1. Guinea-pig vaccination experiments have shown that these animals can be rendered completely immune from infection with virulent strains of L. icterohaemorrhagiae when they are treated with non-virulent living vaccines, or formalinized, heat-killed, phenolized, and dettolized suspensions of virulent cultures.

2. Vaccination with homologous strains of L. icterohaemorrliagiae produced better immunity than when heterologous strains such as L. hebdomadis or L. icterohaemorrhagiae Rachmat are employed.

3. Immune bodies are demonstrable in the serum of guinea-pigs vaccinated with L. icterohaemorrhagiae Weil, and a lytic titre of 1/6 appears to indicate that sufficient protective antibodies are present.

4. Following upon vaccination and inoculation with virulent cultures, carrier conditions have developed in animals treated with chemically killed vaccines of L. icterohaemorrhagiae Weil and with living non-virulent suspensions of the heterologous strain L. hebdomadis and L. icterohaemorrhagiae Rachmat.

Fatal general infection can be readily production in mice by spraying with pneumococcal culture in a closed chamber without resorting to any artificial means of lowering the animal's resistance.

In the experiments recorded the proportion of unprotected mice which developed septicaemia varied considerably, the highest being nine out of ten. These irregularities may be partly attributable to variations in (1) the fineness of the spray, and (2) the virulence of the culture.

In unprotected mice death from septicaemia rarely occurs before the 3rd day after spraying and may be delayed for a week or more.

Vaccination by subcutaneous and intraperitoneal inoculation with heated cultures afforded protection against infection by inhalation to 11 out of 13 mice. Two succumbed to septicaemia although they had resisted 14 days earlier an intraperitoneal dose of 0·0001 c.c. of culture. The culture used for spraying was evidently in a highly virulent state since nine out of the ten controls died of septicaemia.

The above experiments were with homologous cultures but tests have also been made of the efficacy of vaccination against heterologous strains. For example, vaccination with Types I and II cultures gave apparently a certain amount of protection against infection by spraying with a mixture of Type III and Group IV strains.

Passive immunity induced by an injection of antipneumococcal serum immediately before spraying was effective against the homologous types in all of a batch of 13 mice. The resistance showed a tendency to diminish with the lapse of time, since on re-spraying the same lot of mice 3 weeks later one mouse developed septicaemia.

In unprotected mice where death was delayed for some days after spraying there was generally no evidence to the naked eye of any local pulmonary lesions. Rarely typical grey consolidation of portions of the lungs was found. A pneumonic condition occurred more frequently in mice in which a slight degree of immunity had been produced. For example, a Type II pneumonia was found in a mouse which had been immunised against Type I.

The production of the carrier state is a regular sequel to spraying even with the most virulent cultures of pneumococci. A large proportion of the mice which survived spraying were nasopharyngeal carriers a fortnight later and the condition persisted in one mouse for 99 days. A carrier of pneumococci may succumb to septicaemia 15 days after the date of infection; it is not known whether any immunity develops in carriers.

The presence, about the pharynx of mice, of Gram-negative bacilli which grow rapidly in culture and are of high virulence when introduced parenterally is a source of difficulty in attempts to demonstrate pneumococci.

An attempt was made to ascertain whether, after spraying, nasopharyngeal carriers of pneumococci were more numerous among normal or among protected mice. The results were inconclusive, but there was no marked indication in the experiments recorded that the state of immunity influenced the carrier condition.

Eleven fabrics selected to provide a representative range of yarns and weaves have been examined microscopically and subjected to a series of tests. The observations were directed towards assessing the potential ability of each fabric to resist penetration by particles, such as skin scales, which might carry micro-organisms. The number, size and shape of pores penetrating through the material were estimated and the penetration of test dusts assessed in several ways. While, generally, the relative merits of the fabrics are similar whatever test or measurement is considered there are a number of significant exceptions which reflect peculiarities of the test system or of a fabric. Comparison with the results of dispersal experiments with volunteers wearing garments made of the fabrics is made in a following paper.

