The nature of the ringworm flora of Birmingham over 17 years was investigated and tabulated by species, geographical distribution and concentration.

The rise and fall of such outbreaks as occurred has been charted.

The persistent preponderance of zoophilic species, in spite of the recent decline in over-all incidence, has been demonstrated.

The genomes of 34 recent United Kingdom isolates of Neisseria meningitidis serogroup C were examined by restriction enzyme digestion and by conventional and pulsed-field gel electrophoresis (PFGE). Strains were assigned to groups on the basis of the Dice similarity coefficient; strains with values of >92% were considered to be clonally related. Twelve clones were identified by PFGE. Strains of two clonal groups predominated. Restriction endonuclease analyses using the ‘high frequency cleavage’ endonuclease Stu I and conventional electrophoresis gave 11 groups; in general it had lower resolving power than PFGE.

Identification of priority populations such as men who have sex with men (MSM) is important in surveillance systems to monitor trends of sexually transmitted infections (STIs). We explored using routinely collected non-behavioural data as a means to establish MSM status in surveillance by assessing anorectal swab as a marker of male-to-male sexual exposure. We used chlamydia testing data from a sexual health clinic, 2007–2012. Men reporting any male sexual partner(s) in the previous 12 months were considered MSM. The dataset was split into development and validation samples to develop a univariate predictive model and assess the model fit. The dataset included 30 358 individual men and 48 554 episodes of STI testing; 45% were among reported MSM and an anorectal swab was performed in 40% of testing episodes. Anorectal swabbing had good diagnostic performance as a marker for MSM status (sensitivity = 87%, specificity = 99%, positive predictive value = 98·6%, negative predictive value = 90·3%). The model showed good fit against the internal validation sample (area under the curve = 0·93). Anorectal swabs are a valid marker of MSM behaviour in surveillance data from sexual health clinics, and they are likely to be particularly useful for monitoring STI trends among MSM with higher risk behaviour.

Pre-existing health conditions may exacerbate the severity of coronavirus disease 2019 (COVID-19). We aimed to estimate the case-fatality rate (CFR) and rate ratios (RR) for patients with hypertension (HBP) and diabetes mellitus (DM) in the New York state. We obtained the age-specific number of COVID-19 confirmed cases and deaths from public reports provided by the New York State Department of Health, and age-specific prevalence of HBP and DM from the Behavioral Risk Factor Surveillance System 2017. We calculated CFR and RR for COVID-19 patients with HBP and DM based on the reported number of deaths with the comorbidity divided by the expected number of COVID-19 cases with the comorbidity. We performed subgroup analysis by age and calculated the CFR and RR for ages of 18–44, 45–64 and 65+ years, respectively. We found that the older population had a higher CFR, but the elevated RRs associated with comorbidities are more pronounced among the younger population. Our findings suggest that besides the elderly, the young population with comorbidity should also be considered as a vulnerable group.

The growth of vaccinia and cowpox in RK13 cells was studied by measurement of infective virus production, gel diffusion and haemagglutination. The effects of virus growth inhibitors on the normal course of infection were then followed. Although the results with the two viruses were essentially similar some differences were detected between them. Inhibitors of DNA synthesis permitted production of many virus-specific soluble antigens. Compounds which inhibit DNA function and compounds that affected energy-yielding reactions had more dramatic effects. The different results obtained suggested that the synthesis of virus-specific materials was sequential and a possible part of the sequence is suggested.

The Phene Plate system for typing Salmonella serotypes (PhP-S) is a simple automated typing method based on biochemical fingerprinting. It gives a quantitative value of the metabolism of various substrates by measuring the speed and intensity of each reaction. The ‘biochemical fingerprint’ of each isolate is used to calculate similarities among the tested strains with a personal computer program. We used this system to examine a collection of 86 strains of Salmonella enteritidis isolated from human sporadic cases in Germany between 1980 and 1992. Twenty-three biochemical phenotypes (BPTs) consisting of 9 common (C) and 14 single (S) BPTs were identified. BPTs C2 and C4 containing 20 and 36 strains respectively accounted for 65% of the isolates. Strains of BPT C2 were found over a wide period of time whereas strains of BPT C4 were isolated during the period between 1988 and 1992. With phage typing, 11 discrete phage types (PTs) and 18 strains designated as non-specific type (NST) were identified. PTs 4 and 8 with 39 and 17 strains respectively were the dominant PTs. Strains of PT 8 were isolated over a wide period of time whereas all (except one) strains of PT 4 were isolated between 1988 and 1992. Combination of biochemical fingerprinting and phage typing divided the strains into 25 phenotypes (BPT:PTs). Whilst phenotype C2:8 was found over a number of different years, phenotype C4:4 was isolated only between 1988 and 1992. These findings indicate the presence of one persistent and one recently emerged phenotype among S. enteritidis strains in Germany. Although both methods identified the presence of both major and less common types, biochemical fingerprinting with the PhP-S system also provided information about relationships between the strains.

