High-throughput sequencing technologies now allow for rapid cost-effective surveys of multiple pathogens in many host species including rodents, but it is currently unclear if the organ chosen for screening influences the number and identity of bacteria detected. We used 16S rRNA amplicon sequencing to identify bacterial pathogens in the heart, liver, lungs, kidneys and spleen of 13 water voles (Arvicola terrestris) collected in Franche-Comté, France. We asked if bacterial pathogen assemblages within organs are similar and if all five organs are necessary to detect all of the bacteria present in an individual animal. We identified 24 bacteria representing 17 genera; average bacterial richness for each organ ranged from 1·5 ± 0·4 (mean ± standard error) to 2·5 ± 0·4 bacteria/organ and did not differ significantly between organs. The average bacterial richness when organ assemblages were pooled within animals was 4·7 ± 0·6 bacteria/animal; Operational Taxonomic Unit accumulation analysis indicates that all five organs are required to obtain this. Organ type influences bacterial assemblage composition in a systematic way (PERMANOVA, 999 permutations, pseudo-F4,51 = 1·37, P = 0·001). Our results demonstrate that the number of organs sampled influences the ability to detect bacterial pathogens, which can inform sampling decisions in public health and wildlife ecology.

The object of the inquiry reported upon in this paper was to determine whether there was any measurable association between the development of intelligence and the incidence of disease in school children.

Dengue virus type 3 genotype III (DENV-3/III) is widely distributed in most dengue-endemic regions. It emerged in Malaysia in 2008 and autochthonously spread in the midst of endemic DENV-3/I circulation. The spread, however, was limited and the virus did not cause any major outbreak. Spatiotemporal distribution study of DENV-3 over the period between 2005 and 2011 revealed that dengue cases involving DENV-3/III occurred mostly in areas without pre-existing circulating DENV-3. Neutralisation assays performed using sera of patients with the respective infection showed that the DENV-3/III viruses can be effectively neutralised by sera of patients with DENV-3 infection (50% foci reduction neutralisation titres (FRNT50) > 1300). Sera of patients with DENV-1 infection (FRNT50 ⩾ 190), but not sera of patients with DENV-2 infection (FRNT50 ⩽ 50), were also able to neutralise the virus. These findings highlight the possibility that the pre-existing homotypic DENV-3 and the cross-reacting heterotypic DENV-1 antibody responses could play a role in mitigating a major outbreak involving DENV-3/III in the Klang Valley, Malaysia.

The results of immunization of 523 children from 9 months to over 5 years of age with two attenuated measles vaccines, ‘Denken’ and ‘Biken’, are described. The clinical reactions following vaccination with both vaccines were mild, but Denken vaccine produced more rashes than the Biken vaccine. The serological conversion was satisfactory for both vaccines but a higher titre of neutralizing and haemagglutination-inhibiting antibodies was found in children immunized with Denken vaccine. The incidence of severe reactions or complications was negligible in this trial. The immunity to diphtheria or tetanus was not altered by vaccination with live measles vaccine.

To assess the relationship between the neutrophil-to-lymphocyte ratio (NLR) and related parameters to the severity of coronavirus disease 2019 (COVID-19) symptoms. Clinical data from 38 COVID-19 patients who were diagnosed, treated and discharged from the Qishan Hospital in Yantai over the period from January to February 2020 were analysed. NLR and procalcitonin (PCT) were determined in the first and fourth weeks after their admission, along with the clinical characteristics and laboratory test results of these patients. Based on results as obtained on the first and fourth weeks after admission, five indices consisting of NLR, white blood cells, neutrophils, lymphocytes (LY) and monocytes (MON) were selected to generate receiver operating characteristic curves, while optimal cutoff values, sensitivities and specificities were obtained according to the Yuden index. Statistically significant differences in neutrophils, LY and the NLR were present in the severe vs. moderate COVID-19 group from the first to the fourth week of their hospitalisation. The cut-off value of NLR for predicting the severity of COVID-19 was 4.425, with a sensitivity of 0.855 and a specificity of 0.979. A statistically significant positive correlation was present between PCT and NLR in the severe group as determined within the first week of admission. NLR can serve as a predictor of COVID-19 disease severity as patients' progress from the first to the fourth week of their hospitalisation. The statistically significant positive correlation between levels of NLR and PCT in severe patients indicated that increases in NLR were accompanied with gradual increases in PCT.