Campylobacter jejuni is a leading cause of human bacterial gastroenteritis throughout the industrialized world. We investigated whether or not differences in gene complement at the lipooligosaccharide (LOS) biosynthesis locus can identify epidemiologically useful binary genomotypes in 87 C. jejuni isolates from poultry-associated multilocus sequence types (STs) collected during the course of a sentinel surveillance study. Using a PCR-based approach, we correlated assignment of both isolate LOS locus class and binary genomotype with ST. We found that isolates within STs 45, 190, 354 and 474 displayed mosaicism in gene complement at the intra-ST level. For example, based upon their binary genomotypes, we assigned individual ST-45 isolates from human clinical cases as probably originating from either a poultry or wild-bird source. However, intra-ST mosaicism in gene complement was observed alongside broader patterns of congruence in LOS locus class and gene complement that distinguished between isolates from different STs.

Previous workers (Stuart-Harris, Pownall, Scothorne & Franks, 1953; May, 1953)have reported studies on the bacterial flora of the sputum in cases of chronic bronchitis. Both pneumococci and Haemophilus influenzae have been reported frequently in the sputum but the source of these organisms, which might be either the patient's own upper respiratory tract or the environment, has not been traced.A long-term study of individuals with and without chronic bronchitis and of their families was therefore begun in an attempt to discern the role of exogenous infection in this disease. Observations were limited to the pneumococcus because serological identification of individual strains was readily possible in this species.

The spread of the Zika virus (ZIKV) in the Americas led to large outbreaks across the region and most of the Southern hemisphere. Of greatest concern were complications following acute infection during pregnancy. At the beginning of the outbreak, the risk to unborn babies and their clinical presentation was unclear. This report describes the methods and results of the UK surveillance response to assess the risk of ZIKV to children born to returning travellers. Established surveillance systems operating within the UK – the paediatric and obstetric surveillance units for rare diseases, and national laboratory monitoring – enabled rapid assessment of this emerging public health threat. A combined total of 11 women experiencing adverse pregnancy outcomes after possible ZIKV exposure were reported by the three surveillance systems; five miscarriages, two intrauterine deaths and four children with clinical presentations potentially associated with ZIKV infection. Sixteen women were diagnosed with ZIKV during pregnancy in the UK. Amongst the offspring of these women, there was unequivocal laboratory evidence of infection in only one child. In the UK, the number and risk of congenital ZIKV infection for travellers returning from ZIKV-affected countries is very small.

One hundred and forty-eight sera from 101 cases of acute postnatal rubella were examined by the radial haemolysis (RH) technique currently recommended by the Public Health Laboratory Service of the United Kingdom. In 75 cases the date of onset of rash was known. No sera were RH positive until the third day after the onset of rash and one serum was still negative at 9 days. By 10 days all sera gave a zone of at least 10 mm. The antibody response detected by RH appears later than that detected by haemagglutination inhibition (HI). Thirty-nine of the 101 cases could be diagnosed by seroconversion or a significant rise in titre using the HI test (diagnosis of the remainder depending upon rubella-specific IgM tests). Using the RH test this figure rises to 48 but in ten of these cases reliance on RH would have meant a delay in diagnosis. The results also indicate that many more sera would need to be tested for rubella-specific IgM if the RH test was used instead of the HI test for evaluating possible cases and contacts of rubella.

M. fortuitum is a rapidly growing mycobacterium associated with community-acquired and nosocomial wound, soft tissue, and pulmonary infections. It has been postulated that water has been the source of infection especially in the hospital setting. The aim of this study was to determine if municipal water may be the source of community-acquired or nosocomial infections in the Brisbane area. Between 2007 and 2009, 20 strains of M. fortuitum were recovered from municipal water and 53 patients’ isolates were submitted to the reference laboratory. A wide variation in strain types was identified using repetitive element sequence-based PCR, with 13 clusters of ⩾2 indistinguishable isolates, and 28 patterns consisting of individual isolates. The clusters could be grouped into seven similar groups (>95% similarity). Municipal water and clinical isolates collected during the same time period and from the same geographical area consisted of different strain types, making municipal water an unlikely source of sporadic human infection.

