Milk samples from 251 nursing mothers were screened for enterotoxigenic staphylococci. The incidence of staphylococci in milk samples was 71·3%. Two hundred and sixteen strains were isolated from 179 mothers. Eighty-six (39·8%) of the 216 strains were found to be toxigenic. Enterotoxin type A (SEA) predominated, with 41 strains (19·0%) elaborating it. Twenty-one strains (9·7%) produced enterotoxin B (SEB) while only eight (3·7%) produced enterotoxin C (SEC). Ten strains (4·6 %) produced all three types. Enterotoxigenic strains usually produced coagulase, thermonuclease and alpha haemolysin.

In this series breast-feeding alone was more common than combined breast and bottle feeding, especially among mothers less than 30 years old. The incidence of reported infantile diarrhoea decreased with increasing age of the mother. Of 16 babies with diarrhoea, 10 (62·5%) had mothers whose milk yielded staphylococci. Six of these were toxigenic. Although no direct relationship between enterotoxigenic staphylococci in the milk of nursing mothers and infantile diarrhoea could be demonstrated, these findings reveal a potential health risk to these infants.

In the epidemiology of bovine viral diarrhoea (BVD), immunotolerant – persistently infected animals (IPI) appear to be major sources of contamination. These animals produce large quantities of replicating virus and have therefore been proposed as being responsible for generating antigenic variability. However, limited studies have failed to detect antigenic or genetic changes in viruses isolated at different times from IPI. An hypothesis is that the immunotolerance of IPI against their homologous strain is accompanied by immune elimination of antigenic variants. The presence of an IPI in a herd could therefore limit antigenic variation, eventually leading to the existence of herd specific strains. To verify this hypothesis we characterized, against a panel of monoclonal antibodies, 37 BVD virus strains isolated from IPI of 12 herds in Eastern Belgium. Intra-herd antigenic variation was compared to inter-herd variation. Antigenic variation within herds was found to be surprisingly high but, nevertheless, significantly lower than variation between herds.

When the manifold system of freeze-drying is used the practice of plugging the tubes containing the product to be dried would seem to be necessary. It should be emphasized that a loose plug implies teased out cotton-wool and not just a loosely fitting one. Virus was recovered from the drying apparatus under various conditions when unplugged tubes were used. No virus contamination could be demonstrated when the tubes were plugged.

1. The epidemic spread of plague in Java usually shows periodicity in that the increase commences in the third quarter, the driest period of the year, the apex being reached in the last months of the year. Afterwards, still in the middle of the wet monsoon, the decrease commences and reaches its lowest point in the second quarter.

2. This seasonal course of plague—in the mountainous parts of Java at least—corresponds with a distinct fluctuation in the flea index during the same period.

3. Whereas under the climatic conditions of the mountainous regions of Java the flea index usually follows the rise and fall of the saturation deficiency, it has been shown that in British India the influence of the saturation deficiency is in an exactly opposite direction.

Intranasal inoculation of 12 young adult mice (strain TO) with Mycoplasma pulmonis protected all of them against vaginal colonization when they were challenged intravaginally 60 days later with the same mycoplasmal strain. In contrast, all 15 mice without a respiratory infection became colonized vaginally (geometric mean titre [GMT] 4·6 × 106 colour-changing units [c.c.u.]) when challenged in the same way. The GMT of serum antibody, measured by a micro-immunofluorescence technique, prior to challenge was 200 and 8 for the oropharyngeally infected and unexposed mice, respectively. The GMT of antibody in vaginal washings from the two groups was 6 and 3, respectively. All four nude BALB/c mice were susceptible to vaginal colonization (GMT 5·6 × 106 c.c.u.) after oropharyngeal infection (GMT 5·1 × 104 c.c.u.) resulting from intranasal inoculation, as were all six nude mice (vaginal GMT 1·4 × 107 c.c.u.) that had not been inoculated intranasally. In contrast, all ten of their immunocompetent counterparts were resistant to vaginal colonization after oropharyngeal infection (GMT 1·3 × 103 c.c.u.), whereas all nine such mice that had not been infected oropharyngeally were susceptible to vaginal colonization (GMT 7·6 × 106 c.c.u.). These results show the important role that a respiratory infection has in protecting the vagina against colonization and that protection is dependent on a functioning T-lymphocyte system.

