It is well established that plague, once it has gained a foothold in a place, tends to recur every year at the same season and that the plague season varies in different places. It has been demonstrated that in Bombay City the periods between the epidemics are bridged over by cases of acute plague amongst the rats accompanied by a few cases in man. Knowing, then, the factors which determine the rise and fall of the epizootic amongst the rats, once the infection is present, we have a fairly complete conception of the seasonal prevalence of human plague in a city such as Bombay. In the case, however, of a large province, such as the Punjab, with scattered villages, the question of the annual recrudescence in the several villages is not so simply answered. For, it will be remembered that in the two Punjab villages of Dhand and Kasel, which were under close observation by the Commission for a whole year, no acute plague was found amongst either man or rats in the long interval between the epidemics. While this is so, a certain number of rats were caught alive, which, although apparently in good health, harboured living and virulent plague bacilli in chronic abscesses (see above, p. 335).

There could be no more suitable preface to emphasise the need for Diphtheria prevention than the following quotation from so high an authority as the metropolitan Asylums Board's Report of 1924–25: “Notwithstanding the great improvement in diagnosis, standard of living, education in matters of hygiene and other public health measures, the fact remains that, for reason not altogether clear, diphtheria appears to be stregthening its forces and gathering power unchecked by science.”

Presence of thermolabile agglutination-inhibiting substances in strains of the genus Shigella has been demonstrated by numerous authors. Archer (1942) used as antigen for agglutination tests with S. alkalescens cultures which had been killed at 100° C., since a thermolabile factor which prevents agglutination by the usual technique had been found present in the organism. The same method was employed by Mendes Silva (1943) in agglutination tests with S. ambigua. Braun & Unat (1943) found in S. paradysenteriae (Flexner) a labile antigen designated ‘O1’ which inhibits O-agglutination of the living bacteria. Schuetze (1944) reported that the insensitivity of S. dysenteriae (Shiga) to agglutination is abolished by heating at 100° C. for 30 min. Weil, Black & Farsetta (1944) reported that boiling for 1 hr. renders inagglutinable strains of S. paradysenteriae (Flexner) fully agglutinable. Recently, Weil et al. (1946) reported that one of the Sachs types contains an inhibiting substance, a heat labile antigen and a heat stable antigen. He observed inhibition of agglutination of living bacteria in many Flexner types, S. alkalescens and S. ambigua. Olitzki, Shelubsky & Koch (1946) reported that there is present in S. dysenteriae (Shiga) a labile substance ‘I’ which inhibits the agglutination of thd living bacteria. They were able to demonstrate a labile antigen in toxic saline extracts but not in the intact bacteria. The present paper reports a method for isolation of this antigen in the form of a relatively concentrated preparation.

One hundred and twenty-nine samples of fresh cream collected in Worcestershire were examined bacteriologically. Sixty (46·5 %) creams had counts of over 100,000 bacteria/ml. The bacteria present were of many varieties, the commonest being Bacillus spp. (aerobic spore formers), Gram-negative bacilli, staphylococci and micrococci. Since most of the creams had been either pasteurized as cream or manufactured from pasteurized milk it was thought that the many bacteria were present because of contamination after pasteurization due to three main causes; unsatisfactory or unhygienic premises, unsuitable equipment, manual handling during the filling and capping process.

The methylene blue test results related well with bacterial counts but there were seven (5·4 %) anomalous results. Although the methylene blue reduction test therefore could serve as a simple and reasonable guide to the hygienic quality of fresh cream, 5·4 % of anomalous results would perhaps make it unsuitable as a statutory test.

We thank Mr R. Colenso, M.A.P.H.E., M.A.P.H.I., Chief Public Health Inspector, and Mr H. Beckett, Milk Sampling Officer of the Worcestershire County Council, for arranging the supply of samples.

A serological survey carried out on 1379 school-children from Skye and Mallaig in the N.W. of Scotland failed to show evidence of subclinical cases of hydatidosis. There appeared to be a relatively low level of exposure to the parasite, as judged by ELISA and IHA tests. Thirty-one children reacted positively in the ELISA; only one child had a transient positive result in the IHA test. Surveillance of these children will be continued for the present but the duration required is uncertain. The local population appeared to be well aware of the mode of spread of the parasite and the methods for its control.

