The conclusions I seek to draw from this part of my investigations are:—

1. That a malarial form of horse-sickness probably occurs naturally.

2. That when animals which are either naturally relatively susceptible, such as the donkey, ox, and goat, or animals which have acquired protection, e.g. “salted” horses, are inoculated with virulent horse-sickness blood, their blood conveys a modified infection of horse-sickness which is malarial in type.

3. That this malarial from is associated with the presence of parasites within the red corpuscles of the blood of the infected animal.

4. That the blood of “salted” horse which have been previously regularly inoculated during several months is of a dangerous order of virulence. Vide former experiments.

5. That the blood of “salted” horses which have only been once inoculated after several months' rest conveys a fairly severe fever.

6. That the blood of “salted” horses, which have not been inoculated for even a year, can still convey infection.

7. That “unsalted” horses which have been inoculated a year previously with “salted” blood convey only a week infection.

8. That a severe attack of malarial horse-sickness gives a considerable degree of protection against subsequent inoculation with “salted” blood.

9. That when regularly inoculated “salted” horses are used to produce blood giving severe fever, such fever may become so severe as to cause death with symptoms of horse-sickness.

10. That the blood of the latter animals which die can produce virulent horse-sickness in clean horses, if used in a considerable dose, i.e. 20 c.c.

A population-based study investigated the burden of illness, including the duration of illness associated with laboratory-confirmed cases of campylobacteriosis in two health unit areas. Questionnaire data were collected for 250 cases. The median duration of illness was 8 days and 66% of cases reported symptoms of moderate severity or greater. A Cox proportional hazards model identified antimicrobial use factors associated with a significantly increased rate of symptom resolution (shorter duration of illness): macrolides for less than the recommended number of days, ciprofloxacin for at least 3 days, and antimicrobials not recommended for campylobacteriosis. The impact of antimicrobial use was consistent regardless of when, during the course of illness, the antimicrobial use began. The effectiveness of ciprofloxacin in these results may be due to the low prevalence of resistance to ciprofloxacin in isolates from this study. The effect of antimicrobials not recommended for campylobacteriosis should be further investigated.

Having examined the blood in a number of the dogs suffering from Piroplasmosis, referred to in the previous papers, I have selected three charts to show the changes I found to take place in the blood during the progress of the disease. For the enumeration of the corpuscles the Thoma-Zeiss haemacytometer was used, and for estimating the haemoglobin, Haldane's modification of Gower's haemoglobinometer.

Graded doses of live and heat-killed cells of Campylobacter jejuni were injected into the yolk-sac of 5-day-old chick embryos, and the 50% lethal dose (LD50) was determined 7 days later. A strain dependent virulence was seen. In the diluted series of cultures the LD50 values for live campylobacter ranged from 106 c.f.u. beyond the last dilution showing growth, that is to less than one organism per embryo. When the 22 strains were tested as heat-killed cells, the chick embryo LD50 values retained the same relative order of toxicity obtained with viable cells, but the LD50 values were increased by + 1 to + 4 log units. Heat-killed cells from strains known to be invasive, but non-toxigenic, were still lethal for the embryos, suggesting that viability was not solely necessary for virulence. Semi-pure lipopolysaccharide from a non-virulent strain of C. jejuni was not toxic to the embryos, but semi-pure and ultracentrifuge-purified lipopolysaccharide from the most lethal campylobacter strains gave LD50 values in the order of 3·0 μg lipopolysaccharide per ml (0·6 µg per embryo) in the yolk-sac assay. No relationship between serotype and lethality was seen. Injection into the yolk-sac appears to be an easy, rapid and reproducible in vivo assay of the virulence of C. jejuni.

In earlier reports on the physique of Oxford undergraduates attending the pilot student health service from 1947 to 1950 emphasis was laid on body shape. Parnell (1952) pointed out the tendency for centrally placed Sheldonian somato-types, that is those with more balanced mid-range body proportions, to occur more frequently in the Oxford sample than in American universities, a tendency incidentally which advances further according to the level of university performance attained. Tanner (1952) emphasized the tendency for Oxford students to show less mesomorphy, that is muscle and bone development, than American students but he reports a comment from Sheldon himself that the distribution at Harvard resembled the Oxford distribution more closely. This approach, by the analysis of body shape, to the problem of physical characteristics accompanying academic selection is of particular interest, but in calculating the somatotype, height is deliberately ignored by being placed as the denominator of all the body proportions employed. Height, however, is an index of body size, as opposed to body shape, and has an importance of its own. This report concerns observations on Oxford undergraduates in which more attention is paid to body size, and particular attention also to variation of weight during university residence.

