The following account of a milk-spread epidemic of scarlet fever in the burgh of Elgin may be of interest to those who are at times faced with similar problems.

HISTORY

The number of cases of scarlet fever notified in the burgh each year from 1920 to 1938 is given in Table 1. This table also shows that the periods of

Table 1. Scarlet fever notifications, 1920–38

maximal incidence, centring on 1921, 1926 and 1934, are related roughly to the periods of maximal incidence of all cases in the area, which area includes the counties of Moray and Nairn and the burghs situated within the counties. A prolonged epidemic occurred in the whole area from 1933 to 1935, the age distribution of cases at different stages of that epidemic (Douglas, 1935) being given in Table 2. It is regretted that present circumstances do not permit of a more detailed analysis of the age and sex distributions of this epidemic. There was no evidence that the disease was spread by milk.

The isoquinoline compound UK 2054 prevents the uptake of influenza virus by susceptible cells. Pre-incubation of virus particles with 500μg./ml. UK 2054 at 37°C. for 2 hr. does not reduce virus infectivity. Host cells vary in their responsiveness to the inhibitory effect of UK 2054; virus multiplication is inhibited in chick allantoic cells by lower concentrations than those required to inhibit virus growth in chick embryo fibroblasts. The effectiveness of UK 2054 is reduced by the presence of serum.

It is concluded that inhibition of influenza virus multiplication by UK2054 might result from interaction of the inhibitor with both virus and cells. Any direct combination between inhibitor and virus is completely reversible.

1. The incidence of cross-infection with Str. pyogenes during a period of four months was compared in two blocks occupied by scarlet-fever patients. One block was nursed by the bed isolation method and the other by the ordinary method in current use for multiple-bed wards. 2. The rules for the bed isolation blook are given. 3. The incidence of cross-infection with Str. pyogenes among patients in the bed isolation block was 20·3%, that among patients in the ordinary block 22·6%. 4. We concluded that the bed isolation nursing technique practised was not effective in reducing cross-infection with Str. pyogenes among scarlet-fever patients. 5. A further test of bed isolation nursing was made for six months, using the extra precaution of vacuum-cleaning the floors. We found that crossinfection was still occurring, but the incidence could not be estimated since the Str. pyogenes strains isolated had to be destroyed at the outbreak of war. At this time the serological typing had not been completed. 6. The importance of dust-borne and droplet-borne infection in addition to that of contact infection is discussed. The type of investigation required to decide whether cross-infection in multiple-bed scarlet-fever wards can be eliminated by the methods at our present disposal is outlined.

Maternal infection in pregnancy is a known risk factor for adverse pregnancy outcome, and a number of zoonotic pathogens may constitute a risk to pregnant women and their fetuses. With animal contact as a proxy for the risk of zoonotic infection, this study aimed to evaluate pregnancy outcome in women with self-reported occupational or domestic contact with livestock compared to pregnant women without such contact. The Danish National Birth Cohort collected information on pregnancy outcome from 100 418 pregnant women (1996–2002) from which three study populations with occupational and/or domestic exposure to livestock and a reference group of women with no animal contact was sampled. Outcome measures were miscarriage, very preterm birth (before gestational week 32), preterm birth (before 37 gestational weeks), small for gestational age (SGA), and perinatal death. Adverse reproductive outcomes were assessed in four different exposure groups of women with occupational or domestic exposure to livestock with no association found between exposure to livestock and miscarriage, preterm birth, SGA or perinatal death. These findings should diminish general occupational health concerns for pregnant women with exposures to a range of different farm animals.

During four months' work with anaerobes, which were derived from wounds, a number of species have been noticed which appear to be hitherto undescribed. Two of these are proteolytic organisms and are not pathogenic to guinea-pigs when administered in large doses.

Graded doses of live and heat-killed cells of Campylobacter jejuni were injected into the yolk-sac of 5-day-old chick embryos, and the 50% lethal dose (LD50) was determined 7 days later. A strain dependent virulence was seen. In the diluted series of cultures the LD50 values for live campylobacter ranged from 106 c.f.u. beyond the last dilution showing growth, that is to less than one organism per embryo. When the 22 strains were tested as heat-killed cells, the chick embryo LD50 values retained the same relative order of toxicity obtained with viable cells, but the LD50 values were increased by + 1 to + 4 log units. Heat-killed cells from strains known to be invasive, but non-toxigenic, were still lethal for the embryos, suggesting that viability was not solely necessary for virulence. Semi-pure lipopolysaccharide from a non-virulent strain of C. jejuni was not toxic to the embryos, but semi-pure and ultracentrifuge-purified lipopolysaccharide from the most lethal campylobacter strains gave LD50 values in the order of 3·0 μg lipopolysaccharide per ml (0·6 µg per embryo) in the yolk-sac assay. No relationship between serotype and lethality was seen. Injection into the yolk-sac appears to be an easy, rapid and reproducible in vivo assay of the virulence of C. jejuni.

In experiments on survival of microbial aerosols, viability should be measured as early as possible in the life of the cloud, but this must not be used as the datum to which subsequent viabilities are related; all viabilities must be related to that of the material from which the cloud was generated. Mathematical models may be used as a convenience in expressing results, but observed viabilities must also be quoted.