From these two series of experiments we can conclude that a cowdung floor, grossly contaminated with a virulent culture of B. pestis, can retain its infectivity for 48 hours but not longer, and that a chunam floor, treated in the same way, does not remain infective even for 24 hours.

The inactivation rates of tissue-culture polio virus have been determined and these have been applied to the irradiation of formalinized vaccine, as an additional inactivation process, using a simple irradiator.

The antigenic potency of the vaccine was apparently unimpaired.

We wish to thank the late Prof. van den Ende for his keen interest and criticism; Dr H. Malherbe and his staff for carrying out many of the titrations; Dr P. D. Winter for co-operation in irradiating samples of vaccine, and Margaret Pakes for invaluable technical assistance.

It has been shown by numerous observers that well-marked serological differences are found between different strains of meningococci. And since the work of Dopter on the relation of “parameningococci” to meningococci and to cerebro-spinal fever, there has arisen a fairly general agreement that among meningococci capable of causing cerebrospinal meningitis two broadly separable groups can be defined by immunological methods. But beyond this point considerable divergences of opinion appear. On the one hand there are a number of recent workers who have failed to convince themselves that the two groups of meningococci are in reality clearly delimited, permanent and independent entities. On the other hand certain other workers claim to have still further subdivided these micro-organisms into four definite and independent types, each of which possesses in itself the value of a bacterial species [cp. Andrewes (1917)].

Since 2003, Connecticut laboratories have reported Gram-positive rod (GPR) isolates detected within 32 h of inoculation from blood or cerebrospinal fluid. The objectives were to rapidly identify inhalational anthrax and unusual Clostridium spp. infections, and to establish round-the-clock laboratory reporting of potential indicators of bioterrorism. From 2003 to 2006, Connecticut's GPR surveillance system identified 1134 isolates, including 657 Bacillus spp. (none B. anthracis) and 241 Clostridium spp. Reporting completeness and timeliness improved to 93% and 92%, respectively. Baseline rates of Bacillus spp., Clostridium spp. and other GPR findings have been established and are stable. Thus far, no cases of anthrax and no unusual clusters of Clostridium spp. have been detected by the GPR surveillance system. This system would probably have confirmed the inhalational anthrax case in Pennsylvania in 2006 3 days sooner than traditional reporting. Using audits and ongoing evaluation, the system has evolved into a highly functional 24/7 laboratory telephone reporting system with almost complete reporting.

There is some suggestion that infection with pandemic influenza may increase long-term mortality risks. Therefore we aimed to determine if exposure to a severe outbreak of pandemic influenza on a troopship in 1918 impacted on lifespan in the survivors. The troopship with the outbreak cohort had 1107 personnel and the comparison cohort was from two contemporaneous troopships (1108 randomly selected personnel). Data were collected from online individual military files. The main finding was that there was no statistically significant difference in the lifespan of the outbreak cohort and the comparison cohort (means of 71·5 and 71·0 years, respectively). Indeed, the outbreak cohort was actually more likely to survive into the period from 1950 onwards (P = 0·036) and to participate in the Second World War (P = 0·043). There were no significant differences between the cohorts in terms of occupational class, but the comparison cohort had a higher proportion of rural occupations (33·3% vs. 27·0%, P < 0·001) and was very slightly older in mid-1918 (27·8 vs. 27·2 years, P = 0·028). In conclusion, this study found no support for the hypothesis that exposure to the 1918 influenza pandemic adversely impacted on the lifespan in the survivors, at least in this male and military-age population.

Recent research has even further emphasized the physiological dangers to which man is exposed when breathing gases at increased tensions. If he breathes air his activity under water is greatly limited by the problems of supply and compressed air illness. The latter is due to the formation of bubbles of nitrogen in the body on return to normal atmosphere. If he breathes oxygen, then he is in grave danger of oxygen poisoning, with convulsions, even at relatively shallow depths (Donald, 1947). During the recent war, mixtures of nitrogen and oxygen were employed for important work where the diver wished to go to considerable depths while carrying his own gases. These mixtures were varied in composition and rate of supply so that oxygen poisoning was avoided, and immediate rapid surfacing was possible, without compressed air illness occurring. However, this ingenious compromise is limited in its application, for as greater depths are reached, the oxygen has to be greatly reduced to avoid convulsions. The resultant rise in the proportion of nitrogen being breathed causes bubble formation in any but the shortest exposures. It is to be doubted whether the maintenance and meticulous supervision required, when using mixtures, will allow the use of these in the more normal conditions of peace-time. It has become increasingly apparent that the prolonged underwater survival of men requires pressure-withstanding devices in which he can exist at normal physiological tensions, i.e. atmospheric pressure. The rigid diving suit and submersible chambers, such as the bathysphere, are in their infancy; but the submarine, where the same conditions apply, is now a highly successful and developed method of underwater existence and locomotion. The further evolution of these devices, and of the submarine, depends mainly on engineering advances and not upon attempting to extend the comparatively rigid limits imposed by human physiology. The maintenance of a healthy atmosphere within a submarine is again a chemical and engineering problem which is capable of solution and constant improvement.

