Since Dick and Dick (1924) Published their method of testing the susceptibility or insusceptibility of human beings to scarlet fever various other workers have reported in vestigations which have confirmed the observations of the Dicks.

1. A quantitative study has been made of the activity of C′1, C′2 and C′4 in the complements of the horse, cat, pig, man, guinea-pig and rabbit.

2. Evidence is presented which suggests that either there may be two types of C′4, the one haemolytic and the other conglutinating, or else that the manifestation of this complement component varies under conditions not yet understood.

3. In certain complements it appears that the serum proteins functioning as C′1 with the bovine anti-sheep red cell antibody are distinct from those functioning as C′1 with an antibody of similar specificity from an immune rabbit serum.

Nuttall was born in San Francisco, California, on 5 July 1862; the second son of Robert Kennedy Nuttall, M.D. (Aberdeen) and his wife, Magdalena, daughter of John Parrott of San Francisco. The Nuttalls were descended from an old Lancashire family, which settled in Ireland in 1707, many of its members serving as officers in the British Army. His father went to Australia, but migrated to San Francisco in 1850 and practised there till 1865. In that year the family came to Europe and remained there till 1876, the children being educated in England, France, Germany and Switzerland. Consequently, Nuttall spoke several languages, a fact which assisted him enormously in his future work and travels.

Mass gatherings (MG) present a number of challenges to public health authorities and governments across the world with sporting events, tournaments, music festivals, religious gatherings and all other MG having historically posed a risk to the spread and amplification of a range of infectious diseases. Transmission of gastrointestinal, respiratory, waterborne and sexually transmitted infectious diseases pose a particular risk: all have been linked to MG events [1–4]. Infection risk often depends on the nature of the mass gathering, and on the profile and behaviour of its participants. The interaction between environmental, psychological, biological and social factors plays a vital part. The risk of outbreaks particularly as a result of respiratory transmission remains high at MG, with the majority of outbreaks over the last two decades resulting from a variety of respiratory and vaccine preventable pathogens [5–7]. Concerns about the spread of infectious diseases at MG are often focussed on crowding, lack of sanitation and the mixing of population groups from different places. Sporting events, which have in recent decades become more complex and international in nature, pose a challenge to the control of communicable disease transmission [8]. Despite this, large scale outbreaks at sporting events have been rare in recent decades, particularly since the rise of more robust public health planning, prevention, risk assessment and improved health infrastructures in host countries [9].

Finally, I must express my hearty thanks to the many medical men and others who have given me aid and hospitality in my wanderings after the truth about beriberi. I must mention particularly Dr Giddy and Captain Vincent on Christmas Island, Drs Ellis, Leask and Murray Robertson in Singapore, Drs Travers, Gimlette, Watson, McClosky and Mr Galloway in Selangor, and Drs M. J. Wright and Connolly in Perak, and Messrs Mason, Ponsford, Sanderson, and Hembrey in Pahang, without whose aid and kindness I could have seen but little. I must also thank my friend Dr G. S. Buchanan, Secretary of the Royal Commission on Arsenical Poisoning, for forwarding me much information.

It would seem from my observations that certain of the current theories of the causation of beriberi will not account for the conditions which have been encountered by me. The dietetic or physiological, the unsound food, the arsenical, and the emanation theories all appear to be insufficiently in accordance with the attendant circumstances to have accounted for the spread of the disease.

It is suggested that certain articles of diet, by virtue especially of containing phosphorised and fatty matters, may tend to ward off the disease when given in sufficient amounts. So far as there was any semblance of a positive result in the observations it is suggestive that beriberi is communicated from person to person more or less directly or through fomites as an actual infection. This infection is not of the nature of a septicaemia (since the internal organs at death prove sterile), but to a surface condition about the upper air passages. From the observation of the throats of a number of patients it is surmised that the redness which is therein seen, especially in early cases, may be intimately connected with the disease. The appearances and disappearances of beriberi and the more or less seasonal waves of prevalence of the disease are not unlike those which are seen in the case of the infective diseases which we meet with in this country. The proneness of the newcomer to suffer fits in also with such a view. The difficulty in tracing out the source of infection in a disease like diphtheria is often great, especially since we know that the causative organism may be carried by unsuspected refractory of immune persons or animals.

With considerations such as these it is held by the writer that there is no inherent impossibility in explaining many of the circumstances connected with the spread of beriberi.

Observed facts seem to show that beriberi should rather be considered in the light of a “gang” or “institutional” disease than as a “place” or “house” disease.

Four antigenic variants of the neuraminidase (NA) of A/Texas/77 (H3N2) virus were selected using monoclonal antibody at a frequency of one variant in 105 parental virions. The antigenic variants failed to react serologically with the monoclonal antibody used for their selection in vitro. The antigenic variants failed also to react serologically with a proportion of sera from children and adults although all of the sera reacted with the parental A/Texas/77 virus. Thus, certain human sera have a restricted antibody repertoire to influenza NA antigen which might enable virus antigenic variants to avoid anti-NA antibody-mediated neutralization in nature.