I am indebted to the many colleagues whose work over the years has consolidated this approach, and particularly to Mr G. J. Harper whose experiments and thinking form the backbone of my discussion.

In Portugal, the recommended age for the second dose of MMR (MMR2) was changed from 10–13 years to 5–6 years for those born in 1994 and afterwards. This study aimed to assess if MMR schedule and time elapsed from the last dose are associated with the concentration of rubella and mumps IgG antibodies. Three Portuguese birth cohorts (convenience samples) were selected for this study (66, 59 and 41 participants born respectively in 1990–1993, 1994–1995 and 2001–2003). Geometric mean concentrations (GMC) for mumps IgG were respectively 36, 30 and 38 RU/ml (P = 0·236) and for rubella IgG were 18, 20 and 17 IU/ml (P = 0·641). For both specific antibodies, no differences were observed with time since MMR2. Receiving MMR2 at 5–6 or 10–13 years was not associated with concentration of both antibodies. The GMC of rubella IgG was lower in males (P = 0·029). Taking into account previous evidence and the logistics needed to change vaccination schedules, it seems reasonable that sustaining very high coverage with two doses of MMR is currently the most pragmatic way to control mumps and rubella rather than any changes to the schedule.

Multiply- and methicillin-resistant Staphylococcus aureus (MRSA) strains have been isolated from five small outbreaks of nosocomial infection in five different hospitals. The MRSA were typed by phage patterns, biochemical traits, resistance phenotypes and plasmid patterns. Three different groups of strains can be distinguished. The MRSA from three outbreaks in one country share identical characters.

Phage typing by the use of the International Basic Set for Phage Typing staphylococci as well as experimental phages does not completely discriminate between the strains. Attribution of several resistance determinants to plasmids in two of the described strain groups proved valuable for strain differentiation.

These multiply-resistant strains are sensitive to vancomycin and to rifampicin.

Records of absenteeism from primary schools are valuable data for infectious diseases surveillance. However, the analysis of the absenteeism is complicated by the data features of clustering at zero, non-independence and overdispersion. This study aimed to generate an appropriate model to handle the absenteeism data collected in a European Commission granted project for infectious disease surveillance in rural China and to evaluate the validity and timeliness of the resulting model for early warnings of infectious disease outbreak. Four steps were taken: (1) building a ‘well-fitting’ model by the zero-inflated Poisson model with random effects (ZIP-RE) using the absenteeism data from the first implementation year; (2) applying the resulting model to predict the ‘expected’ number of absenteeism events in the second implementation year; (3) computing the differences between the observations and the expected values (O–E values) to generate an alternative series of data; (4) evaluating the early warning validity and timeliness of the observational data and model-based O–E values via the EARS-3C algorithms with regard to the detection of real cluster events. The results indicate that ZIP-RE and its corresponding O–E values could improve the detection of aberrations, reduce the false-positive signals and are applicable to the zero-inflated data.

1. The nature of the probit-log survival-time relationship in the disinfection of standard cultures of Bact. coli at 51° C. at pH values ranging from 2·8 to 8·8 has been studied.

2. It is concluded that there is a very close approximation to a bilinear form in all cases, though there was evidence that a continuous curve concave upwards and to the left would provide a better fit.

3. Probit limits, corresponding to the range of percentage mortality within which, having regard to the experimental error involved, an observation might lie, have been worked out. The range covered by these probit limits decreases as the percentage mortality rises.

4. These limits have been used to decide whether a bilinear or a single straight line treatment should be applied to certain sets of data. It is suggested that they would often materially assist in deciding the range over which linearity may be assumed in any given case.

This study was conducted to determine the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Malaysian hospitals. A total of 264 MRSA isolates from eight hospitals were subjected to typing by pulsed-field gel electrophoresis (PFGE) of SmaI restricted DNA. Antibiotic disk susceptibility testing was also carried out to determine their resistance patterns. Thirty-one PFGE pattern types were identified. Three major pattern types A, ZC and K were found with type A the predominant profile in c. 80% of strains and present in all hospitals. Unlike type A, other DNA pattern types were unique to the hospitals in which they were isolated. PFGE type A also consisted of strains that were multiply antibiotic resistant. The presence of a single predominant PFGE type in Malaysian hospitals is an important finding which suggests that inter-hospital spread of MRSA had occurred frequently and regularly.

As the on-going severe acute respiratory syndrome coronavirus 2 pandemic, we aimed to understand whether economic reopening (EROP) significantly influenced coronavirus disease 2019 (COVID-19) incidence. COVID-19 data from Texas Health and Human Services between March and August 2020 were analysed. COVID-19 incidence rate (cases per 100 000 population) was compared to statewide for selected urban and rural counties. We used joinpoint regression analysis to identify changes in trends of COVID-19 incidence and interrupted time-series analyses for potential impact of state EROP orders on COVID-19 incidence. We found that the incidence rate increased to 145.1% (95% CI 8.4–454.5%) through 4th April, decreased by 15.5% (95% CI −24.4 −5.9%) between 5th April and 30th May, increased by 93.1% (95% CI 60.9–131.8%) between 31st May and 11th July and decreased by 13.2% (95% CI −22.2 −3.2%) after 12 July 2020. The study demonstrates the EROP policies significantly impacted trends in COVID-19 incidence rates and accounted for increases of 129.9 and 164.6 cases per 100 000 populations for the 24- or 17-week model, respectively, along with other county and state reopening ordinances. The incidence rate decreased sharply after 12th July considering the emphasis on a facemask or covering requirement in business and social settings.

