Several infections have been linked to telomere shortening and in some cases these associations have varied by sex. We assessed the association between seropositivity to four persistent pathogens (cytomegalovirus (CMV), herpes simplex virus-1, Helicobacter pylori, Chlamydia pneumoniae), and total pathogen burden on leukocyte telomere length in a diverse US sample. Data came from the Multi-Ethnic Study of Atherosclerosis, a population-based cohort study. We utilized cross-sectional survey data, and biological samples from participants tested for pathogens and telomere length (N = 163). Linear regression was used to examine the association between seropositivity for individual pathogens as well as total pathogen burden and telomere length, adjusting for various confounders. CMV seropositivity and increased total pathogen burden level were significantly associated with shorter telomere length among females (β = −0·1204 (standard error (s.e.) 0·06), P = 0·044) and (β = −0·1057 (s.e. = 0·05), P = 0·033), respectively. There was no statistically significant association among males. Our findings suggest that prevention or treatment of persistent pathogens, in particular CMV, may play an important role in reducing telomere shortening over the life course among women. Future research is needed to confirm these novel findings in larger longitudinal samples.

Hepatitis B vaccination is recommended for men who have sex with men (MSM) in many countries, but information on vaccine coverage is scarce. We studied hepatitis B vaccination programmes and coverage among MSM in Europe to guide prevention. From a large (N = 174 209) pan-European MSM survey (EMIS-2010), we used data on self-reported hepatitis B vaccination, age, education, settlement size and disclosure of the same-sex sexual orientation (‘outness’). We excluded participants with a history of hepatitis B. In multilevel (participants, countries) logistic regression models, we calculated adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). We analysed data of 163 987 MSM in 38 European countries: 38.3% were ‘out’ to all or almost all, 56.4% reported vaccination against hepatitis B and 65.5% lived in countries with free recommended hepatitis B vaccination for MSM. In the final model the odds for being vaccinated increased with outness (‘out to all or almost all’: aOR 1.76, 95% CI 1.70–1.83 vs. ‘out to no one’) and with living in countries, where hepatitis B vaccination was recommended and free-of-charge for MSM (aOR 2.21, 95% CI 1.47–3.32 vs. ‘no or unclear recommendation’). To increase hepatitis B vaccination coverage among MSM, implementation of MSM-specific recommendations and improvement of the societal climate for MSM is needed.

1. A study of factors involved in the transmission of haemolytic streptococci has been made by experiments with healthy carriers and individuals whose upper respiratory passages were contaminated with Chromobacterium prodigiosum.

2. The following conclusions were reached: (a) Expulsion of haemolytic streptococci in droplet spray is determined by the nature of the expiratory activity (Fig. 1), the concentration of the organism in the saliva (Table 3) and the volume of salivary flow (Fig. 6).

(b) Droplets and droplet-nuclei are less important vehicles of transmission because of the extremely low content of haemolytic streptococci in them (Figs. 2–5)

(c) Dust particles carrying haemolytic streptococci and liberated by agitation of handkerchiefs more effectively pollute the air than violent expiratory activities (Figs. 4 and 5).

(d) Hands and clothing readily become contaminated by heavy nasal carriers (Table 4) and the former serve as the principal means of contaminating the environment and other individuals.

3. A diagram showing probable mechanisms of transmission is given (Fig. 7) in which hand contact is represented as a more important pathway of spread than air-borne dust which, in turn, is more important than either droplets or droplet-nuclei.

The classical time series decomposition method was used to compare the temporal pattern of rabies in Chile before and after the implementation of the control programme. In the years 1950–60, a period without control measures, rabies showed an increasing trend, a seasonal excess of cases in November and December and a cyclic behaviour with outbreaks occurring every 5 years. During 1961–1970 and 1971–86, a 26-year period that includes two different phases of the rabies programme which started in 1961, there was a general decline in the incidence of rabies. The seasonality disappeared when the disease reached a low frequency level and the cyclical component was not evident.