Drinking water has long been supposed to play an important part in the causation of endemic goitre. Estimations by v. Fellenberg (1923, 1924) in Switzerland and by Mcclendon and Hathaway (1924) in the United States have shown that, in these countries, drinking water in goitre areas contains less iodine than in goitre-free areas. The iodine content of several waters has been estimated at this Institute. The results show that in this country there is no correlation between presence of goitre and a low iodine content in drinking water. It is true that the lowest figure (Swindon) is for water from a goitre area, but the next one (Aberdeen) is not. The figures for Cumberland and Derbyshire, both goitre areas, are not low.

This study aims to evaluate the predictive role of age-adjusted Charlson comorbidity index (ACCI) scores for in-hospital prognosis of severe fever in thrombocytopenia syndrome (SFTS) patients. A total of 192 patients diagnosed with SFTS were selected as the study subjects. Clinical data were retrospectively collected. Receiver operating characteristic curves were used to evaluate the diagnostic value of ACCI for the mortality of SFTS patients, and Cox regression models were used to assess the association between predictive factors and prognosis. The 192 SFTS patients were divided into two groups according to the clinical endpoints (survivors/non-survivors). The results showed that the mortality of the 192 hospitalized SFTS patients was 26.6%. The ACCI score of the survivor group was significantly lower than that of the non-survivor group. Multivariate Cox regression analysis showed that the increased ACCI score was a significant predictor of poor prognosis in SFTS. Kaplan–Meier survival analysis showed that SFTS patients with an ACCI >2.5 had shorter mean survival times, indicating a poor prognosis. Our findings suggest that ACCI, as an easy-to-use clinical indicator, may offer a simple and feasible approach for clinicians to determine the severity of SFTS.

The etiology of tetanus and gas gangrene presents a biological problem of an unusual nature. When the organisms which cause these diseases are deprived of toxin, by washing in tap-water saline or by washing and then heating, they are non-pathogenic to laboratory animals. In a recent investigation of the problem we have shown that soluble ionisable calcium salts enable detoxicated B. tetani, B. Welchii, B. oedematiens and vibrion septique to exert their pathogenic powers. We concluded that calcium owes this property to its local action on the tissues.

1. Avian tubercle bacilli were grown in hanging-drop cultures in embryo extract prepared as for tissue culture, but diluted to 25–5% of its usual concentration.

2. Microscopic branching colonies of pseudomycelia developed in the surface film of the hanging drops during the first few days of incubation, after which growth declined.

3. The development of these colonies was studied on the warm stage and proceeds as follows:

(a) The original rods elongate into filaments.

(b) The filaments multiply by ordinary fission and also by forming fine, pin-like terminal sprouts which grow into independent bacilli.

(c) After division the daughter filaments usually remain in contact at the site of fission; their terminal growth continues at an angle to the former cleavage plane and the colony thus acquires its characteristic branching structure.

(d) The colony enlarges and ramification becomes increasingly complex until about the fifth day of incubation when growth declines. The bacilli remain filamentous.

4. When transferred to embryo extract of normal concentration the pseudomycelial colonies revert to the ‘standard’ type of development characteristic of the more concentrated medium, i.e. they pass through a phase of filamentous proliferation followed by disintegration of the filaments into short discrete rods.

5. The development of a pseudo-mycelium is compared with the three common types of growth previously seen in more concentrated embryo extract.

6. The results of this investigation shed light on the controversial question of whether the ‘mycelial’ form of the tubercle bacillus is a single individual formed by ‘true’ lateral budding or a composite structure produced by the terminal, angular growth of coherent but independent bacilli. Our observations on the living organisms have shown that under appropriate experimental conditions both these forms may develop.

Fleas (Aphaniptera, Siphonaptera) are wingless insects which run or hop about. They are for the most part parasitic in their habits, being found only on the homoiothermic vertebrates, especially on those which build nests or have more or less fixed haunts or homes. Like the majority of other parasites they have the body flattened, but differ from most parasitic insects in that this flattening is in a lateral direction, so that the transverse diameter of the body is small and the vertical diameter great. Attention has already been drawn to certain other morphological peculiarities of these insects (vol. VII. p. 446).

The authors have determined the vitamin A content of the liver in persons who had succumbed to sudden death in Copenhagen in 1939 and 1943 and in Oslo in 1943–4. The values in Oslo after three years of war and severe rationing were higher than in Copenhagen, the population of which had a much milder rationing during the war. The values in Copenhagen for 1943 were somewhat lower than those for 1939. The most plausible explanation of these findings seems to be that the pre-war vitamin A reserve in Norway was high.

A metabolic inhibition test based upon phosphatase production is described. This is of value for those Mycoplasma species which produce phosphatase but which cannot be examined by the previously published metabolic inhibition techniques.

1. A method is described for estimating the disinfecting power of chemical substances on small cylindrical blood-clots of standard dimensions (about 1·5 mm. in diameter) containing a measured number of bacteria (Staph. aureus). It is capable of giving guidance for the use of disinfectants under the described conditions.