Mycobacterium bovis infects the wildlife species badgers Meles meles who are linked with the spread of the associated disease tuberculosis (TB) in cattle. Control of livestock infections depends in part on the spatial and social structure of the wildlife host. Here we describe spatial association of M. bovis infection in a badger population using data from the first year of the Four Area Project in Ireland. Using second-order intensity functions, we show there is strong evidence of clustering of TB cases in each the four areas, i.e. a global tendency for infected cases to occur near other infected cases. Using estimated intensity functions, we identify locations where particular strains of TB cluster. Generalized linear geostatistical models are used to assess the practical range at which spatial correlation occurs and is found to exceed 6 in all areas. The study is of relevance concerning the scale of localized badger culling in the control of the disease in cattle.

A study of the kinetics of inactivation of foot-and-mouth disease virus type SAT 2 strains revealed that in most cases the rate of neutralization was not rectilinear. Deviations from first-order kinetics observed represented biphasic or parabolic and stepwise reactions. The initial rate was rapid and showed no lag phase or shoulder. The effects of deviations from linearity could be minimized by dilution of antiserum to a suitable extent. Treatment of virus–antibody mixtures with anti-species globulin resulted in enhancement of the rate of neutralization of homologous and heterologous reactions without significantly altering the relation between the two. This treatment also considerably reduced the amount of the persistent fraction. In attempt to disaggregate virus it was observed that sodium dodecyl sulphate inhibited neutralization of virus by specific antiserum.

Pertussis remains a public health concern in most countries. This cross-sectional study aims to investigate the distribution of pertussis toxin antibodies (anti-PT IgG) in Tunisian children and adolescents aged 3–18 years, to define optimal age for booster vaccination. Anti-PT IgG concentrations of enrolled participants were measured using commercial enzyme-linked immunosorbent assay. Concentrations were classified as: indicative of current/recent infection if ⩾100 IU/ml, indicative of recent exposure to Bordetella pertussis within the last year if 40–100 IU/ml and less likely revealing a recent exposure to B. pertussis if <40 IU/ml. Between March and June 2018, a total of 304 participants (mean age: 9.3 years) were included in this study. Overall, 12.8% (95% confidence interval (CI) 9.1%–16.6%) were seropositive (IgG levels ⩾40 IU/ml). Among them, 14.7% (95% CI 2.3%–23.3%) had levels indicative of a current/recent infection. The multivariate Poisson regression analysis suggested associations between female gender, as well as age group 13–18 years and 3–5 years and higher anti-PT IgG concentrations. Our results are consistent with the notion that vaccine-induced immunity decline, as well as circulation of pertussis among school children and adolescents enables them to be reservoirs of infection and disease transmission to vulnerable infants. Booster dose of acellular pertussis vaccine for school entrants is therefore recommended.

1. Pneumonic Plague epidemics arise as a secondary manifestation of Bubonic Plague.

2. The prevalence of purely septicaemic cases towards the end of the epidemic is significant as a probable explanation of its decline and termination.

3. Subacute or chronic plague may exist among tarabagans (Arctomys bobac) in Mongolia and Siberia, giving rise to periodical outbreaks of bubonic plague in man, as a result of direct infection from injury due to skinning by trappers or marmot eaters.

4. The tarabagan is easily susceptible to pneumonic plague produced by inhalation of B. pestis in spray form.

5. The existence of Pneumonic Plague carriers has been proved in the 1921 Manchurian epidemic.

6. Rooms where patients have died of pneumonic Plague are not particularly dangerous. In all four instances recorded, sick patients travelling in railway carriages have not infected their fellow passengers.

7. Disinfectants and antiseptics, even in strengths above those usually employed, have very little effect upon plague sputum. Alcohol is the surest means of sterilising the hands and gloves in plague work.