The study characterizes a collection of 67 neonatal septicaemic Escherichia coli isolates on the basis of phylogroup, serotype, virulence, antibiotic resistance and also the association of CTX-M-producing E. coli and the ST131 clone in a developing country. Phylogroups B2 and D were predominant (33% and 19%, respectively). The most prevalent virulence factors (VFs) were traT (69%) and iucC (68%) and most VFs were concentrated in the B2 isolates. High levels of resistance (⩾70%) to cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole was recorded but meropenem remained the most active antimicrobial. Six (9%) of the study isolates belonged to the ST131 clone, five of which were from the same hospital, and were either indistinguishable or closely related by pulsed-field gel electrophoresis. Although the prevalence of CTX-M-15-producing isolates was high (81%), the ST131 clone was relatively infrequent (11%) in extended spectrum β-lactamase (ESBL)-producers. The ST131 clone was characterized by the presence of blaCTX-M-15, qnrS, aac(6′)-Ib-cr, IncF plasmids and virulence determinants such as iucC, papC, traT, usp, hlyA, iroNE.coli, cnf, and sat. We conclude that clonal spread of ST131 did not contribute directly to the high prevalence of CTX-M-15 in our settings.

The history and epidemiology of bovine tuberculosis in cattle herds in East Sussex are described. Since 1960, following the compulsory eradication scheme for tuberculosis, the incidence of herd infection has been low. The epidemiological features of herd infection have been sporadic incidents, with only small numbers of cattle becoming infected in the majority of incidents. There was no evidence of endemic Mycobacterium bovis infection in the cattle population in East Sussex in recent years, but a low risk of infection for cattle on the South Downs, from badgers, was apparent.

One case of hospital-acquired listeriosis was linked to milkshakes produced in a commercial-grade shake freezer machine. This machine was found to be contaminated with a strain of Listeria monocytogenes epidemiologically and molecularly linked to a contaminated pasteurized, dairy-based ice cream product at the same hospital a year earlier, despite repeated cleaning and sanitizing. Healthcare facilities should be aware of the potential for prolonged Listeria contamination of food service equipment. In addition, healthcare providers should consider counselling persons who have an increased risk for Listeria infections regarding foods that have caused Listeria infections. The prevalence of persistent Listeria contamination of commercial-grade milkshake machines in healthcare facilities and the risk associated with serving dairy-based ice cream products to hospitalized patients at increased risk for invasive L. monocytogenes infections should be further evaluated.

Mycoplasma fermentans is suspected in the development of ‘Gulf War illness’ in veterans of Operation Desert Storm. We conducted a matched case-control study for the prevalence of M. fermentans-specific antibodies before and after the operation, as well as seroconversion rates in veterans with and without complaints of ‘Gulf War illness’. Cases consisted of Gulf War veterans, who complained of various illnesses and were enrolled in the second phase of the health evaluation by the Army Comprehensive Clinical Examination Program (CCEP). Controls were selected from Gulf War veterans who did not participate in the registry and did not request a health evaluation by the CCEP. Before operation deployment, 34 out of 718 of the cases (4·8%) and 116 out of 2233 of the controls (5·2%) tested positive for M. fermentans-specific antibodies. There was no difference in rates of seroconversion between cases and controls (1·1 vs. 1·2%) to M. fermentans during Operation Desert Storm. Thus, there is no serological evidence that suggests infection by M. fermentans is associated with development of ‘Gulf War illness’.