We analysed nosocomial MRSA cases between January 2004 and December 2006 in a retrospective case-control study in a 250-bed tertiary-care teaching hospital. During the study period, 265 nosocomial Staphylococcus aureus infections were identified in 231 patients. There was a significant increase in methicillin resistance in isolates (MRSA) from these infections with frequencies for 2004 of 39/88 (44·3%), 2005 (62/80, 77·5%), and 2006 (75/97, 77·3%) (P<0·001). Multivariate analysis showed that associated factors for nosocomial MRSA infection were prolonged hospitalization (OR 3·982, 95% CI 2·235–7·094, P<0·001), mechanical ventilation (OR 3·052, 95% CI 1·666–5·590, P<0·001), surgical operation (OR 2·032, 95% CI 1·102–3·748, P=0·023), and male sex (OR 2·000, 95% CI 1·081–3·699, P=0·027). The determination of associated factors for methicillin resistance in nosocomial S. aureus infections in hospitals will play an important role in efforts to reduce MRSA infection rates.

Sources of information for monitoring infectious disease are routine data, special surveys and ad hoc investigations. In practice much use is necessarily made of routine notifications and laboratory records although this reporting is often incomplete and may therefore be biased.

In a retrospective study of a 16-year series (up to 1968) of routine records concerning the diagnosis of gastroenteritis at one Public Health Laboratory we found it possible to identify biases. During school outbreaks of dysentery, laboratory investigation of diarrhoea increased appreciably and such response to publicity affects the use of routine data in surveillance. Although the patients examined were probably representative diagnostically, their selection may not have reflected the age incidence of disease. Valid geographical comparisons within the urban area were not feasible because medical practitioners differed in their use of laboratory facilities and in their habits of notification. Nevertheless, as far as can be established retrospectively, these data did reflect time trends in disease incidence and so had value for monitoring purposes.

Several of the biases defined are likely to apply to other sets of routine data. A further communication will describe a statistical method of correcting for quantifiable bias.

Strains of poliovirus were obtained from 13 of the 18 persons in England and Wales with paralytic episodes after administration of oral vaccine in 1962. They have been studied using three marker tests: the R.C.T.40 test, intratypic serodifferentiation and inhibition by dextran sulphate. For comparison a number of strains from subjects with non-paralytic vaccine-associated reactions and from patients with paralytic poliomyelitis not related to vaccine were also tested.

Of the eight patients excreting type 1 strains seven came from South Wales where an outbreak was in progress. They all resemble naturally occurring strains from the outbreak in growing at 39·3° but not at 39·8° C.

Only one subject excreted type 2 virus which was of vaccine type.

The type 3 strains included a series from a family group where a range of results from vaccine to the wild range was obtained. Three other patients with vaccineassociated paralysis excreted type 3 strains with the characteristic of naturally occurring strains.

Community-onset methicillin resistant Staphylococcus aureus (CO-MRSA) became a prominent cause of infection in North America in 2003, with a peak in the epidemic noted by multiple groups in the USA between 2005 and 2007. We reviewed rates of MRSA in two hospitals in Vancouver, Canada, to observe changes in epidemiology from 2003 to 2011. Episodes of emergency department (ED) MRSA bacteraemia and wounds were extracted from the laboratory database, with rates calculated per 10 000 ED visits. All cases were assumed to be community onset, as they were diagnosed in the ED. A peak in ED MRSA bacteraemias occurred in 2005, at 7·8/10 000 ED visits. By 2011, rates of ED bacteraemia declined significantly to 3·3/10 000 ED visits (P⩽0·03). MRSA wound rates peaked at 82·2 cases/10 000 ED visits in 2007 with a subsequent significant decline to 34·3 cases in 2011 (P = 0·04). We have demonstrated a significant decline in CO-MRSA within our population, consistent with reports from the USA, suggesting a substantial change in the epidemiology of CO-MRSA in certain North American cities.

The experiments reported below followed the observation that living dysentery bacteria (S-variant) are not agglutinated after 4 hr. contact with an homologous antiserum. Somewhat later agglutination appears, but does not reach the end-titre. The next day fine granula are visible on the bottom of the test-tube which are readily dispersed by gentle shaking. This form of agglutination was designated ‘soft’. If the bacteria are heated for 30 min. at 100°C. agglutination appears within 2 hr. at all dilutions up to the end-titre of the serum. The next day a heavy sediment is visible, and in low serum dilutions a cuticula covers the bottom of the test-tubetities injected intravenously were 0·1, 0·25, 0·5 and 1·0 mg.; the latter were relatively harmless and quantities of 0·2–2·0 mg. were injected.

