Twenty-one strains of Haemophilus ducreyi were analysed by Western blotting using two antisera produced in mice. Common antigens of molecular weights 58, 46, 41, 28, 22 and 16 kDa were detected in all the strains. The antigens were protein in nature, since they could not be detected in whole-cell lysates which had been treated with proteinase K. The H. ducreyi strains showed antigenic cross-reactivity with strains of H. influenzae and H. parainfluenzae, but showed minimal or no cross-reactivity with seven other species of bacteria.

In August 2015 a gastroenteritis outbreak occurred following a wedding. An outbreak investigation was undertaken and a cohort study was conducted using an online survey. Of 140 guests, 134 received the survey and 113 responded (84·3% response rate). Seventy respondents met the case definition of vomiting and/or diarrhoea within 72 h of the wedding (61·9% attack rate). Fifteen exposures were associated with illness; on stratification, all were confounded by the ham hock starter. Multivariable analysis showed a significant association with exposure to ham hock (risk ratio 6·62, 95% confidence interval 2·19–20·03). Eight guests and two catering staff submitted stool samples. All tested positive for norovirus GI-6 infection, including a food handler who had vomiting less than 48 h before the wedding. A single genotype was detected among all samples, suggesting a single source of contamination. The transmission pattern suggested point-source exposure. The most plausible cause of the outbreak was transmission from an infected food handler via contaminated food. This highlights the importance of appropriate exclusions for symptomatic food handlers. Additionally, the food handler's stool sample was submitted 7 days after symptom resolution. The potential for extended viral excretion, and the extremely low infective dose of norovirus, may mean that current exclusion guidelines are not of sufficient duration.

A controlled trial of influenza vaccines in a boys' public school from November 1970 to October 1975 provided an opportunity to study the response to vaccine and the effect on subsequent natural challenge in boys with differing natural experience of influenza A strains. The response to influenza A (H3N2) vaccines was assessed by estimating homotypic and heterotypic antibodies to the surface antigens. Previous natural experience of influenza A was found to influence vaccine response and the effect of natural challenge. The antibody response to revaccination with the same strain showed a progressively poorer response to second and third doses. The protective effect of naturally acquired and vaccine-induced antibodies was assessed during two outbreaks of influenza A which occurred in the trial period.

The Salmonella Reference Centre in Johannesburg received 14059 strains of human origin between 1979 and 1984. A significant proportion (6·3%) proved to belong to subspecies II. The majority were cultured from faecal material, usually associated with symptoms related to the gastrointestinal tract. They comprised 884 isolates, represented by 203 serotypes, of which 45 were new serotypes.

The poor hygienic conditions found in many rural areas, together with possible contamination of food and water by wild animals, may contribute to the greater frequency of human S.II infections and the widespread occurrence of unusual serotypes in man in this geographic region.

To compare the effects of subcutaneous and intradermal methods of administration of TAB vaccine for primary immunization against enteric infections an investigation was carried out on 257 Army recruits.

The general and local reactions were more unfavourable by the intradermal method. The agglutinin responses were better with the intradermal route.

Many infectious diseases exhibit repetitive or regular behaviour over time. Time-domain approaches, such as the seasonal autoregressive integrated moving average model, are often utilized to examine the cyclical behaviour of such diseases. The limitations for time-domain approaches include over-differencing and over-fitting; furthermore, the use of these approaches is inappropriate when the assumption of linearity may not hold. In this study, we implemented a simple and efficient procedure based on the fast Fourier transformation (FFT) approach to evaluate the epidemic dynamic of scarlet fever incidence (2004–2010) in China. This method demonstrated good internal and external validities and overcame some shortcomings of time-domain approaches. The procedure also elucidated the cycling behaviour in terms of environmental factors. We concluded that, under appropriate circumstances of data structure, spectral analysis based on the FFT approach may be applicable for the study of oscillating diseases.