The morphology of faecal microflora of nine healthy human volunteers was studied by digital image analysis of microscopic slides. Weekly specimens were collected during an 8-week period. Seven morphometrical parameters were derived: the means and medians of components 1, 2 and 3, and morphometrical entropy. Statistically significant differences among subjects were found for means of components 1 and 2, medians of components 1, 2 and 3, and entropy. The stability in normal circumstances provides an excellent basis for the detection of pathological change in gut flora balance.

A survey of the coverage, distribution and the factors associated with use of influenza and pneumococcal vaccines among general practitioners (GPs) in primary care and in hospital settings was carried out in 53 general practices in Scotland taking part in the ‘Continuous Morbidity Recording’ (CMR) programme. The annual vaccine distribution increased substantially among 53 general practices from 1993 to 1999 and in Scotland as a whole from 1984 to 1999. From the questionnaire, overall coverage was 43% (95% CI 38–48) for influenza vaccine in the 2000–1 season and 13% (95% CI 9–16) for pneumococcal vaccine in the last 5 year period, in high-risk patients recommended for these vaccines by the Department of Health (DoH). Influenza vaccine coverage was highest in the elderly (65 years of age and above) at 62% (95% CI 59–74). Although pneumococcal vaccination is not currently recommended for all elderly, coverage of this vaccine was also higher in this group (22%, 95% CI 16–29). In the majority of patients (influenza vaccine, 98% and pneumococcal vaccine, 94%), vaccination was carried out in general practice. Only 2% of patients had received pneumococcal vaccination in a hospital setting. The level of influenza and pneumococcal vaccination varied with the level of deprivation. Most GPs considered that the responsibility for influenza and pneumococcal vaccination lay with them. Forty-five percent of GPs reported having a written policy with set target for influenza vaccination and 11% for pneumococcal vaccination.

We have been able to confirm all the experimental results of Felix and his collaborators in regard to the Vi antigen and its significance in mouse infections. In the interpretation of some of the findings we are, however, not quite in agreement with Felix.

When large doses of living V forms of typhoid bacilli are injected into the mouse they cause acute intoxication followed by death within 2 days—if the animals die. Surviving animals are clinically healthy after this time, often earlier, but they are nevertheless found to be massively infected in the organs and blood for several days.

When smaller, non-intoxicating, doses are used it is not possible to demonstrate any difference between the V form and the W form of the same strain in regard to the severity of the infection they cause; so that we may conclude that the Vi antigen plays no part in the virulence of the typhoid bacillus in the mouse. (Remember in this connexion that the dysentery bacillus is also very toxic for mice injected in large doses, while its virulence, i.e. the ability to grow in the mouse is = 0; but when rapidly fatal doses are used a massive growth of dysentery bacilli can also be demonstrated here, the cause being that the natural immunity has become partly neutralized by the intoxication.)

Like Felix we find that only the V form can be used both for active vaccination and the production of sera which protect against lethal doses of V forms in mouse experiments. We consider that this is due to the antitoxic effect. Our experiments show that the anti-bacterial effect in vaccination experiments differs little whether the V or the W form is used as vaccine, so long as the vaccinal effect is tested with non-toxic doses of bacilli. As shown in earlier experiments, the bactericidal effect in actively vaccinated animals is often a relatively slow process.

Only the Vi antibody containing sera can protect prophylactically with certainty against the toxic effect of living typhoid bacilli. On the other hand; the bactericidal effect prophylactically of 0 and 0 + Vi sera is very similar when tested against non-toxic doses of “virulent” typhoid bacilli.

