Vibrios heated at 100°C. in saline suspension agglutinate in a generalised manner and often to a high titre with the antisera of the Q proteins of the cholera vibrio. The antibodies concerned are not inactivated by the carbohydrate fraction of V. cholerae. Occasional strains of vibrio react similarly in the living state with these Q (choiera) agglutinins. The antiserum of the Q2 substance of S V. cholerae seems to possess agglutinating properties additional to those of anti-Q1 and anti-Q2 R sera, rather more specific and possibly related to “carbohydrate” receptors. There is reason to believe that the Q proteins are true constituents of the living vibrio and are not serological artefacts due to reagents and heat. It seems that these substances and their antibodies are important contributors to the “non-specific O agglutination” of vibrios recently discussed by Gardner and Venkatraman.

Teenagers are important carriers of Neisseria meningitidis, which is a leading cause of invasive meningococcal disease. In China, the carriage rate and risk factors among teenagers are unclear. The present study presents a retrospective analysis of epidemiological data for N. meningitidis carriage from 2013 to 2017 in Suizhou city, China. The carriage rates were 3.26%, 2.22%, 3.33%, 3.53% and 9.88% for 2013, 2014, 2015, 2016 and 2017, respectively. From 2014 to 2017, the carriage rate in the 15- to 19-year-old age group (teenagers) was the highest and significantly higher than that in remain age groups. Subsequently, a larger scale survey (December 2017) for carriage rate and relative risk factors (population density, time spent in the classroom, gender and antibiotics use) were investigated on the teenagers (15- to 19-year-old age) at the same school. The carriage rate was still high at 33.48% (223/663) and varied greatly from 6.56% to 52.94% in a different class. Population density of the classroom was found to be a significant risk factor for carriage, and 1.4 persons/m2 is recommended as the maximum classroom density. Further, higher male gender ratio and more time spent in the classroom were also significantly associated with higher carriage. Finally, antibiotic use was associated with a significantly lower carriage rate. All the results imply that attention should be paid to the teenagers and various measures can be taken to reduce the N. meningitidis carriage, to prevent and control the outbreak of IMD.

This study examined the geographical distribution and diversity of the intrinsic OXA-51-like class D carbapenemases among Acinetobacter baumannii clones recovered in three major Greek regions from 2000 to 2005. The blaOXA-66 allele was exclusively detected among clonally distinct A. baumannii isolates recovered in the regions of Thessaloniki and Larissa. This sequence was also the most widespread among A. baumannii isolates in Athens, while less frequent were blaOXA-69 and blaOXA-65 alleles. These findings highlight the high prevalence of a specific blaOXA-51-like allele in Greece, possibly indicating that our A. baumannii clones might have originated from a common ancestor. However, the possibility that blaOXA-51-like variants, with blaOXA-66 predominating, are widely disseminated among several unrelated A. baumannii strains cannot be excluded.

The passive protection of mice against an intracerebral infection with Bordetella pertussis, by antiserum introduced directly into the brain with the infecting organisms, was compared with the protection afforded by intraperitoneal antiserum. The antibody effective by the intracerebral route is that which is adsorbed onto the infecting organisms, although it does not affect the viability of the organisms in vitro in the absence of complement.

Passive protection against organisms introduced intracerebrally takes place in one of two ways, depending on the size of the challenge: (1) after 3–4 days' growth, the growth rate declines so that the number of organisms does not reach the figure lethal for the mouse; (2) the organisms do not appear to multiply, as their numbers decline from the moment of injection, so that the brain is sterile after 2 days.

Many of the mice protected against a challenge of 50,000 organisms (ca. 100 LD50) by intraperitoneal or intracerebral antiserum recover by the first mechanism. The second mechanism operates after a smaller challenge of 5000 organisms (ca. 10 LD50), irrespective of whether the antiserum is given intracerebrally with the challenge, or intraperitoneally within several hours of challenge. Too much antiserum given intracerebrally with a 50,000 challenge, but not with a 5000 challenge, inhibits protection.

In some mice, virulent antibody-treated organisms which have not been killed, grow very slowly over a long period, but are eventually eliminated from the brain.

In a previous paper (Lancet, 4·I·1913), we published a preliminary report on this subject and are now able to give further particulars of our results and to discuss in detail certain points arising from them.

The virulence of nine strains of Klebsiella was tested in mice inoculated by peritoneal and oral routes, the latter being a convenient method of inducing pneumonic infections.

