Salmonella typhimurium strain 1566 administered to mice by the intraperitoneal route was considerably more lethal than the same dose administered subcutane-ously. This could be measured hi terms of mortality, infectivity and mean survival time of those mice that died.

1. Organisms biochemically resembling the metadysentery bacilli of Castellani (1927) or sensu largo B. coli anaerogenes of Lembke (1896) have been recovered locally from the urinary passages of man.

2. These organisms were found in cases of enteric-like fevers, pyelitis and cystitis.

3. Similar to Dudgeon's slow lactose-fermenting bacilli of the urinary tract, they have been shown to possess marked haemolytic action for red blood corpuscles.

4. Serologically, they appear to fall into at least two groups of bacilli.

5. They are believed to be pathogenic.

The prominence given to the intravascular use of antiseptics has hardly been in accord with the results achieved by this method.

The injection of formalin in various amounts and strengths has been given an extended trial in the treatment of pulmonary tuberculosis, and is claimed to have produced beneficial results. Similarly Baccelli has injected corrosive sublimate intravenously in the treatment of syphilis, cerebro-spinal meningitis, and acute rheumatism in man. In animals he has used intravenous injections of corrosive sublimate in the treatment of aphtha epizootica. In this disease he claims that the intravenous injections of corrosive sublimate are of undoubted use in terminating an attack of the disease.

1. The problem of louse control by powders has been shown to be twofold, namely (a) to kill the lice present on a verminous person at the time of treatment, and (b) to prevent reinfestation of a deloused person or infestation of a clean person. In these experiments no single insecticide was found that would fulfil both functions.

2. The work shows the necessity of using laboratory tests (‘cell tests’) in conjunction with insecticide tests on the parasite living under natural conditions (‘field trials’).

3. The technique and results of the cell tests and the field trials are described in detail. In the field trials naturally louse-infested persons living in verminous surroundings were treated and examined daily to observe the true insecticidal value of each preparation.

4. Naphthalene was found to be the most effective insecticide for killing body lice quickly. It failed to give any protection against reinfestation.

5. The vegetable insecticides, derris and pyrethrum, were found to be toxic to Pediculns humanus corporis, but either alone or in combination with each other they were inferior to other combinations of insecticides.

6. The combination of high-boiling tar acids and derris resulted in the combined chemicals being more toxic to lice than either alone. This proved an activation effect, and the theory of activation is discussed.

7. Activated derris, while slow in killing lice, was shown to be the best preparation which gave protection against reinfestation.

8. The preparation referred to as A.L. 63 was outstanding as the best preparation that controlled body lice and which fulfilled the original conditions stipulated for a successful louse powder for human use. The formula is:

H.B.T.A. 2 %

Derris root 14·3 % giving 1 % rotenone and a minimum of 3 % extract in the final product

Naphthalene 50·0 %

China clay 33·7 %

The nature of each chemical in this formula is defined.

9. A.L. 63, when applied to the clothing of a verminous person, killed 95% of all lice on the treated garment in 24 hr., and gave complete protection against reinfestation for an average of 5 days, and partial protection for 8 days. When applied to clean garments as a prophylactic measure, A.L. 63 gave complete protection for an average of 7…8 days, and partial protection for approximately 16 days.

10. Patients living in a verminous environment were made to wear one shirt continuously for a month without washing it. Even under these conditions they were protected from infestation by treatment of the inside of the shirt, at 8-day intervals, with A.L. 63.

11. A short history is given of the use of A.L. 63 in the British army from 1940 to 1944.

During this work we have had much help and sympathy from many people, but we would like to place on record our especial thanks to the following: Prof. P. A. Buxton, of the London School of Hygiene and Tropical Medicine, for supplying us with the original material for establishing a louse colony, and for his great interest and encouragement during the work; Dr W. E. Parry, the Divisional Police Surgeon at Spitalfields, for his kindness in describing the best areas to search for suitable patients, and his assistance in finding suitable accommodation for establishing the ‘clinic’; those numerous volunteers, within the Cooper, McDougall and Robertson organization, who offered to feed lice when the colony was being maintained at the Research Station, and suffered much discomfort while doing so.

Fifty-six cases examined for Dysentery bacilli. All save one were clinically dysentery, and all save two were negative for amoebae and other protozoa.