The therapeutic value of potent Vi sera under the experimental conditions given was nil.

A five year collaborative study of influenza in volunteer families from 1973–78 covered a period in which there were outbreaks every year but no major epidemics of influenza. Volunteers over the age of 15 years were bled before and after each of the five winters, and virus isolation was attempted from as many as possible when they reported episodes of illness. Children under 15 in the volunteer families were also swabbed when they were ill. Although most families experienced one or more attacks by influenza viruses, there was little transmission within families.

The factors influencing the rate of progress in Echinococcus granulosus control in New Zealand were analysed by hydatid control area using stepwise multiple regression techniques. The results indicated that the rate of progress was related positively to initial E. granulosus prevalence in dogs and the efficiency with which local authorities implemented national control policy, and negatively to the Maori proportion in the local population and the number of dogs per owner. Problems in analysis of the New Zealand data are discussed and improved methods of monitoring progress in hydatid disease control programmes are described.

In a previous communication the authors drew attention to the occurrence of complement-fixation by normal serum along with various non-antigenic substances, and recorded the results of a study of this phenomenon with particular reference to the serum principle or principles concerned in the reaction (Mackie and Finkelstein, 1928). Though no conclusive interpretation of the results could be offered, a close analogy was established between the reacting agent of the serum and a natural antibody, e.g. a natural haemolysin, and the observations appeared to be of significance in relation to natural immunity phenomena.

This study describes the incidence rate of reported lymphogranuloma venereum (LGV) in men who have sex with men (MSM) in Barcelona from 2007 to 2012. Epidemiological, clinical and sexual behaviour characteristics of LGV cases are described. Seroadaptive behaviours as a transmission risk factor were assessed by a telephone questionnaire during 2012. Data were handled on a strictly confidential basis. LGV annual rate ratios in MSM were compared with cases from 2007. Differences were statistically analysed with a Poisson test. The incidence rate of LGV in MSM aged 15–69 years ranged from 32·1/105 MSM per year in 2007 to 182·7/105 MSM per year in 2012. In 2012, 31/51 LGV cases (61%) answered the telephone questionnaire, of which 84% (26/31) were HIV positive, 39% (12/31) reported having sex according to their partners’ serostatus and 7% (2/31) used strategic positioning. The incidence of LGV has increased since 2007 and mainly affects HIV-positive MSM. It is probable that seroadaptation has facilitated LGV transmission.

The anticoagulant rodenticide flocoumafen was evaluated against Rattus rattus and Bandicota bengalensis, In no-choice 24 h feeding tests 100% mortality occurred at 0·00125% concentration of the poison in the bait in the case of B. bengalensis and at 0·00375% in R. rattus. Feeding of 0·0025% poison bait in 1-day, no-choice and 2-day choice tests resulted in 60% and 75% mortality of R. rattus, respectively, and 100% of B. bengalensis. The differences between the consumption of plain food in the pretreatment period and of poison bait in no-choice tests were non-significant, except in one case. The rodents consumed significantly more (P < 0·01) poison bait than the plain alternative in the choice trials. Median period of survival and its 95% confidence limits of R. rattus and B. bengalensis, at the 100% mortality dose levels of the poison, were 6·3 (5·04–7·88) and 6·2 (4·92–7·81) days respectively.

Ringtail in infant rats is shown to depend on humidity over a wide temperature range. It is not due to infection or diet, but probably to chronic cooling by evaporation, convection and conduction.

Rats should either be bred in cages with solid floors, or else be given environmental conditions resembling those in the natural nest, which keep the young at a low saturation deficit during the early post-natal period.

I am glad to express my thanks to M. Potter, Senior Animal Technician, for his invaluable aid in keeping the records of the experimental programmes, and to G. Dimmock for his help in building and maintaining apparatus. I am also grateful to the University of London for the loan of a Cambridge portable potentiometer.