1. ACTH, cortisone, sphingomyelin and sphingosine produce a delayed in-hibition of the skin reaction in cattle sensitized to Trichomonas foetus antigen when they are injected intramuscularly. The inhibition is greatest 6–9 hr. after injection of the inhibitor, but may sometimes be further delayed. This reaction is associated with an absolute lymphopoenia of slightly variable duration.

N-acetylsphingosine retains the desensitizing effect of crude sphingomyelin and is of much the same potency as cortisone acetate of Merck.

2. The lymphopoenia associated with the injection of ACTH and cortisone occurs also with sphingosine, and these three substances are also alike in not producing the desensitizing effect until some hours after the injection.

3. Phenergan, a synthetic anti-histamine, has a different action, and its desensitizing effect which appears to depend on a direct antagonizing of the oedema-provoking substance resulting from the junction of antibody and antigen (hapten) takes effect apparently as soon as the injected drug itself is present at the site of the injection of the specific testing fluid.

4. Methods of testing the capacity of the hormones and drugs to prevent the skin reaction locally and to nullify the action of the in vitro antigen-antibody mixtures which can produce a reaction in normal animals are described.

Phenergan alone of the substances dealt with has any power to act locally. Phenergan mixed with the antigen-antiserum complex in vitro prevents the formation of the characteristic swelling in a normal animal.

Phenergan mixed with the specific testing fluid prevents the development of the skin reaction when the mixture is injected intradermally into a sensitive animal.

Cortisone and sphingosine do not have this action.

We are indebted to the Medical Research Council for supplies of ACTH and cortisone and to Sir Charles Harington for N-acetylsphingosine.

The personal encouragement of Prof. H. G. Lamont and the support afforded by the Ministry of Agriculture, Northern Ireland, are gratefully acknowledged.

The practice of foodborne illness outbreak investigations has evolved, shifting away from large-scale community case-control studies towards more focused case exposure assessments and sub-cluster investigations to identify contaminated food sources. Criteria to include or exclude cases are established to increase the efficiency of epidemiological analyses and traceback activities, but these criteria can also affect the investigator's ability to implicate a suspected food vehicle. A 2010 outbreak of Salmonella ser. Hvittingfoss infections associated with a chain of quick-service restaurants (Chain A) provided a useful case study on the impact of exclusion criteria on the ability to identify a food vehicle. In the original investigation, a case-control study of restaurant-associated cases and well meal companions was conducted at the ingredient level to identify a suspected food vehicle; however, 21% of cases and 22% of well meal companions were excluded for eating at Chain A restaurants more than once during the outbreak. The objective of this study was to explore how this decision affected the results of the outbreak investigation.

Brucellosis is a widespread zoonosis caused by small bacteria of the genus Brucella. The promoter polymorphisms of IL-10 (-1082 loci, -819 loci and -590 loci) are closely related to the production of IL-10, leading to the alteration of development and pathogenesis of Brucellosis. However, the previous results were controversial. In the present study, we conduct the meta-analysis to get a more precise result of IL-10 polymorphisms with Brucellosis risk. The quality of the studies was assessed according to a predefined scale. The odds ratio (OR) and 95% confidence interval (CI) were counted to evaluate the association strength. No significant association was found between position -1082 loci or -590 loci polymorphism and Brucellosis risk. The significant association was found in Asian population of position -819 (T vs. C: OR 0.60, 95% CI 0.44–0.82, P = 0.001), homozygote comparison (TT vs. CC: OR 0.24, 95% CI 0.09–0.62, P = 0.003) and recessive genetic model (TT vs. TC/CC: OR 0.22, 95% CI 0.05–0.91, P = 0.036). The present meta-analysis demonstrates that IL-10-819 loci polymorphism is not associated with Brucellosis risk of Caucasian population but may contribute a decreased risk to Asian population. And neither IL-10-1082 loci nor -592 loci polymorphism is associated with Brucellosis risk.

