Invasive meningococcal disease (IMD) completeness of reporting has never been assessed in New York City (NYC). We conducted a capture–recapture study to assess completeness of reporting, comparing IMD reports made to the NYC Department of Health and Mental Hygiene (DOHMH) and records identified in the New York State hospital discharge database [Statewide Planning and Research Cooperative System (SPARCS)] by ICD-9 codes from 1989 to 2010. Reporting completeness estimates were calculated for the entire study period, and stratified by year, age group, clinical syndrome, and reporting system. A chart review of hospital medical records from 2008 to 2010 was conducted to validate hospital coding and to adjust completeness estimates. Overall, 2194 unique patients were identified from DOHMH (n = 1300) and SPARCS (n = 1525); 631 (29%) were present in both. Completeness of IMD reporting was 41% [95% confidence interval (CI) 40–43]. Differences in completeness were found by age, clinical syndrome, and reporting system. The chart review found 33% of hospital records from 2008 to 2010 had no documentation of IMD. Removal of those records improved completeness of reporting to 51% (95% CI 49–53). Our data showed a low concordance between what is reported to DOHMH and what is coded by hospitals as IMD. Additional guidance to clinicians on IMD reporting criteria may improve completeness of IMD reporting.

1. An apparently pure rabbit iso-antibody marked with 131I has been shown to adsorb specifically to a greater extent on some rabbit cells than on others. This accords with previous evidence that the same iso-antibody exhibits a higher titre with the cells which are shown here to absorb more marked antibody than with those which adsorb less.

2. Saturation of two of these red cell types by repeated application of fresh quantities of the 131I iso-antibody until no more is specifically adsorbed, suggests that the number of functional antigenic sites is six or seven times greater on the one than on the other cell.

3. There is no apparent difference in the amount of 131I iso-antibody adsorbed by any one type of rabbit cell in comparative titrations using 3·3 % MgSO4.7H2O medium instead of normal saline.

1. One hundred and eighty-seven freshly isolated strains of Haemophilus pertussis, together with ten laboratory strains and eleven strains of H. parapertussis were submitted to tests of their morphological, biochemical and antigenic properties in relation to their virulence to mice.

2. The naturally occurring H. pertussis strains form a single antigenic type differing from that of the attenuated laboratory strains.

3. H. parapertussis forms, as previously claimed, a distinctive type with characteristic properties closely related to H. pertussis.

Our thanks are due to Col. H. J. Bensted, Prof. J. W. McLeod and Drs A. Beck, D. G. Evans, G. Eldering, J. Marks, M. T. Parker, M. Pittman and H. Proom for supplying strains used in this investigation.

Hospital isolates of Enterobacter cloacae were analysed by polyacrylamide gel electrophoresis for enzyme polymorphism and the results were compared with established serotyping, phage typing and biotyping techniques. Initially, the diversity of electromorphs of 13 enzymes was determined on a representative set of 62 distinct strains. Two broad clusters of strains were found in the species, and analysis by serotype suggested a limited diversity within the most frequent o serotvpes. A subset of three enzymes, lactate dehydrogenase, 6-phosphogluconate dehydrogenase, glutamate dehydrogenase and an unidentified marker, were selected and used to type groups of hospital isolates. There was good general agreement between the two systems, although the enzyme method failed to distinguish between some strains with the same serotype. This method provided useful epidemiological information and, in the absence of established typing systems, it is a practical approach to subdividing the species.

From the investigations of past workers, from those recently made with modern refinements by Gardner and Venkatraman (1935) and from my own studies, it is clear that in their serological diversity the vibrios rival the group of coliform bacilli.

1. Faeces from apparently healthy Bantu school children of a periurban district of Johannesburg were examined eight times at regular intervals over a period of 1 year.

2. Of 75 children, 29·3 % experienced at least one salmonella infection and 2·7 % one shigella infection. It is suggested that over a year nearly all children will have one, and many of them several, infections with these pathogens. The infections occurred at a low rate throughout the year.

3. In most cases the infections were asymptomatic. A few of the children showed evidence of being salmonella carriers of long standing.