The extreme diversity of opinion as to the identity of the Klebs-Loeffler bacillus and the bacillus of Hofmann, and the importance of the subject from the public health standpoint, make it desirable to bring forward any facts which may assist in arriving at a solution of the problem.

This study included all patients, with known HIV-1 status, admitted to hospital over a 5-year period with serum ferritin values exceeding 1500 μg/l. Markedly elevated serum ferritin levels are associated with a host of causes which poses a diagnostic dilemma, as the aetiology is often highly dependent on local epidemiology. We evaluated patients' records retrospectively to determine underlying causes of possible hyperferritinaemia. Aetiologies associated with hyperferritinaemia varied significantly depending on HIV-1 status. In patients infected with the HIV-1 virus, infectious causes predominated with Mycobacterium tuberculosis accounting for more than 50% of the patient population with an odds ratio of 17·98 (95% confidence interval 8·31–38·88) in HIV-positive compared to HIV-negative patients. Of the HIV-1-negative patients, hereditary haemochromatosis accounted for less than 2% of patients and chronic renal failure was the most common diagnosis. The finding of hyperferritinaemia should prompt determination of HIV-1 status, as this impacts significantly on aetiological epidemiology. In HIV-1-positive patients, aggressive investigation for mycobacterial infection should be undertaken in cases of combined hyperferritinaemia and positive HIV-1 serology.

H9 avian influenza virus played a key role during generation of the novel H7N9 virus. A surveillance programme was conducted to assess the H9 virus in relation to the risk of H7N9 virus contamination in the environment. Risk of H7N9 virus contamination in the presence of H9 virus was higher than without (adjusted odds ratio 4·49, 95% confidence interval 3·79–5·31). Adjusted odds ratios of the H7N9 virus associated with co-presence of H9 virus and interacting factors were 4·93 (rural vs. urban area), 46·80 (live poultry markets vs. other premises), 6·86 (Huzhou vs. Hangzhou prefecture), 40·67 (year 2015 vs. 2013), and 9·63 (sewage from cleaning poultry vs. poultry faeces). Regular surveillance on gene variability of H7N9 and H9 viruses should be conducted and extra measures are needed to reduce co-circulation of H7N9 and H9 viruses in the environment.

The method in which the mortality in childhood varies from age to age is a matter of very considerable interest. With each increase of unhygienic circumstances the death-rate among infants is well known to rise and it is commonly taken as a criterion of the measure of the unheathiness of the environment. In a rough way this is quite true but it is not the only criterion, any year of life might equally well be taken. The investigation in this note is based on a tabulation mande from the data published by the Registrar-General of England for the decade 1891–1900. In order tp make the statistics as homogeneous as possible the registration districts have been grouped accroding to the infantile mortalites, intervals of ten being taken in the unit. Thus those districts with death-rates between 80 and 90 have had their populations and deaths grouped togeather, those between 90 and 100 likewise and so on.

1. The nature of the probit-log survival-time relationship in the disinfection of standard cultures of Bact. coli at 51° C. at pH values ranging from 2·8 to 8·8 has been studied.

2. It is concluded that there is a very close approximation to a bilinear form in all cases, though there was evidence that a continuous curve concave upwards and to the left would provide a better fit.

3. Probit limits, corresponding to the range of percentage mortality within which, having regard to the experimental error involved, an observation might lie, have been worked out. The range covered by these probit limits decreases as the percentage mortality rises.

4. These limits have been used to decide whether a bilinear or a single straight line treatment should be applied to certain sets of data. It is suggested that they would often materially assist in deciding the range over which linearity may be assumed in any given case.

Instances are recorded in the literature of mammalian -tubercle bacilli having lost their virulence completely during long cultivation on artificial media. In a paper published in 1925 I gave an account of the results of investigating two such strains which had been deposited in the National Collection of Type Cultures by Dr Nathan Raw. These strains were stated by Dr Raw to be lineal descendants of strains which had been given to him in 1906, one (human) by Prof. R. Koch, who had isolated it from the sputum of a case of human pulmonary tuberculosis, the other (bovine) by Prof. A. Calmette, who had obtained it from a mesenteric gland of a cow.

A total of 45 strains of Vibrio cholerae O1 isolated from 10 different places in India where they were associated with cases of cholera between the years 2007 and 2008 were examined by molecular methods. With the help of phenotypic and genotypic tests the strains were confirmed to be O1 El Tor biotype strains with classical ctxB gene. Polymerase chain reaction (PCR) analysis by double – mismatch amplification mutation assay PCR showed 16 of these strains carried the ctxB-7 allele reported in Haitian strains. Sequencing of the ctxB gene in all the 45 strains revealed that in 16 strains the histidine at the 20th amino acid position had been replaced by asparagine and this single nucleotide polymorphism did not affect cholera toxin production as revealed by beads enzyme-linked immunosorbent assay. This study shows that the new ctxB gene sequence was circulating in different places in India. Seven representatives of these 45 strains analysed by pulsed – field gel electrophoresis showed four distinct Not I digested profiles showing that multiple clones were causing cholera in 2007 and 2008.

