In order to determine whether non-lactose fermenting bacilli are numerous in fresh milk, a series of experiments was made in the early part of this year on samples of fresh dairy milk, taken in Dumfriesshire, for routine bacteriological examination. The samples were brought to the laboratory with the least possible delay, and in no case did more than seven or eight hours elapse between the time of milking and the inoculation of plates. In the majority of instances, the interval was much shorter.

1. It has been shown that certain nitrite-destroying organisms when grown along with V. Cholerae prevent the appearance of the cholera-red reaction. This is not due to the non-formation of nitrite, but to its rapid destruction by the enitrite-destroying organisms.

2. Certain nitrite-destroying organisms fail to prevent the cholera-red reaction.

3.It has been shown in the case of the B. dysenteriae (Flexner) that the failur to prevent the cholera-red reaction is due to an inhibition of the growth of both organisms when grown together.

During an epidemic of Sonne dysentery in Tooting Bec Hospital of which the epidemiological aspects have been described by one of us (Buckle, 1938), and during a recurrence of this epidemic, a number of strains were isolated of the causal organism (140) and various bacilli which were somewhat similar in their cultural and biochemical behaviour. It was thought that a close bacteriological and serological examination of these might be useful in giving information about the constancy of behaviour of the Sonne group, the question of possible biochemical subgroups of Sonne bacilli (Bojlén. 1934), and the relationship of the dysenteroid organisms isolated to the true dysentery bacilli, their classification, and significance.

Hay Fever is a disease which on account of its peculiar interest has attracted the attention of the medical world ever since it was first accurately described by Bostock of London in 1819. To what extent the disease occurred before his time is difficult to determine; but from the fact that his observations were at once confirmed by a number of contemporary medical men it is probable that at the time of his writing it was not very uncommon. We have no exact knowledge of the existence of the disease in England prior to the nineteenth century, and indeed many authors hold that the chief etiological factors were not present in earlier times. It is my purpose in this paper to discuss the researches recently carried out by Prof. Dunbar at the State Institute of Public Health in Hamburg, which have very considerably increased our knowledge of the interesting malady, and have also narrowed the field for its future investigation.

The India-ink Immuno-reaction (IIR) was used as a simple, convenient procedure for the detection of carriers of enteric organisms in an unselected sample of patients attending a mission clinic at Kubacha in a remote area of Kaduna State, northern Nigeria. To assess the reliability of this procedure in difficult working conditions a similar population from the same clinic was subsequently examined by routine bacteriological culture techniques. Because of a temporary shortage of suitable anti-sera we were unable also to examine specimens from this second group by IIR.

A further group of patients attending the out-patients clinic of the General Hospital in Kaduna with symptoms of acute enteric disease was investigated using both IIR and routine culture.

Proportionally more positive results were obtained for Salmonellae, Shigellae and Vibrios with IIR than with routine culture. A larger scale controlled survey is desirable to evaluate the procedure further.

Rates of acquisition and loss of Brugia malayi microfilaraemia were estimated using the parasitological data of a cohort of population in Shertallai, South India. The rate of acquisition of microfilaraemia was found to be dependent on age but not gender. The decline in the rate of acquisition of microfilaraemia in adults above 35 years could be due to the development of acquired immunity. The mean reproductive lifespan for the periodic Brugia malayi adult female worm was estimated to be 34 years and it was independent of host age and gender. The age-specific estimated proportion of population at risk (microfilaria carriers who lost their microfilaria in course of time) of developing lymphoedema approximately mirrored the observed age specific prevalence of lymphoedema in the study-population. On an average, 99% of population at risk developed manifestations of disease. The estimated population at risk of developing disease in different endemic areas is compared and its epidemiological significance is discussed.

Tuberculosis (TB) is generally considered a disease that principally afflicts the low-income segments of a population. In the Nanshan District of Shenzhen, China, with the economic transformation and a new Headquarters Economy (HE) emerging, there are now more cases in office workers than in manufacturing workers. To illustrate this trend, we describe a small TB outbreak in an office building located in the centre of the rapidly growing HE district. Two active pulmonary tuberculosis cases were found in workers who shared an office, and whole genome sequencing showed that the genetic distance between the strains of the two cases was just one single nucleotide polymorphism, consistent with intra-office transmission. Investigation of 30 other workers in the same or adjacent offices with interviews, interferon-gamma release assays (IGRAs) and chest X-rays, identified one new TB case and latent tuberculosis infection (LTBI) in 40.0% (12/30) of the contacts. The offices were under-ventilated. None of the IGRA positive, asymptomatic contacts agreed to receive treatment for LTBI, presumably due to TB stigma, and over the next 2 years 69.0% (20/29) of the contacts were lost to follow-up. Treatment for LTBI and stigma of TB remain challenges here. Office workers in the HE of rapidly economic developing areas should be targeted with increased vigilance by TB control programmes.

Immunization of men with various amounts of salmonella antigens gave a linear relationship between the logarithm of the dose and the logarithm of the titres of the antibodies produced. No secondary response was observed for any of the doses used. These doses of salmonella vaccine did not interfere with or stimulate simultaneous primary or secondary vaccination with tetanus and diphtheria vaccine.

