A technique involving the suppression of normal intestinal flora with antibiotics, and the introduction of streptomycin-resistant coliforms was used for the study of infections in mice.

It was shown that Escherichia coli, both the enteropathogenic and normal faecal strains, tend to colonize the upper intestinal tract as well as the lower region. An oral dose of ten or less cells could produce a chronic infection. Infections were asymptomatic even with an initial dose of 109 bacteria. There was no indication of growth advantages for enteropathogenic coliforms in competition with normal.

A mathematical model has been developed which allows estimation of the epidemiological and economic effects of different tetanus vaccination strategies. The model was used to simulate the epidemiology of tetanus in italy from 1955 to 1982, and then applied to a district of Tuscany by utilizing data obtained from a seroepidemiological survey carried out in the same area. For this district we simulated vaccination programmes designed to reach, within 1 or 10 years, coverages of 60 or 90% of the population aged over 10 years who had not been exposed to the neonatal vaccination programme. The most effective strategy, from both the epidemiological and economic point of view, seems to be 90% coverage reached in 1 year's time. Benefits would be increased by improving the reliability of vaccinal anamnesis.

Gatherings where people are eating and drinking can increase the risk of getting and spreading SARS-CoV-2 among people who are not fully vaccinated; prevention strategies like wearing masks and physical distancing continue to be important for some groups. We conducted an online survey to characterise fall/winter 2020–2021 holiday gatherings, decisions to attend and prevention strategies employed during and before gatherings. We determined associations between practicing prevention strategies, demographics and COVID-19 experience. Among 502 respondents, one-third attended in person holiday gatherings; 73% wore masks and 84% practiced physical distancing, but less did so always (29% and 23%, respectively). Younger adults were 44% more likely to attend gatherings than adults ≥35 years. Younger adults (adjusted prevalence ratio (aPR) 1.53, 95% CI 1.19–1.97), persons who did not experience COVID-19 themselves or have relatives/close friends experience severe COVID-19 (aPR 1.56, 95% CI 1.18–2.07), and non-Hispanic White persons (aPR 1.57, 95% CI 1.13–2.18) were more likely to not always wear masks in public during the 2 weeks before gatherings. Public health messaging emphasizing consistent application of COVID-19 prevention strategies is important to slow the spread of COVID-19.

In 1929, for the third time in the present century, cerebrospinal fever occurred in Glasgow in epidemic form. The first epidemic, which was by far the most severe, was in 1906–8, the total number of cases recorded being 1363. Descriptions of the events of these years were given by Dr A. K. Chalmers (1906) in the Annual Reports of the Medical Officer of Health of Glasgow for 1906 and 1907, and also in a paper read before the Epidemiological Society. In this outbreak the fatality rate of cases treated in hospital was given as 74·8 per cent. by Currie and Macgregor (1908). The total number of cases admitted to hospital was 910. The incidence of the disease was highest during the months of January to May of 1907, and there was a slight recrudescence in the same months of the following year. The characteristics of the epidemic form of cerebro-spinal fever were present in so far as there occurred several instances of multiple infection in the same house, and a number of cases showed the exanthem peculiar to the disease.

‘And the hand of the Lord was heavy upon the Azotians, and he destroyed them, and afficted Azotus and the coasts thereof with emerods. And in the villages and fields in the midst of that country, there came forth a multitude of mice; and there was the confusion of a great mortality in the city.

Cholera is one of the major public health problems in the state of Odisha, India since centuries. The current paper is a comprehensive report on epidemiology of cholera in Odisha, which was documented from 1993. PubMed and Web of Knowledge were searched for publications reporting cholera in Odisha during the period 1993–2015. The search was performed using the keywords ‘Odisha’ and/or ‘Orissa’ and ‘Cholera’. In addition, manual search was undertaken to find out relevant papers. During the study period, a total of 37 cholera outbreaks were reported with an average of >1.5 cholera outbreaks per year and case fatality ratio was 0.3%. Vibrio cholerae O1 Ogawa serotype was the major causative agent in most of the cholera cases. The recent studies demonstrated the prevalence of V. cholerae O1, El Tor variants carrying ctxB1, ctxB7 and Haitian variant tcpA allele associated with polymyxin B sensitivity and these variants are replacing the proto type El Tor. The first report of variant ctxB7 in Odisha during super-cyclone 1999 predicted its emergence and subsequent spread causing cholera outbreaks. The prevalence of multidrug-resistant V. cholerae at different time periods created alarming situation. The efficacy trial of oral cholera vaccine (OCV, Shanchol) in a public health set-up in Odisha has shown encouraging results which should be deployed for community level vaccination among the vulnerable population. This paper has taken an effort to disseminate the valuable information of epidemiology of cholera that will influence the policy-makers and epidemiologists for constant surveillance in other parts of Odisha, India and around the globe.

