Fluorescent antibody techniques were used for detection of plague antigens in infected mouse carcasses stored at 4°–5° C., 20°–25° C. (room temperature) and 370° C. for periods as long as 340 days in certain cases. Tissues of two guinea-pigs infected with Pasteurella pestis were examined after 7 years storage at room temperature. The efficacy of the fluorescent antibody test was compared with blood agar plate culture and animal inoculation during periods in which viable plague bacilli were presumed to be present, and compared with Larson's modified Ascoli test for the presence of soluble plague antigens during periods in which plague bacteria were presumed to be non-viable.

Fluorescent antibody tests were superior to animal inoculation or cultural methods in detection of P. pestis antigens in mouse carcasses stored for 4 days or longer at 37° C., for 8 days or longer at 20°–25° C. (room temperature), and for 34 days or longer at 4°–5° C. Upon examination of specimens presumed to lack viable plague organisms the fluorescent antibody test and precipitin tests were approximately equal in efficiency for detection of plague antigens in carcasses stored for 16–82 days at 37° C. and for 16–82 days at 20°–25° C. Ten of 21 mice stored for longer periods (140 and 340 days) at 4°–5° C. were negative by precipitin tests, whereas 19 of the same 21 rodents were positive by fluorescent antibody tests. In addition, after 7 years storage at room temperature tissues of two plague-infected guinea-pigs were negative by Larson's modified Ascoli test but positive by the fluorescent antibody test.

The experiments now described were carried out in Lagos and Khartoum, and although the hoped-for end-result, the production of a sheep strain of neurovaccinia, was not realized, certain points of interest have arisen and are recorded in the hope that they may be of help to other workers concerned with vaccinia vaccine production.

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.

This study aimed to investigate differences in the antimicrobial susceptibility of members of the Mycobacterium abscessus complex (MABC): subsp. massiliense and subsp. abscessus, and to identify associations between strain genotypes and antimicrobial resistance phenotypes. A total of 383 clinical MABC isolates (subsp. abscessus: n = 218, 56.9%; subsp. massiliense: n = 163, 42.6%; subsp. bolletii: n = 2, 0.5%) were characterised using multilocus variable number tandem repeat (VNTR) typing and drug susceptibility testing. Most isolates exhibited susceptibility to amikacin, clarithromycin and azithromycin but resistance to cefoxitin and minocycline was statistically more associated with isolates unclustered by VNTR type. The Simpson's diversity indexes of VNTR typing for M. abscessus and M. massiliense isolates were 0.999 and 0.997, respectively. Genotyping of M. abscessus and M. massiliense isolates by VNTR may provide valuable information for predicting resistance phenotype.

This study examined relationships between foodborne outbreak investigation characteristics, such as the epidemiological methods used, and the success of the investigation, as determined by whether the investigation identified an outbreak agent (i.e. pathogen), food item and contributing factor. This study used data from the Centers for Disease Control and Prevention's (CDC) National Outbreak Reporting System and National Environmental Assessment Reporting System to identify outbreak investigation characteristics associated with outbreak investigation success. We identified investigation characteristics that increase the probability of successful outbreak investigations: a rigorous epidemiology investigation method; a thorough environmental assessment, as measured by number of visits to complete the assessment; and the collection of clinical samples. This research highlights the importance of a comprehensive outbreak investigation, which includes epidemiology, environmental health and laboratory personnel working together to solve the outbreak.

Radioimmunoassay (RIA) for rubella-specific IgM antibodies was compared with haemagglutination-inhibition (HI) in conjunction with gel filtration for the diagnosis of rubella infection in pregnant women during a 1-year period. In total 476 women were investigated of whom 221 were tested for rubella IgM. Both techniques gave positive results with 64 sera, and RIA alone with one additional serum.

Difficulties associated with the removal of non-specific HI activity were encountered with four sera all of which were negative by RIA.

RIA was found to have practical advantages over the gel filtration method but is at present technically more difficult to perform.