Thirty Japanese clinical isolates of Mycobacterium tuberculosis were analysed by pyrazinamide susceptibility testing and pyrazinamidase assay, as well as polymerase chain reaction for single-strand conformational polymorphism and direct sequencing of the gene encoding pyrazinamidase (pncA). All sensitive isolates showed pyrazinamidase activity and a wild-type pncA gene, but three resistant isolates had pncA gene mutations and lacked pyrazinamidase activity. The latter isolates showed a minimum inhibitory concentration of at least 100 mg/l by the 7H10 agar proportion method and 400 mg/l by the 7H9 liquid medium method. Isolate 28 showed T-to-C change at position 11, leading to Leu4→Ser substitution; isolate 29 had an 8-bp deletion from position 382; and isolate 30 had A-to-C change at position 29, leading to Gln10→Pro substitution. The deletion has not been described previously. This is the first demonstration of pncA gene mutations in PZA-resistant M. tuberculosis strains isolated from Japanese patients.

Numerous investigators have reported an increased incidence of pneumonia caused by Gram-negative bacilli and other secondary pathogens in transplant recipients infected by cytomegalovirus (CMV). To determine if CMV infections are related to colonization of the upper respiratory tract by Gram-negative bacilli, we examined prospectively 22 renal transplant recipients with sequential bacteriological, virological and biochemical examinations performed just prior to and at various times after transplantation. Only 11% of subjects had Gram-negative bacilli isolated from gargle specimens prior to transplantation, as compared to 54% after transplantation. More importantly, after transplantation, subjects with active CMV infections were more likely to have prolonged oropharyngeal carriage of Gram-negative bacilli than subjects without CMV infections (36% v.. 25%). During active CMV infections, the rate at which Gram-negative bacilli were isolated from gargle specimens rose from 28 to 47%. During culture-positive CMV infections, the isolation rate reached 57% and was significantly different from that of CMV-negative samples (P < 0·01). The increased rate of Gram-negative bacillary isolation from gargle specimens during CMV infections was not a function of type of immunosuppresive agents used, rejection episodes, antibiotic administration, concomitant hepatitis B, Epstein–Barr (EBV) virus, or herpes simplex virus infections, or alterations in salivary fibronectin concentrations.

Borrelia burgdorferi isolates were obtained from Ixodes ricinus from three sites in Switzerland. They were examined by SDS-PAGE and immunoblotting. The phenotypes, in respect of three outer surface proteins (Osp), differed between the sites of collection. In site 1, most isolates had an OspA of 31 kDa and an OspB of 34 kDa: in site 2, isolates presenting an OspA of 33 kDa dominated and in site 3, the isolates with an OspA of 32 kDa and an OspB of 35 kDa were most frequent. This distribution differed significantly. About half of the isolates from sites 1 and 3 reacted with anti-OspA monoclonal antibody H5332 compared to 29% from site 2. Site 1 isolates reacted significantly more frequently (81 %) with another anti-OspA monoclonal antibody LA-31 than isolates from site 3 (P < 0·0001). These findings have implications for the epidemiology of Lyme borreliosis, for the further development of serodiagnostic reagents and for the development of a vaccine.

Titres of haemagglutination-inhibiting antibody have been measured repeatedly in young women during a period of 6–8 years after the administration of RA27/3 and Cendehill attenuated rubella vaccines. Mean antibody titres were initially 217 after RA27/3 and 159 after Cendehill, but the difference diminished after the first year. Antibody titres were subsequently well maintained in both groups and did not reveal any need for regular revaccination. Mean titres in the Cendehill group were partly maintained by symptomless reinfection which was commoner after Cendehill than after RA27/3. Significant falls in titre were equally common after both vaccines, but low titres of 30 or less were more frequent in subjects who had received Cendehill.

Mean neutralizing antibody titres were initially 15·4 after RA27/3 vaccine and 9 after Cendehill. Titres remained higher after RA27/3 for 3 years, but the difference then diminished and became insignificant during the fifth year.

Revaccination of women with low antibody titres produced significant increases in 69% of subjects when standard RA27/3 vaccine was used; a special preparation of RA27/3 of higher potency produced a similar number of rises (70%) but elicited higher titres and might occasionally be useful for revaccinating women who are likely to come into contact with rubella. Challenge with RA27/3 vaccine produced weaker responses in women who had experienced natural infection than in those whose antibody was vaccine-induced.