A cluster of Legionnaires' disease (LD) with 10 confirmed, three probable and four possible cases occurred in August and September 2016 in Dendermonde, Belgium. The incidence in the district was 7 cases/100 000 population, exceeding the maximum annual incidence in the previous 5 years of 1.5/100 000. Epidemiological, environmental and geographical investigations identified a cooling tower (CT) as the most likely source. The case risk around the tower decreased with increasing distance and was highest within 5 km. Legionella pneumophila serogroup 1, ST48, was identified in a human respiratory sample but could not be matched with the environmental results. Public health authorities imposed measures to control the contamination of the CT and organised follow-up sampling. We identified obstacles encountered during the cluster investigation and formulated recommendations for improved LD cluster management, including faster coordination of teams through the outbreak control team, improved communication about clinical and environmental sample analysis, more detailed documentation of potential exposures obtained through the case questionnaire and earlier use of a geographical information tool to compare potential sources and for hypothesis generation.

In rapidly growing and high-burden urban centres, identifying tuberculosis (TB) transmission hotspots and understanding the potential impact of interventions can inform future control and prevention strategies. Using data on local demography, TB reports and patient reporting patterns in Dhaka South City Corporation (DSCC) and Dhaka North City Corporation (DNCC), Bangladesh, between 2010 and 2017, we developed maps of TB reporting rates across wards in DSCC and DNCC and identified wards with high rates of reported TB (i.e. ‘hotspots’) in DSCC and DNCC. We developed ward-level transmission models and estimated the potential epidemiological impact of three TB interventions: active case finding (ACF), mass preventive therapy (PT) and a combination of ACF and PT, implemented either citywide or targeted to high-incidence hotspots. There was substantial geographic heterogeneity in the estimated TB incidence in both DSCC and DNCC: incidence in the highest-incidence wards was over ten times higher than in the lowest-incidence wards in each city corporation. ACF, PT and combined ACF plus PT delivered to 10% of the population reduced TB incidence by a projected 7%–9%, 13%–15% and 19%–23% over five years, respectively. Targeting TB hotspots increased the projected reduction in TB incidence achieved by each intervention 1.4- to 1.8-fold. The geographical pattern of TB notifications suggests high levels of ongoing TB transmission in DSCC and DNCC, with substantial heterogeneity at the ward level. Interventions that reduce transmission are likely to be highly effective and incorporating notification data at the local level can further improve intervention efficiency.

1. Rabbit cells show a marked variation in agglutination when reacting with apparently homologous iso-antisera.

2. This phenomenon has been investigated in two ways:

(a) Samples of apparently homologous antisera have been absorbed with (i) strongly agglutinating cells, (ii) poorly agglutinating cells. It was found that strongly agglutinating cells absorbed the antibody completely and rapidly from the serum, whilst poorly agglutinating cells, though they absorbed it completely, did so much more slowly. Also, when a serum which had been absorbed with poorly agglutinating cells until these no longer reacted with it was titrated against strongly agglutinating cells, these were still strongly agglutinated. This showed a source of serious error when investigating new sera by absorption techniques and when using weak antisera for grouping purposes.

(b) Poorly agglutinating cells were injected into rabbits, and the antisera so obtained were examined against strongly agglutinating cells and against the poorly agglutinating cell used as the antigen. The antibody response was poor; two out of eight rabbits developed an antibody, and strongly agglutinating cells reacted more strongly with these antisera than the poorly agglutinating cells which had been used as the antigen.

3. Three hypotheses for this variation in agglutination have been put forward and discussed:

(a) That the variation is due to cross reactions between numbers of closely related antigen-antibody systems. The results of the investigations 2 (a) and 2(b) suggest that this is unlikely.

