We conducted a matched case-control (MCC), test-negative case-control (TNCC) and case-cohort study in 2016 in Lusaka, Zambia, following a mass vaccination campaign. Confirmed cholera cases served as cases in all three study designs. In the TNCC, control-subjects were cases with negative cholera culture and polymerase chain reaction results. Matched controls by age and sex were selected among neighbours of the confirmed cases in the MCC study. For the case-cohort study, we recruited a cohort of randomly selected individuals living in areas considered at-risk of cholera. We recruited 211 suspected cases (66 confirmed cholera cases and 145 non-cholera diarrhoea cases), 1055 matched controls and a cohort of 921. Adjusted vaccine effectiveness of one dose of oral cholera vaccine (OCV) was 88.9% (95% confidence interval (CI) 42.7–97.8) in the MCC study, 80.2% (95% CI: 16.9–95.3) in the TNCC design and 89.4% (95% CI: 64.6–96.9) in the case-cohort study. Three study designs confirmed the short-term effectiveness of single dose OCV. Major healthcare-seeking behaviour bias did not appear to affect our estimates. Most of the protection among vaccinated individuals could be attributed to the direct effect of the vaccine.

One of the main concerns about the fast spreading coronavirus disease 2019 (Covid-19) pandemic is how to intervene. We analysed severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) isolates data using the multifractal approach and found a rich in viral genome diversity, which could be one of the root causes of the fast Covid-19 pandemic and is strongly affected by pressure and health index of the hosts inhabited regions. The calculated mutation rate (mr) is observed to be maximum at a particular pressure, beyond which mr maintains diversity. Hurst exponent and fractal dimension are found to be optimal at a critical pressure (Pm), whereas, for P > Pm and P < Pm, we found rich genome diversity relating to complicated genome organisation and virulence of the virus. The values of these complexity measurement parameters are found to be increased linearly with health index values.

The seasonality of canine births was investigated using records from the Kennel Club and the breeding centre for the Guide Dogs for the Blind Association. In these populations a distinct seasonal pattern was found with a greater number of puppies being born in the summer months than the winter. The hypothesis that the greater number of puppies acquired as pets during the summer months may Contribute to the seasonal rise in human campylobacter cases, seen at this time, is discussed.

Measles is a notifiable disease, but not everyone infected seeks care, nor is every consultation reported. We estimated the completeness of reporting during a measles outbreak in The Netherlands in 2013–2014. Children below 15 years of age in a low vaccination coverage community (n = 3422) received a questionnaire to identify measles cases. Cases found in the survey were matched with the register of notifiable diseases to estimate the completeness of reporting. Second, completeness of reporting was assessed by comparing the number of susceptible individuals prior to the outbreak with the number of reported cases in the surveyed community and on a national level.

We found 307 (15%) self-identified measles cases among 2077 returned questionnaires (61%), of which 27 could be matched to a case reported to the national register; completeness of reporting was 8.8%. Based on the number of susceptible individuals and number of reported cases in the surveyed community and on national level, the completeness of reporting was estimated to be 9.1% and 8.6%, respectively. Estimating the completeness of reporting gave almost identical estimates, which lends support to the credibility and validity of both approaches. The size of the 2013–2014 outbreak approximated 31 400 measles infections.

In the absence of an established gold standard, an understanding of the testing cycle from individual exposure to test outcome report is required to guide the correct interpretation of severe acute respiratory syndrome-coronavirus-2 reverse transcriptase real-time polymerase chain reaction (RT-PCR) results and optimise the testing processes. Bayesian network models have been used within healthcare to bring clarity to complex problems. We use this modelling approach to construct a comprehensive framework for understanding the real-world predictive value of individual RT-PCR results.

We elicited knowledge from domain experts to describe the test process through a facilitated group workshop. A preliminary model was derived based on the elicited knowledge, then subsequently refined, parameterised and validated with a second workshop and one-on-one discussions.