2. No practicable disinfectant regularly sterilized heavily infected clots (400,000 cocci) in 5 min. at 17–20° C.

3. In 30 min. the following were the only substances that were uniformly successful with heavily infected clots: 2·5% iodine in aqueous KI solution; 50% Chloros, containing about 5% chlorine; 70% alcohol containing 0·1% acriflavine. (The first of the three was tested on a larger scale than the others, and its potency is therefore the more firmly established.)

4. Reduction of the number of cocci in the clot increased the range of effective disinfectant solutions. Thus with 4000 cocci per clot regular clot disinfection was achieved in 30 min. with the following additional solutions: ethyl alcohol 70 and 50%; Chloros 25%; phenol 2·5% and lysol 1·25%. A few tests indicated that Zephiran (and probably CTAB) at 1 or 2% concentration would also pass this less exacting test.

Pen and field trials were conducted to assess the performance of the acute rodenticide pyriminil against the house mouse (Mus musculus L.). Four types of poison treatment were carried out using penned family groups of warfarin-resistant mice supplied with alternative plain foods. In each treatment pyriminil was included at 2% in a wholemeal flour/pinhead oatmeal/corn oil bait. Mortality was highest (46/54; 85·2%) when poison bait was offered for 4 days following 3 days of pre-baiting The same pre-baiting and poisoning technique was adopted in five field trials carried out against mice infesting farm building The efficacy of each poison treatment was estimated from the results of pre- and post-treatment census baitings; treatment success ranged between 53·7% and 96·7%, mean 80·5% It is concluded that pyriminil treatments are best carried out after a period of pre-baiting and that when pyriminil is used in this manner it is about as effective as zinc phosphide for the control of mice

The general consideration of these results only tends to confirm the conclusions already arrived at. A uniform type of life evidently tends to a fairly uniform excretion of tissue cells from the udder. The case of Goat II also emphasises the effect of outside causes in increasing temporarily this excretion, while some of the samples of human milk show plainly that very high cell counts are not by any means necessarily connected with any diseased or disordered condition of the mammary gland.

We again emphasise the view we have already stated, viz. that in the cow the udder must be looked upon as an organ which has by breeding and selection been brought to an artificial condition of milk secretion and that this has been accompanied by a stimulation of the tissues to cell proliferation and that this proliferation may quite easily be caused to become abnormally great, leading to the appearance of an increased number of cells in the secretion. In support of this view we lay great stress on the fact constantly noticed by us, viz. that when the cell count is high for any reason, the cells themselves are always well-defined, showing little signs of degeneration, and also stain in a much more characteristic and definite manner, a fact which is diffcult to explain if they are to be considered to be blood elements.

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global public health crisis. The objectives of this study were to analyse the dynamic trend in specific antibodies in the serum of patients infected with SARS-CoV-2 within 12 months after recovery and to make a preliminary assessment of the protective effect of vaccination. Eighty-seven patients with confirmed COVID-19 who were admitted to our hospital from January to February 2020 were followed after recovery. Three-millilitre blood samples were collected for specific antibody detection at four time points: 1, 6 and 12 months after recovery and 1 month after vaccination. The changes in specific immunoglobulin G (IgG) antibody and total antibody levels over 12 months were analysed. Moreover, an independent comparison of the neutralising antibody levels of patients after vaccination with those of healthy medical staff after vaccination was performed to compare the inhibition rates of the neutralising antibody to the virus. No statistically significant difference in the sex distribution between groups was observed (P > 0.05). Older patients had a greater risk of developing severe and critical COVID-19 (P < 0.05). The percentages of subjects positive for IgG antibodies at 1, 6 and 12 months after recovery were 88.5%, 75.9% and 50.6%, respectively. The rate of IgG antibody conversion from positive to negative was not uniform across time points: the change was slow in the first 6 months but increased significantly in the last 6 months (P < 0.05). The positive rate of critically ill patients in the first 6 months was 100.0%. The trend over time in total antibody levels was similar to that of IgG antibody levels. Over 12 months, the sample/cut off value of total antibodies continued to decrease, while that of different disease severities was significantly different (P < 0.05). After vaccine administration, the total antibody level exceeded the detection level in the first month, which was independent of disease severity (P > 0.05). Significant differences were observed in the inhibition rate of the neutralising antibody against the virus in the disease group and the control group (P < 0.05). IgG antibody produced by patients naturally infected with SARS-CoV-2 has a duration of no less than 1 year, and the change trend graph of total antibody levels was the same as that of IgG antibody levels. Under vaccine stimulation, the positive rate of IgG antibody was as high as 100%, and the total antibody concentration reached the highest level, which was independent of disease severity. Neutralising antibodies following vaccination in patients who recovered from COVID-19 had a higher inhibition rate against SARS-CoV-2 than those of vaccinated healthy controls, indicating that these COVID-19 patients had a lower risk of reinfection and were better protected.