A total of 637 strains of Salmonella bareilly received from different parts of India between 1959 and 1985 were phage typed using five locally isolated wild phages. The overall typability was 94·5% and 11 different phagc types could be defined. Phago types 10 and 1 were the most prevalent and the geographical and source distribution is described.

No hygienist has any doubt that diseases of the intestinal tract, especially the enteric fevers, may be spread by the consumption of shellfish. Clinical experience, often repeated, led to this conclusion long before the bacteriologist had been able to detect the presence of the causative organism in the shellfish. In fact it is only within the past year that definite proof has been afforded by the exceedingly valuable work of Wilson (1928), who found B. typhosus in cockles taken from Belfast Lough.

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 Japanese quarantine system monitors incoming passengers to detect imported pathogens at international airports. At one airport, we found that 74% of 13315 travellers returning with diarrhoea had visited only one country before entering Japan. On the basis of our results, we hypothesized that the international distribution and potential source of bacterial strains could be inferred by analysing strains isolated from travellers returning to Japan. In order to demonstrate the potential for this system, we randomly selected five Shigella sonnei strains and examined their restriction fragment length polymorphism patterns. One set of strains appeared to be closely related, while three sets, isolated from travellers who visited different countries were possibly related. These results suggest that international distributions and potential sources of S. sonnei may be inferred by monitoring isolates from passengers arriving at a Japanese quarantine station.

It has long been recognized that there is a relationship between environment and health and examples of this association are easy to cite—overcrowding tends to spread infection. But our knowledge of the exact part played by occupational as distinct from economic and social environment is as yet imperfect.' The liability of the worker to ill-health, apart from any inborn constitutional weakness, is determined broadly by two factors. The first is the influence of the type of work directly upon the worker, an influence inherent in the actual occupation and the conditions under which the work is done. This might be regarded as the direct occupational risk. The second is the economic and social environment conditioned by the occupation followed: this might be termed the indirect occupational risk. This distinction was recognized by the Eegistrar-General who stated that both factors are essentially components of the total occupational risk since ' If a man is obliged by his place of work and his rate of pay to live in an insanitary area, the extra risk of death involved is, in a wider but very real sense, part of the occupational risk'. The purpose of the present paper is to try to disentangle the parts played by each in determining the occupational mortality from a specific disease like tuberculosis. The difficulty which previously presented itself was the absence of a standard which could be regarded as a measurement of the indirect occupational risks. The Registrar-General, in his last Occupational Mortality Supple-ment, has provided an approximate index, by publishing data on the mortality of males following particular occupations and also that of their wives. His viewpoint was.'. for no trade could longer be regarded as directly prejudicial to health if it were found to entail as much excess risk for the wife as for the husband. In such a case excess mortality would evidently be in the main attributable to the social conditions implied.' Greenwood likewise stated that ‘the wives share the social and geographical advantages of their husbands’ occupation but, with relatively ummportant exceptions, are not exposed to their specific occupational risks’. The purpose of the present paper is to try to disentangle the parts played by each in determining the occupational mortality from a specific disease like tuberculosis. The difficulty which previously presented itself was the absence of a standard which could be regarded as a measurement of the indirect occupational risks. The Registrar-General, in his last Occupational Mortality Supplement, has provided an approximate index, by publishing data on the mortality of males following particular occupations and also that of their wives. His viewpoint was. ‘..for no trade could longer be regarded as directly prejudicial to health if it were found to entail as much excess risk for the wife as for the husband. In such a case excess mortality would evidently be in the main attributable to the social conditions implied.’ Greenwood likewise stated that ‘the wives share the social and geographical advantages of their husbands’ occupation but, with relatively ummportant exceptions, are not exposed to their specific occupational risks'.

It will be convenient to summarise the results of the foregoing observations and the conclusions which appear justified by a comparison of results obtained by the two methods of standardisation under consideration, namely (1) cutaneous, on the human subject, and (2) intracutaneous (intradermal) on the guinea-pig.

1. In the absence of knowledge regarding the essential chemistry of tuberculin, a chemical method of standardisation is excluded.

2. The phenomena of allergic reactivity point to a biological basis for standardisation.

3. The allergic reactions have been studied in the sensitised animal and in the human tuberculised subject.

4. Tuberculins of unknown potency have been compared with a tuberculin of known potency which has been selected as standard.

5. Comparative observations have been made as between the standard and the unknown tuberculin, by (a) making use of different dilutions, and (6) assessing results in animals (sensitised) and in human (tuberculised) subjects.

6. In the sensitised guinea-pig the intracutaneous method has been used, and a definite procedure followed in the determination of results.

7. In the human tuberculised subject the cutaneous method has been used, and similar procedure followed for the determination of results. The method and results are illustrated in the text.

8. The results in the two sets of observations are definite and comparable. Both afford a basis for standardisation.

9. The average probable errors by the two methods are approximately equal, that is, the accuracy of the one method is approximately equal to that of the other.