The disappearance of the resistant mutant from an artificial mixture of normal antibiotic-sensitive organisms and a resistant mutant after varying numbers of subcultures is known as the Welsch phenomenon. Welsch's observations have been confirmed and experiments devised to show that the resistant strain disappears because it grows more slowly than the normal sensitive strain which eventually, during the successive subcultures, overgrows it.

Skin and soft tissue infection (SSTIs) due to Staphylococcus aureus, particularly community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), are common in human immunodeficiency virus (HIV)-infected populations in the United States. Studies have differed as to the importance of epidemiological and immunological factors in this relationship, and have employed conflicting strategies for variable selection in multivariate analyses. Developments in causal inference methods in epidemiology have emerged in the last decade to clarify relationships between variables and identify appropriate variables to include in and exclude from multivariate analysis. In this paper, we develop a causal diagram to clarify the pathways linking CA-MRSA and HIV. We focus on the role played by trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis, prescribed to many severely immunocompromised HIV patients and potentially protective against SSTIs, which both mediates and moderates the relationship between immunological parameters and SSTI risk. We demonstrate, using simulated data, that statistical models may yield biased results if they do not account for how HIV viral load may also be a marker of adherence to TMP-SMX prophylaxis. We conclude with a proposed causal model that includes both the epidemiological as well as immunological factors that may explain the increased risk of initial and recurrent SSTI risk in HIV-infected populations.

Interesting results were obtained with cultures in ammonia agar, from them it is evident that the nitroso-bacterium grows readily through this medium whether inoculated on the centre of a plate or when covered with the agar jelly itself. Further, the presence of 5 to 10% of beef broth in the ammonia agar allows of better development.

Potassium phosphate agar containing bouillon gelatine but no free ammonia, on being inoculated with cultures of nitroso-bacteria, also developed nitrification; the organic matter was broken down, ammonia formed, and nitrites built up.

Nitrification in ordinary bouillon agar plates shows that organic matter does not necessarily form a barrier to the process; and further, that two of the cultures had only been fed with inorganic salts for three and four years respectively prior to the inoculation into the plates, is good evidence that gradual additions of organic matter are not absolutely necessary.

Calcium sulphate blocks allowed me to work with a larger amount of very active culture: from these it was found that urine was a very good culture medium indeed. Also that peptone water diluted with water, or peptone beef broth, milk, or blood serum diluted with ammonium sulphate could be used as culture media; sometimes these checked nitrification for a time but it afterwards became well established.

The experiments with undiluted urine were wholly successful and stand as a further proof of nitrification in presence of organic matter.

From these results it is clear that the nitroso-bacterium is a very powerful nitrite-forming micro-organism, that it is not readily destroyed, and that a certain amount of organic matter is essential to its greatest development, but for this a large amount of culture must be used.

In conclusion I have to offer my deepest thanks to Sir William Power for the great help that he has given me and for the kindness that he has always shown; also to others who have most kindly advised me my grateful thanks are due.

The observations reported here show that the T Vi antigen is effective in stimulating antibodies when it is attached to the cells. It is also clear that the Vi antigen is readily removed in aqueous solutions, but in such organic solvents as acetone, chloroform, ether, alcohol, carbon tetrachloride and benzene it is retained by the cell. In alcohol-water mixtures the Vi antigen is progressively more soluble in those solutions where the alcohol concentration is less than 70 %. However, its solubility in water is limited, and by making progressively heavier suspensions it was found that a point is reached at which Vi antigen is retained by the cell, the suspending solution apparently being saturated. Such an aqueous suspension is able to stimulate the production of Vi antibody.

The administration of dried organisms in peanut oil resulted in the production of antibodies against both O and Vi antigens. This was in contradistinction to the results obtained when mineral oil, mineral oil + saline, or peanut oil + saline were used: in these cases the O antibody titre was lower and Vi antibodies were produced in low titre or not at all. It seems clear that the presence of water in the vaccine has the effect of removing the antigenicity of the Vi hapten; water-free, vegetable-oil vaccine is suggested by these studies as an effective agent for immunizing against all of the antigens of Salmonella typhi. The use of such a vaccine in producing active and passive immunity in animals is discussed in the paper which follows.

1. The outbreak was one of bacterial food poisoning due to the consumption of infected milk.

2. The casual organism was B. enteritidis of Gaertner (Dublin).

3. A case of gastro-enteritis occured in an employee in the institution some days previously. This man's serum possessed agglutinins for for Gaertner'sbacillus, but the organism was not isolated from a specimen of his faeces taken 44 days after this attack.

4. This employee is supposed to have been the source of the organism which infected the milk. Two hypotheses are put forward to explain the mechanism of infection.

5. Servants who took the infected milk in their tea escaped infection. The milk was added to the tea in bulk and the experiments described satisfactoryily account for their escape.

The rapid decline of the birth-rate in nearly all countries of western Europe has naturally attracted much attention. Some have studied the probable effects upon the absolute size and the age constitution of the population, and the consequence entailed upon the military and economic strength of a nation. Others have drawn attention to resulting change's in the relative importance of diseases of young, adult and old ages. Changes in mere numbers depend wholly, and the other changes to a considerable extent, upon quantitative factors; they must occur even if the quality of those born differs in no way from that of those produced when fertility was at a higher level. But, if the quality of births changes with their quantity, then the consequences of decrease of numbers may be better or worse than mere numerical changes would involve.