The type identity of strains of Pseudomonas aeruginosa from primary and recurrent blood stream infection (BSI) has not been widely studied. Twenty-eight patients were identified retrospectively from 2008 to 2013 from five different laboratories; available epidemiological, clinical and microbiological data were obtained for each patient. Isolates were genotyped by iPLEX MassARRAY MALDI-TOF MS and rep-PCR. This showed that recurrent P. aeruginosa BSI was more commonly due to the same genotypically related strain as that from the primary episode. Relapse due to a genotypically related strain occurred earlier in time than a relapsing infection from an unrelated strain (median time: 26 vs. 91 days, respectively). Line related infections were the most common source of suspected BSI and almost half of all BSI episodes were associated with neutropenia, possibly indicating translocation of the organism from the patient's gut in this setting. Development of meropenem resistance occurred in two relapse isolates, which may suggest that prior antibiotic therapy for the primary BSI was a driver for the subsequent development of resistance in the recurrent isolate.

The second patient with Arizona gastroenteritis to be diagnosed in Britain had just returned from the United States, where his illness began.

In a cohort of 272 treatment-naive individuals with chronic hepatitis C infection acquired on a known date who were enrolled in the UK HCV National Register, a progressive improvement in response to treatment was found with the evolution of antiviral therapies from 20% (25/122) for interferon monotherapy to 63% (55/88) for pegylated interferon+ribavirin therapy. Multivariable analysis results showed increasing age to be associated with poorer response to therapy [odds ratio (OR) 0·84, 95% confidence interval (CI) 0·72–0·99, P=0·03] whereas time since infection was not associated with response (OR 0·93, 95% CI 0·44–1·98, P=0·85). Other factors significantly associated with a positive response were non-type 1 genotype (P<0·0001) and combination therapies (P<0·0001). During the first two decades of chronic HCV infection, treatment at a younger age was found to be more influential in achieving a sustained viral response than treating earlier in the course of infection.

There have not been wanting those who have alleged that isolation hospitals have failed to fulfil the object for which they were erected, inasmuch as scarlet fever has during the last few years been prevalent to an exceptional extent. Those who argue thus, are in favour of diminishing expenditure on the erection and maintenance of isolation hospitals, and consider that we must trust to “improved sanitation” for diminishing and possibly in the end annihilating infectious diseases.

The Schick test was carried out on 500 recently confined women and their new-born infants. The Schick reaction was positive in as many as 73 % of the mothers and in 60 % of their infants. The infants were positive reactors in 82% of all the cases in which their mothers were positive.

The reaction of the new-born infants was, as a rule, weaker than that of the mothers. It often happened that when the mother's reaction was faintly positive, her infant's reaction was negative.

When the mothers had been immunized with diphtheria toxoid, the overwhelming majority of both the mothers and their new-born infants were negative. Immunization of Schick-positive women with diphtheria toxoid during pregnancy is recommended as a preventive of diphtheria in infancy, as by this means the antitoxin level of the new-born infant can be raised.

We wish to acknowledge our indebtedness to Jörgen Lövset, M.D., chief physician, Hospital for Gynaecology and Obstetrics, Bergen, Norway, for permission to use the material for this investigation.

To assess areas at risk for poliovirus circulation in Ecuador, we first selected provinces at highest risk based on low immunization coverage with three doses of oral poliovirus vaccine, and a low number of reported cases of acute flaccid paralysis (AFP). Subsequently, we reviewed discharge data for the period 1996–2000 for diagnoses compatible with AFP in the only two national referral hospitals in Quito, and at least two main hospitals in each of the six selected provinces. Environmental samples from one or two cities/towns in each selected province were tested for poliovirus. Of the 14 identified AFP-compatible cases, 8 (57%) had been previously reported and investigated. We visited four out of the six unreported cases; none of those four had sequelae compatible with poliomyelitis. From the 14 environmental samples taken, we identified Sabin viruses in six of the samples; no vaccine-derived polioviruses were isolated. Using this methodology, we found no evidence of undetected poliovirus circulation in Ecuador.

In the period following the last war a large acceleration has occurred in the rate of decline of the death-rates of the younger age groups. The oldest age groups have not shared in this improvement. This course of the death-rates is in striking contrast to the predictions of two decades ago when it was thought that any substantial improvement in the age specific rates was most likely to occur at the older ages. A large part of the fall at younger ages has been due to the decrease in mortality from infectious diseases and tuberculosis. The death-rates at ages 5–24 are now probably almost at a minimum and if a further appreciable improvement is to be made in them the death-rate from violence must be reduced. Violent deaths account for roughly one-third of all deaths in this age range.