This study included 502 staphylococcus strains; Staphylococcus saprophyticus (297 strains) S. cohnii (47), S. xylosus (10), S. epidermidis (67) and S. aureus (81). Mitomycin C induction was performed on 100 isolates of S. saprophyticus and all induced strains were reacted with each other. Twenty-six strains proved to be lysogenic. Phages were propagated and titrated. With 12 of the phages there were three frequent associations, named lytic groups A, B and C, which included 75% of all typable strains. Typability of the system was 45% and reproducibility was between 94.2% and 100%. Phages did not lyse S. aureus and S. epidermidis strains, but they lysed S. saprophyticus and only rare strains of other novobiocin resistant species. Effective S. saprophyticus typing serves ecological purposes and tracing the origin of urinary strains from the skin or mucous membranes. Phage typing in association with plasmid profiling previously described, are anticipated as complementary methods with strong discriminatory power for differentiating among S. saprophyticus strains.

Imprecise values arise when bacterial colonies are too numerous to be counted or when no colonies grow at a specific dilution. Our objective was to show the usefulness of multiple imputation in analysing data containing imprecise values. We also indicate that interval censored regression, which is faster computationally in situations where it applies, can be used, providing similar estimates to imputation. We used bacteriological data from a large epidemiological study in daycare centres to illustrate this method and compared it to a standard method which uses single exact values for the imprecise data. The data consisted of numbers of FC on children's and educators' hands, from sandboxes and from playareas. In general, we found that multiple imputation and interval censored regression provided more conservative intervals than the standard method. The discrepancy in the results highlights both the importance of using a method that best captures the uncertainty in the data and how different conclusions might be drawn. This can be crucial for both researchers and those who are involved in formulating and regulating standards for bacteriological contamination.

Successive waves of COVID-19 transmission have led to exponential increases in new infections globally. In this study, we have applied a decision-making tool to assess the risk of continuing transmission to inform decisions on tailored public health and social measures (PHSM) using data on cases and deaths reported by Member States to the WHO Regional Office for Africa as of 31 December 2020. Transmission classification and health system capacity were used to assess the risk level of each country to guide implementation and adjustments to PHSM. Two countries out of 46 assessed met the criteria for sporadic transmission, one for clusters of cases, and 43 (93.5%) for community transmission (CT) including three with uncontrolled disease incidence (Eswatini, Namibia and South Africa). Health system response's capacities were assessed as adequate in two countries (4.3%), moderate in 13 countries (28.3%) and limited in 31 countries (64.4%). The risk level, calculated as a combination of transmission classification and health system response's capacities, was assessed at level 0 in one country (2.1%), level 1 in two countries (4.3%), level 2 in 11 countries (23.9%) and level 3 in 32 (69.6%) countries. The scale of severity ranged from 0 to 4, with 0 the lowest. CT coupled with limited response capacity resulted in a level 3 risk assessment in most countries. Countries at level 3 should be considered as priority focus for additional assistance, in order to prevent the risk rising to level 4, which may necessitate enforcing hard and costly lockdown measures. The large number of countries at level 3 indicates the need for an effective risk management system to be used as a basis for adjusting PHSM at national and sub-national levels.

In Atlantic Canada, the traditional risk factor for acquisition of Q fever infection has been exposure to infected parturient cats or newborn kittens. In this study we describe the first case of Q fever in Nova Scotia acquired as a result of direct exposure to sheep. A serosurvey of the associated flock was undertaken using an indirect immunofluorescence assay (IFA) testing for antibodies to phase I and phase II Coxiella burnetii antigens. This serosurvey revealed that 23 of 46 sheep (50%) were seropositive for the phase II antibody. Four of these sheep had titres of 1:64 including three nursing ewes, one of which had delivered two lambs that died shortly after delivery. Only one ewe had phase I antibodies but had the study's highest phase II antibody titre (1:128). Molecular studies using polymerase chain reaction (PCR) failed to detect C. burnetii DNA in any of the milk specimens.

Reports have suggested that isoniazid treatment may be associated with poor concentration and subtle reduction in memory. This study examines attentional function and processing speed in a group of 25 adolescents who received isoniazid prophylaxis for at least 6 months. As adolescents often face major educational assessment milestones, such cognitive side effects may have important implications. Participants were assessed before treatment, 1 month into treatment and at least 1 week after treatment cessation. Measures included the Paced Auditory Serial Addition Test and subtests of the appropriate Wechsler scale sensitive to attention and speed of information processing. Isoniazid does not appear to cause significant adverse effects on attentional function in adolescents.