4. Eighteen different salmonella types were recovered. Salmonella typhi, S. paratyphi B and S. paratyphi C were absent. The organisms were highly resistant to penicillin, erythromycin and novobiocin and a few strains were also resistant to chloramphenicol and tetracycline.

5. The drinking water was of poor quality and may well be implicated in the transmission of the infections.

Our thanks are due to the Director of this Institute, Dr J. H. S. Gear, for permission to publish this paper; to Mr R. G. Robinson for assessing the microorganisms'sensitivity to antibiotics; and to the South African Council of Scientific and Industrial Research, Pretoria, for a grant enabling us to meet the transport expenses.

The geographical distribution of the different species of rat flea is one of the most important factors governing the spread of plague.

Xenopsylla cheopis is the most effective transmitter of both epidemic and epizootic bubonic plague in all parts of the world.

The relative immunity of certain parts of India and Ceylon from plague is to be primarily attributed to the prevalence of an inefficient plague-carrying flea on the rats of these localities, viz. Xenopsylla astia.

Climatic conditions play only a secondary part in limiting the spread of the disease in these relatively plague-free localities.

Plague infection can be maintained in such localities by the importation of cheopis-infested merchandise.

Climate does not exert an equal effect upon the transmitting power of different species of flea.

Numerous attempts to transmit plague from rat to rat by means of X. astia at room temperature during the plague season in Colombo have all failed. X. astia, however, can carry plague from rat to rat under climatic conditions favourable to plague transmission. Continuous transmission of plague from rat to rat has been obtained with X. cheopis in Colombo under exceptionally unfavourable climatic conditions.

Both plague and X. cheopis have a very irregular distribution within limits of Colombo City. The coefficient of correlation between two periods of human plague incidence and percentage of cheopis to total rat fleas of all species in 14 districts of the city is ·95, probable error ± ·02 for both periods.

There is a close relation between premises infested with X. cheopis and premises where plague-infected rats are found.

A three-fold relationship exists between the amount of imported grain, the prevalence of cheopis on rats, and the incidence of plague in the localities where grain is stored in Colombo.

The measures so far devised for combating plague among Oriental populations, tolerant of all forms of animal life, have not proved conspicuously successful.

Due recognition of the importance of the flea species factor should lead to marked improvement in plague preventive measures in many parts of the world.

A rat flea survey of all the principal plague areas, especially the ports, becomes urgently necessary.

The exports from localities where X. cheopis is found to be prevalent upon the rats should be considered actively dangerous when the locality is plague infected, and potentially dangerous even if it is plague free, since the continual importation of cheopis into a locality where this flea is not indigenous may eventually result in the extension of plague infection to a new area.

I agree with Glen Liston and Norman White, that the export of produce, especially grain, from plague-infected ports should be controlled by international agreement.

The limitation of imported cheopis and plague to definite zones in such localities as Colombo greatly facilitates the task of plague prevention, since all available resources can be concentrated simultaneously, or successively, on the infected areas.

In such instances it is possible to mark out the potentially plague-infected zones by the simple and accurate method of surveying the rat fleas.

Ten years have now elapsed since I tentatively put forward the suggestion that the spread of epizootic plague in the East Indies might be governed by the flea species factor. At first I adopted a cautious attitude towards my own hypothesis. I believe that the evidence now available warrants its acceptance by epidemiologists without further hesitation.

If so, the discovery is but further testimony to the essential unity of science in its bearings on the welfare of the human race, for it is the natural outcome of the purely zoological researches of Rothschild and Jordan on the systemics of the Siphonaptera.

Human skin scales which have been shed naturally bear a flora of micro-organisms which is unknown until tested. To replace these scales in a study of the micro-environment of both the human body and of models a method has been devised of making synthetic scales which behave both physically and aerodynamically in a similar way to the natural material. The synthetic materials carry no natural flora and it is possible to include in them test markers of several kinds to assist in identification after dispersion.

After the 2003 SARS epidemic, China started constructing a primary-level emergency response system and focused on strengthening and implementation of policies, resource allocation. After 17 years of restructuring, China's primary-level response capabilities towards public health emergencies have greatly improved. During the coronavirus disease 2019 epidemic, primary-level administrative and medical personnel, social organisations, volunteers, etc. have played a significant role in providing professional services utilising the primary-level emergency response system of 17 years. However, China's organisations did not learn their lesson from the SARS epidemic, and certain problems are exposed in the system. By analysing the experience and shortcomings of China's disease prevention and control system at the primary level, we can focus on the development of disease control systems for major epidemics in the future.

