The results obtained in these investigations were negative throughout, but perhaps are worth recording as tending to show that the formation of such ‘anti-bodies’ as cytolysins and precipitins is not a necessary reaction on the part of any living organism to the presence of foreign cells or substances.

The way in which rats and mice eat whole grains of wheat, barley, oats and maize has been studied.

Rats (Rattus norvegicus and R. rattus) hold grains with the long axis parallel to that of the body and eat the germ end of the grain in preference to the rest.

Mice (Mus musculus) hold grains with the long axis at right angles to that of the body and attack first the cheeks of all grains except maize, of which only the germ and scutellum are eaten.

It is suggested that texture is in the main responsible for the selection of a particular part of a grain.

In the first place cultures of the nitroso-bacterium were developed in inorganic solutions. These carried to a 5th dilution exhibited practically a pure culture of this species.

Secondly, cultures of the nitroso-bacterium were inoculated into solutions containing small quantities of organic matter. In these they were able to oxidise the ammonia present. It was found that a culture developing in the presence of small quantities of organic matter was better able to oxidise the ammonia in higher percentages of organic matter than a culture taken directly from an inorganic solution.

In growing this species on plates silica jelly has the disadvantage of being difficult to prepare. It was 18 months before I obtained a satisfactory plate. This jelly grows the nitroso-bacterium well, but other species can also develop colonies on it. Ammonia agar also grows the species, as shown by the oxidation of the ammonia, and the colonies assume a characteristic form.

As to beef broth agar and gelatine, these media grew colonies of a micro-organism similiar to the nitroso-bacterium from oxidised ammonia cultures. Pieces of these plates containing such colonies in pure culture frequently oxidised ammonia in solutions. On the other hand pieces of such plates showing no colonies never produced any oxidations of the ammonia. Furthermore the single colonies from silica and ammonia agar plates, which oxidised the ammonia in the media into which they were sub-cultured, grew well on beef broth agar and gelatine.

From the above results I have come to the following conclusions:

(1) That the nitroso-bacterium grows well on any ordinary medium.

(2) That the supposed parallel organism is no other than the nitroso-bacterium itself.

(3) That in the presence of large percentages of organic matter the nitroso-bacterium, although growing very profusely, loses for a time the power of converting ammonia into a nitrite.

In June 2015, an outbreak of cryptosporidiosis with 35 cases (23 probable and 12 laboratory-confirmed) occurred among 191 attendees of a residential rehabilitation holiday for paediatric organ transplant patients (n = 49) and their families at a hotel in Somogy county, Hungary. The overall attack rate was 18%. Most of the cases were transplanted children who experienced severe acute disease and required adjustment to their tacrolimus immunosuppression. A retrospective case-control study suggested an association between recreational water exposures and illness: cases were seven times more likely than controls to have swum in the children's pool (odds ratio 7.17; 95% confidence interval 2.9–17.2; P < 0.0001) and five times more likely to have used the jetted whirlpool (odds ratio 5.25; 95% confidence interval 2.1–13.1; P < 0.0001). This was the first outbreak of cryptosporidiosis in Hungary and it is especially unfortunate that it affected vulnerable children who experienced severe symptoms. Cryptosporidium presents specific infection control difficulties in treated recreational water venues; the link to a whirlpool is unusual and highlights the importance of the age-appropriate use of these facilities and reminding users not to immerse their heads or swallow the water. Cryptosporidiosis is more commonly linked to children’ pools where improved bather hygiene and promoting exclusion of diarrhoea cases could help to avoid similar outbreaks.

Hepatitis C virus (HCV) infection is one of the leading causes of death and morbidity associated with liver disease. Risk factors identified for the transmission of HCV include contaminated blood products, intravenous drug use, body piercing, an infected mother at birth, sexual activity, and dental therapy, among others. However, the exact diversity of the HCV genotype and genetic variation among patients with low-risk factors is still unknown. In this study, we briefly described and analysed the genotype distribution and genetic variation of HCV infections with low-risk factors using molecular biology techniques. The results suggested that genotype 1b was predominant, followed by genotypes 2a and 1a. Genetic variations in the 5′ UTR sequences of HCV were identified, including point mutations, deletions, and insertions. The frequency of genetic variations in 1b was higher than in 2a. This study provides considerable value for the prevention and treatment of liver disease caused by HCV among patients with low-risk factors and for the development of HCV diagnostic reagents and vaccines.