10. If this be so, a strong plea may be advanced in favour of the human test. Shortly expressed: human (tuberculised) subjects are readily available for observation. The procedure involves little preparation, and the results are easily read with exactness. The tuberculin under test is to be used thereafter in relation to the human subject. This fact enhances the value of the test observations.

If it be objected that in intracutaneous injection the amount of tuberculin introduced is measured more precisely, it may fairly be maintained that the droplet application of tuberculin is limited to a sharply defined area of skin surface and, further, that the clear skin of the human subject allows of more accurate estimation of the diameters of the areas of reaction.

The present enquiry has shown that assays on a variety of human (tuberculised) subjects yield consistent results, and similarly, assays on various animals give consistent results. Yet the animal results are not always contistent with the human results. The explanation of the discrepancy is not very clear. It is not impossible that certain strains of tuberculin act in less degree on the human subject and in greater degree on the animal, and conversely. The occurrence of such differences might be misleading and even involve risk, if standardisation tests were limited to animals without control from observations on the human subject.

If we grant, as the records have shown, that the procedure in relation to the human subject is sound and is innocuous to the human subject of the test, much may be said for the simplicity of the method and for the clarity of results obtained. As the tuberculins under test are destined for use on human subjects—for diagnostic and therapeutic purposes—it would seem reasonable, and probably safer, to base the standardisation of tuberculin (for human purposes) on observations in relation to man.

Foot-and-mouth disease virus isolates of types O, A and SAT 2, from diseased animals in herds routinely vaccinated twice a year were compared antigenically with the vaccine strains in the complement-fixation, neutralization and radial immunodiffusion tests. It was found that strains which had readily infected vaccinated cattle had R values against the vaccine strain in the complement- fixation and radial immunodiffusion tests of 30 or less, while strains causing primary outbreaks with little spread had R values of 30–40. Threefold differences in humoral neutralizing antibody concentration between the field variant and the vaccine strain in sera from vaccinated animals were likely to be significant in terms of protection.

A multiple-tube technique based on peptone water incubated at 44 °C for 24 h followed by detection of indole was found to be sensitive and specific for the detection of Escherichia coli in oysters and mussels. The method has the advantage of providing rapid results and is both less expensive and less time-consuming than other MPN techniques.

Residents of long-term care facilities (LTCFs) were disproportionately affected by the COVID-19 pandemic. We assessed the extent to which hospital-associated infections contributed to COVID-19 LTCF outbreaks in England. We matched addresses of cases between March 2020 and June 2021 to reference databases to identify LTCF residents. Linkage to health service records identified hospital-associated infections, with the number of days spent in hospital before positive specimen date used to classify these as definite or probable. Of 149,129 cases in LTCF residents during the study period, 3,748 (2.5%) were definite or probable hospital-associated and discharged to an LTCF. Overall, 431 (0.3%) were identified as index cases of potentially nosocomial-seeded outbreaks (2.7% (431/15,797) of all identified LTCF outbreaks). These outbreaks involved 4,521 resident cases and 1,335 deaths, representing 3.0% and 3.6% of all cases and deaths in LTCF residents, respectively. The proportion of outbreaks that were potentially nosocomial-seeded peaked in late June 2020, early December 2020, mid-January 2021, and mid-April 2021. Nosocomial seeding contributed to COVID-19 LTCF outbreaks but is unlikely to have accounted for a substantial proportion. The continued identification of such outbreaks after the implementation of preventative policies highlights the challenges of preventing their occurrence.

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.

We aimed to estimate the secondary attack rate of mpox among UK household contacts and determine factors associated with transmission to inform public health management of contacts, during the global outbreak in 2022. Information was collected via NHS and public health services and included age, gender, place of residence, setting, and type of contact. Aggregate information was summarized for the UK. Record level data was combined for England, Wales and Northern Ireland, and multivariable logistic regression was used to determine factors associated with transmission. The secondary attack rate among UK household mpox contacts was 4% (60/1 526). Sexual contact with the index case was associated with a 11-fold increase in adjusted odds of becoming a case in England, Wales, and Northern Ireland (95% CI 5.5–22, p < 0.001). Household contacts outside of London had increased odds compared to London residents (adjusted OR 2.9, 95%CI 1.6–5.4, p < 0.001), while female contacts had reduced odds of becoming a case (aOR: 0.41, 95% CI: 0.15–0.95). We found a low overall secondary attack rate among household mpox contacts with strong evidence of increased transmission risk associated with sexual contact. This evidence will inform the risk assessment of contacts and support prioritization of those with close intimate contact for follow up.

HArris & LEong (1936) found that vitamin B1; adsorbed from urine, could be measured by the rat bradycardia method of assay. The amount of vitamin B1 excreted was found to correspond in general with both the dietary intake and the physiological state of the subjects.