Causal relationships elicited describe the interactions of pre-testing, specimen collection and laboratory procedures and RT-PCR platform factors, and their impact on the presence and quantity of virus and thus the test result and its interpretation. By setting the input variables as ‘evidence’ for a given subject and preliminary parameterisation, four scenarios were simulated to demonstrate potential uses of the model.

The core value of this model is a deep understanding of the total testing cycle, bridging the gap between a person's true infection status and their test outcome. This model can be adapted to different settings, testing modalities and pathogens, adding much needed nuance to the interpretations of results.

To control hepatitis A spread by vaccination, accurate estimation of transmissibility is vital. Regan et al. (2016) proposed a model of hepatitis A virus (HAV) transmission and used least squares to calibrate model to the 1991/1992 HAV outbreak in men who have sex with men (MSM) in Sydney, Australia. Based on the estimate of R0, they obtained the critical immunity of 70% and showed that when the proportion immune <70%, there is a definite chance for outbreaks to take place. The immunity level from previous surveys ranges from 32% to 64% after 1996 while no outbreaks in Australian MSMs have been reported since 1996. Further noticing the ill-distributed parameters, we argue that their estimate of R0 is not accurate. In this study, we revisited their model by Bayesian inference, which has privilege over least squares. We obtained the appropriate posterior distributions of parameters and the estimate of R0 ranges from 1.38 to 2.89, indicating a critical immunity of 65%. The reduction in critical immunity and outbreak probabilities predicts the absence of outbreaks in Australian MSMs since 1996. Our study shows the importance of using appropriate methods to provide reliable and accurate estimates of the model parameters especially the transmissibility.

B-cell non-Hodgkin lymphoma (B-cell NHL) is the second commonest malignancy in the stomach. We determined the distribution of Helicobacter pylori outer membrane protein Q (HopQ) allelic type, cytotoxin-associated gene (cag)-pathogenicity activity island (cag-PAI) and vacuolation activating cytotoxin A (vacA) genes, respectively, in patients with B-cell NHL. We also compared them with their distribution in non-ulcer dyspepsia (NUD). H. pylori was cultured from gastric biopsy tissue obtained at endoscopy. Polymerase chain reaction was performed. Of 170 patients enrolled, 114 (63%) had NUD and 56 (37%) had B-cell NHL. HopQ type 1 was positive in 66 (58%) in NUD compared with 46 (82%) (P = 0·002) in B-cell NHL; HopQ type 2 was positive in 93 (82%) with NUD compared with 56 (100%) (P < 0·001) in B-cell NHL. Multiple HopQ types were present in 46 (40%) in NUD compared with 46 (82%) (P < 0·001) in B-cell NHL. CagA was positive in 48 (42%) in NUD vs. 50 (89%) (P < 0·001) in B-cell NHL; cagT was positive in 35 (31%) in NUD vs. 45 (80%) (P < 0·001) in B-cell NHL; left end of the cagA gene (LEC)1 was positive in 23 (20%) in NUD vs. 43 (77%) (P < 0·001) in B-cell NHL. VacAs1am1 positive in B-cell NHL in 48 (86%) (P < 0·001) vs. 50 (44%) in NUD, while s1am2 was positive in 20 (17%) in NUD vs. 46 (82%) (P < 0·001) in B-cell NHL. H. pylori strains with multiple HopQ allelic types, truncated cag-PAI evidenced by expression of cagA, cagT and cag LEC with virulent vacAs1 alleles are associated with B-cell NHL development.