Common childhood infectious diseases have been associated with a reduced risk of following haematopoietic malignancies, but investigations on multiple myeloma (MM) are scarce. Information about 213 MM cases and 1128 healthy controls were obtained from a multicentre population-based Italian case-control study. The association between chickenpox, measles, mumps, pertussis and rubella and the MM risk was estimated by unconditional logistic regression, adjusting for age, gender and residence area. No association was found between MM risk and any considered infectious disease. The number of infections was slightly inversely associated with the risk of MM, but statistical significance was not reached (OR 0.87, 95% CI 0.55–1.4 for 1-2 diseases vs. none and OR 0.68, 95% CI 0.41–1.1 for 3-5 diseases, respectively, P = 0.131). We did not find a clear evidence that common infections during childhood are associated with the subsequent risk of developing MM.

The stock diet for rats and mice, diet 41 cubed, can be rendered sterile to broth by autoclaving at 15 lb./sq. in. for 20 min. without impairment of the nutritive value for breeding mice.

The last 30 years have been changes in emphasis in the study of streptococci and streptococcal diseases. Earlier work concentrated mainly on the sources and methods of cross-infection and descriptive epidemiology of Streptococcus pyogenes in its major manifestations of respiratory, cutaneous and invasive infection and in the complications of rheumatic fever (RF), scarlet fever (SF) and post-streptococcal glomerulonephritis (PSGN).

The principle of the aerosol centrifuge is described, and an elementary mathematicaltreatment is given.

The relations between the behaviour of the centrifuge and its dimensions, speed and airflow have been tested experimentally on three machines. It is shown that the mathe-matical formulae given are an adequate basis for design.

Various applications are mentioned.

The direct complement fixation test was performed to follow the antibody response in chickens infected with avian infectious bronchitis virus. Concentrated allantoic fluid (4 units) was used as an antigen and allowed to react with serially diluted antiserum in the presence of two complete units of guinea-pig complement for 3 hr. at 4°C. and ½ hr. at 37°C. before the addition of sensitized cells. Serum was unheated and used either fresh or within one month of storage at −30°C. Individual birds showed a rise and fall of complement-fixing antibody both after primary and secondary inoculations. The complement-fixing antibody was detected as early as the seventh day after primary inoculation. The highest complement fixation titre (1/32 to 1/64) was recorded from 14 to 21 days after inoculation with a subsequent gradual decline.

The results of the direct complement fixation tests have been correlated with the serum neutralization test. The neutralizing antibodies usually appeared by the 14th day but were not detected at a significant titre until the 21st day after primary inoculation. Serum neutralizing antibodies were still present at high titres even after 7 weeks of infection but the complement-fixing antibodies had disappeared by that time.

Cryptosporidium is a zoonotic protozoan parasite with public health importance worldwide. The objectives of this study were to (1) conduct a meta-analysis of published literature for oocyst shedding and diarrhoea outcomes, and (2) develop recommendations for standardization of experimental dose–response studies. Results showed that for the outcome of oocyst shedding in faeces, the covariates ‘experimental species’, ‘immunosuppression’, ‘oocyst dose’ and ‘oocyst dose’ × ‘age’ were all significant (P ⩽ 0·05). This study suggests that exposing mice, piglets, or ruminants, and using immunosuppressed experimental hosts, is more likely to result in oocyst shedding. For the outcome of diarrhoea in experimentally infected animal species, the key covariates ‘experimental species’, ‘age’ and ‘immunosuppression’ were significant (P ⩽ 0·2). Therefore, based on the results of this meta-analysis, these variables should be carefully reported and considered when designing experimental dose–response studies. Additionally, detection of possible publication bias highlights the need to publish additional studies that convey statistically non-significant as well as significant results in the future.

Nineteen (22·9%) of 83 sera collected before vaccination from adult volunteers aged 21–64 years were without neutralizing antibody to poliomyeitis at levels of 0·15 i.u./ml for types I and II and 0·1 i.u./ml for type III. Some correlations were found between the history of previous vaccination and the presence of antibody but these were not well defined.

Vaccination with a single dose of trivalent oral polio vaccine elicited fourfold or greater antibody responses to one or more poliomyelitis types in 53 (63·9%) volunteers, the percentage antibody responses being inversely related to the titre of antibody present before vaccination. Types I, II or III poliomyelitis virus were recovered from 76·8 % of faecal samples collected 1 week after vaccination. The percentage recovery progressively declined thereafter until virus was recovered from 10·5 % of samples collected 6 weeks after vaccination.