At similar doses, shorter survival was observed in young mice. Injected by the intraperitoneal route, organisms from 16 hr. old cultures proved more virulent than those from older cultures, but no such difference was obtained orally. Repeated subculture of a virulent strain failed to attenuate its oral virulence and killed suspensions of the same strain were without effect. With only two exceptions, all strains were more virulent when administered orally than intraperitoneally. Wherever possible the concept of relative virulence was employed in making statistical comparisons. It is, however, considered that virulence is an unsatisfactory taxonomic discriminant.

We would like to thank Dr I. Friedmann, Dr F. Fulton and Dr G. Meynell for their helpful criticism. We are also indebted to Dr Lynne Reid for her comments and to Mr G. B. Newman for checking the calculations. Thanks are also due to Mr G. D. Breach and Mr G. Latchford for technical assistance, to Mr D. Connolly for preparation of graphs and Mrs A. Gorvin for secretarial assistance.

1. There occurs in nature an organism belonging to the group of Gram-positive aerobic sporing bacilli which closely resembles B. anthracis, especially in its cultural characters.

2. These organisms occur commonly in materials that are frequently examined for the presence of B. anthracis.

3. The B. anthracoides is pathogenic to guinea-pigs and mice under experimental conditions, and would appear to occupy a position between the virulent B. anthracis and the non-pathogenic members of the group of aerobic sporing bacilli, e.g. B. subtilis, B. mesentericus.

4. Subcutaneous injection of cultures of B. anthracoides produces a local inflammation with gelatinous oedema and a fatal septicaemia.

5. Only large doses of living organisms are lethal and attempts to increase the virulence of this organism by various methods have not proved successful.

6. Individual animals vary considerably in their resistance to the organism.

7. With the exception of B. anthracis, the B. anthracoides contrasts with the other members of the group in its pathogenic properties under experimental conditions. Twenty-five strains of this organism have been isolated, each of which possesses pathogenic properties. The pathogenicity of 49 strains of other representatives of the group has been tested, and only one of these was found to have lethal effects.

In outbreaks of foodborne disease associated with retail outlets, the outlet often closes as a precaution before the specific food vehicle has been identified. Suspect food vehicles may be named as part of general control measures. A conventional case-control study cannot be performed because both cases and potential controls are likely to be aware of the hypothesis and therefore potentially biased. Modern sales recording systems in many food retail outlets may provide a basis for constructing a virtual cohort and allow a statistical inference to be made about various possible vehicles of infection. In 2007, an outbreak of E. coli O157 infection in Paisley, Scotland, was linked to cooked meat from a supermarket delicatessen using descriptive epidemiology. Construction of a virtual cohort allowed a relative risk and confidence interval to be estimated which supported the hypothesis of cooked beef topside being the vehicle of infection. This novel method could be valuable in the investigation of future outbreaks.

Hepatitis B constitutes a severe public health challenge in China. The Community-based Collaborative Innovation hepatitis B (CCI-HBV) project is a national epidemiological study of hepatitis B and has been conducting a comprehensive intervention in southern Zhejiang since 2009.

The comprehensive intervention in CCI-HBV areas includes the dynamic hepatitis B screening in local residents, the normalised treatment for hepatitis B infections and the upcoming full-aged hepatitis B vaccination. After two rounds of screening (each round taking for 4 years), the initial epidemiological baseline of hepatitis B in Qinggang was obtained, a coastal community in east China. By combining key data and system dynamics modelling, the regional hepatitis B epidemic in 20 years was predicted.

There were 1041 HBsAg positive cases out of 12 228 people in Round 1 indicating HBV prevalence of 8.5%. Of the 13 146 people tested in Round 2, 1171 people were HBsAg positive, with a prevalence of 8.9%. By comparing the two rounds of screening, the HBV incidence rate of 0.192 per 100 person-years was observed. By consulting electronic medical records, the HBV onset rate of 0.533 per 100 person-years was obtained. We generated a simulated model to replicate the real-world situation for the next two decades. To evaluate the effect of interventions on regional HBV prevalence, three comparative experiments were conducted.

In this study, the regional hepatitis B epidemic in 20 years was predicted and compared with HBV prevalence under different interventions. Owing to the existing challenges in research methodology, this study combined HBV field research and simulation to provide a system dynamics model with close-to-real key data to improve prediction accuracy. The simulation also provided a prompt guidance for the field implementation.