Twenty cases (35·7%) yielded dysentery-like bacilli.

From these twenty cases thirty-six organisms were isolated and studied. Of these—

Six corresponded with no familiar pathogenic organism.

Six resembled B. Shiga. Two agreed completely both by fermentation and agglutination. One also gave typical fermentation and agglutination results but was at first a motile organism, although in later generations it became non-motile. The other three are less definitely Shiga bacilli.

Five were mannite-fermenting organisms but only one agreed very closely in its fermentation reactions with B. Flexner and it was not agglutinated by Flexner serum.

Sixteen cultures from ten separate cases corresponded closely with Morgan's bacillus.

Eight of these agreed completely in their characters with Morgan's No. 1 bacillus.

Three differed only from Morgan's No. 1 in being non-motile.

Five presented characters intermediate between those of Morgan's No. 1 and Bowman's “Bac. S.”

Of six cases yielding Morgan's bacillus, agglutination with the patient's own serum was positive in five.

Three cultures showed affinities with the Bac. enteritidis.

Polyvalent anti-dysenteric serum treatment tried on a considerable number of cases was a complete failure.

1. The efficiency of plating of phage 13 on the semi-resistant strain Ps. LIII-3bi decreases as the initial bacterial population on the plate is diminished. Addition of Ps. LII extract to the phage before plating with low bacterial concentrations increases the plating efficiency (exhibition effect).

2. An extract of a strain Ps. LIII-lb which is fully sensitive to phage 13 also causes exhibition of this phage on Ps. LIII-3bi.

3. It is suggested that dissolved phage 13 receptors present in extracts of Ps. LII and Ps. LIII-lb have an affinity not only for the phage but also for suitable bacteria and thus cause exhibition. Inhibition (e.g. of phage 14 by the Ps. LII extract) is due to phage receptors having no tendency to adsorb to bacteria.

4. The phage-exhibiting and inhibiting properties of a freeze-dried extract of Ps. LII active when dissolved in 0.85 % NaCl are lost if the solid is dissolved in water and the solution so obtained further diluted with 0.85 % NaCl. Activity is recovered slowly if NaCl is added to the aqueous solution, instantly if the solution is freeze-dried and the residue dissolved in 0.85 % NaCl.

5. The inhibitory properties of the Ps. LII extract for phage 14 are more sensitive to heat and acidity or alkalinity than the exhibitory properties for phage 13.

6. The absence of cross-precipitin reactions between Ps. LII and Ps. LUI-lb suggests that the phage 13 receptors of the two organisms are non-antigenic or different. I am grateful to Prof. M. van den Ende and my colleagues in this Unit for helpful discussions.

The effects produced upon bacteria by environmental conditions constitute factors which until recently have been studied with but too little regard to scientific accuracy, even by the bacteriologist investigating the conditions under which pathogenic bacteria occur in nature, and whilst probably leading a saprophytic existence.

Despite consistent public health efforts, the burden of viral disease in India remains high. The present study was undertaken to understand the aetiology, frequency and distribution of viral disease outbreaks in the state of Odisha between 2010 and 2019. This was a prospective study conducted at the Virology Research and Diagnostic Laboratory located at ICMR-Regional Medical Research Centre, Bhubaneswar, Odisha, wherein all the outbreaks of viral aetiologies were investigated and analysed to provide a comprehensive picture of the state of viral disease outbreaks in the region. A total of 191 suspected viral outbreaks were investigated by the team from VRDL during September 2010 and September 2019 reported from all the 30 districts of Odisha. Annual number of suspected cases ranged from 185 to 1002. The most commonly suspected outbreaks were of viral hepatitis (55 outbreaks; 1223 cases) followed by dengue (45 outbreaks; 1185 cases), chickenpox (30 outbreaks; 421 cases), viral encephalitis (27 outbreaks; 930 cases), measles (23 outbreaks; 464 cases), chikungunya (10 outbreaks; 593 cases) and rubella (1 outbreak; 60). The outbreaks peaked in frequency and intensity during the months of July and September. The epidemiology of viral disease outbreaks in the region is presented in the study. Health system preparedness based on evidence is essential for early detection and adequate response to such viral outbreaks.