8. We have cultivated B. pestis from seemingly dry sputum of partients.

9. The mask is the principal means of personal protection against Pneumonic Plague.

10. The problem of successful vaccination against Pneumonic Plague still awaits solution.

Many clinics in rural western Kenya lack access to safe water and hand-washing facilities. To address this problem, in 2005 a programme was initiated to install water stations for hand washing and drinking water in 109 health facilities, train health workers on water treatment and hygiene, and motivate clients to adopt these practices. In 2008, we evaluated this intervention's impact by conducting observations at facilities, and interviewing staff and clients about water treatment and hygiene. Of 30 randomly selected facilities, 97% had water stations in use. Chlorine residuals were detectable in at least one container at 59% of facilities. Of 164 interviewed staff, 79% knew the recommended water-treatment procedure. Of 298 clients, 45% had received training on water treatment at a facility; of these, 68% knew the recommended water-treatment procedure. Use of water stations, water treatment, and client training were sustained in some facilities for up to 3 years.

In the absence of perfect reference standard, classical techniques result in biased diagnostic accuracy and prevalence estimates. By statistically defining the true disease status, latent class models (LCM) constitute a promising alternative. However, LCM is a complex method which relies on parametric assumptions, including usually a conditional independence between tests and might suffer from data sparseness. We carefully applied LCMs to assess new campylobacter infection detection tests for which bacteriological culture is an imperfect reference standard. Five diagnostic tests (culture, polymerase chain reaction and three immunoenzymatic tests) of campylobacter infection were collected in 623 patients from Bordeaux and Lyon Hospitals, France. Their diagnostic accuracy were estimated with standard and extended LCMs with a thorough examination of models goodness-of-fit. The model including a residual dependence specific to the immunoenzymatic tests best complied with LCM assumptions. Asymptotic results of goodness-of-fit statistics were substantially impaired by data sparseness and empirical distributions were preferred. Results confirmed moderate sensitivity of the culture and high performances of immunoenzymatic tests. LCMs can be used to estimate diagnostic tests accuracy in the absence of perfect reference standard. However, their implementation and assessment require specific attention due to data sparseness and limitations of existing software.

The antigenic variation of influenza A 2 virus and the antibody present in the population to different variants are described and related to the occurrence of epidemics of influenza in England since 1957.

Gender inequality has severe consequences on public health in terms of delay in diagnosis of pulmonary tuberculosis (PTB). In order to explore gender-related differences in diagnosis delay, a cross-sectional study of 10 686 patients diagnosed with PTB in Yulin from 1 January 2009 to 31 December 2014 was conducted. Diagnosis delay was categorised into ‘short delay’ and ‘long delay’ by four commonly used cut-off points of 14, 30, 60 and 90 days. Logistic regression analysis was used to analyse gender differences in diagnostic delay. Stratified analyses by smear results, age, urban/rural were performed to examine whether the effect persisted across the strata. The median delay was 31 days (interquartile range 13–65). Diagnostic delay in females at cut-off points of 14, 30, 60 and 90 days had odds ratios (OR) of 0.99 (95% CI 0.91–1.09), 1.09 (95% CI 1.01–1.18), 1.15 (95% CI 1.05–1.26) and 1.18 (95% CI 1.06–1.31), respectively, compared with males. Stratified analysis showed that females were associated with increased risk of longer delay among those aged 30–60 years, smear positive and living in the rural areas (P < 0.05). The female-to-male OR increased along with increased delay time. Further inquiry into the underlying reasons for gender differences should be urgently addressed to improve the current situation.

Actinomycotic lesions in tissues from a consecutive series of forty-four oxen slaughtered in this country have been examined and compared with fifty specimens imported chiefly from Argentina.

The British cases can be divided into two groups, according as the specific granules do not or do contain Gram-staining organisms.

The first group, characterised by the presence of granules consisting of clubs without Gram-staining organisms, contains 40 cases. In these the lesions were situated in the cheek, palate, tongue, or lymphatic glands in relation to the mouth and pharynx. From twenty-three of the forty cases, cultures of a non-Gram-staining organism were obtained, which were identical in their characters on nutrient agar plates and in shake glucose agar tubes; and five of the strains were found identical when tested on a large series of differential media. One of the cultures was inoculated into a calf, and produced a local lesion with the characters of a natural lesion.