This study aimed to evaluate the contrast-enhanced ultrasound (CEUS) features of ureteral tuberculosis (UTB) and ureteral malignant tumour and to explore its application value in the differentiation of UTB from ureteral tumour. The ultrasound (US) and CEUS imaging features of 33 and 12 cases of pathologically confirmed UTB and ureteral malignant tumour, respectively, were retrospectively evaluated, and echo of the ureteral wall, abnormal echo of the lumen, degree of ureteral dilation and CEUS patterns of the two diseases were statistically analysed. The results revealed that the lumen echo of UTB was hyperechoic or anechoic, whereas that of ureteral tumour lesions was hypoechoic (χ2 = 28.22, P < 0.001). The wall echo of the obstruction site differed between the two diseases; in UTB, the ureteral wall was thickened but the outer wall remained intact, whereas in ureteral tumour, both the malignant tumour wall and outer wall were irregular (χ2 = 30.25, P < 0.001). CEUS of UTB revealed nonenhancement or heterogeneous enhancement in the lumen, whereas that of ureteral tumours revealed significant homogeneous enhancement (χ2 = 30.25, P < 0.001). Thus, CEUS can reveal lesion microcirculation and be used to evaluate blood supply characteristics in the lesion, indicating that it has high potential for differentiating the two diseases.

Family feasting during the Spring Festival is a Chinese tradition. However, close contact during this period is likely to promote the spread of coronavirus disease 2019 (COVID-19). This study developed a dynamic infectious disease model in which the feast gatherings of families were considered the sole mode of transmission. The model simulates COVID-19 transmission via family feast gatherings through a social contact network. First, a kinship-based, virtual social contact network was constructed, with nodes representing families and connections representing kinships. Families in kinship with each other comprised of the largest globally coupled network, also known as a clique, in which a feast gathering was generated by randomly selecting two or more families willing to gather. The social contact network in the model comprised of 215 cliques formed among 608 families with 1517 family members. The modelling results indicated that when there is only one patient on day 0, the number of new infections will reach a peak on day 29, and almost all families and their members in the social contact network will be infected by day 60. This study demonstrated that COVID-19 can spread rapidly through continuous feast gatherings through social contact networks and that the disease will run rampant throughout the network.

1. A new series of compounds has been found which markedly inhibits the growth of Mycobacterium tuberculosis and M. smegmatis.

2. These substances are strongly haemolytic against human red blood cells.

3. The effectiveness of the antibacterial and haemolytic actions depends upon the length of the alkyl chain.

4. The antibacterial and haemolytic actions are reduced by human serum.

This paper examines the geographical impact of the British Government's wartime evacuation scheme on notified rates of two common acute childhood diseases (scarlet fever and diphtheria) in the 1470 local government districts of England and Wales, 1939–1945. Drawing on the notifications of communicable diseases collated by the General Register Office (GRO), we establish pre-war (baseline) disease rates for the 1470 districts. For the war years, techniques of binary logistic regression analysis are used to assess the associations between (a) above-baseline (‘raised’) disease rates in evacuation, neutral and reception districts and (b) the major phases of the evacuation scheme. The analysis demonstrates that the evacuation was temporally associated with distinct national and regional effects on notified levels of disease activity. These effects were most pronounced in the early years of the dispersal (1939–1941) and corresponded with initial levels of evacuation-related population change at the regional and district scales.

Maternal syphilis not only seriously affects the quality of life of pregnant women themselves but also may cause various adverse pregnancy outcomes (APOs). This study aimed to analyse the association between the related factors and APOs in maternal syphilis. 7,030 pregnant women infected with syphilis in Henan Province between January 2016 and December 2022 were selected as participants. Information on their demographic and clinical characteristics, treatment status, and pregnancy outcomes was collected. Multivariate logistic regression models and chi-squared automatic interaction detector (CHAID) decision tree models were used to analyse the factors associated with APOs. The multivariate logistic regression results showed that the syphilis infection history (OR = 1.207, 95% CI, 1.035–1.409), the occurrence of abnormality during pregnancy (OR = 5.001, 95% CI, 4.203–5.951), not receiving standard treatment (OR = 1.370, 95% CI, 1.095–1.716), not receiving any treatment (OR = 1.313, 95% CI, 1.105–1.559), and a titre ≥1:8 at diagnosis (OR = 1.350, 95%CI, 1.079–1.690) and before delivery (OR = 1.985, 95%CI, 1.463–2.694) were risk factors. A total of six influencing factors of APOs in syphilis-infected women were screened using the CHAID decision tree model. Integrated prevention measures such as early screening, scientific eugenics assessment, and standard syphilis treatment are of great significance in reducing the incidence of APOs for pregnant women infected with syphilis.