1. Numerical counts on gelatin media are of very limited value for surface well examinations and are quite useless for open draw-wells. The blood-heat enumeration is of use, but still of but limited value.

2. The influence of rainfall and local conditions generally is marked for this class of waters with regard to their bacterial content.

Whether the well is uncovered, or covered and provided with a pump has a very important influence upon the bacteriological results. For a good many wells which show very bad bacteriological findings the cause of pollution is frequently due to surface pollution rather than to pollution of the ground water through the soil. If these wells are properly protected they will become suitable sources of drinking supply.

3. The results obtained confirm the value of B. coli and streptococci estimations as the best tests by which to judge the freedom from pollution of such waters.

The streptococci results are of great value, only second in importance to the B. coli determinations. In numerical distribution these two organisms closely agree. The presence of streptococci is more reliable as evidence to deduce pollution than their absence is to exclude it.

4. An opinion regarding the freedom of surface wells from pollution is best formed on the basis of combined topographical and bacteriological investigation.

5. Inspection alone is frequently quite insufficient for the purpose of determining if a well is contaminated and if it should be closed.

Of the 50 wells examined no less than 31 had to be classed as doubtful (Series C), topographical examination alone affording insufficient data for the expression of a decided opinion.

In view of the fact that pure water supplies are not easy to obtain in many rural districts, a water supply, which may have been in use for many years, cannot be condemned in the absence of clear evidence that it is unsatisfactory and dangerous.

6. In surface well waters a large proportion of the coli-like organisms isolated are atypical in one or more particulars.

7. Typical B. coli implanted into soil showed some alteration of character, but the changes were not extensive and no evidence was obtained that the widely aberrant organisms met with in different soils and waters ever represent typical B. coli altered by unfavourable environment.

8. Organisms closely allied to B. coli, but differing in one or more characters, possess significance as indicators of faecal contamination.

The more nearly the organism isolated resembles an “excretal” B. coli the greater is its significance as an indicator of pollution. Consequently the fewer the number required to condemn a sample water in which they occur. Stated as a working proposition, the more the characters of the coli-like organisms deviate from that which for convenience may be spoken of as the typical form, the greater the proportionate number of them required to condemn the water.

9. The presence of ‘excretal’ B. coli in 10 c.c. or less of a surface well water points to undesirable pollution and is sufficient to condemn the water.

The evidence for the incubation period of Legionnaires’ disease is based on data from a small number of outbreaks. An incubation period of 2–10 days is commonly used for the definition and investigation of cases. In the German LeTriWa study, we collaborated with public health departments to identify evidence-based sources of exposure among cases of Legionnaires’ disease within 1–14 days before symptom onset. For each individual, we assigned weights to the numbered days of exposure before symptom onset, giving the highest weight to exposure days of cases with only one possible day of exposure. We then calculated an incubation period distribution where the median was 5 days and the mode was 6 days. The cumulative distribution reached 89% by the 10th day before symptom onset. One case-patient with immunosuppression had a single day of exposure to the likely infection source only 1 day before symptom onset. Overall, our results support the 2- to 10-day incubation period used in case definition, investigation, and surveillance of cases with Legionnaires’ disease.

The primary object of these papers is to attempt to give a brief review of the present state of opinion regarding the many questions involved in the subject of immunity,—a review intended chiefly for those whose work is concerned with other fields of hygienic research. The carrying out of this aim has necessitated the re-statement of many facts familiar to bacteriologists, in order that the continuity of the discussion might be maintained. Wherever it has been considered advisable the details of the data which have formed the basis of theory have been given, but as a rule the leading results have been alone dealt with, partly because details might obscure the general principles it was intended to emphasise, partly because considerations of space have made an exhaustive treatment of the subject impossible.

Studies on reproduction in a colony of albino mice before and after length of daylight was made constant show no change in litter size. However, there was an increase in the number of post-partum pregnancies after light was made constant and, during the first month thereafter, females were older at first parturition than in previous months.