The present experimental model offered the opportunity to study particular aspects concerning the avirulence stability of live streptomycin-dependent (Sm D) Salmonella vaccines, under conditions resembling human enteric fever. The results seem to indicate that, in practice, the risk of reversion to a virulent form during oral antityphoid vaccination with Sm D strains remains slight even after the interruption of concomitant streptomycin administration.

This paper reports a study carried out to clarify the mechanisms involved in adsorption of influenza A and B viruses on iron oxide. Accordingly, the amounts of virus that are adsorbed from virus suspensions of varying concentrations per unit surface area of magnetic or non-magnetic oxide at fixed temperature and time have been determined. The principles involved are clearly the same as those involved in multiple equilibria during the interaction of particles with a large number of combining sites with different intrinsic affinity. Consequently, the amount of virus that is adsorbed per unit mass of iron oxide depends on the size of the adsorbent area, not on its magnetic property. Owing to a significant difference between the affinities of influenza A and B particles for the binding sites on iron oxide, unit surface area of the adsorbent is invariably capable of adsorbing significantly greater amounts of influenza A than B particles. The practical implications of these findings are that a better understanding of the mechanisms involved in virus adsorption on iron oxide will permit a more efficient separation of virus particles from impurities. The simplicity and the rapidity of the technique and the cheapness of the equipment required suggest that the iron oxide method is of great value for both small- or large-scale viral purification, whether it is used as a single step procedure or as a primary step followed by zonal separation.

Because non-name-based case registries have recently been used for reporting human immunodeficiency virus infection, this study attempted to define the sensitivity, specificity and accuracy of case registry matches using non-name-based registries. The AIDS, sexually transmitted disease (STD), and tuberculosis (TB) case registries were matched using all available information to establish the standard. The registries were then matched again using five increasingly less specific criteria to compare sensitivity, specificity and accuracy. The registries were then also transformed into non-name-based codes as if they were the HIV registry and matched again. With name-based registries, sensitivities increased as the matching criteria became less exacting, while the accuracy declined slightly. Specificities remained close to 100% due to the relatively small number of matched cases. Results from matches of non-name-based registry matches were similar to those of the name-based registry matches. Non-name reporting can be used for data matching with acceptable accuracy.

1. A general survey of diphtheria in Glasgow during 1934–42 has been made. Over 11,000 strains of C. diphtheriae have been typed and the incidence of the types is recorded.

2. The period has been marked by a change in the predominant type of organism from intermedius to gravis, and gravis infections are now responsible for most of the mortality, though the average case fatality rate due to them is not high.

3. Diphtheria on the whole has been mild and complications relatively few, but some shift in the death-rate incidence to the higher age periods with increase in the corresponding case fatality rate has taken place. A small shift in the age incidence of diphtheria is noted.

4. Some account of the effect of immunization is given.

5. Comment is made upon colony variation among the types of C. diphtheriae.

Information about the changing epidemiology of drug-resistant tuberculosis (TB) in hospitals in China over the past decade remains largely unknown. This study examined the susceptibility patterns and trends of drug-resistant TB cases in the 309 Hospital in Beijing, China. Mycobacterium tuberculosis isolates were retrospectively identified, drug susceptibility test (DST) results and clinical data were analysed for the period 1997–2009. Of the 5523 culture-positive TB patients, 47·1% had resistance to any anti-TB drug, 14·8% had mono-resistant TB, 19·8% had poly-resistant TB, 19·4% had multidrug-resistant TB (MDR-TB), and 1·3% had extensively drug-resistant TB (XDR-TB). Drug-resistant TB was significantly associated with age group, residential situation, and TB treatment history (P<0·001). During 1997–2000, the percentage of TB patients with any resistance, mono-resistant TB, poly-resistant TB, MDR-TB and XDR-TB all increased significantly (P<0·001). During 2000–2003, the increasing trends of MDR-TB and XDR-TB cases were reversed. During 2004–2009, the percentage of TB patients with any resistance, mono-resistant TB, poly-resistant TB, MDR-TB and XDR-TB all declined significantly (P<0·001), but the prevalence of MDR-TB and poly-resistant TB cases remained high. Our study provides evidence demonstrating that intensive TB control measures have helped reverse the increasing trends of drug-resistant TB in China, but continuous surveillance of drug-resistant TB and better case management are still needed to further reduce the remaining high prevalence of drug-resistant TB.