To determine the burden of skin and soft tissue infections (SSTI), the nature of antimicrobial prescribing and factors contributing to inappropriate prescribing for SSTIs in Australian aged care facilities, SSTI and antimicrobial prescribing data were collected via a standardised national survey. The proportion of residents prescribed ⩾1 antimicrobial for presumed SSTI and the proportion whose infections met McGeer et al. surveillance definitions were determined. Antimicrobial choice was compared to national prescribing guidelines and prescription duration analysed using a negative binomial mixed-effects regression model. Of 12 319 surveyed residents, 452 (3.7%) were prescribed an antimicrobial for a SSTI and 29% of these residents had confirmed infection. Topical clotrimazole was most frequently prescribed, often for unspecified indications. Where an indication was documented, antimicrobial choice was generally aligned with recommendations. Duration of prescribing (in days) was associated with use of an agent for prophylaxis (rate ratio (RR) 1.63, 95% confidence interval (CI) 1.08–2.52), PRN orders (RR 2.10, 95% CI 1.42–3.11) and prescription of a topical agent (RR 1.47, 95% CI 1.08–2.02), while documentation of a review or stop date was associated with reduced duration of prescribing (RR 0.33, 95% CI 0.25–0.43). Antimicrobial prescribing for SSTI is frequent in aged care facilities in Australia. Methods to enhance appropriate prescribing, including clinician documentation, are required.

Excessive weight loss due to protein calorie malnutrition (PCM) is a significant problem in Nigerian children. This syndrome may be difficult to differentiate from the wasting disease caused by human immunodeficiency virus type 1 (HIV-1) infection. We studied 70 children admitted to the Baptist Medical Center in Ogbomosho, Nigeria in 1990 with PCM for prevalence of antibodies to HIV-1 and HIV-2. The cohort was from low-risk mothers and had a median age of 25 months (range, 4 months–9 years) with a weight deficit of at least 20% of the theoretical weight for age. Two sera were positive for anti-HIV-1 by both ELISA and Western blot (WB). A high prevalence of samples negative for HIV-1 antibody by ELISA were repeatedly reactive (11%, 8/70) or indeterminate (46%. 32/70) by WB. None of the sera was positive for antibody to HIV-2. There was no correlation of ELISA positivity or extent of WB banding with successful recovery from malnutrition. These results indicate a relatively low but significant prevalence of HIV-1 infection in Nigerian children with PCM. The high prevalence of indeterminate reactions in WB assays for HIV-1 suggests that other procedures may be necessary for confirmatory diagnosis of HIY-1 infection in this African population.

London, Ontario is a mid-sized Canadian city which appears to be experiencing a syndemic predominately amongst its marginalized populations. Since 2014, rates of HIV, hepatitis A (HAV), hepatitis C (HCV), and invasive group A streptococcal disease have climbed well above provincial rates amid increasing use of injection drugs. Rates of infective endocarditis have also been on the rise. Extensive public health and community-based efforts were taken in response to these concurrent outbreaks. These efforts included establishing improved client care pathways, creating specialized teams to engage underhoused clients, providing mass immunization, and developing new health promotion campaigns. Rates of HIV and HAV were subsequently controlled locally while rates of HCV, iGAS and infective endocarditis remain high within the community and throughout the province.

Measles is a major cause of childhood morbidity and mortality in many parts of the world. Estimates of the case-fatality rate (CFR) of measles have varied widely from place to place, as well as in the same location over time. Amongst populations that have experienced famine or armed conflict, measles CFR can be especially high, although past work has mostly focused on refugee populations. Here, we estimate measles CFR between 1970 and 1991 in a rural region of Bangladesh, which experienced civil war and famine in the 1970s. We use historical measles mortality data and a mechanistic model of measles transmission to estimate the CFR of measles. We first demonstrate the ability of this model to recover the CFR in the absence of incidence data, using simulated mortality data. Our method produces CFR estimates that correspond closely to independent estimates from surveillance data and we can capture both the magnitude and the change in CFR suggested by these previous estimates. We use this method to quantify the sharp increase in CFR that resulted in a large number of deaths during a measles outbreak in the region in 1976. Most of the children who died during this outbreak were born during a famine in 1974, or in the 2 years preceding the famine. Our results suggest that the period of turmoil during and after the 1971 war and the sustained effects of the famine, is likely to have contributed to the high fatality burden of the 1976 measles outbreak in Matlab.

