The titres of the complement-fixation test and the agglutination test run parallel in rabbit sera, but not in human sera. These facts are explained in connexion with the specificity of complement.

With regard to the influence of malarial infection on the Wassermann test some controversy prevails:

Wassermann and Lange (1913) refer to Meyer and Bonfiglio who, working in Italy, obtained a positive reaction in 80 per cent. of the cases where the blood contained parasites; in some of their cases positive reactions were obtainable for several months after the disappearance of fever and parasites. For this reason Wassermann and Lange advise to put every case, coming from a malaria-infected country and showing a positive reaction, under quinine treatment and to repeat the test after a lapse of six weeks.

From consideration of the above evidence the following conclusions may be drawn:

(1) The prevalence of diphtheria-like bacilli in the fauces of scarlet fever patients on admission to hospital does not definitely follow that of diphtheria outside either in seasonal or yearly prevalence.

(2) The majority of such patients show no clinical evidence of the added infection. It is believed that they are instances of scarlet fever developing in diphtheria carriers, and the presence of the organism does not affect the prognosis. However, cases which present such clinical evidence as a mem branous angina are to be considered as instances’ of true double infection and in them the prognosis is bad.

(3) Bacteriological examination of a series of cases belonging to the former group reveals the presence of true virulent diphtheria bacilli in about 36 per cent., and these organisms may persist in a virulent state for a considerable period.

(4) Routine bacteriological examination to find these cases and their sub sequent isolation materially reduces the incidence of post-scarlatinal diphtheria.

The cases which from the subject of the following note occurred in the district of Dr Chas. Jackson, M.O.H., of Fulham, and I am greatly indebted to him for so kindly furnishing me with their histories and with samples of the patients' serum.

In twenty-five consecutive cases in which nasopharyngeal cultures have been made from patients suffering from bacteriologically proved cerebro-spinal meningitis, meningococci have been obtained.

A striking similarity between the organisms from the two sites has been shown to exist for not only are they of the same agglutinable type but in the majority of instances individual peculiarities of agglutination have corresponded. The closeness of relation has been further demonstrated by the carbohydrate reaction in one case in which the unusual property of bleaching glucose litmus broth to a yellow colour was possessed by both organisms. Nevertheless, in a certain number of instances, though organisms of a different agglutinable type have not been isolated, as by other workers, there have been found certain minor variations of agglutination. That most if not all of these variations are due to alteration of the agglutinable capacity of one of the organisms seems probable, as in the six cases where most marked difference existed (Nos. 1, 3 and 24 of Type I and Nos. 15, 16 and 18 of Type II) the chances of the other alternative, namely that a second infection had happened in each case to be of the same agglutinable type, are remote.

In the twenty-five cases the proportion of the types present has been shown to agree with that found by other workers during the same period. Seven of the infections (28 per cent.) have been due to Type I and eighteen (72 per cent.) to Type II.

Ten of the cases have occurred in children under the age of two years, and the proportion of the two types among them has been approximately the same as among older patients.

The writer is indebted to the members of the staff of St Bartholomew's Hospital for permission to publish their cases, and gratefully acknowledges the encouragement and assistance of Professor Andrewes at whose instigation these investigations were conducted.

The following contribution to the aetiology of cerebrospinal meningitis is published with a view to calling attention to the possible part played by dust in the causation of this disease. The strong connection between dusty occupations and cases of cerebrospinal fever, as here detailed afford, it is believed, a prima facie presumption that dust may be one of the vehicles of the specific germ.

The prominence recently given to the Rous sarcoma has increased the confusion of hypotheses about malignancy. With a view to clarification, one may say that there are three simple hypotheses of outstanding importance, viz.: (1) the living virus hypothesis, which regards living viruses as the actual and effective cause of both the avian and the mammalian disease; (2) the autogenous enzyme hypothesis, which ascribes both diseases to the development within living cells of an ens malignitatis resembling an enzyme rather than a virus; and (3) the “chronic irritation” hypothesis, which explains mammalian malignancy on this principle and considers fowl sarcoma to be of a different nature.

Nasal colonization with Staphylococcus aureus occurred in 18% of babies leaving a maternity unit and had risen to 40% by 6 weeks after birth. S. aureus was first acquired by 34·5% of babies after discharge. Female infants were more likely to be colonized than males. Colonization was not significantly different between babies receiving standard postnatal care and those nursed on the Special Care Baby Unit.

Crystal violet (CV) tests showed that purple-reacting isolates accounted for approximately 60% of strains, whether first detected at hospital discharge or subsequently acquired. Purple-reacting strains, once acquired, were significantly better able to persist than non purple-reacting strains and formed a cumulatively higher proportion of the strains isolated at 6 weeks after birth than at hospital discharge. CV purple-reactions were significantly associated with lysis by phages of groups III and I and non-purple-reactions were significantly associated with lysis by phages of group II and/or 94/96.