In several lately published studies, the association between single-nucleotide polymorphism (SNP, rs12252) of IFITM3 and the risk of influenza is inconsistent. To further understand the association between the SNP of IFITM3 and the risk of influenza, we searched related studies in five databases including PubMed published earlier than 9 November 2017. Ten sets of data from nine studies were included and data were analysed by Revman 5.0 and Stata 12.0 in our updated meta-analysis, which represented 1365 patients and 5425 no-influenza controls from four different ethnicities. Here strong association between rs12252 and influenza was found in all four genetic models. The significant differences in the allelic model (C vs. T: odds ratio (OR) = 1.35, 95% confidence interval (CI) (1.03–1.79), P = 0.03) and homozygote model (CC vs. TT: OR = 10.63, 95% CI (3.39–33.33), P < 0.00001) in the Caucasian subgroup were discovered, which is very novel and striking. Also novel discoveries were found in the allelic model (C vs. T: OR = 1.37, 95% CI (1.08–1.73), P = 0.009), dominant model (CC + CT vs. TT: OR = 1.48, 95% CI (1.08–2.02), P = 0.01) and homozygote model (CC vs. TT: OR = 2.84, 95% CI (1.36–5.92), P = 0.005) when we compared patients with mild influenza with healthy individuals. Our meta-analysis suggests that single-nucleotide T to C polymorphism of IFITM3 associated with increasingly risk of severe and mild influenza in both Asian and Caucasian populations.

The cellular fatty acid composition of 41 strains of suspected Campylobacter jejuni, 23 from human cases of gastroenteritis and 18 from animals, was examined by gas-liquid chromatography. Three of the 23 human isolates and 2 of 18 animal isolates did not contain 19:0 cyclopropane fatty acid and were identified as C. laridis. The remaining 36 strains had cellular fatty acid profiles consistent with C. jejuni but could be divided into three groups on the ratio of the concentration of 18:1 and 19:0 eycloproprane. Most human isolates (85%) were in groups II or III whereas most animal isolates (56%) were in group I. It is proposed that gas-liquid chromatographic analysis of cellular fatty acids is a relatively easy method for epidemiological typing of C. jejuni isolates.

In the present study an attempt has been made to determine the relative importance of several factors on the mortality rates of infancy. In view of the differences in the rates at the several ages under one year and of the differential decline in these rates within recent years, it has been suggested that for any complete consideration of the death rates in infancy, some subdivision of the rate, either of a biological or temporal character, must be effected, and each of these subdivisions examined separately. The infant mortality rate has been treated in three broad categories, namely, the antenatal, neo-natal and post-natal death rates; and it has been shown that each of these depends on different factors.

Considered as death rates per unit of time the neo-natal rate is much higher than at any other period of life. The ante-natal death rate is much lower than this, and the post-natal rate lowest of all.

In relation to these rates, the influence of three, presumably important, factors have been measured. These are:

1. The provision of skilled attendance to mothers in childbed.

2. The health of the mothers.

3. Environmental and social conditions.

The indices used as measures of these three variables and their limitations have been pointed out. The author feels only too conscious of these limitations and, with such vital statistical data as the only indices available of the factors the influence of which on the mortalities of infancy it is desired to measure, it is probable that any conclusions drawn from such an analysis should be accepted with some degree of caution and reserve. Nevertheless. I am firmly convinced that even these (to the clinician and administrator) rather crude results are immeasurably superior to expressions of opinion, unsupported by facts, so frequently found forming the basis of much of the medical literature on the subject. That we have so relatively little exact quantitative knowledge of the influential factors concerned in the growth, nutrition and mortality of infants is surely not for lack of opportunity of collecting the requisite data. An admirable machinery for such a purpose—the various maternity and child welfare centres—is in extensive operation throughout this country; and if the medical officers in charge of these centres could only be persuaded to collect and analyse (or have analysed) periodically the data contained in suitably framed and completed questionnaires, many questions of scientific importance as well as of the efficacy of administrative efforts would soon cease to be subjects of controversy.

Our results show that, of these factors, only the provision of skilled medical assistance to mothers in childbed is of importance in connection with antenatal mortality. The general health of the mother and external environmental conditions have no direct influence on the death rate at this period of life. The magnitude of the correlation leads to the further conclusion that a great part of the still-birth rate is not to be controlled by improvements in even all of these factors.

The neo-natal death rate is related both to variations in external environment and in the obstetrical assistance available for mothers in childbed. At this state of life, again, the health of the mother has no substantial influence on the death rate. External surroundings and the quality of the obstetrical assistance afforded to the mother are of approximately equal importance in determining these rates; but here again the conclusion is advanced that the greater part of the death rate at this stage of life is beyond human efforts of control.

The post-natal death rate seems to offer the greatest scope for administrative measures. In this case the health of the mother would appear to come first in order of importance, environment also is of some importance, whereas the effects of variations in obstetrical services have now ceased to be reflected on the mortality of infancy.

In isolated rural communities there is a part of the post-natal death rate which could be eliminated by the speedy arrival of skilled medical assistance.