We utilized a disease progression model to predict the number of viraemic infections, cirrhotic cases, and liver-related deaths in the state of Rhode Island (RI) under four treatment scenarios: (1) current HCV treatment paradigm (about 215 patients treated annually, Medicaid reimbursement criteria fibrosis stage ⩾F3); (2) immediate scale-up of treatment (to 430 annually) and less restrictive Medicaid reimbursement criteria (fibrosis stage ⩾F2); (3) immediate treatment scale-up and no fibrosis stage-specific Medicaid reimbursement criteria (⩾F0); (4) an ‘elimination’ scenario (i.e. a continued treatment scale-up needed to achieve >90% reduction in viraemic cases by 2030). Under current treatment models, the number of cirrhotic cases and liver-related deaths will plateau and peak by 2030, respectively. Treatment scale-up with ⩾F2 and ⩾F0 fibrosis stage treatment criteria could reduce the number of cirrhotic cases by 21·7% and 10·0%, and the number of liver-related deaths by 19·3% and 7·4%, respectively by 2030. To achieve a >90% reduction in viraemic cases by 2030, over 2000 persons will need to be treated annually by 2020. This strategy could reduce cirrhosis cases and liver-related deaths by 78·9% and 72·4%, respectively by 2030. Increased HCV treatment uptake is needed to substantially reduce the burden of HCV by 2030 in Rhode Island.

Escherichia coli O157 isolates from cattle in Japan (n = 91) and in the USA (n = 415) were compared by pulsed-field gel electrophoresis of endonuclease-cleaved genomic DNA, location of the stx genes and bacteriophage typing. Three isolates from cattle in Japan with high similarity to isolates from cattle in the USA were found. Isolates from cattle farms in Japan and the USA may share a common source.

Strong notifiable disease surveillance systems are essential for disease control. We sought to determine if a brief informational session between clinic and health department employees followed by reminder faxes and a newsletter would improve reporting rates and timeliness in a notifiable disease surveillance system. Ambulatory clinics were randomized to an intervention group which received the informational session, a faxed reporting reminder and newsletter, or to a control group. Among intervention and control clinics, there were improvements in the number of cases reported and the timeliness of reporting. However, there were no statistically significant changes in either group. Despite improved communication between the health department and clinics, this intervention did not significantly improve the level or the timeliness of reporting. Other types of interventions should be considered to improve reporting such as simplifying the reporting process.

A small epidemic of nursery-associated hepatitis A (HA), in which silently infected children played a cryptic role in transmitting the illness to adult contacts, was investigated. It was found that a male nurse had transmitted HA to four children before he fell ill. He was not heard from for about two months as he was a part-time worker and was admitted to a local hospital in another prefecture. Two of the four silently infected children transmitted HA to their parents who then revealed the presence of nursery-associated HA. The epidemic was terminated by injection of human gamma globulin to nursery children and to antibody-negative parents, nursery staff and other contacts except for two breakthrough cases.

Since 1984 a change in the epidemiological pattern of meningococcal disease in Italy has occurred with a predominance of Neisseria meningitidis of serogroup C (76%), serotype 2a and a high proportion of strains resistant to sulphonamides (71%). In order to understand better the epidemiology of the group C N. meningitidis strains responsible for the disease over the last years in Italy, we studied the genetic features of phenotypically closely related strains, by enzyme electrophoresis. The results showed that the genetic and the phenotypic characteristics of the 57 strains studied were similar, suggesting the spread of a single clone during recent years in our country.

This result is in agreement with the circulation of strains typical of epidemic situations, despite the decreasing incidence of meningoccal disease in Italy.

The objectives of this study were to characterize faeco-orally transmitted parasitic diseases and to identify the factors associated with these diseases, with emphasis on environmental factors, in children ranging from 1 up to 5 years old residing in substandard settlement areas. A population-based cross-sectional epidemiological design was used in a non-random selection of 29 out of the 78 substandard settlement areas in the municipality of Juiz de Fora, Brazil. A sample of 753 children were assessed from the target population consisting of all children of the appropriate age range residing in the selected areas. Data were collected by means of domiciliary interviews with their mothers or with the person responsible for them. The Hoffmann–Pons–Janer method was used in the parasitological examination of faeces. Binary logistic regression models were used to identify the factors associated with the diseases. A total of 319 sample children presented faeco-orally transmitted parasitic diseases. The factors associated with these parasitic diseases included the children's age, family income, number of dwellers in the domicile, consumption of water from shallow wells, consumption of water from natural sources, absence of covered domiciliary water reservoirs, and the presence of sewage flowing in the street.

In a comparative study of 24 different rubella virus strains, all but three formed small plaques in RK 13 cell cultures; of these one was the vaccine strain HPV-77, one was isolated from a congenitally infected infant, and the third was recovered from an adult who contracted severe rubella while handling this congenital strain. Whereas the plaque size of the vaccine strain was stable after further passage in cell culture, the plaque size of the other two rapidly diminished when the virus was passed in monkey kidney cells, and one of them was also reduced by passage in RK 13 cells. Cell culture passage of the typical small plaque strains did not result in altered plaque size.