Sample frequency distributions are given of height and weight measurements of London elementary school children made during the period 1935–8. In addition these measurements have been analysed in order to determine the seasonal fluctuation in rates of growth. The rate of increase in height appears to reach a maximum in the latter part of spring and a minimum in the middle of autumn. The rate of increase in weight appears to reach a maximum in the latter part of autumn and a minimum in the middle of spring. Tables and graphs are given showing, for each sex, the variation in the rates of growth throughout the calendar year. I wish to thank the County Medical Officer of Health, W. Allen Daley, M.D., F.R.C.P., for permission to publish this paper and for encouragement in its preparation; Mr L. Coward, F.I.A., and Mr E. Lewis Faning, Ph.D., for statistical criticism; and Mr J. H. Farrar for drawing the diagrams.

The London County Council takes no responsibility for the views expressed in this paper which are personal only.

The sera of healthy blood donors from the Wellington area of New Zealand, collected between 1976 and 1980, were analysed by the complement fixation test for antibody to Mycoplasma pneumoniae. A high prevalence of antibody to this organism was demonstrated and the occurrence of an M. pneumoniae epidemic in New Zealand within the survey period was shown to be reflected i the immune status of this healthy adult population. This would suggest that during an epidemic many people within the Wellington community may have M. pneumoniae infections involving littl overt illness.

In view of the number of cases of epidermal cancer, especially cancer of the scrotum, which have occurred amongst cotton mule spinners within recent years, constituting this the foremost occupational cancer in our country, it may be opportune to investigate the exact duration of employment in the mule rooms that would seem to be necessary before the disease manifests itself. How long must the individuals be exposed to the action of the cancerinducing influence before the cancerous response is elicited? The Departmental Committee on Mule Spinners' Cancer having found that the “influence” or agent in this case is mineral oil, which Leitch has proved experimentally to have cancer-producing properties, how long does it take to act?

It is almost impossible to avoid some confusion when one has to deal with diseases which it is difficult to define clearly either by means of symptoms and lesions, or by means of some causal agent capable of demonstration in the majority of cases.

The object of the experiments detailed below, which were made at the suggestion of Dr W. Hunter, was to ascertain whether media containing neutral-red afford a rapid means of detecting Bacillus coli in water and estimating the number present.

Whilst the studies of A. C. Houston and MacConkey have extended our knowledge of the characters of the bacilli found in faeces, and those of Dudgeon and Sargent have done the same with regard to colon bacilli met with in cases of appendicitis, the fermentative activities of pathogenic colon bacilli occurring in urine have not been investigated to any great extent.

Arginine has been shown to be essential for the replication of several orthopoxviruses in mouse sarcoma 180 cells and in chick embryo fibroblast cultures. Both host systems are characterized by their inabilities to utilize citrulline for the biosynthesis of arginine due to deficiencies in the requisite cellular enzymes and cell multiplication is absolutely dependent on the availability of exogenous arginine. Virus replication in such cells maintained with citrulline results from the induction of virus-specific enzymes. Significant virus yields in the absence of exogenous arginine or citrulline can arise from the replenishment of intracellular amino acid pools by increased utilization of arginyl residues in cellular proteins. The extent of the phenotypic expression of these characters in infected cells permitted significant discrimination between the viruses examined. Distinctions could be drawn between rabbitpox, ectromelia, cowpox, buffalopox and vaccinia strains. However, cowpox could not be distinguished from other viruses isolated from diseased animals in European zoos.

In 1996 an outbreak of severe soft tissue infections caused by Vibrio vulnificus unexpectedly erupted in fish consumers in Israel with relatively little morbidity in fish farmers. To test the hypothesis that recurrent exposure of fishermen to the virulent strain may have provided protection against severe or symptomatic disease, we investigated the association between the immune response to V. vulnificus biotype 3 lipopolysaccharide (BT3 LPS) and disease susceptibility in fish farmers and fish consumers. Serum samples were tested for IgA and IgG of anti-BT3 LPS in fishermen and fish consumers who suffered from V. vulnificus BT3 infections and their matched controls. Pre-existing levels of IgG (IgG0) of anti-BT3 LPS were significantly lower in diseased fishermen who developed disease associated with the homologous biotype, compared to controls. In multivariate analysis, levels of IgG0 anti-BT3 LPS remained the only variable significantly associated with disease occurrence in fishermen. Higher levels of pre-existing IgG anti-BT 3 LPS antibodies may be associated with protection against severe or symptomatic disease with the homologous biotype in fishermen but not in subjects from the general public.