Foreign statistics have been collected and analysed to enquire into the causation of still-births. An obvious defect in these was pointed out, namely, the large proportion of deaths due to unknown causes. A comparison of these figures with those collected from several maternity hospitals has shown that hospital figures give a biassed view of the problem. The proportion of deaths due to causes in which the life of the mother as well as that of the foetus is endangered is greatly magnified, and consequently will produce a too optimistic estimate of the amount of amelioration which will result from increased attention to pregnant and parturient women. The statistics which have been given in this section show that in a really random sample of the population only a small proportion of still-births is the result of causes which can be controlled by this method, and that the chief causes of ante-natal death are developmental defects of the foetus and prematurity.

A short study has been made of certain statistico-anatomical features of the foetus and infant. From this it has been inferred that the foetus is physically in a state of extreme instability, that the conditions which kill in utero are rapidly fatal to the foetus, and that this instability is a somewhat more prominent feature in the male than in the female. As infancy advances, visceral variability decreases steadily, so that it would seem probable that some time is necessary for the foetus to adapt itself to its new mode of existence after birth. This state of unstable equilibrium in early life may provide some reason for the higher mortalities at these ages.

The phage types and antimicrobial susceptibilities of 226 isolates of Salmonella enterica serovar Typhi from imported cases in Japan between 2001 and 2006 were investigated. Most (93·8%) had travelled to Asian countries, particularly South East Asia. Twenty-one phage types were identified with E1 (30·5%), UVS (15·9%) and B1 (9·3%) being the most common. The frequency of multidrug-resistant strains reached 37·0% in 2006 with phage types E1 and E9 predominating. Almost half (48·2%) of the isolates were resistant to nalidixic acid and two isolates displayed high-level fluoroquinolone resistance. Three mutations, two in gyrA and one in parC, were identified in both isolates.

In nine laboratories 1% lactose ricinoleate broth has been investigated as a possible alternative to brilliant green bile broth as a confirmatory medium for coliform organisms and Escherichia coli.

Although the results varied considerably from one laboratory to another, in the sum of the results and in the majority of the participating laboratories 1% lactose ricinoleate produced fewer false negative reactions than brilliant green bile broth as a confirmatory medium at both 37 and 44° C.

Although both media are satisfactory, 1% lactose ricinoleate broth can be recommended as an alternative to brilliant green bile broth for the confirmation of coliform organisms and Esch. coli from presumptive positive tubes in the examination of water samples, as it is not subject to the known variability of brilliant green and ox-bile.

Active pulmonary tuberculosis was diagnosed in a 4-month-old infant 16 days after hospitalization; 186 exposed individuals were traced and one conversion detected. Although the risk of tuberculosis transmission in paediatric hospitals is low, paediatricians in low-incidence countries should maintain a high level of alert for timely identification of cases.

Herpesviruses can remain dormant in once-infected hosts and, upon reactivation, cause such hosts to become infectious. This phenomenon of latency and reactivation may enable herpesviruses to persist for a long time in small host populations. To quantify the effect of reactivation on persistence, the time to extinction of bovine herpesvirus type 1 (BHV-1) in small cattle populations was calculated. For realistic parameter values the mean time to extinction is already more than 100 years in a population of 10 animals. In a population of 20 animals the time to extinction is approximately 2000 years. The effects of vaccination on persistence were also studied, revealing that continued vaccination of the whole population could result in much faster eradication. For instance, in an isolated herd of 20 animals BHV-1 could be eradicated in 44 years.

The objective of this study was to compare the occurrence of Salmonella spp. found in the animal environment in pig herds with different Salmonella risks (61 herds with low seroprevalence, 81 herds with high seroprevalence) on a broad scale. The environmental samples were divided into two types: direct (n=1105) and indirect (n=1220) environmental samples. All samples were tested for Salmonella spp. via real-time polymerase chain reaction. Most of the indirect environments were more often Salmonella-positive in the high-seroprevalence herds than in the low-seroprevalence herds; significantly higher were compartment aisles [odds ratio (OR) 3·45, 95% confidence interval (CI) 1·61–7·41], driving boards (OR 3·06, 95% CI 1·38–6·92) and the central aisle of the barn (OR 3·03, 95% CI 1·35–6·83). The overall results show that especially areas in the indirect environment are the major, but mostly underestimated causes of residual Salmonella.