Leprosy is a granulomatous disease, infectious and transmissible, which affects the skin and peripheral nerves, having Mycobacterium leprae as causative agent. The manifestation of this disease causes cutaneous lesions, peripheral neuropathies and, in more extreme cases, may generate deformities and disabilities in affected individuals. Patents were identified using the descriptor ‘leprosy’ and code A61K of the international patent classification, which indicates only products that meet human needs. The analysis was made using the WIPO, ESPACENET and USPTO databases, until the month of September 2016. Through this review, we found a variety of in vitro, pre-clinical and clinical studies relating to the treatment of leprosy with different types of compounds and forms of administration. New treatment proposals should include pain reduction capabilities, prevention or limitation of the appearance of cutaneous lesions, as well as prevention of the progression of the disease to more severe stages that may lead to loss of function or potentiate the individual's immune response to the M. leprae bacillus in order to prevent bacterial spread. We concluded that any patents developed with natural products were not found in the treatment of leprosy. All the deposited products were synthetic origin, mostly tested in humans and of varied forms of administration.

The distribution of salmonella agglutinins among 2117 normal sera from 1054 male and 1063 female adult population of Ibadan is described, and the relation of the distribution of the agglutinins with the antigens of salmonella strains isolated over 2-year period in a hospital in Ibadan, Nigeria, is discussed.

We wish to thank Prof. B. G. T. Elmes and Dr J. B. Lawson for their help with the collection of specimens. Our thanks are due to Mr R. J. Leeming, F.I.M.L.T. for his technical assistance.

(Part of the material upon which this paper is based is included in a thesis for submission for the Cambridge M.D. degree by one of us (D.M.).)

We investigated an outbreak of Salmonella enteritidis involving at least 19 British tourists returning from one hotel in another European country. A retrospective cohort study of 47 hotel guests identified lasagne as the most likely vehicle of transmission (RR 11·5; 95% CI 3·0–44·1; P<0·0001). However, difficulties in information exchange and lack of formal mechanisms to agree on the aims of the cross-national investigation hampered efficient management of the outbreak. The factors leading to contamination of the food vehicle were not identified and therefore specific action to prevent reoccurrence could not be taken. There is need to develop protocols for cross-national investigations of outbreaks in Europe which should include specifying objectives, roles and responsibilities of investigators and control agencies, with formal reporting of the outcome of the investigation.

The purpose of this study is to determine how demographic and exposure factors related to giardiasis vary between travel and endemic cases. Exposure and demographic data were gathered by public health inspectors from giardiasis cases reported from the Region of Waterloo from 2006 to 2012. Logistic regression models were fit to assess differences in exposure to risk factors for giardiasis between international travel-related cases and Canadian acquired cases while controlling for age and sex. Multinomial regression models were also fit to assess the differences in risk profiles between international and domestic travel-related cases and endemic cases. Travel-related cases (both international and domestic) were more likely to go camping or kayaking, and consume untreated water compared to endemic cases. Domestic travel-related cases were more likely to visit a petting zoo or farm compared to endemic cases, and were more likely to swim in freshwater compared to endemic cases and international travel-related cases. International travellers were more likely to swim in an ocean compared to both domestic travel-related and endemic cases. These findings demonstrate that travel-related and endemic cases have different risk exposure profiles which should be considered for appropriately targeting health promotion campaigns.

A total of 4551 sera from 863 Strain 19 vaccinated and non-vaccinated adult cattle, independent of disease status, were tested by five serological methods to detect the presence of antibodies to B. abortus. Results from Standard Agglutination Tube (SAT), Buffered Brucella Antigen or card (CT), Complement Fixation (CF), Enzyme Linked Immunosorbent Assay (ELISA) and Rivanol (Riv) methods were compared.

There was a 95% probability for agreement among CT negative sera, between serological methods, for all groups of vaccinated and non-vaccinated cattle. The agreement between tests with Riv Positive sera, excluding the calfhood and adult vaccinated group tested by the CF method, was 91–100%. The probability of a serum which was serologically negative by other methods being Riv negative was 98%. The usefulness of serological results from Riv (≥ 1/50) tests for classifying the reactor status of cattle are of doubtful supplemental value to confirm card test positive results.

Vaccination history is an important consideration when evaluating serological data on cattle sera particularly from SAT and CF methods.