It is emphasized that as heat exchange is controlled by the temperature of that boundary layer of molecular dimensions which separates a cooling body from its environment and from which evaporation occurs, attempts to relate heat loss with internal temperature have resulted only in empirical formulae. A rational formula involving the temperature of the evaporating surface is suggested, and it is shown how in the case of a system of sufficient simplicity all the terms can be either measured or derived from experiments.

The results of experiments with a small moistened cylinder are detailed illustrating the effect of wind velocity upon evaporative and convective heat loss under the one condition when the evaporating surface remains at constant temperature notwithstanding variations in wind, namely, when the whole system has been cooled to wet-bulb temperature. Evaporative loss is found to vary as V0.65, convective as V0.70.

Experiments are next described showing the effect of wind upon evaporative and convective losses when, the internal temperature being constant, the temperature of the evaporating surface fluctuates in consequence of varying wind velocity. Heat loss now varies very closely as V0.5 at velocities greater than 1 m./sec. At velocities below 1 m./sec. the same relation of heat loss to velocity obtains if due allowance be made for natural convection. This square root function is fortuitous, and heat loss varied between the square root and cube root of the velocity as the internal conductivity was diminished.

Attention is drawn to the impossibility of forming general conclusions from observations on any particular system, as the way in which the rate of heat loss varies with the velocity of the wind depends not only upon the internal conductivity of the system but also on its size and shape.

Observations are described showing the influence of varying the internal temperature on total and evaporative heat loss with constant wind velocity and constant atmospheric conditions. These experiments furnish data from which the surface temperature can be derived from measurements of evaporation, and show that the temperature of the surface and the rate of loss of heat by convection are both linear functions of the internal temperature at any one wind velocity. They also show that the values of the constants of the system derived from experiments at the temperature of the wet bulb are applicable when the cylinder is heated.

An analysis of the results of the experiments with varying internal temperature indicates that the temperature of the evaporating surface (ts) is related to the internal temperature (t1) and that of the wet bulb (tw) by the expression The value of C with varying wind velocity is ascertained by experiments, thus affording another means of arriving at the temperature of the evaporating layer. Values of ts obtained in this way are compared with those determined by observing the rate of evaporation and show reasonable agreement.

It is shown how, knowing the temperature of the evaporating layer, the constants of the system employed and the effect of velocity of wind upon heat exchange, the rate of loss of heat by evaporation and by convection under given conditions can be predicted. Instances of the agreement between predicted and observed values are given.

From the formula representing the influence of atmospheric conditions on heat loss it can be shown, by calculation, that if the wet-bulb temperature remains constant considerable variations in the temperature of the dry-bulb influence but slightly the heat loss from the moist cylinder.

It will be seen that the analysis of the effects of environmental changes on the heat loss from a simple physical system such as was used presents no serious difficulties. Such an analysis, unfortunately, does not enable deductions to be made with reference to systems of different physical characteristics. How observations on such systems can be related in other than a qualitative manner to the effects of corresponding changes on living creature differing in size and shape and degree of moistening of their surfaces is not clear. When account is taken of the ability of living beings to alter the vascularity of their surface tissues and so to vary the temperature of the body surface while other factors remain constant, the difficulties in relating the cooling of any physical system to the loss of heat from animals become painfully apparent.

The most hopeful method of assessing the effect of air movement and atmospheric conditions on the heat loss from the human body seems to be in terms of a subjectively determined standard such as the effective temperature scale of Houghton & Yaglou. The validity of such a scale has received support from observations by Houghton et al. (1924) and Vernon & Warner (1932) on the relation of pulse rate, body temperature, metabolism and other physiological variables to “effective temperature”.

In the preceding reports on infant mortality in counties during 1908 (Cd. 5263), in 241 urban areas in 1907–10 (Cd. 6909), and in Lancashire (Cd. 7511), the chief environmental circumstances favouring excessive infant mortality have been enumerated and to some extent discussed.

So much has been written concerning Piroplasmosis as it occurs in different animals in various parts of the world that one may be pardoned for directing attention to the fact that the disease exists at home and is constantly coming before the notice of the veterinarian at this time of the year.