(b) That the disposition of antigen sites on the surface of the red cell is a factor determining the agglutinability of the cell. It is considered that this might play a subsidiary role in the phenomenon as it is shown in the rabbit.

(c) That rabbit red cell agglutinability is mainly determined by the number of antigen sites on the cell available to the antibody. The experimental results can be explained on this hypothesis, and it is suggested that this may be the main factor accounting for the behaviour of rabbit red cells. It is pointed out that supporting evidence for this is afforded by measurements with radio iodinated antisera.

Gas production by coliform organisms and Escherichia coli from lauryl tryptose lactose broth (LTLB) was compared with that from brilliant green (lactose) bile broth (BGB). These media were compared with lauryl tryptose mannitol broth (LTMB) with and without added tryptophan for both gas and indole production. At 37 °C, LTLB and BGB were both satisfactory for gas production, but at 44 °C, LTLB gave fewer false-negative results and was thus significantly less inhibitory than BGB. However when LTLB and LTMB were compared as single-tube confirmatory media, LTLB give a high proportion of false-negative reactions in the indole test at 44 °C. The substitution of mannitol for lactose and the addition of tryptophan yielded a satisfactory medium for both confirmation of gas production and the demonstration of indole at 44 °C.

Serum proteins adsorbed from the culture medium were detected in Mycoplasma bovis antigens, the number and type of proteins depending on the serum used in the medium. The α-globulins cross-reacted with α-globulins from different types of sera but the γ-globulins did not. The removal of non-specific medium antibodies by absorption showed that they affected the gel diffusion and growth precipitation tests, producing cross-reactions between M. bovis and M. bovigenitalium, but that the complement fixation, tube agglutination, and growth inhibition tests were not similarly affected. The presence of serum proteins in the antigens changed their specific reactivity in all the tests. The production of antibodies to serum proteins was increased by the use of an adjuvant, but it appeared that production of specific antibodies to the mycoplasmas was not.

In January 1940 British Ministry of Health circular 1307 proposed the introduction of mass childhood diphtheria immunization. This was a policy reversal after a decade during which opportunities for diphtheria prophylaxis were ignored, or resisted on grounds of cost. Diphtheria toxoid was to be the first of many centrally funded childhood immunizations in the UK and it set a pattern that has now held good for over 70 years. The circumstances in 1940 were particularly fortuitous, and diphtheria toxoid has since given successive generations of children a lifetime's protection from the disease; but difficulties have been experienced in introducing and evaluating some of the more recent immunizations, and in maintaining and justifying them in the face of parental scepticism and academic or pressure-group opposition, however ill-founded this may have been. The task of decision-making with regard to new candidate vaccines demands a careful balancing against the costs of the expected benefits during the recipient's lifespan.

Ferrets immunized with an H3N2 recombinant of A/PR/8/34 and A/Scotland/ 840f74 (RIT 4025 vaccine strain) were almost completely protected against a challenge with the homologous strain A/Scotland/ 840/ 74. The protection was lower but highly significant when the challenge was performed with the heterologous A/Victoria/3f75 wild strain. The protection afforded by the vaccine strain was measured by three indicators: absence of temperature rise, absence or reduction of virus shedding and absence or reduction of nasal protein increase when compared with uninoculated controls.

Heterotypic immunity in this animal model was not significant when these three indicators were measured after a challenge inoculation performed 5 weeks after immunization.

During the first phase of the COVID-19 pandemic in 2020, concerns were raised that healthcare workers (HCWs) were at high risk of infection. The aim of this study was to explore the transmission of COVID-19 among HCWs during a staff outbreak at an inpatient ward in Sweden 1 March to 31 May 2020. A mixed-methods approach was applied using several data sources. In total, 152 of 176 HCWs participated. The incidence of COVID-19 among HCWs was 33%. Among cases, 48 (96%) performed activities involving direct contact with COVID-19 patients. Contact tracing connected 78% of cases to interaction with another contagious co-worker. Only a few HCW cases reported contact with a confirmed COVID-19 case at home (n = 6; 12%) or in the community (n = 3; 6%). Multiple logistic regression identified direct care of COVID-19 patients and positive COVID-19 family contact as risk factors for infection (adjusted OR 8.4 and 9.0 respectively). Main interventions to stop the outbreak were physical distancing between HCWs, reinforcement of personal hygiene routines and rigorous surface cleaning. The personal protective equipment used in contact with patients was not changed in response to the outbreak. We highlight HCW-to-HCW transmission of COVID-19 in a hospital environment and the importance of preventing droplet and contact transmission between co-workers.

