1.The results are reported of a study cases of pneumonia, of upper respiratory indection and of family contacts of cases of pneumoia for evidence of influenza-virus infection between October 1947 and April 1949.

2. During an inter-epidemic period in relation to influenza, two sporadic cases of influenza-virus A infection were detected, one in a case of pneumo-coccal pneumonia and the other in a family contact of a case of pneumonia. These were the only instances of virus infection detected amoung 158 individuals including seventy-eight cases of pneumonia.

3. The epidemic of influenza from February to April 1949 was associated with an increase in number of notified cases of pneumonia, particularly in those over 45 years of age compared with the notifications in 1948. Deaths from pneumonia also increased, particularly in those of 65years or over.

4. During the period of influenza prevalence, direct tests of specimens in eggs and serological tests gave positive evidence of influenza prevalence, direct tests of specimens in eggs and serological tests gave positve evidence of influenza virus A infection in many instances. Twenty-six of forty-one cases of upper respiratory infection between February and April 1949 were positive for influenza A and one was a case of influenza B.

5. Eifgteen of fifty-five cases of pneumococcal and staphyococcal pneumoniaccal and staphylococcal pneumonia, eight of fifteen cases of bronchitis, one of two cases of bronchiectasis and four of six cases of congestive heart failure gave serological or cultural evidence of influenza virus A infection during the period of February to April 1949.

6. The mechanism of influenza-virus infection in relation to bacterial infection of the lower respiratory tract is discussed.

Over a period of about 10 months samples were taken at frequent intervals from various stages of treatment at two sewage works; one of these was a small rural works treating only domestic sewage, and the other treated the sewage of an industrial town. These samples were submitted to bacteriological and to chemical examination.

The total plate counts, the counts of coli-aerogenes bacteria, and the counts of Streptococcus faecalis in settled sewage were higher in the warmer than in the colder months of the year.

Though the average total numbers of bacteria in the sewage containing trade wastes were appreciably higher than that of the domestic sewage the counts of faecal organisms were somewhat lower.

Treatment at the works considerably reduced not only the polluting strength of the sewage but also the numbers of bacteria. At the works receiving sewage from an industrial town an average of about 80% of bacteria in settled sewage were removed by treatment in the bio-aeration plant, percolating filters, and humus tanks, and a further 8–10% were removed by subsequent treatment in pressure sand or anthracite filters. At the small rural works, where the rate of treatment was much lower, rather more than 90% of the bacteria were, on the average, removed by treatment in percolating filters and humus tanks, and a further 6% by subsequent passage through shallow gravity sand filters.

The final effluents discharged from the works still contained large numbers of bacteria. Their effect on the bacterial content of the streams to which they are discharged may be gauged from the fact that, in the effluent from the small rural sewage works, which was of consistently good quality when judged by chemical criteria, there were on the average about 160,000 cells of faecal Bacterium coli and about 20,000 faecal streptococci per 100 ml. Numbers in the effluent from the works in the industrial town were even higher. Sand filters of the type investigated here could therefore not be relied upon to produce an effluent of good bacterial quality.

The 44°C. test in MacConkey broth, prescribed by the Ministry of Health (1939) for examination of water, was found, when applied to samples of sewage or sewage effluent, to be almost specific for Bacterium coli, type I. Growth with formation of acid in sodium azide broth incubated at 45° C. was found to be an almost specific test for Streptococcus faecalis.

When samples of domestic sewage are treated with doses of chlorine lower than the chlorine demand bactericidal action depends not only on the proportion of the demand satisfied but also on the absolute size of the dose. With doses just sufficiently large to leave residual chlorine detectable by o-tolidine, reduction in the plate count of bacteria after contact for 15 min. ranged in various tests from 96·2 to 98·7%.

With domestic sewage reduction in bacterial count after addition of chlorine is followed, after an interval, by aftergrowth of survivors which rapidly brings the population to its original level or higher. For this interval to be prolonged the initial concentration of chlorine must be considerably greater than the chlorine demand. This accords with the fact that the rapid reaction of chlorine with constituents of the sewage, which occurs in the first few minutes, is followed by a slower absorption which takes place over a prolonged period, so that the initial bactericidal action of residual chlorine tends to be lost after a time. For many purposes the effectiveness of chlorination should be judged not only by the percentage of bacteria destroyed after a short period of contact but also by the interval which elapses before aftergrowth becomes appreciable.

In samples of sewage treated with doses of chlorine sufficient to destroy the protozoa, surviving bacteria eventually reached a level of population much higher than that of the untreated sewage. The majority of such bacteria were found to be Gram-negative, non-sporing rods, which included strains of Proteus and of Pseudomonas pyocyanea. Tests with a pure culture of a species of Proteus showed that the organisms surviving chlorination are not intrinsically capable of reaching a higher population than the parent culture.

When sewage contains small quantities of gas liquor or thiocyanate the bactericidal action of doses of chlorine lower than the demand is much more prolonged than the action of comparable doses in domestic sewage, owing to the formation of cyanogen chloride.

Comparative tests of the action of chlorine and of cyanogen chloride on pure cultures of Bacterium coli in peptone water and on the mixed flora of sewage showed that the bactericidal effect of cyanogen chloride was more persistent than that of a comparable dose of chlorine. With sewage and with some brands of peptone the immediate effect of the chlorine, on the other hand, was often considerable.

‘The Association of certain types (alpha; and β) of Bact. coli with infantile gastro-enteritis’

By J. Smith

‘The Association of certain types (α and β) of Bact. coli with infantile gastro-enteritis’ By J. Smith p. 222, column 1, five lines from the bottom of the page, should read: ‘that the α type should be given the antigenic formula 0 111 B4 and the β type 0 55 B5, since Dr Kauffmann is now satisfied that what was provisionally called 0 112 should now be termed 0 55.’

A simple cubed diet is described, completely adequate to sustain rapid growth and intensive reproduction in mice and rats.

1. The use of compound cubed diets for monkeys is discussed.

2. Experiments are described which seem to show that a cubed diet, supplemented only by greenfood and water, can be completely adequate for growth and reproduction.

An outbreak of eighteen cases of pemphigus neonatorum in a maternity department is described.

Strains of Staph. aureus isolated from the infants, the mothers and the staff during several weeks of intensive investigations were classified by phage typing.

The findings indicated that, during the latter part of the outbreak at least, the adults were not the source of infection.

There was evidence of wide dissemination of the epidemic strain of Staph. aureus among the healthy infants in the nursery. It is suggested that the main path of infection was from infant to infant.

Methods of controlling established outbreaks are discussed.