Rises in antibody titre after revaccination consisted mainly of IgG, but traces of IgM antibody were detected in one vaccinee who had recently experienced natural reinfection and in 1 woman with naturally acquired antibody who had been challenged with high titre RA27/3 vaccine.

Backward trajectories of winds were determined to identify possible sources of eastern equine encephalitis virus associated with isolation of virus from mosquitoes or birds or outbreaks in horses between 1980 and 1985 in Maryland, New Jersey, New York and Michigan, USA.

The results of the trajectory analyses suggested that eastern equine encephalitis virus could have been carried by infected mosquitoes on surface winds at temperatures 13 °C or higher from North Carolina north-eastwards along the Atlantic Coast to Maryland and New Jersey and thence to upstate New York and from western Kentucky to Michigan. Landing of mosquitoes was associated with the presence of a cold front and rain leading to variations in the location and timing of outbreaks from year to year. The mosquito responsible was most likely to have been Culiseta melanura, but Coquillettidia perturbans and Aedes sollicitans could also have been involved.

There may be a continual cycle of eastern equine encephalitis virus in mosquitoes and birds in south-eastern USA, from where the virus could be distributed by infected mosquitoes on the wind along the Gulf and Atlantic Coasts and up the Mississippi Valley.

Rabies was eradicated from the UK in 1922 through strict controls of dog movement and investigation of every incident of disease. Amendments were made to the UK quarantine laws and the Pet Travel Scheme (PETS) was subsequently introduced in 2000 for animals entering the UK from qualifying listed countries. European Regulation 998/2003 on the non-commercial movement of pet animals initiated the European Union Pet Movement Policy (EUPMP) in July 2004. The introduction of EUPMP harmonized the movement of pet animals within the EU (EUPMPlisted) but raised the possibility of domestic animals entering the UK from a non-EU state where rabies is endemic (EUPMPunlisted). A quantitative risk assessment was developed to estimate the risk of rabies entering the UK from Turkey via companion animals that are incubating the disease and enter through PETS or EUPMP compared to quarantine. Specifically, the risk was assessed by estimating the annual probability of rabies entering the UK and the number of years between rabies entries for each scheme. The model identified that the probability of rabies entering the UK via the three schemes is highly dependent on compliance. If 100% compliance is assumed, PETS and EUPMPunlisted (at the current level of importation) present a lower risk than quarantine, i.e. the number of years between rabies entry is more than 170 721 years for PETS and 60 163 years for EUPMPunlisted compared to 41 851 years for quarantine (with 95% certainty). If less than 100% compliance is assumed, PETS and EUPMPunlisted (at the current level of importation) present a higher risk. In addition, EUPMPlisted and EUPMPunlisted (at an increased level of importation) present a higher risk than quarantine or PETS at 100% compliance and at an uncertain level of compliance.

In order to analyse the impact of vaccination against cytomegalovirus (CMV) on congenital infection incidence using current vaccines tested in phase II clinical trials, we simulated different scenarios by mathematical modelling, departing from the current vaccine characteristics, varying age at vaccination, immunity waning, vaccine efficacy and mixing patterns. Our results indicated that the optimal age for a single vaccination interval is from 2 to 6 months if there is no immunity waning. Congenital infection may increase if vaccine-induced immunity wanes before 20 years. Congenital disease should increase further when the mixing pattern includes transmission among children with a short duration of protection vaccine. Thus, the best vaccination strategy is a combined schedule: before age 1 year plus a second dose at 10–11 years. For CMV vaccines with low efficacy, such as the current ones, universal vaccination against CMV should be considered for infants and teenagers.