1. Calculated values of the virtual sterilization time (v.s.t.) have been used in an analysis of the effect of temperature on the concentration exponent of the reaction between phenol and Bact. coli cultures under rigidly standardized conditions.

2. Within the experimental range of temperature and concentration employed, the exponent calculated from the formula Cn × t = K was satisfactorily constant from 20° to 35° C., but it apparently increased at 39° C.

3. This formula is unsatisfactory in that it cannot apply to concentrations near the threshold value without a change in the value of n. Accordingly, a new method of treating these data has been suggested which makes allowance for this threshold or minimum concentration. A corresponding ‘maximum’ concentration has been arbitrarily fixed at which the v.s.t. is 10 min. and the value of (v.s.t. – 10) thus varies from infinity to zero between these concentration limits.

4. Sigmoid curves asymptotic to ordinates at the minimum and maximum concentrations must be obtained when log (v.s.t. – 10) is plotted against concentration and the equation of the Pearl-Verhulst logistic curve, which is of the required type, has been used successfully to express the relationship between v.s.t. and concentration at constant temperature.

5. One of the constants of this formula partakes of the nature of a concentration exponent and this may be constant over the full effective concentration range and for all temperatures.

6. The logistic formula relating v.s.t. to concentration at constant temperature is closely related to that connecting v.s.t. with temperature at constant concentration. The two formulae become interconvertible if certain assumptions are made concerning the relationships between the minimum and maximum concentrations and temperature.

Salmonella enterica serotype Abortusovis, an ovine host-specific serotype, rare in most countries, is responsible for epidemic abortion episodes in Spain. With the aim of surveillance and detection of the spread of specific clones, 55 Abortusovis isolates collected during 1996–2001 from flocks in 11 provinces, were studied using XbaI–PFGE. Despite the fact that the strains were geographically and spatially related, PFGE demonstrated an epidemiologically acceptable discriminating power, identifying 20 clones (similarity, 52–96%). Clones Sabv6, 1, 5 were disseminated in seven, five and two areas respectively, while another 17 clones appeared in single places. Clones from nearby geographic regions showed a high relatedness (one band of difference in the PFGE profile) Sabv1-2-3, Sabv5-6, Sabv7-8, and Sabv13-14, suggesting a common ancestor. Co-isolation in the same flock (Sabv5-6, Sabv1-3, Sabv1-6) was detected. PFGE surveillance detected the predominance and widespread distribution of clone Sabv6 in 21 out of the 55 Abortusovis serotype episodes studied in Spain.

Different countries have adopted strategies for the early detection of SARS-CoV-2 since the declaration of community transmission by the World Health Organization (WHO) and timely diagnosis has been considered one of the major obstacles for surveillance and healthcare. Here, we report the increase of the number of laboratories to COVID-19 diagnosis in Brazil. Our results demonstrate an increase and decentralisation of certified laboratories, which does not match the much higher increase in the number of COVID-19 cases. Also, it becomes clear that laboratories are irregularly distributed over the country, with a concentration in the most developed state, São Paulo.