Type for type, the titres and percentages of antibody responses and virus shedding in faeces were similar following trivalent oral poliomyelitis vaccines whether prepared in monkey kidney or human diploid cell substrates. Some change in reproductive capacity temperature (r.c.t./40) marker was found in faecal isolates from volunteers vaccinated with monkey kidney and human diploid grown vaccines but no change in ‘d’ marker was found.

In 1927 Hilda M. Woods and I contributed to this Journal a study of some aspects of a syndrome called “Status Thymicus,” “Status Thymico-Lymphaticus” or simply “Status Lymphaticus.” We were moved by three considerations: (1) that Prof. H. M. Turnbull had placed at our disposal a long series of weighings of the Thymus, the alleged principal villain of the piece; (2) that every year a not inconsiderable number of deaths are put to the account of this syndrome; (3) that the first volume of Prof. J. A. Hammar's monograph on the Thymus had recently been published. Since our publication, the annual quota of victims shows no signs of diminution (Table I) and the second volume of Prof. Hammar's work has appeared.

Further India has been affected by plague to a small extent in comparison to the Indian Empire. Some considerable interest therefore attaches to the comparatively unimportant local outbreaks which occur, from time to time, in the Malay Peninsula. It is generally very difficult to explain the reason for their limitation and to determine, with any degree of accuracy, the source of the infection. Kelanthan, a small but populous and fairly healthy Native Malay State, situated in geographical position between 4° 45′ and 6° 25′ lat. N., and 101° 30′ and 102° 40′ long. E., has only been exploited by European enterprise during the last seven or eight years. The State seems hitherto to have escaped from plague. The Kelantan Malays in fact, so late as 1905, looked upon plague as a new disease and, for want of a better name, then referred to it as the “penyakit leher” or “neck sickness.” Numerous deaths from this so-called “neck sickness” were reported by the natives of the interior to have occurred at some remote villages in the month of May 1905. The illness appeared from the clinical descriptions given by the Malays at the time to have been bubonic plague. It was not thought necessary however by the Kelantan Government to take any special precautions to prevent its spread, and the disease disappeared of its own accord in a few months' time.

The risk ratio quantifies the risk of disease in a study population relative to a reference population. Standard methods of estimation and testing assume a perfect diagnostic test having sensitivity and specificity of 100%. However, this assumption typically does not hold, and this may invalidate naive estimation and testing for the risk ratio. We propose procedures that control for sensitivity and specificity of the diagnostic test, given the risks are measured by proportions, as it is in cross-sectional studies or studies with fixed follow-up times. These procedures provide an exact unconditional test and confidence interval for the true risk ratio. The methods also cover the case when sensitivity and specificity differ in the two groups (differential misclassification). The resulting test and confidence interval may be useful in epidemiological studies as well as in clinical and vaccine trials. We illustrate the method with real-life examples which demonstrate that ignoring sensitivity and specificity of the diagnostic test may lead to considerable bias in the estimated risk ratio.

An epidemic of acute haemorrhagic conjunctivitis (AHC) recurred at Lucknow during July to September 1975, after a gap of 4 years. Out of the 35 cases investigated thoroughly, 20 Entero-70-like cytopathogenic agents were isolated from the conjunctiva which were neutralized by antisera against AHC virus J670/71 of Japan. Seroconversion was seen in 7 out of 11 paired sera from patients. Serological study was also done on 100 sera after 1975 epidemic. There were no neutralizing antibodies in the pre-epidemic period, while 18% of sera after the first epidemic and 32% after the second epidemic showed antibodies. The incidence of antibodies was highest (43%) in children aged below 10 years. Of the children born after the first epidemic, 44% had antibodies. Thus our findings show that the AHC virus appeared for the first time at Lucknow in 1971 and the almost complete absence of disease in children, and its mildness during second epidemic, may be due to immunity.

In a previous paper (1912) a rough analysis of certain statistical data was made which seemed to show that the age of the parent at the birth of the offspring was a factor in its susceptibility to the Zymotic Diseases.

A test is described for assessing the sanitizing effect of napkin treatment products on naturally urine-wetted and faecally-contaminated napkins. This test defines in-use conditions which closely resemble typical domestic situations. One napkin treatment product (‘Napisan’), tested at two different concentrations and with challenges of different numbers of babies' napkins, performed satisfactorily under the conditions used.