Coliforms were readily obtained from many soils. In samples taken from sites exposed to animal contamination Bact. coli type I occurred predominantly. A large number of samples taken from grassy banks, only remotely exposed to contamination, were found to contain intermediates. It was found that the greater the probable degree of contamination of the soil the higher was the proportion of Bact. coli type I, and that the less the probable degree of contamination the higher was the proportion of intermediates. It is difficult to explain this merely on the basis of the prolonged survival of intermediates in soil, and it would appear obvious that the source of these intermediates lay elsewhere than in animal faeces. The numbers in which they were found in soil, however, were not of the order expected of bacteria living in their natural environment, and consequently it was equally difficult to conclude that these intermediates were actively established in soil.

The effectiveness of calciferol (vitamin D2) against Rattus norvegicus was investigated in field trials on twenty-three farms with rat infestations partly resistant to warfarin. At 0·01% combined with warfarin at 0·025% no rodenticidal effect of the calciferol was discernible. At 0·025% with warfarin at the same concentration, results were better, but not appreciably better than is often obtained with warfarin alone against resistant rat populations. When the concentration of calciferol was stepped up to 0·1%, four out of five treatments in which the poison was applied directly gave complete control. The fifth may have partly failed because of poison shyness caused by under-baiting. Five out of six more treatments done after ‘pre-baiting’ were also successful. The sixth failed for reasons unconnected with the choice of poison.

Six further infestations that were not responding adequately to warfarin treatments were quickly controlled when, in three instances, calciferol at 0·1% was used instead and, in three more, it was used together with warfarin. It is concluded that calciferol at 0·1% is an effective poison against R. norvegicus either combined with warfarin or not, but that because at 0·1% its effect is subacute rather than chronic, there may be a case in some environments for using it only after pre-baiting.

Helicobacter pylori culture on gastric biopsy was performed on 4964 subjects aged <18 years from 1988 to 2007 at a central laboratory in Brussels. The total number of biopsies increased markedly from 941 in 1988–1993 to 1608 in 2004–2007. Biopsies were repeated at least once for 922 subjects (603 initially negative and 319 initially positive for H. pylori). Persistence rate of H. pylori at 1 year after initial positive biopsy was greater in the 1998–2007 cohort than in the 1988–1997 cohort (72·7% vs. 45·8%, P = 0·002), suggesting a tailored selection of candidates for biopsy with non-invasive tests (13C urea breath test). Of 68 subjects initially positive and re-examined subsequently after a documented cure, re-infection/relapse rate was 48·6% within 5 years post-elimination of H. pylori. Acquisition rate over 10 years follow-up in the initially negative cohort (603 patients) was 38·7% (re-infection/relapse vs. acquisition: P < 0·001). Multivariate analysis showed a fourfold greater risk of H. pylori acquisition in children of non-European origin vs. European origin (P < 0·001). Clarithromycin and metronidazole susceptibility were determined in 226 and 223 paired positive cultures in cases of re-infection/relapse or persistence. An initial non-susceptibility profile was highly predictive of a subsequent non-susceptibility profile, and the non-susceptible proportion increased markedly from 13·3% to 21·2% for clarithromycin (P < 0·001) and from 27·3% to 35·0% for metronidazole (P = 0·014), with no difference regarding European or non-European origin.

The epidemiology and transmission dynamics of sheep scrapie is as yet poorly understood. Here we present a theoretical analysis of the transmission dynamics within a sheep flock, concentrating on how persistence properties depend on transmission scenario and flock size. Patterns of disease persistence and extinction are studied analytically using branching-process approximations and numerically using stochastic model simulations. For a given basic reproduction number, disease extinction is most likely when late-stage infected animals are responsible for most of the transmission. This effect can be understood in terms of aggregation in the distribution of the number of secondary infections arising from a single primary infection. The presence of an environmental reservoir reduces the probability of extinction.

Following an outbreak of 2009 pandemic influenza A (H1N1) at a residential summer camp for boys aged 10–16 years, we assessed secondary household transmission of the novel virus after their return home. Of 212 study participants who attended camp, 49 had confirmed or probable influenza for a primary attack rate of 23%. Of 87 exposed household contacts who did not attend camp, only three instances of probable transmission were observed, for a household secondary attack rate of 3·5%. All secondary cases occurred in households where the ill camp attendee returned home 1 day after onset of illness, with an attack rate of 14·3% in household contacts in this category. Returning home after peak infectivity to others and advanced warning prior to reintegration of sick individuals into the household probably contributed to the overall low secondary attack rate observed.