Population-based seroprevalence studies on coronavirus disease 2019 (COVID-19) in low- and middle-income countries are lacking. We investigated the seroprevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) antibodies in Sergipe state, Northeast Brazil, using rapid IgM−IgG antibody test and fluorescence immunoassay. The seroprevalence was 9.3% (95% CI 8.5–10.1), 10.2% (95% CI 9.2–11.3) for women and 7.9% (IC 95% 6.8–9.1) for men (P = 0.004). We found a decline in the prevalence of SARS-CoV-2 antibodies according to age, but the differences were not statistically significant: 0–19 years (9.9%; 95% CI 7.8–12.5), 20–59 years (9.3%; 95% CI 8.4–10.3) and ≥60 years (9.0%; 95% CI 7.5–10.8) (P = 0.517). The metropolitan area had a higher seroprevalence (11.7%, 95% CI 10.3–13.2) than outside municipalities (8.0%, 95% CI 7.2–8.9) (P < 0.001). These findings highlight the importance of serosurveillance to estimate the real impact of the COVID-19 outbreak and thereby provide data to better understand the spread of the virus, as well as providing information to guide stay-at-home measures and other policies. In addition, these results may be useful as basic data to follow the progress of COVID-19 outbreak as social restriction initiatives start to be relaxed in Brazil.

Agglutinins and precipitins. Cultures of S. aureus isolated from infections in man were used for the inoculations. It is well known that rabbits are very susceptible to this organism, and previous inoculation with vaccines, attenuated cultures, or with carefully graduated doses of the live coccus does not confer adequate protective immunity, although the animal's serum contains immune bodies, such as agglutinins and precipitins, to a high titre.

The mortality patterns obtained with S. dublin injected intraperitoneally in both control and immunized mice could be described fairly well by curves of a simple Poisson type, based upon the assumption that the receipt of one or more organisms of a type capable of growing in the host resulted in death, and that both vaccination and passive protection simply reduced the proportion of this type.

In June 2019 the Health Protection Team in Yorkshire and Humber, England, was notified of cases of hepatitis A virus (HAV) infection in staff at a secondary school. Investigation revealed that an earlier case worked as a food handler in the school kitchen. Indirect transmission through food from the canteen was considered the most likely route of transmission. Cases were described according to setting of exposure. Oral fluid was obtained from students for serological testing. Environmental investigations were undertaken at settings where food handling was considered a potential transmission risk. Thirty-three confirmed cases were linked to the outbreak. All of those tested (n = 31) shared the same sequence with a HAV IB genotype. The first three cases were a household cluster and included the index case for the school. A further 19 cases (16 students, 3 staff) were associated with the school and consistent with indirect exposure to the food handler. One late onset case could not be ruled out as a secondary case within the school and resulted in vaccination of the school population. Five cases were linked to a bakery where a case from the initial household cluster worked as a food server. No concerns about hygiene standards were noted at either the school or the bakery. Oral fluid samples taken at the time of vaccination from asymptomatic students (n = 219, 11–16 years-old) showed no evidence of recent or current infection. This outbreak included household and foodborne transmission but limited (and possibly zero) person-to-person transmission among secondary school students. Where adequate hygiene exists, secondary transmission within older students may not occur.

Following an outbreak of vanA-positive Enterococcus faecium in 2005 in Kyoto prefecture, regional surveillance of vancomycin-resistant enterococci (VRE) was initiated. This revealed vanA- or vanB-positive Enterococcus gallinarum in multiple facilities. Eighty-eight vanA-positive E. gallinarum faecal carriers from 12 facilities and ten vanB-positive E. gallinarum faecal carriers from eight facilities were found. Pulsed-field gel electrophoresis profiles of the first isolate from each facility showed that 11 of the 12 vanA isolates and three of the eight vanB-positive E. gallinarum isolates belonged to a single clone. This study confirms the clonal spread of vanA- or vanB-positive E. gallinarum in a region and underlines the importance of surveillance of VRE for the presence of vancomycin resistance determinants.

The incidence of Industrial Lead Poisoning is closely related to those sections of the manufactures which involve the production of dust. In white-lead works, paint-grinding shops, litharge grinding, electrical accumulator works, etc., the dust takes the form of minute particles of the special compound of lead manipulated by the workman. In smelting, desilverising, trimming metals and in file cutting, finely divided metallic lead, or a lead oxide, is present in the workshop air.