Maternity units remain a significant route whereby strains of S. aureus with some characteristics associated with a hospital origin gain access to the community.

Experiments I–VIII.

I shows that under the conditions shown the plates were covered with innumerable colonies 7 feet above ground level to ground level. The beds and trestles were used to keep the hut always uniform.

II shows that 8 feet above ground, i.e. on top of the crossbeams, the same conditions obtain.

III, IV, V, and VI show that the same condition exists in the area between the beds or trestles. The beds make no difference, better or worse.

VII shows practically the same condition high up on the beam between the beds. The inverted plates naturally show less colonies, as the organisms mostly fall on to the plates.

VIII confirms the above.

There is only one conclusion to draw from these experiments, and that is that practically speaking there is no difference in the number of organisms on the ground floor and 8 feet above it, in the ordinary men’s sleeping huts, Barrack Design 230/14.

Influenza C virus antigen could be detected by immunofluorescence in chick amniotic epithelium 4 hr. after inoculation with undiluted amniotic fluid. Antigen could be detected in the nucleus of rhesus monkey kidney tissue cultures 10 hr. after infection. Only cytoplasmic fluorescence was observed 17–21 hr. after infection.

The pattern of replication was similar to that reported for group I myxoviruses, indicating that the virus is correctly classified as an influenza virus.

1. The abscesses in the viscera, especially the spleen, and in the peripheral lymphatic glands, some of which contain living plague bacilli, which have been previously described as “chronic plague in rats” are shown to be plague lesions in the process of healing. The name “resolving plague” is more appropriate.

2. These lesions are found most frequently towards the close of, and immediately after, the acute plague epidemic.

3. They have been found frequently in rats in Belgaum and Poona, and a re-examination of Bombay rats shows that they also occur there. We had previously only found them in the Punjab villages.

A split-product influenza A vaccine which contained an influenza B strain (B/Hong Kong/8/73) and two influenza A strains, antigenically identical with A/Fort Dix/741/76 (HswlNl) and A/Victoria/3/75 (H3N2), was offered to personnel of the CPHL. Changes in the antibody status were followed with serum samples collected from 153 participants on the day of vaccination and 1, 13 and 18 months thereafter. During the two epidemic seasons in the trial period there were only four serological influenza A infections (2·6%) among the vaccinees. This is one eighth of the corresponding infection rate (22%) in the general population estimated on the basis of other indices.

The vaccinees' antibody response was strongly influenced by the age of the individual subjects. During the trial period the decrease in the antibody titres slowed down. The geometric mean titres of homologous HI antibodies were still substantially higher at the end of the period than at the beginning. This also applied to heterologous antibodies against H1N1 viruses in persons born between 1926 and 1952. In participants born after 1952, the vaccine was not able to evoke these antibodies, and in participants born in or before 1925 the boosting effect was poor.

The purpose of surveys of amoebae or other organisms is the estimation of the carrier rate in a population, that is, of the proportion of persons who carry a given parasite. As a rule, the tests do not infallibly detect the presence of the organism in a known carrier. Thus simple estimation from a single examination of each member of a sample is not applicable.

The stability of the biological reagents used in routine immunological procedures is a matter of practical interest to the public health worker, and an attempt has been made in the following research to estimate the period during which the diluted toxin used in the Schick test for the estimation of susceptibility to diphtheria remains potent. In the early days of Schick testing, although Leete (1920) reported that a diluted toxin retained its potency for as long as 5 weeks, it has hitherto been considered inadvisable to use a toxin at a longer interval than 48 hours after it had been diluted to its proper strength. Glenny, Waddington and Pope (1928) and O'Brien, Okell and Parish (1928) have introduced a new diluent consisting of a solution of a combination of crystal borax 57, boric acid 84 and sodium chloride 99 parts. A 1·5 per cent, solution of this mixture is now used as a diluent and has the effect of sustaining the potency of the diluted toxin over a greater period of time. In our work over 400 persons have been tested with toxins made up according to this formula, a comparison being made in each individual between the reactions elicited by an aged toxin, stored for varying periods at room temperature or in the cold room, with those produced by a fresh toxin. Enough toxin was made up at the beginning of the experiment to last over a considerable period of time, samples being sent to us by post periodically together with batches of freshly diluted toxin. The testing of reagents was carried out immediately on receipt, the lower age groups being selected in any series of individuals as being likely to give the largest number of reactors. The actual testing was performed practically throughout by one of us (J. C. J. McEntee) so as to maintain uniformity of technique. Each pair of toxins was controlled by a single injection of inactivated toxin and the results were scrutinised at the 4th and 10th days, a record of the comparative intensities of the positives being made at the same time. The results are recorded in Table I.

1. The incidence of haemolytic streptococci in the patients of a Hospital School for rheumatic children was determined over a period of 1 year.