That out breaks of plague are associated with a more or less simultaneous mortality amongst rats is an observation of great antiquity. After the discovery of the bacillus by Yersin and Kitasato this concomitant disease of rats was identified as plague, and during the last twelve years the association of rat plague and human plague has been shown to be almost invariable. The relationship has been so striking that many observers who have studied the question on the spot, e.g. Yersin, Ogata, Simond, Thompson, Koch, Gaffky and many others, have arrived at the opinion that from an epidemiological point of view one must regard plague as essentially a rat-disease in which human beings may participate.

Whether the vaccine virus is filterable or not has been the subject of experiment and discussion for many years and since Negri's results published in 1905, from which he deduced that the virus was filterable, numerous experiments dealing with the subject have been made by many workers.

Tuberculosis (TB) in children is a critical public health issue. In Bohol, Philippines, we found a high tuberculin skin test (TST)-positive prevalence (weighted prevalence = 6.4%) among 5476 children (<15 years) from 184 villages, with geographically isolated communities having prevalence as high as 29%. Therefore, we conducted a geospatial and hot spot analysis to examine the association between villages with high TST-positive prevalence (⩾6.5%) and access to medical care (distance (in kilometres and minutes of travel time) to the municipal Rural Health Units (RHU)), access to healthcare resources (distance to Provincial Health Office (PHO)) and socioeconomic determinants of health. Hot spot analysis revealed significant clusters of TST-positive prevalence in villages farthest from the PHO. Based on univariate analysis, the following variables associated with high prevalence were included in the multivariate model: minutes of travel time to the PHO, distance to the PHO, island villages and total deprivation based on socioeconomic indicators. In the final model, only distance to PHO in minutes was significant (P = 0.005). When evaluated further, greater than 1-hour drive significantly increased risk for TST-positivity (P = 0.003). Distance to healthcare resources likely increases the risk of TB transmission within the community. Expanding TB control efforts to geographically isolated areas is critical.

The prevalence rate of coinfection Chagas disease (CD) and HIV in Brazil is between 1.3 and 5%. Serological tests for detecting CD use total antigen, which present cross reactivity with other endemic diseases, such as leishmaniasis. It is urge the use of a specific test to determinate the real prevalence of T. cruzi infection in people living with HIV AIDS (PLWHA). Here, we evaluated the prevalence of T. cruzi infection in a cohort of 240 PLWHA living in urban area from São Paulo, Brazil. Enzyme Linked Immunosorbent Assay, using epimastigote alkaline extract antigen from T. cruzi (ELISA EAE), returned a 2.0% prevalence. However by Immunoblotting, using trypomastigote excreted-secreted antigen (TESA Blot) from T. cruzi, we detected a prevalence of 0.83%. We consider that the real prevalence of T. cruzi-infection in PLWHA is 0.83%, lower than reported in literature; this is due to TESA Blot specificity, probably excluding false positives for CD immunodiagnosis. Our results demonstrate a real need to apply diagnostic tests with high sensitivity and specificity that can help assess the current status of CD/HIV coinfection in Brazil in order to stratify the effective risk of reactivation and consequently decreasing mortality.

As astroviral infection rapidly increased in the summer of 2022 in Korea, this study aimed to determine the cause and genotype of astroviruses during this period. From January to December 2022, we tested 43,312 stool samples from patients with acute gastroenteritis utilizing multiplex PCR to detect HAstV. For the HAstV-positive samples, we determined the genotypes of the HAstVs by PCR and sequencing. The monthly positive rate from 2015 to 2022 showed a notable and abrupt increase of HAstV infection between June and August 2022, peaking at 9.8% in July 2022. The annual positivity rate of HAstV remained at 2–3% between 2015 and 2019, and then decreased to 0.5% in 2020, followed by an increase to 1.5% in 2021 and 3.6% in 2022.The genotyped astroviruses in 2022 were all identified as HAstV-1 type, and the nucleotide identity% among them was >99%. The GenBank accession number for the strain genetically closest to the strains identified in our study was ON571597.1, which was HAstV-1 isolated from Pingtan in 2019. Our results provide recent epidemiological data on HAstVs in Korea. The decline and surge in astrovirus positivity in recent years may be related to the COVID-19 pandemic.

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.

The purpose of this study was to identify predictors of increasing incidence of Spotted Fever Group rickettsioses (SFGR) in Illinois, with a specific focus on weather variables. We analysed cases of SFGR reported to the Illinois Department of Public Health from 2004 to 2013. Surveillance definitions changed in 2008 and 2010, but those changes alone did not account for observed spikes in incidence in 2008, 2012 and 2013. A total of 590 cases of SFGR occurred, with the majority in the southernmost portion of the state. Only 3·4% of the reported cases were considered confirmed under the case definition. Increased mean winter temperature (IRR 1·32, CI 1·25–1·40) and increased precipitation (IRR 1·08, CI 1·04–1·11) were each associated with increased incidence of SFGR. Our findings show that weather appears to play a significant role in explaining the increasing annual incidence of SFGR in Illinois.