It is impossible to say with certainty that the outbreak of illness in Manchester was due to ergot, but the evidence available strongly supports the view that ergot was the cause. The train of symptoms and pathological changes, though not necessarily peculiar to ergot poisoning, are strongly suggestive of this origin and this conclusion is reinforced by the fact that all the sufferers consumed rye bread made from rye which contained a significant proportion of ergot. The ergot isolated from this rye, after being kept for many months under conditions which were unfavourable for the preservation of its toxic properties, was found at the expiration of this period to contain some toxin and the amount found was consistent with the ergot having been highly active when fresh and therefore quite capable of causing the outbreak of illness which developed at a period shortly after the harvest when the toxic properties of ergot are greatest.

As a result of my inquiry the following facts of interest have emerged:

1. A considerable quantity of rye is grown in England and Wales and more than half of it is allowed to ripen. The districts in which most of it is grown are Yorkshire, Lancashire, Cheshire, Monmouth and Essex. Rye in this country is seldom, if ever, free from ergot and the degree of infection varies from year to year in each district according to the season, weather, seed and other conditions.

2. Rye bread is eaten to a large extent (in Liverpool and Manchester at any rate) by Jews, and rye for these towns is obtained almost exclusively from Lancashire and Yorkshire.

3. The rye grain is usually not treated in any way before milling, that is to say, no attempt is made to remove any ergot which may be present; it is ground into meal in the condition in which it comes from the threshing machine.

4. On the assumption that some of the rye consumed in Manchester contained 1 per cent. of ergot, a half-pound loaf of bread of which this rye is a constituent would contain 4 to 5 grains of ergot. Although this is a relatively small dose, it is possible that if consumed over lengthy periods, especially if the ergot were in an actively toxic state, pathological conditions might ensue.

5. The samples of rye actually examined by the Public Analyst were not found to be toxic. This may possibly be accounted for on the ground that the method employed for extracting the toxin was not satisfactory, or to the fact that the ergot examined was at least six months old, by which time it would normally have lost most if not all of its toxicity.

6. Damp weather favours the growth of ergot and the climatic conditions of the summer of 1927 were just those most suited to the development of ergot. It is probable therefore that the rye crop was heavily infected and the ergot rich in toxins.

The clinical characters of the outbreak, so far as they have been recorded, strongly support the view that ergot was responsible; all the necessary factors and conditions for the production of illness were present and it is not surprising that it occurred.

In view of the potential danger the obvious preventive measures to which I have already referred should be put into operation. Rye crops should be grown with such precautions as to reduce the risk of ergot infection to a minimum. Millers of rye for human consumption should install the necessary machinery to remove, so far as possible, any small proportion of ergot which the rye may contain.

To establish the frequency of infectious aetiology in Mexican adult patients with cervical lymphadenopathies (CLAs), 87 consecutive patients with enlarged cervical lymphatic nodes, HIV negative and without anti-tuberculous treatment, were selected from a tertiary-level speciality concentration hospital. Histopathological studies, investigation of acid-fast bacilli, cultures in Löwenstein–Jensen and Mycobacterium growth indicator tube (MGIT) media, and in-house polymerase chain reaction (PCR) with IS6110-based primers for Mycobacterium tuberculosis complex were performed in resected lymphatic nodes. Non-infectious aetiology corresponded to 45 cases (52%). Tuberculosis was suspected in 42 cases (48%) by histology and confirmed positive results were obtained by staining in 8 (19%), by culture in 23 (55%), and by PCR in 34 (81%) patients. All were confirmed after therapeutic success. In addition to the epidemiological transition process occurring in Mexico, tuberculosis remains an important cause of CLA. Histopathology with confirmatory studies including PCR can detect tuberculous aetiology.

