The final choice of a suitable dilution of a given toxin will be made, partly from the difficult comparison with other known toxins, but mainly from the results of clinical observations in patients in the early stage of scarlet fever and in convalescents.

It is difficult to titrate scarlet fever toxin with accuracy. It will probably be found that by careful choice of subject and by several readings of the reactions at different intervals after the injection, one can differentiate between toxins of values x and 2x.

Among the formulae which describe relationships found in physics, chemistry and biology is one commonly known as the “adsorption formula.” It graduates for a considerable range of experiment the amount of adsorption which takes place at the bounding layers of solids, fluids and gases or immiscible fluids in presence of different concentrations of the substance adsorbed. It may be written in the form x = aCn where x is the amount of the substance adsorbed; C the concentration of the adsorbed substance after equilibrium has been attained; n is an absolute constant less than unity; and a is a constant depending in value on the units of measurement.

At the present time owing to the difficulties arising from was conditions, and the stress of work due to the special circumstances in which the study of bacteriology is being prosecuted, we have had in some cases to modify established methods of bacteriological procedure and introduce new technique.

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 brucellin skin test and the lymphocyte transformation test were compared in heifers infected with virulent Brucella abortus strain 544, heifers vaccinated against brucellosis and unexposed cattle. Results of the in vitro lymphocyte transformation test were consistently positive for all 9 Brucella-infected heifers while the skin test was consistently positive for 6 of the 9 heifers. In 7 heifers repeatedly vaccinated with B. abortus strain-19 vaccine the in vitro test classified 3 animals as positive whereas the skin test identified all the animals as infected during most of the experimental period. Four heifers injected with a single dose of B. abortus strain 19 were consistently negative to the lymphocyte transformation test while the skin test classified all the animals as infected during most of the experimental period. The skin test gave strong reactions indicative of Brucella infection in heifers vaccinated with ‘Duphavac’ and ‘Abortox’ vaccines whereas the lymphocyte transformation test was consistently negative with these vaccines. The two tests were negative in unexposed cattle. It was concluded that the in vitro test correlated better with Brucella isolation than the in vivo test did and that the lack of agreement between the results of the two tests is likely to be due to the different antigens used in the assays.

This study assessed accuracy of (a) recording Vibrio vulnificus infection on death certificates and (b) International Classification of Disease (ICD)-9 codes for V. vulnificus. Patients with microbiologically confirmed V. vulnificus infection were identified as part of co-ordinated surveillance in four USA Gulf Coast states between 1989 and 1993. Of 60 deaths, 51 death certificates were reviewed and V. vulnificus was recorded as the immediate cause of death on 11 (22%). There was no ICD-9 code for V. vulnificus infection, thus no patients had an ICD-9 code indicating V. vulnificus infection. Of 23 certificates where V. vulnificus was recorded on the death certificate, only 5 (22%) were coded for Gram-negative, septicaemia. This study highlights the importance of teaching physicians how to provide epidemiologically meaningful data on death certificates and the need for accurate ICD mortality codes.

We have previously referred to the fact that a certain number of Bombay rats were immune both to subcutaneous and to cutaneous inoculations of virulent plague bacilli. In paper V, p. 505 above, we were able to record that 59% of rats in Bombay could withstand the rubbing on scarified surfaces of emulsions of spleens of rats which had died of acute plague. The fact that a large number of rats in India, where plague had occurred, were more or less immune has been noted by Simond and Walton.

Tuberculosis (TB) in immigrants is becoming a challenge in eliminating TB in Japan. We investigated the epidemiology of TB in foreign students in Japan in 2015–2019. A total of 2007 foreign students with TB whose median age was 22.5 years (1243 (61.9%) were males) were registered. The notification rates peaked in 2016 at 164.0 per 100 000 population and decreased towards 2019. Of the 2007, 535 were from Vietnam, 444 from China and 395 from Nepal. The notification rates were 596.6 per 100 000 person-years (PYs) for Myanmar, 595.4 for the Philippines and 438.6 for Cambodia. The rates were much higher than those of the general populations in their countries of origin for Myanmar, the Philippines, Cambodia, Indonesia, Nepal, Mongolia, Vietnam and China. In comparison with the years 2010–2014, the notification rates for foreign students decreased for the students from Nepal, Vietnam and China. The TB notification rate of the foreign students in Japan can be a good surrogate indicator for the risk of TB among the immigrant subpopulation in Japan and should continuously be monitored. Those who are at higher risk of TB may be annually screened for TB to prevent TB outbreaks.

In 1901 Miss Anderson (H.M. Principal Lady Inspector of Factories) and Dr Legge (H.M. Medical Inspector Factories) were instructed by H.M. Chief Inspector of Factories to investigate the conditions of labour in the Tinning of metals and metal articles with a view to the preparation of regulations for the conduct of this industry. Difficulties having arisen in assigning a cause for the plumbism undoubtedly existing among workers, and preparation of regulations appearing impossible without some knowledge of the source of illness, the writer was instructed to assist them experimentally in determining the causes.

Sera from two rabbits bled after one, two and three inoculations of concentrated type 1 poliovirus tissue culture fluid were assayed for neutralizing activity by a quantal and a plaque method. The plaque counts in these tests have been shown to approximate to a Poisson distribution as determined by the relationship between the variance and the mean of replicate counts. However, there is a considerable scatter of the points in such a comparison and this accounts for the absence of the expected increase in accuracy of this plaque method over the quantal.

The relationship between the antibody content of the sera determined by the two methods is non-linear. This can be attributed to inhomogeneity of the antibody produced which increases with the number of antigenic stimuli given.

The origin and object of the following paper can be explained in a few words. In April, 1904, the writer published a series of 280 blood examinations (to which were added about 150 more) of natives of southern Angola (Portuguese West Africa) without recording a single instance of the presence either of trypanosomes or of spirochaetes in the circulation. Quite recently in the course of an investigation of the endemic malaria of the same district, 513 examinations made among the same people and with the same technique revealed 3 individuals harbouring trypanosomes and 4 showing spirochaetes in their blood. These observations, together with the fact that a year or so ago the natives reported no cases of Tick Fever, while recently statements are made by them that the Tick Fever of the upper Zambezi has reached Angola, and also the fact that Sleeping Sickness is reported to be advancing southward through the province, have led me strongly to suspect that these diseases have lately begun to spread markedly in my part of the colony, and that one or both of them may not inconceivably assume in the near future epidemic proportions.

The larva about to turn into a pupa comes to rest, the thoracic region becomes swollen, and the pupa gradually issues through a dorsal slit in the larval cuticle, which is ultimately thrown off with all its exterior chitinous appendages as well as those parts of the spiracles etc. which are superfluous.

The routine title of the long ‘note’ by Glenny and Südmersen reproduced here [1] hides two of the most significant findings in theoretical and applied immunology: a brief description of diphtheria toxoid and a comprehensive account of the primary and secondary immune response. The introduction of antitoxin treatment of diphtheria was heralded, in 1896, without exaggeration as ‘the most important advance of the [19th] Century in the medical treatment of acute infective disease’ [2]. However, there were problems with the standardization and potency of antitoxin. The former was solved by Ehrlich who, in his analysis of toxin–antitoxin interaction, postulated the existence of ‘toxoid’, a non-toxic component of toxin which combined with antitoxin [3]. The latter was solved by the general observation that repeated injections of gradually increased doses of toxin induced increasingly potent antitoxins, an important basis upon which the present paper was founded.

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.