Although many people became infected and recovered during the COVID-19 epidemic, the immunity duration and re-infection in recovered patients have recently attracted many researchers. The aim of this study was to evaluate the recurrence of the infection in recovered individuals over a 9-month period after the onset of the COVID-19 epidemic. In this study, data related to COVID-19 patients in Shahroud city were collected using the electronic system for registering suspicious patients and also by checking patients' hospital records. In this study, from 20 March 2020 to 20 November 2020 (9 months), a total of 8734 suspected patients with respiratory symptoms were observed and followed up. RT-PCR was positive for 4039 patients. During this period, out of the total number of positive cases of COVID-19, 10 cases became re-infected after complete recovery. The risk of re-infection was 2.5 per thousand (0.95 CI 1.2–4.5). The mean time interval between the first infection and re-infection was 134.4 ± 64.5 days (range 41–234 days). The risk of re-infection between male and females was not statistically different (1.98 per 1000 women and 2.96 per 1000 men). Exposure to COVID-19 may not establish long-term protective immunity to all patients and may predispose them to re-infection. This fact can be reminded that the use of masks, social distancing and other preventive measures are very important in recovered patients and should be emphasised especially in health care personnel who are more exposed to the virus.

The isolation of fusiform bacilli from typical tropical ulcer is described and an account is given of the motility and staining properties of the organisms cultivated.

Experimental inoculations, both in man and animals, are recorded in tabular form and the results of the investigation discussed.

Understanding how seasonality shapes the dynamics of tuberculosis (TB) is essential in determining risks of transmission and drug resistance in (sub)tropical regions. We developed a relative fitness-based multidrug-resistant (MDR) TB model incorporated with seasonality and a probabilistic assessment model to assess infection risk in Taiwan regions. The model accurately captures the seasonal transmission and population dynamics of TB incidence during 2006–2008 and MDR TB in high TB burden areas during 2006–2010 in Taiwan. There is ∼3% probability of having exceeded 50% of the population infected attributed to MDR TB. Our model not only provides insight into the understanding of the interactions between seasonal dynamics of TB and environmental factors but is also capable of predicting the seasonal patterns of TB incidence associated with MDR TB infection risk. A better understanding of the mechanisms of TB seasonality will be critical in predicting the impact of public control programmes.

Monitoring injecting drug users' (IDUs) health is challenging because IDUs form a difficult to reach population. We examined the impact of recruitment setting on hepatitis C prevalence. Individual datasets from 12 studies were merged. Predictors of HCV positivity were sought through a multilevel analysis using a mixed-effects logistic model, with study identifier as random intercept. HCV prevalence ranged from 21% to 86% across the studies. Overall, HCV prevalence was higher in IDUs recruited in drug treatment centres compared to those recruited in low-threshold settings (74% and 42%, respectively, P < 0·001). Recruitment setting remained significantly associated with HCV prevalence after adjustment for duration of injecting and recent injection (adjusted odds ratio 0·7, 95% confidence interval 0·6–0·8, P = 0·05). Recruitment setting may have an impact on HCV prevalence estimates of IDUs in Europe. Assessing the impact of mixed recruitment strategies, including respondent-driven sampling, on HCV prevalence estimates, would be valuable.

Sinks in a new long-stay hospital (LSH) were cultured weekly during 4 consecutive months to evaluate the microbial profile before and after occupancy of the hospital. From the elderly patients admitted to the patient care rooms oral and rectal specimens were collected to examine the contribution of the patients' flora to the sink contamination. Isolates were typed biochemically, serologically and by susceptibility pattern. Before occupancy Gram-negative bacilli were not isolated. Once the elderly patients, who were highly colonized on admission, occupied their rooms identical strains gradually contaminated the sinks. Escherichia coli, Klebsiella, Pseudomonas and Acinetobacter species were the major correlating strains. The mean concentration of the correlating isolates was higher in throat and intestines compared to the mean concentration of the non- correlating strains. These strains seem to have a greater chance to be shed and then transferred via the hands of personnel to sinks. This resport shows that the major route of environmental contamination is from patient carriers to sinks, and not the reverse way.