We used microbiology and pharmacy data from health-maintenance organizations to determine whether antibiotic use by a household member increases the risk of penicillin-non-susceptible pneumococcal disease. Though it has been well established that an individual's antibiotic use increases one's risk of antibiotic-resistant infection, it is unclear whether the risk is increased if a member of one's household is exposed to antibiotics. We therefore conducted a case-control study of patients enrolled in health maintenance organizations in Western Washington and Northern California. Cases were defined as individuals with penicillin-non-susceptible pneumococcal infection; controls were individuals with penicillin-susceptible pneumococcal infection. Socioeconomic variables were obtained by linking addresses with 1997 census block group data. One-hundred and thirty-four cases were compared with 798 controls. Individual antibiotic use prior to diagnosis increased the odds of penicillin non-susceptibility, with the strongest effect seen for β-lactam use within 2 months (OR 1·8, 95% CI 1·2, 2·8). When household antibiotic use by persons other than the patient were considered, at 4 months prior to diagnosis there was a trend towards an association between penicillin non-susceptibility and β-lactam antibiotic use, and a possible association in a small subgroup of patients with eye and ear isolates. However, no significant overall pattern of association was seen. We conclude that though antibiotic use of any kind within 2 months prior to diagnosis is associated with an increased risk of penicillin-non-susceptible pneumococcal disease, there is no significant overall pattern of association between household antibiotic use and penicillin-non-susceptible pneumococcal infection.

The object of a paper by Fry (1930, p. 313)1 was “to ascertain…the relation of syphilis to malignant disease as determined by the Wassermann reaction.” The conclusion reached (p. 322) was: “In general, from the above figures, there is no evidence that syphilis plays any direct or very important part in the production of cancer.”

1. A study of the suspension of dried faeces used in the Chick-Martin test, and of the process of disinfection in this test has shown that:

(a) The suspension of faeces is unstable, and rapidly forms a compact deposit.

(b) Surviving bacteria in critical dilutions of the disinfectant are contained exclusively in this deposit.

(c) Uncontrolled factors affect the degree of subdivision of the particles of faeces.

(d) The degree of subdivision of these particles materially affects the activity of a disinfectant in their presence.

2. It is suggested that these facts among others may account for inconstant results which the test is said to give.

3. A suspension of yeast is proposed as a possible alternative form of organic matter in such a test.

There is interest in the potential of companion animal surveillance to provide data to improve pet health and to provide early warning of environmental hazards to people. We implemented a companion animal surveillance system in Calgary, Alberta and the surrounding communities. Informatics technologies automatically extracted electronic medical records from participating veterinary practices and identified cases of enteric syndrome in the warehoused records. The data were analysed using time-series analyses and a retrospective space–time permutation scan statistic. We identified a seasonal pattern of reports of occurrences of enteric syndromes in companion animals and four statistically significant clusters of enteric syndrome cases. The cases within each cluster were examined and information about the animals involved (species, age, sex), their vaccination history, possible exposure or risk behaviour history, information about disease severity, and the aetiological diagnosis was collected. We then assessed whether the cases within the cluster were unusual and if they represented an animal or public health threat. There was often insufficient information recorded in the medical record to characterize the clusters by aetiology or exposures. Space–time analysis of companion animal enteric syndrome cases found evidence of clustering. Collection of more epidemiologically relevant data would enhance the utility of practice-based companion animal surveillance.

Incomplete antibodies demonstrable by the Coombs antiglobulin technique were found in almost all guinea-pigs inoculated subcutaneously with Brucella abortus. They were detected between the 20th and 30th day after infection and reached a peak between the 50th and 70th day, at which time their titre was 4—8 times that of the ordinary agglutinins.

Paper electrophoresis of sera from infected guinea-pigs showed a great increase in y-globulin as infection developed. Smaller increases in α1- and β-globulin were observed.