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 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.

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) 855 primary cases of typhoid fever in households in Birmingham were investigated.

(2) In 124 or 14·5% of these cases a history of mussel eating within four weeks of the onset of the disease was obtained.

(3) In 17 instances the histories were conclusive of mussel infection.

(4) The curve of mussel-typhoid cases arranged in their weeks of commencement tallies closely with the importation of mussels into Birmingham.

(5) Mussel infection is one of the causes contributing to the autumnal rise of enteric fever.

(6) Some of the sources from which mussels are sent to the Birmingham market are known to be exposed to dangerous sewage contamination.

(7) 65 samples of mussels obtained on entering the Birmingham market from 22 different known sources were analysed bacteriologically.

(8) The results in terms of (a) the total number of organisms, (b) the number of glucose-fermenters, (c) the number of spores of Bacillus enteritidis sporogenes, and (d) the number of Streptococci shew that pollution to a dangerous degree of a large proportion of mussels placed on the market for human consumption exists.

(9) 14 experiments were carried out in relation to mussels subjected to mussels subjected to moist heat at 100°C.

(10) These shew that the ordinary method of cooking to mussels does not remove the risk of typhiod infection and that mussels may be heated in a steam steriliser at 100° C. continuously for as long as four and a half hours without sterilisation.

(11) Legisaltion is necessary to prohibit the gathering of mussels for human consumption from mussel beds exposed to sewage contamination.

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.

Hand, foot and mouth disease (HFMD) is a common infection in the world, and its epidemics result in heavy disease burdens. Over the past decade, HFMD has been widespread among children in China, with Shanxi Province being a severely affected northern province. Located in the temperate monsoon climate, Shanxi has a GDP of over 2.5 trillion yuan. It is important to have a comprehensive understanding of the basic features of HFMD in those areas that have similar meteorological and economic backgrounds to northern China. We aimed to investigate epidemiological characteristics, identify spatial clusters and predict monthly incidence of HFMD. All reported HFMD cases were obtained from the Shanxi Center for Disease Control and Prevention. Overall HFMD incidence showed a significant downward trend from 2017 to 2020, increasing again in 2021. Children aged < 5 years were primarily affected, with a high incidence of HFMD in male patients (relative risk: 1.316). The distribution showed a seasonal trend, with major peaks in June and July and secondary peaks in October and November with the exception of 2020. Other enteroviruses were the predominant causative agents of HFMD in most years. Areas with large numbers of HFMD cases were primarily in central Shanxi, and spatial clusters in 2017 and 2018 showed a positive global spatial correlation. Local spatial autocorrelation analysis showed that hot spots and secondary hot spots were concentrated in Jinzhong and Yangquan in 2018. Based on monthly incidence from September 2021 to August 2022, the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) of the long short-term memory (LSTM) and seasonal autoregressive integrated moving average (SARIMA) models were 386.58 vs. 838.25, 2.25 vs. 3.08, and 461.96 vs. 963.13, respectively, indicating that the predictive accuracy of LSTM was better than that of SARIMA. The LSTM model may be useful in predicting monthly incidences of HFMD, which may provide early warnings of HFMD epidemics.

Laboratory studies were performed on 128 children clinically diagnosed as measles when seen at the Infectious Diseases Hospital, Kenyatta National Hospital (IDH), Nairobi (86 cases) and the Rural Health Training Centre, Maragua, Central Province (42 cases) between 9 July and 31 August 1984. A concurrent measles infection was confirmed in 95% of the children seen at IDH and in 85% of those seen at Maragua, with similar proportions of confirmations in children who had, and who had not, received measles vaccine. No differences in the number of sero-conversions nor in the absolute levels of acute or convalescent HI antibody titres could be detected between vaccinated and unvaccinated children. Analysis of the cases seen at Maragua indicates that about two thirds of the children who had received vaccine were protected. A pilot study of vaccinating children at 8 months and again at 12–13 months is suggested in an attempt to eradicate measles.