The Democratic Republic of the Congo (DRC) officially reports low coronavirus disease 19 (COVID-19) prevalence. This cross-sectional study, conducted between September and November 2021, assessed the COVID-19 seroprevalence in people attending Goma’s two largest markets, Kituku and Virunga. A similar study in a slum of Bukavu overlapped for 1 month using identical methods. COVID-19-unvaccinated participants (n = 796 including 454 vendors and 342 customers, 60% of whom were women) were surveyed. The median age of vendors and customers was 34.2 and 30.1 years, respectively. The crude and adjusted anti-SARS-CoV-2 antibody seroprevalence rates were 70.2% (95% CI 66.9–73.4%) and 98.8% (95% CI 94.1–100%), respectively, with no difference between vendors and customers. COVID-19 symptoms reported by survey participants in the previous 6 months were mild or absent in 58.9% and 41.1% of participants with anti-SARS-CoV-2 antibodies, respectively. No COVID-19-seropositive participants reported hospitalisation in the last 6 months. These findings are consistent with those reported in Bukavu. They confirm that SARS-CoV-2 spread without causing severe symptoms in densely populated settlements and markets and suggest that many COVID-19 cases went unreported. Based on these results, the relevance of an untargeted hypothetical vaccination programme in these communities should be questioned.

Multiply- and methicillin-resistant Staphylococcus aureus (MRSA) strains have been isolated from five small outbreaks of nosocomial infection in five different hospitals. The MRSA were typed by phage patterns, biochemical traits, resistance phenotypes and plasmid patterns. Three different groups of strains can be distinguished. The MRSA from three outbreaks in one country share identical characters.

Phage typing by the use of the International Basic Set for Phage Typing staphylococci as well as experimental phages does not completely discriminate between the strains. Attribution of several resistance determinants to plasmids in two of the described strain groups proved valuable for strain differentiation.

These multiply-resistant strains are sensitive to vancomycin and to rifampicin.

1. The incidence of cross-infection with Str. pyogenes during a period of four months was compared in two blocks occupied by scarlet-fever patients. One block was nursed by the bed isolation method and the other by the ordinary method in current use for multiple-bed wards. 2. The rules for the bed isolation blook are given. 3. The incidence of cross-infection with Str. pyogenes among patients in the bed isolation block was 20·3%, that among patients in the ordinary block 22·6%. 4. We concluded that the bed isolation nursing technique practised was not effective in reducing cross-infection with Str. pyogenes among scarlet-fever patients. 5. A further test of bed isolation nursing was made for six months, using the extra precaution of vacuum-cleaning the floors. We found that crossinfection was still occurring, but the incidence could not be estimated since the Str. pyogenes strains isolated had to be destroyed at the outbreak of war. At this time the serological typing had not been completed. 6. The importance of dust-borne and droplet-borne infection in addition to that of contact infection is discussed. The type of investigation required to decide whether cross-infection in multiple-bed scarlet-fever wards can be eliminated by the methods at our present disposal is outlined.

1. Many horses immunised against other bacteria or bacterial products will give a large local reaction to mallein, but this is usually not associated with a rise in temperature. In the case of horses injected with diphtheria toxin, the size of the swelling appears to related to the degree of immunity attained. This point has not yet been established in the case of horses immunised against other bacterial products.

2. This local reaction disappears rapidly and can thus be distinguished from the reaction in the case of glandered horses.

3. In the few cases when a rise in temperature took place (3 cases out of 56) the curve was markedly different from that obtained in the case of glandered animals.

4. Other bacterial products react similarly to mallein upon immune horses.

An outbreak in May 1937 of about 130 cases of mild Sonne dysentery with no deaths. The outbreak was spread by ice-cream made under very unsatisfactory conditions, but no carrier case or specific source of infection ascertained. The very scattered nature of the outbreak, involving five different sanitary areas, with place of preparation in a sixth, is a feature of interest.

A modification of the metabolic inhibition test for titrating poliomyelitis antibody is described. The method depends on the substitution of galactose for glucose in the initial medium to eliminate colour change during the period of virus activity. Neutralization is detected by the addition of glucose at the end of the period, when the usual colour changes associated with this type of test occur. A statistical analysis of the results obtained is given.

This method can also be used for titrating antibodies to other enteric viruses.

Thanks are due to Dr Hélène Mair, Dr D. R. Gamble and Dr A. D. Macrae for strains of enteroviruses, and to Miss Patricia Jerram, for valuable technical assistance in the early days of this work.