Enzyme-linked immunoabsorbent assay (ELISA) was used to titrate virus-specific IgG, IgM and IgA levels in nasal secretions, lung lavage fluids and serum samples sequentially obtained from lambs experimentally infected with bovine respiratory syncytial virus (RSV). Virus-specific IgG and IgM responses were measured by the indirect double antibody sandwich ELISA using anti-bovine RSV monoclonal antibody, as capture antibody, and peroxidase-conjugated anti-sheep IgG and anti-sheep IgM. Virus-specific IgA antibodies were measured by antibody capture assay using anti-sheep IgA (α–chain specific) and anti-bovine RSV monoclonal antibodies.

Bovine RSV-specific IgM and IgA antibodies were detected in the serum samples within 6 days post-inoculation (p.i.). Virus-specific IgC antibodies appeared in serum samples 4 days later. In nasal secretions, IgA antibodies appeared 7 days p.i. but IgM antibodies were not detected until 12–16 days p.i. In serum samples, IgM titres were predominant for the first 2 weeks p.i. IgC titres becoming predominant thereafter. In nasal secretions and lung lavage fluids, IgA titres were significantly higher than IgM or IgG titres up to 21 days p.i. (0·01).

The Lf values of diphtheria toxoid alone and in combination with tetanus toxoid or tetanus toxoid plus pertussis vaccine, dried by sublimation in vacuo, sealed under nitrogen, exposed to elevated temperature and rehydrated thereafter were not altered. Lf values declined in samples sealed under air. The values for Kf in the above preparations increased in relation to increased temperatures of exposure for a given time or following exposure to a given temperature for increased time intervals. The sensitivity of the system of testing used was greater following the addition of ‘helper’, a fast flocculating solution of diphtheria toxin, and in the case of dried diphtheria toxoid stored under adverse conditions (sealed under air) for two years, the addition of ‘helper’ was necessary to obtain a flocculation reaction. In general, the results obtained indicated a very high stability for preparations sealed under nitrogen, and a significantly lower stability for preparations sealed under air.

A schedule for the routine serotyping of strains of Bordetella pertussis based on agglutinin production in mice to the K-antigens has been worked out. Mice have been found as satisfactory as rabbits but far more economical for the production of the very small volumes of serum which are required. Agglutinin production, used in conjunction with direct agglutination, provides definitive information about serotype.

M protein gene typing was used to analyse Streptococcus pyogenes clinical isolates collected between 1983 and 1995 in an area of central Italy from patients presenting different types of infections; the same isolates were also characterized by means of DNA fingerprinting.

M type 1 was the most common (50% of study strains), followed by M types 4, 12 and 6. The proportion of M type 12 decreased with time, whereas M type 1 increased, in agreement with data obtained in many different areas. Most invasive strains belonged to types M1 (30%) and M12 (30%); on the other hand, the M1 type did frequently occur also among non-invasive isolates. DNA fingerprinting showed a correlation between M types and DNA patterns. This report provides epidemiological information from a geographic area not sampled recently, and further shows the usefulness of the M genotyping technique, which offers potential advantages over conventional serological typing methods.

Growth of bacteria in an infusion of flax under quiescent conditions resulted in the formation of an acidic liquor with an appreciable content of volatile acids. When a similar infusion was aerated by a continuous current of air, the liquid tended to become alkaline and the content of volatile acids was much smaller and in some cases negligible. Aeration reduced the polluting strength of the liquor, as measured by oxygen absorbed from permanganate and by the biochemical oxygen demand, by much larger amounts than did growth under quiescent conditions.

Experiments with infusion in which the natural flora was allowed to grow, and with sterile infusion inoculated with pure strains of different types of bacteria, showed that the general effect of aeration was to alter the metabolism of the bacteria in the direction of more complete oxidation of the substrate. Balance sheets for carbon showed that the organic carbon lost from the culture was accounted for by the CO2 evolved. Thus carbohydrates, which under anaerobic conditions were fermented to organic acids, neutral volatile compounds, and gases, were oxidized, when the conditions were sufficiently aerobic; to CO2 and water.

The magnitude of the effects observed depended largely on the nature of the organisms present, and partly on the strength of the infusion in which they grew. With pure cultures of Bact. coli, Bact. aerogenes and Bacillus subtilis, and with the natural mixed flora of the flax, aeration at moderate rates in bottles for 3–5 days reduced the value for oxygen absorbed from permanganate by 43–52 %, and the biochemical oxygen demand by 26–92 %, indifferent experiments. The organic carbon content of the infusion was reduced by 30–31 % by Bact. aerogenes, by Bacillus subtilis and by the mixed flora. With streptococci and with a strain of Achromobacterium the effects observed were very small. Aeration at higher rates with diffused air in small open tanks reduced the organic carbon content of a flax infusion by 50 % in about 80 hr., and of a beetroot infusion by 50 % in about 60 hr. Sugar was destroyed during the aeration and disappeared rapidly from the flax infusion in the early stages.