This first group shows complete identity in the histological features and in the anatomical distribution of the disease with Actinobacillosis described by Lignières and Spitz in Argentina. The bacillus obtained has the characters of the Actinobacillus, except that the production of typical granules in the peritoneal cavity of guinea-pigs, described by Lignières and Spitz, has not been demonstrated.

All the imported specimens which were examined microscopically exhibited the characters of the lesions of this first group, but the causal organism was not obtained in pure culture.

The second group contains the remaining four British cases. The specific granules were composed of clubs and Gram-staining organisms, including branching filaments. The lesions were situated in each case in the inferior maxilla. The investigation of the biological characters of the organisms concerned is still in progress.

These results show that Actinobacillosis is widespread in the world, and forms a considerable proportion of the cases of disease in oxen known under the name of Actinomycosis.

Serum and cervical secretions were collected from patients with cervical dysplasia, carcinoma-in-situ (CIS), squamous cell carcinoma (cervical SCC), and controls with normal cervices, attending clinics within the West Lambeth Health District, London. Enzyme-linked immunosorbent assays were used to examine cervical secretory IgA (sIgA) and serum IgG and IgA antibodies to herpes simplex virus (HSV). Sexual and demographic factors were considered during data analysis, which involved fitting multiple linear or multiple logistic regressions to HSV antibody levels. Prevalence of sIgA-HSV and levels of serum antibodies to HSV in all groups were compared with those of gynaecology controls. Caucasian women with mild dysplasia had a significantly higher prevalence of sIgA-HSV. Serum IgG levels to HSV (IgG-HSV) were significantly elevated in women with mild dysplasia and severe dysplasia/ClS. Serum IgA levels to HSV1 (IgG-HSV1) were significantly higher in women with cervical SCC (after adjusting for smoking habits) and other genital tumours. Significantly higher levels of serum IgA to HSV2 (IgA-HSV2) were also found among Caucasian women with cervical SCC. The possible role of HSV as a co-factor in cervical carcinogenesis is discussed.

Before proceeding to describe the imago of Anopheles, we wish to record some observations regarding the hibernation of the larvae of various Culicidae. Grassi (1900, p. 47)1 considered that A. bifurcatus hibernated chiefly in the larval form, for he found the larvae of this species in midwinter in Southern and Central Italy, the imagines being rarely encountered. It was quite different with A. maculipennis. In this case the imagines congregated in houses, huts, caverns, etc., whereas no larvae could be found during the winter. Though he assumed that it was so, his finding the larvae in midwinter in the first instance did not prove that they hibernated, for they might well have been derived from late-laid eggs.

In a multi-laboratory trial, minerals-modified glutamate medium (MMGM) was compared with lauryl tryptose lactose broth (LTLB) in the multiple tube method for the enumeration of coliform organisms, including Escherichia coli, in water. Samples of raw and chlorinated waters yielded a total of 2313 positive tube-reactions with MMGM and 2174 with LTLB. These were interpreted either as E. coli; other coliform organisms; or as false positive reactions. The results at first reading (18 or 24 h) and at 48 h have been analysed statistically in terms of (i) most probable numbers of coliform organisms; (ii) positive reactions and their interpretation; and (iii) whether or not the sample yielded any E. coli or other coliform organisms. All three analyses indicated the same trends. For the detection of E. coli in raw waters LTLB was better than MMGM at 18–24 h, but MMGM was better at 48 h with waters containing small numbers of coliform organisms; for raw waters with greater numbers of organisms, both media performed equally well. Analysis of a subset of samples read at both 18 and 24 h indicated that the superiority of LTLB over MMGM with raw waters disappeared by 24 h. For chlorinated waters, LTLB yielded more positive gas reactions at 18–24 h, but fewer of these were E. coli than with MMGM; at 48 h MMGM was clearly better than LTLB for total coliform organisms including E. coli – especially if the numbers were small. MMGM therefore remains the medium of choice for the detection of E. coli as an indicator of faecal contamination of chlorinated drinking water supplies. It is also better for the detection of small numbers of E. coli in other waters.