An outbreak of Salmonella enteritidis PT 6B food poisoning, the first reported of this recently described phage type, resulted in illness among 46 of 49 members of a camping group in North Wales. 33 of whom were hospitalized. Epidemiological evidence (P < 0·0001) indicated that a lemon meringue pie was the vehicle of infection. Fresh shell eggs, stored after purchase at ambient temperature, appear to be the most likely source of infection, with multiplication during preparation and subsequent storage of the pie a significant contributory factor. Campers may be at greater risk than others and should consider the use of cold boxes for the transport and storage of eggs, and avoid the preparation of lightly cooked egg products under these basic conditions.

A randomized control trial on verocytotoxigenic Escherichia coli (VTEC)-infected farms found evidence that: (1) keeping animals in the same group; (2) maintaining dry bedding; (3) preventing direct contact with neighbouring cattle; and (4) maintaining a closed herd, were associated with a reduced risk of infection in youngstock aged 3–18 months. This study evaluated these interventions using a cost-effectiveness framework for UK dairy farms. Keeping animals in the same group was considered to have negligible cost and was feasible for herds containing over 77 dairy cows. Assuming equal efficacy of the remaining interventions, preventing direct contact between neighbouring cattle is most cost-effective with a median annual cost of £2.76 per cow. This compares to £4.18 for maintaining dry bedding and £17.42 for maintaining a closed herd using quarantine procedures. Further model validation and exploration of other potential benefits are required before making policy decisions on VTEC control.

We conducted probabilistic data linkage of three population datasets for the Northern Territory (NT), Australia, to describe the incidence of preterm births, stillbirths, low birthweight and small for gestational age (SGA) per 1000 NT births; and influenza and pertussis hospitalisations per 1 00 000 NT births in infants <7 months of age, in a pre-maternal vaccination era. The Perinatal Trends dataset (1994–2014) formed the cohort of 78 382 births. Aboriginal mother–infant pairs (37%) had disproportionately higher average annual rates (AR) for all adverse birth outcomes compared to their non-Aboriginal counterparts; rate ratios: preterm births 2.2 (AR 142.4 vs. 64.7); stillbirths 2.3 (AR 10.8 vs. 4.6); low birthweight 2.9 (AR 54 vs. 19); and SGA 1.7 (AR 187 vs. 111). Hospitalisation (2000–2015) and Immunisation Register datasets (1994–2015), showed that influenza hospitalisations (n = 53) and rates were 42.3 times higher in Aboriginal infants (AR 254 vs. 6); and that pertussis hospitalisations (n = 37) were 7.1 times higher in Aboriginal infants (AR 142.5 vs. 20.2) compared to non-Aboriginal infants. These baseline data are essential to assess the safety and effectiveness of influenza and pertussis vaccinations in pregnant women from the NT. Remote living Aboriginal women and infants stand to benefit the most from these vaccines.

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.

Examination of sera from 184 children aged between 0 and 12 years and 161 adults revealed a close correlation between age and the level of humoral anti-RS virus immunity. Secretory IgG antibodies were found in children in their first months of life. Evidence for their release into secretions from the serum was obtained. This might explain the positive correlation between serum antibody levels in women recently confined with the morbidity due to RS virus in children during their first months of life. Secretory IgA antibodies were found from 4 months untill old age. The secretions of children and adults contained virus-neutralizing activity which was non-immunoglobulin in nature, as well as antibodies. However, in contrast to secretory antibody this material did not prevent development of severe RS virus infections.