To inform coverage by potential vaccines, we aimed to systematically review evidence on the prevalence and distribution of non-typhoidal Salmonella enterica serogroups and serovars. We searched four databases from inception through 4 June 2021. Articles were included that reported at least one non-typhoidal S. enterica strain by serogroup or serovar isolated from a normally sterile site. Of serogrouped isolates, we pooled the prevalence of serogroup O:4, serogroup O:9, and other serogroups using random-effects meta-analyses. Of serotyped isolates, we pooled the prevalence of Salmonella Typhimurium (member of serogroup O:4), Salmonella Enteritidis (member of serogroup O:9), and other serovars. Of 82 studies yielding 24,253 serogrouped isolates, the pooled prevalence (95% CI) was 44.6% (36.2%–48.2%) for serogroup O:4, 45.5% (37.0%–49.1%) for serogroup O:9, and 9.9% (6.1%–13.3%) for other serogroups. Of serotyped isolates, the pooled prevalence (95%CI) was 36.8% (29.9%–44.0%) for Salmonella Typhimurium, 37.8% (33.2%–42.4%) for Salmonella Enteritidis, and 18.4% (11.4%–22.9%) for other serovars. Of global serogrouped non-typhoidal Salmonella isolates from normally sterile sites, serogroup O:4 and O:9 together accounted for 90%, and among serotyped isolates, serovars Typhimurium and Enteritidis together accounted for 75%. Vaccine development strategies covering serogroups O:4 and O:9, or serovars Typhimurium and Enteritidis, have the potential to prevent the majority of non-typhoidal Salmonella invasive disease.

Current World Health Organization (WHO) reports claim a decline in COVID-19 testing and reporting of new infections. To discuss the consequences of ignoring severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, the endemic characteristics of the disease in 2023 with the ones estimated before using 2022 data sets are compared. The accumulated numbers of cases and deaths reported to the WHO by the 10 most infected countries and global figures were used to calculate the average daily numbers of cases DCC and deaths DDC per capita and case fatality rates (CFRs = DDC/DCC) for two periods in 2023. In some countries, the DDC values can be higher than the upper 2022 limit and exceed the seasonal influenza mortality. The increase in CFR in 2023 shows that SARS-CoV-2 infection is still dangerous. The numbers of COVID-19 cases and deaths per capita in 2022 and 2023 do not demonstrate downward trends with the increase in the percentages of fully vaccinated people and boosters. The reasons may be both rapid mutations of the coronavirus, which reduced the effectiveness of vaccines and led to a large number of re-infections, and inappropriate management.

The risk factors specific to the elderly population for severe coronavirus disease 2019 (COVID-19) caused by the Omicron variant of concern (VOC) are not yet clear. We performed an exploratory analysis using logistic regression to identify risk factors for severe COVID-19 illness among 4,868 older adults with a positive severe acute respiratory coronavirus 2 (SARS-CoV-2) test result who were admitted to a healthcare facility between 1 January 2022 and 16 May 2022. We then conducted one-to-one propensity score (PS) matching for three factors – dementia, admission from a long-term care facility and poor physical activity status – and used Fisher's exact test to compare the proportion of severe COVID-19 cases in the matched data. We also estimated the average treatment effect on treated (ATT) in each PS matching analysis. Of the 4,868 cases analysed, 1,380 were severe. Logistic regression analysis showed that age, male sex, cardiovascular disease, cerebrovascular disease, chronic lung disease, renal failure and/or dialysis, physician-diagnosed obesity, admission from a long-term care facility and poor physical activity status were risk factors for severe disease. Vaccination and dementia were identified as factors associated with non-severe illness. The ATT for dementia, admission from a long-term care facility and poor physical activity status was −0.04 (95% confidence interval −0.07 to −0.01), 0.09 (0.06 to 0.12) and 0.17 (0.14 to 0.19), respectively. Our results suggest that poor physical activity status and living in a long-term care facility have a substantial association with the risk of severe COVID-19 caused by the Omicron VOC, while dementia may be associated with non-severe illness.

1. None of forty-eight strans of Brucella abortus, ten of Br. melitensis and seven or Br.suis were shown to be lysogenic.

2. It was not possible to ‘adapt’ bacteriophages that were active upon other species of bacteria to lyse brucellas.

3. Thirty samples of faeces, mainly from cows, four sewage samples, twelve specimens of uterine fluid from cows that had aborted, and twenty samples of bulk milk failed to yield bacteriophages active upon brucellas.