Although handwashing is an effective way to prevent infections, there is scarce evidence on predictors of handwashing during a pandemic. This paper aims to identify behavioural and demographic predictors of handwashing. The study surveyed 674 adults in Malaysia in May 2020 regarding whether the time spent on social media predicted handwashing contingent on gender and number of children. More time spent on social media was positively associated with handwashing for males with three or more children. However, for males without children, social media use was negatively associated with handwashing. The association was not significant for males with one or two children. For females, more time spent on social media was significantly linked to more handwashing only for females with one child. Gender, a traditional predictor of handwashing, was a useful predictor only for those who spent more than three hours per day on social media and had at most one child. Number of children was a novel negative predictor for males who did not use social media and who averaged one hour per day on social media, a positive predictor for males who spent lots of time on social media, but not a predictor for females. In sum, social media use predicts handwashing, and is thus a helpful variable for use in targeted health communication during a pandemic – particularly through social media. Further, more conventional predictors like gender and number of children exhibit contingency effects with social media use.

The objective of the study was to assess whether genotypic characterization by means of DNA-fingerprinting pattern (DFP) and multilocus enzyme electrophoresis (MEE) profile as compared to phenotypic characterization would improve the differentiation of Neisseria meningitidis strains associated with outbreaks from strains associated with sporadic cases of meningococcal disease. In addition, the differentiation of serogroup C carrier strains from those associated with an outbreak of serogroup C meningococcal disease was investigated.

A total of 118 N. meningitidis strains were available for the study: 59 from patients involved in outbreaks of meningococcal disease (2 serogroup B and 2 serogroup C), 37 from patients considered to be sporadic cases and 22 serogroup C carrier strains.

Among the 59 strains from patients involved in outbreaks the 4 strains isolated from the patient registered as the first in each outbreak were designated the index strains. Among the remaining 55 outbreak strains 52 were either DFP-identical or DFP-indistinguishable when compared with the one relevant out of the 4 index strains. This was only the case for 17 of the 37 strains isolated from sporadic cases caused by the same serogroup of meningococci during the outbreak periods, and 5 of the 22 meningococcal strains isolated from healthy carriers. Among the 56 (52 + 4) DFP-identical or DFP-indistinguishable outbreak strains 5 different electrophoretic types were identified by MEE.

Among 59 assumed outbreak strains a total of 4 were identified as genotypically distinct. Among the 37 mainly DFP-indistinguishable or DFP-different strains from sporadic cases 17 different ETs were identified, and among the 22 mainly DFP-different carrier strains 13 different ETs were identified. Two strains among those selected from sporadic cases were identical to the outbreak strain. None of the local serogroup C carrier strains isolated during the outbreak of serogroup C disease were identical to the outbreak strain.

Both DNA-fingerprinting and MEE improved the differentiation of meningococci when compared with phenotypic characterization. The results indicate that tracing a virulent strain within an open group of contacts is irrelevant.

Seasonal influenza is a significant public health concern globally. While influenza vaccines are the single most effective intervention to reduce influenza morbidity and mortality, there is considerable debate surrounding the merits and consequences of repeated seasonal vaccination. Here, we describe a two-season influenza epidemic contact network model and use it to demonstrate that increasing the level of continuity in vaccination across seasons reduces the burden on public health. We show that revaccination reduces the influenza attack rate not only because it reduces the overall number of susceptible individuals, but also because it better protects highly connected individuals, who would otherwise make a disproportionately large contribution to influenza transmission. We also demonstrate that our results hold on an empirical contact network, in the presence of assortativity in vaccination status, and are robust for a range of vaccine coverage and efficacy levels. Our work contributes a population-level perspective to debates about the merits of repeated influenza vaccination and advocates for public health policy to incorporate individual vaccine histories.

We examined the uptake of HIV testing in black Africans living in England before the introduction of national testing guidelines. Analyses were conducted using data from an anonymous self-completed questionnaire linked to oral fluid samples to establish HIV status in black Africans attending community venues in England in 2004. Of 946 participants, 44% had ever been tested for HIV and 29% had been tested in the previous 24 months. Of those with undiagnosed HIV, 45% had previously had a negative HIV test. Almost a third of people tested in the UK had been at general practice. Uptake of HIV testing was not associated with perceived risk of HIV. These findings highlight the need for the implementation of national HIV testing guidelines in the UK, including the promotion of testing in general practice. Regular testing in black Africans living in the UK should be promoted regardless of their HIV test history.