2. In the total of 1644 throat and 1644 nasal swabs, group A strains were isolated from 20 throat and two nasal swabs. Eighty-seven strains of Lancefield's groups C and G and 54 strains of groups other than A, C, or G were isolated

3. There was no evidence of cross-infection.

4. Factors contributing to the low incidence of group A strains and the absence of cross-infection are discussed.

5. The carriage of groups C and G strains did not appreciably affect the erythrocyte sedimentation rate.

6. Although no direct evidence is available, the experience of the present study suggests that the incidence of streptococci in an institution for rheumatic children may be reduced by: (a) bacteriological screening before admission; (b) regular swabbing and Lancefield's grouping of streptococci isolated for the early detection of group A strains; and (c) administration of penicillin or sulphadiazine prophylactically to even a limited number of children.

We thank Prof. R. S. Illingworth for his advice in the writing of this paper, Dr J. L. Emery for laboratory facilities, Dr R. E. O. Williams for his advice in the planning of the investigation, and the matron and sisters of Ash House Hospital School, Sheffield, for their assistance.

The expenses of the investigation were defrayed by a grant from the Medical Research Council.

The use of the hypergeometric distribution in calculations of sample volumes for safety testing is criticized. Alternative interpretations of the concept of ‘infective ml. doses’ lead to slightly different solutions, the simplest of which, involving the exponential function, is recommended for general use.

We evaluated the incidence rate of culture-positive central nervous system tuberculosis (CNS TB) in France in 2007 and its time trend between 1990 and 2007. We used a capture–recapture analysis by using data recorded in 2007 by the mandatory notification system and the national network of the National Reference Centre (NRC). The 2007 sensitivity of the NRC was 79·4%. The previous sensitivity for 2000 (75·6%) and that for 2007 yielded a pooled estimate of 77·4% (95% confidence interval 64·8–88·0), which was used to extrapolate the number of culture-positive CNS TB cases from those reported in four surveys (1990, 1995, 2000, 2007). The extrapolated number of culture-positive CNS TB cases fell from 90 to 35 between 1990 and 2007, and the extrapolated incidence rates fell from 1·6 to 0·55 cases/million (P < 0·001). This favourable trend should be closely monitored following the change of the BCG vaccination policy in 2007.

Good results were obtained by Ferry, Pryer and Fisher (1925) in the treatment of cases of scarlatina with concentrated antitoxin, obtained from horses treated with toxin of scarlatina derived from streptococci. This antitoxin was supplied commercially by Parke, Davis and Co. It has been used in the present investigation.

1. That there is reason to believe that sporadic cases of cerebro-spinal fever occurred in Hong Kong previous to the outbreak of the epidemic in 1918.

2. That the epidemic followed a widespread infection of influenza colds.

3. That the mortality out of a total of 1040 cases was 85–48 per cent.

4. That the most susceptible age was found to be the age period under five years.

The younger the individual, the greater the susceptibility, with the added proviso that the extremes of life suffered most.

5. That once the epidemic was established, a drop in the temperature, steadily maintained, accompanied by an increase in the saturation of the air as regards moisture, associated with a lack of sunshine, was found to be followed after a lag of a few days, by a rise in the number of cases. This lag showed a tendency to increase as the epidemic progressed, from three to four days at the beginning to six to seven days at the end of the epidemic.

6. That the number of cases in any given area varied directly with the overcrowding in that area, and this bears out the contention that overcrowding is one of the most important features in the epidemiology of cerebro-spinal fever.

7. That the housing conditions in Hong Kong are such as to necessitate immediate action on the part of the Government, to safeguard the public health of the colony.

8. That new entries to Hong Kong formed a large proportion of the cases, and that this appears to be an important factor in the epidemiology of the disease.

9. That the poorest, most hard worked and badly housed portion of the community suffered most in the epidemic.

10. That the recognition and isolation of carriers is impracticable in an epidemic of any considerable dimensions.

11. That in the present condition of the knowledge of the means by which infection is spread, the wearing of a screen composed of some impervious material such as celluloid would seem to afford complete protection to the wearer against droplet infection.

12. That known carriers should be compelled to wear this screen until such time as they are proved free from the meningococcus. Thus protected, the carrier could pursue his usual avocation and the community be safeguarded from infection at a minimum of expense.

Phylogenetic analysis was performed on the haemagglutinin and neuraminidase subtype N2 genes of low-pathogenic avian influenza viruses (LPAIVs) detected in Ireland between 2003 and 2007. Nucleotide sequences were compared to previously published sequences from the National Centre for Biotechnology Information. Sequences from viruses of the same subtype isolated in different years were compared to examine the possibility that LPAIVs may have been maintained in Ireland from year to year. All viruses had closest identity with published sequences of European lineage, supporting the conclusion that LPAIVs had been introduced to Ireland by dabbling ducks that had migrated from Europe. The data suggested that different subtypes of virus had been introduced each year. However, there was evidence that some LPAIVs may have been maintained in the sedentary waterfowl population for consecutive seasons. Furthermore, almost identical H6 and H10 sequences with different N types were found in isolates from the same season, suggesting that reassortment had occurred.