The work described in this paper was carried out in connexion with an investigation of retting of flax and disposal of waste waters, made, as an extramural research, for the Ministry of Supply as part of the programme of the Water Pollution Research Board of the Department of Scientific and Industrial Research. The paper is published by permission of the Chief Scientific Officer, Ministry of Supply, and of the Department.

Two live attenuated measles vaccines developed in baby calf kidney cells, a similar vaccine produced in chick embryo chorioallantoic cells and five vaccines prepared from human diploid cells (HDC) have been studied by subcutaneous injection in groups of susceptible and immune children in three field trials. The results indicated that the vaccine developed in chick embryo cells which caused mild clinical reactions, had induced a lower seroprotection rate in susceptible children and only a low rise in hemagglutination-inhibition (HI) antibody titre in previously immunized children. The serological responses induced by vaccines developed in HDC or in calf kidney cells were satisfactory in both susceptible and immune children. The superiority of HDC grown measles vaccine for revaccination is discussed.

The dose—response relationships between two strains of lymphocytic choriomeningitis virus (WE3 and Armstrong) and two hosts (mice and L cell tube cultures) were determined. The statistical analysis showed that, if infection was regarded as the response, and in the case of Armstrong virus in mice also death, the shapes of the empirical dose—response curves did not deviate from expectation which was based on the zero term of the Poisson distribution. Hence, the hypothesis that individual infectious units are capable of initiating infection and that co-operation is not required, was not contradicted. Furthermore, the units of assay were found to be equally susceptible under the experimental conditions applied.

By way of contrast, the relationship between WE3 virus and mice dying after intracerebral inoculations was found to be more complex. In this case the empirical curve did not run the expected sigmoid course at all, but rather was bell-shaped with a maximum of mortality (92%) at approximately 50 ID 50.

The work was supported by a research grant from the Deutsche Forschungs-gemeinschaft.

The incidence of scarlet fever has increased dramatically in recent years in Chongqing, China, but there has no effective method to forecast it. This study aimed to develop a forecasting model of the incidence of scarlet fever using a seasonal autoregressive integrated moving average (SARIMA) model. Monthly scarlet fever data between 2011 and 2019 in Chongqing, China were retrieved from the Notifiable Infectious Disease Surveillance System. From 2011 to 2019, a total of 5073 scarlet fever cases were reported in Chongqing, the male-to-female ratio was 1.44:1, children aged 3–9 years old accounted for 81.86% of the cases, while 42.70 and 42.58% of the reported cases were students and kindergarten children, respectively. The data from 2011 to 2018 were used to fit a SARIMA model and data in 2019 were used to validate the model. The normalised Bayesian information criterion (BIC), the coefficient of determination (R2) and the root mean squared error (RMSE) were used to evaluate the goodness-of-fit of the fitted model. The optimal SARIMA model was identified as (3, 1, 3) (3, 1, 0)12. The RMSE and mean absolute per cent error (MAPE) were used to assess the accuracy of the model. The RMSE and MAPE of the predicted values were 19.40 and 0.25 respectively, indicating that the predicted values matched the observed values reasonably well. Taken together, the SARIMA model could be employed to forecast scarlet fever incidence trend, providing support for scarlet fever control and prevention.

Our population-based study objectives were to describe characteristics and outcomes of Escherichia coli bloodstream infections (BSIs), and to evaluate factors associated with outcomes. We included incident E. coli BSIs from western interior residents (British Columbia, Canada; 04/2010–03/2020). We obtained data including patient demographics, location of onset, infection focus, Charlson comorbidity index (CCI), antimicrobial resistance, 30-day all-cause mortality and length of hospital stay (LOS). Using multivariable logistic regression models fitted with generalised estimating equations, we estimated factors associated with 30-day mortality and long post-infection LOS (>75th percentile). We identified 1080 incident E. coli BSIs in 1009 patients. The crude incidence and 30-day mortality rates were 59.1 BSIs and 6.8 deaths/100 000 person-years, respectively. The 30-day case fatality risk was 11.5%. Compared to community-acquired E. coli BSIs, either healthcare-associated or nosocomial cases had higher odds of 30-day mortality. Older cases, non-urogenital BSI foci and CCI ⩾ 3 had higher odds of 30-day mortality compared to younger cases, urogenital foci and CCI < 3. In patients that survived to discharge, those with extended-spectrum β-lactamase (ESBL)-producing E. coli BSIs, nosocomial BSIs, and CCI ⩾ 3 had higher odds of long post-infection LOS compared to those with non-ESBL-producing, community-acquired and healthcare-associated, and CCI < 3. There is a substantial disease burden from E. coli BSIs.