increase in incidence but it cannot necessarily be attributed to private market vaccine coverage alone. Increasing varicella vaccination uptake in the private market might affect varicella transmission and epidemiology, but not to the level of interrupting transmission.

Legionella isolates recovered in 21 different Spanish provinces over 8 years from both clinical (67 isolates) and environmental (181) samples, mostly from case-associated buildings, are described: 92·5% of clinical isolates were L. pneumophila serogroup 1 (SGI), only five isolates belonging to other species or serogroups: two L. pneumophila SG6, two SG8 and one L. bozemanii SG1 not clearly related with clinical infection.

L. pneumophila SG1 accounted for 53·6% of isolates from the environment, followed by SG8 (27·6%). SG3 (9·4%) and SG6 (7·2%). Three isolates were labelled as SG8/10.

Subtyping of L. pneumophila SG1 by the standardized panel of monoclonal antibodies revealed 90·3% of clinical and 78·3% of environmental isolates as belonging to Pontiac subgroup. Pontiac isolates were further divided into 55·3% Philadelphia 1 or Allentown 1, 21·9% Benidorm 030E and 20·4% Knoxville 1.

Characterization of samples from four outbreaks in which both clinical and environmental isolates had been recovered permitted the recognition of three Philadelphia 1 or Allentown 1 and one Knoxville 1 strains as the aetiological agents.

An outbreak of hepatitis A virus (HAV) infection affected Roma populations living in three prefectures of northeastern Greece. Between July and November 2007, 124 cases were reported. We carried out investigations to characterize the pathogen, to identify the source of infection and the route of transmission. Using the RT–PCR technique, HAV strains of the same genotype were detected in all sera from a subset of patients with acute disease. These showed more than 99·8% identity, suggesting a common source. A questionnaire was also completed to collect clinical and epidemiological information. The outbreak affected mainly Roma children aged <10 years. An inspection of Roma settlements showed that poor sanitary conditions were associated with the HAV outbreak.

We undertook a national paediatric seroprevalence survey of measles, mumps and rubella (MMR) in Singapore to assess the impact of the national childhood immunization programme against these three diseases after introduction of the trivalent MMR vaccine in 1990. The survey involved 1200 residual sera of Singapore residents aged 1–17 years collected from two hospitals between 2008 and 2010. The overall prevalence of antibodies against measles, mumps and rubella was 83·1% [95% confidence interval (CI) 80·9–85·1], 71·8% (95% CI 69·1–74·2) and 88·5% (95% CI 86·6–90·2), respectively. For all three diseases, the lowest prevalence was in children aged 1 year (47·8–62·3%). The seroprevalence of the vaccinated children declined over time. The national MMR immunization programme is effective in raising the herd immunity of the childhood population, although certain age groups are more susceptible to infection, in particular, those who are not eligible for vaccination at age <15 months.

Changes in respiratory pathogen testing can affect disease burden estimates. Using linked data, we describe changes in respiratory virus testing among children born in Western Australia in 1996–2012. We extracted data on respiratory specimens from these children from birth to age 9 years. We estimated testing rates by age, year, Aboriginal status and geographical location. Predictors of testing among children hospitalised at least once before their 10th birthday were identified using logistic regression. We compared detection methods for respiratory viruses from nasal/nasopharyngeal (NP) specimens by age and year. Of 83 199 virology testing records in 2000–2012, 80% were nasal/NP specimens. Infants aged <1 month had the highest testing rates. Testing rates in all children increased over the study period with considerable yearly fluctuations. Among hospitalised children, premature children <32 weeks gestation had over three times the odds of being tested (95% CI 3·47–4·13) than those born at term. Testing using molecular methods increased from 5% to 87% over the study period. Proportion of positive samples increased from 36·3% to 44·4% (P < 0·01); this change was greatest in children aged 2–9 years. These findings will assist in interpreting results from future epidemiology studies assessing the pathogen-specific burden of disease.

A study of the biological characters of 1636 cultures of coliform bacteria, isolated from milk and bovine faeces, shows that the coliform group consists of a large number of different types. These types are so closely interlinked in characters and in relations to environment as to justify their inclusion in one genus. Nevertheless, to facilitate the identification of types, the group may be subdivided into subgroups, the Voges-Proskauer, Koser, inositol and indole reactions being reliable and outstanding criteria for this purpose. These characters show almost perfect correlations with various other characters. Thus Voges-Proskauer-negative types have a low CO2 to H2 ratio and are methyl-red-positive; Voges-Proskauer-positive types have a high CO2 to H2 ratio, are methyl-red-negative and Koser-positive. Koser-negative types are not highly resistant to brilliant green, are non-capsulated, do not form thick mucoid colonies and are Voges-Proskauer-negative, inositol-negative and indole-positive. Koser-positive types are highly resistant to brilliant green, and with the exception of group 2 and certain members of group 3, are frequently encapsulated and form thick, mucoid colonies. Non-inositol-fermenters are as a rule motile and adonitol-negative. Inositol-fermenters are Koser-positive, adonitol-positive, sucrose-positive and raffinose-positive; are frequently encapsulated and form thick, mucoid colonies; and as a rule are non-motile. Indole-negative types are Koser-positive, while indole-positive types are generally Koser-positive or negative according to whether the inositol reactions are positive or negative.

In a Belgian wool-processing factory, living anthrax spores were found in raw goat hair and air dust, but confirmed anthrax cases had never been reported. Anthrax vaccines are not licensed nor recommended in Belgium. We conducted a B. anthracis seroprevalence study to investigate risk factors associated with positive serology and advise on protective measures. Overall 12·1% (8/66) employees were seropositive; 30% of persons processing raw goat hair and 20% of persons sorting raw goat hair were seropositive compared to 3% in less exposed jobs [adjusted prevalence ratio (aPR) 44·4, P=0·001; aPR 14·5, P=0·016, respectively). The number of masks used per day was protective (aPR 0·3, P=0·015). Results suggest a dose–response association for those processing raw goat hair. Host-related factors probably played a role as antibody response varied from person to person within an exposure group. Workers exposed to raw goat hair should be offered higher protection against anthrax and have access to anthrax vaccines.