Influenza surveillance enables systematic collection of data on spatially and demographically heterogeneous epidemics. Different data collection mechanisms record different aspects of the underlying epidemic with varying bias and noise. We aimed to characterize key differences in weekly incidence data from three influenza surveillance systems in Melbourne, Australia, from 2009 to 2012: laboratory-confirmed influenza notified to the Victorian Department of Health, influenza-like illness (ILI) reported through the Victorian General Practice Sentinel Surveillance scheme, and ILI cases presenting to the Melbourne Medical Deputising Service. Using nonlinear regression, we found that after adjusting for the effects of geographical region and age group, characteristics of the epidemic curve (including season length, timing of peak incidence and constant baseline activity) varied across the systems. We conclude that unmeasured factors endogenous to each surveillance system cause differences in the disease patterns recorded. Future research, particularly data synthesis studies, could benefit from accounting for these differences.

The designation, Newington, is proposed for those cultures of S. anatum having the antigenic formula III XV: eh: 1, 4, 6. A new type, New Brunswick, is described which is represented by the formula III XV: lv: 1, 7 +. Attention is called to the inadequacy of the symbols currently employed in the representation of the non-specific antigens to express correctly the non-specific phases of the Nyborg and New Brunswick types.

An investigation into the classification of strains of Shigella sonneiby the method of phage-typing (using unadapted bacteriophages) is described.

829 strains, obtained during 3 years from twelve regions in England (including Monmouthshire) were examined by a standard technique. There were fifty-two outbreaks (involving 587 strains) from which two or more strains were isolated.

Results confirmed the finding by Hammarström in Sweden that such classification was possible, strains falling into twenty phage-types of which thirteen were found more than once. All strains were typable, 74% belonging to the same type. In forty-seven outbreaks the phage-type was uniform, the commonest type occurring in thirty-eight of these. In five outbreaks the phage-type was not uniform.

It is concluded that this method of phage-typing, because of evidence of type instability and because the majority of strains belong to the same phage-type, has little practical value as a routine procedure in the control of Sonne dysentery in this country.

A 14-month survey was undertaken in a diagnostic bacteriology laboratory to determine the incidence of Serratia spp. in routine clinical specimens. Gram-negative organisms with enterobacteria-like colonies were tested by a simple screening procedure. Fifty-eight strains of S. marcescens and two strains of S. liquefaciens were isolated from 59 patients. The strains were usually nonpigmented and exhibited multiple antibiotic resistance. Serotyping and determination of bacteriocine sensitivity patterns revealed that the majority of infections were sporadic, although episodes of cross-infection did occur.

S. marcescens was considered to contribute significantly to morbidity and mortality in 53% of patients and appears to be of increasing importance in hospital-acquired infections.

Antibody responses to influenza virus immunizations were examined among junior high school students. The students received two doses of a commercial split-product vaccine containing influenza A H1N1 during a 2-year period following the first appearance of H1N1 virus in the winter of 1977–78. In haemagglutination-inhibition (HI) tests, the students who had been infected with H1N1 virus in 1977–78 showed a better response and wider cross-reactivity to the drift strain than the students who had not experienced earlier H1N1 influenza infection. Neuraminidase-inhibition (NAI) antibody titres after immunization depended upon a history of natural infection with H1N1 virus, since students not previously infected showed no significant NAI antibody rise after immunization.

The aim of the study was to describe the epidemiology and determinants of anti-hepatitis A seroprevalence in 2- to 19-year-olds in the USA for 2007–2008. This study was conducted in a sample of 2621 individuals aged 2–19 years in the USA using data from National Health and Nutrition Examination Survey (NHANES) 2007–2008. The overall seroprevalence of anti- hepatitis A virus (HAV) in this population was 39% (95% confidence interval 32·6–45·3). HAV seroprevalence was higher in Mexican Americans than other ethnic groups, in younger persons, and in those who reported previous vaccination compared to those who did not. We concluded that anti-hepatitis A seroprevalence rates are increasing in younger individuals in the USA, indicating a shift of seroprevalence over time due to vaccination status. Findings are consistent with a persistent influx of infection through international travel and migration and highlight the need to discern hepatitis A infection from vaccination status when assessing the effectiveness of vaccination using seroprevalence data.