Measles elimination goals have been adopted in a range of countries, sub-regions, and regions since the WHO declared an elimination goal by 2015 or 2020. All countries attempt to achieve and maintain high coverage through routine immunization programmes. This routine strategy, however, does not ensure the elimination goal of measles. Many developed countries, such as the United States, that have succeeded in interrupting measles transmission earlier, are now experiencing outbreaks with an increasing number of cases. Using a stochastic, age-structured model of measles vaccination dynamics, we explore and characterize the transient dynamics of measles susceptibility in the years following the implementation of routine vaccination at the herd immunity threshold. We demonstrate how a population could face risks of potentially large outbreaks even within few years of vaccination. We characterize different risk profiles depending on the incidence pattern in the years prior to vaccination. These results suggest that the classic critical vaccination threshold is necessary to achieve herd immunity, but not sufficient to prevent long periods of transient, super-critical dynamics. Our results suggest the need of future work for more careful monitoring of the impacts of current immunization programmes, and developing models that take into account more complicated vaccination strategies, demographic factors, and population movements.

(1) Samples of faeces of 391 cows in apparently good health have been examined and it has been demonstrated that 6 (1.53 per cent.) of the cows were excreting tubercle bacilli.

(2) When the faeces of almost all the cows on founrteen farms were examined it was found that five cows on four farms were excreting tubercle bacilli.

Our thanks are due to the Medical Research Council for the grant which enabled us to carry out this investigation.

A survey of mild respiratory disease in a primary school was undertaken over a 2-year period to determine which of the newer respiratory viruses were responsible for these illnesses.

The over-all isolation rate was low but a wide variety of viral agents was isolated.

None of these caused epidemics but it is suggested they may be the cause of a low but constant absentee-rate throughout the year.

An examination was made of 200 Wassermann sera, thirty-eight sera from typhoid, twenty-five from paratyphoid B and thirty-one from tuberculous cases, for somatic agglutinins to a range of Salmonellas representative of the O groups then available.

In the Wassermann sera O agglutinins, except to Bact. typhosum and Bact. paratyphosum B, were rare, and the titres against these organisms were low, attaining a titre of 1: 80 against Bact. typhosum in one serum only.

The sera of the enteric cases mostly possessed agglutinins to both Bact. typhosum O and Bact. paratyphosum B O. Cross-relations with Bact. paratyphosum A, Bact. london and, to a less extent, Bact. paratyphosum C, were common in the typhoid sera. Otherwise there was no evidence of relation amongst the somatic groups tested.

The response to T.A.B. inoculation of fifteen individuals suggested also the relation of some organism in the vaccine to Bact. london and its probable lack of relation to the other somatic groups.

There was no evidence of increased frequency of Salmonella agglutinins in tuberculous cases.

The cross-relations of the Salmonellas was found to be due to the possession of minor antigenic components and not to possession of X antigen, which was absent from the suspensions used. X agglutinins were not more frequent in the pathological than in the Wassermann sera.

The relation of these findings to the diagnostic agglutination test is discussed, and the possibility of error consequent upon the use of suspensions containing X antigen is pointed out.

Salmonella is the second most commonly reported human foodborne pathogen in England and Wales, and antimicrobial-resistant strains of Salmonella are an increasing problem in both human and veterinary medicine. In this work we used a generalized linear spatial model to estimate the spatial and temporal patterns of antimicrobial resistance in Salmonella Typhimurium in England and Wales. Of the antimicrobials considered we found a common peak in the probability that an S. Typhimurium incident will show resistance to a given antimicrobial in late spring and in mid to late autumn; however, for one of the antimicrobials (streptomycin) there was a sharp drop, over the last 18 months of the period of investigation, in the probability of resistance. We also found a higher probability of resistance in North Wales which is consistent across the antimicrobials considered. This information contributes to our understanding of the epidemiology of antimicrobial resistance in Salmonella.