A case-controlled study of the incidence of heat-labile enterotoxin-producing Escherichia coli (LT+ETEC) and other enteric pathogens in travellers returning to the Sheffield area was conducted from May 1984 to April 1986. LT+ETEC were found in 35 (5.8%) of 600 travellers to developed countries (mainly popular Mediterranean holiday resorts), 36 (11.3%) of 320 travellers to less-developed countries, and 11 (0.9%) of 1282 control patients whose illness was not associated with recent travel abroad. A seasonal peak of LT+ETEC infection was observed only in travellers to developed countries, with infections being significantly commoner in August to October. There was no significant deviation from expected age/sex distribution of LT+ETEC infection. Strains of LT+ETEC from travellers produced more toxin than strains from control patients, strains from travellers to less-developed countries producing most of all.

Following the subcutaneous injection of typhoid vaccine into rabbits the average antibody response was estimated from day to day, and found to vary for agglutination, bactericidal action, phagocytosis (including tropins), “precipitation” and probably for complement-fixation according to the dose of vaccine.

As estimated by the maximal value reached by the serum the response increases with increasing dose in nearly all cases. This increase becomes relatively less and less as the dose increases, and its progress suggests that with a sufficiently large dose a limiting-value might be reached, which if not actually a true limit would be practically one.

The observed relationship between dose and effect is such as to suggest that the combination of antigen and reacting-cell takes place in accordance with the rules governing adsorption processes; but this does not hold for the response in bactericidal power.

With increasing vaccine-dose the date at which the maximal value is reached gets later for the various antibodies, with again exception of the bactericidal power.

The precipitation observed differs from the usual precipitation reaction and is perhaps really an agglutination-phenomenon.

Phagocytosis was observed in three ways, and the bearing of the results on the mechanism of the action of the antibody concerned is considered; and the relationship between the bactericidal and other antibodies is also discussed.

It will be accepted that milk containing large numbers of bacteria, as well as the products of their growth, is less suitable for food than unpolluted milk. A bacteriological examination of the milk in great cities generally will show that much of it in hot weather, and some of it at all seasons of the year, abounds in bacteria. Clinical experience also teaches that much of the milk in hot weather is unsuitable for food, especially for infants; because in them, owing to the rapidity with which the milk passes through the stomach, gastric digestion is almost no safeguard against the entrance of disturbing microorganisms into the intestines. Even pasteurization of milk charged with bacteria and their products does not restore it to its original condition, for the dead bodies of the bacteria and their toxins still remain. The changes in milk which are most deleterious being now known to be due to bacteria, it is theoretically conceded by all, that commercial cow's milk, the substitute for maternal milk, should be as nearly free as practicable from bacteria.

Corynebacterium kutscheri and its alleged avirulent variant were re-examined in C57Bl/6 and Swiss Lynch mice. It was confirmed that while C57B1/6 mice were resistant and Swiss Lynch susceptible to C. kutscheri, the alleged atypical variant was avirulent in both mouse strains. However, following inimunosuppression of C57B1/6 mice with hydrocortisone acetate, it was not possible to reactivate latent C. kutscheri or the alleged atypical variant; this was contrary to previous reports. Moreover, sequential hysterectomy derivation over four generations of C57B1/6 mice did not eliminate their resistance to C. kutscheri compared with conventionally born animals. Vaccination with live attenuated C. kutscheri protected susceptible mice against virulent challenge; vaccination with the alleged atypical variant afforded no such protection. The suggested role of the alleged avirulent variant in resistance to C. kutscheri is challenged and an alternative explanation of such resistance is proposed.

1. A mixture of serum and its anti-serum has the property of fixing or deviating complement and thus interfering with haemolysis. In this there is a close analogy to the fixation of complements by cellreceptors in association with immune-bodies.

2. A large number of different complements may be fixed by the same combination of serum and anti-serum: some complements however may not be fixed.

3. The amount of homologous serum necessary to produce a distinct deviation of complement is extremely small—·000,01 c.c. and even less: as a rule it is many times less than the amount necessary to give a visible precipitate with the anti-serum.

4. When a precipitate forms, the deviating substance is present in the precipitate and may be so exclusively: precipitation is however not essential, as the deviation phenomenon may be given by an anti-serum without the formation of a precipitate.

5. The precipitin and deviation tests give results which are in great part in accord as regards specificity.

6. For any given amount of anti-serum there is an optimum amount of homologous serum which gives maximum deviation of complement: above as well as below the optimum the deviation diminishes.

7. The deviation phenomenon produces an effect similar to an “anti-complement” action and the views generally held with regard to anti-complements require revision. It is however still left an open question whether true anti-complements exist.