Mass gatherings are believed to increase the transmission of infectious diseases although surveillance systems have shown a low impact. The Catholic Jubilee was held in Rome, Italy in 2000. We conducted a case-control study to analyse the risk factors of giardiasis among residents. All diseases reported to the laboratory surveillance system from January 2000 to May 2001 were compared with hospital controls concurrently selected in the same season as cases and frequency-matched for age and birth country. Fifty-two cases (44·1%) and 72 controls were enrolled. In the multivariable analysis factors associated with giardiasis among adults were: travelling abroad (OR 24·2, P>0·01), exposure to surface water (OR 4·80, P=0·05), high educational level (OR 3·8, P=0·03). Having a maid from a high-prevalence country was independently associated (OR 2·3) although not statistically significant. This is the only exposure that changed during the Jubilee.

In early March 2020, a COVID-19-outbreak occurred in the district of Tirschenreuth, Germany. The outbreak was characterised by a rapid increase in case numbers and a comparatively high crude case fatality ratio (CFR; 11%). Until the beginning of May 2020, 1122 cases were reported in the district. To investigate the outbreak, we analysed surveillance and other data available at the district health department, including data on cases living in care facilities and public health measures applied. Furthermore, we compared the number of tests performed in Tirschenreuth and in Germany as a whole. We interviewed the first 110 cases in order to investigate potential exposures at the beginning of the outbreak. We found that returning ski-travellers from Austria and Italy and early undetected community transmission likely initiated the outbreak which was then accelerated by Bavarian beer festivities. Testing of mainly acute cases in the district of Tirschenreuth resulted in a higher rate of positive tests compared to the whole of Germany. Despite adjustment for age, the CFR continued to exceed the German mean which was due to spread to vulnerable populations. Strict public health measures likely contributed to control the outbreak by mid-April 2020.

A survey of Coxiella burnetii infection (Q fever) in sheep flocks and goat herds in Great Britain was undertaken. A total of 5791 sheep (384 flocks) and 522 goats (145 herds) were examined for C. burnetii antibodies using an ELISA. Overall, 53 sheep (37 flocks), and four goats (four herds), tested positive. Estimates of individual animal, between-flock/-herd and within-flock/-herd crude prevalences were 0·9%, 10·2% and 9·0%, respectively, for sheep, and 0·8%, 3% and 26·3%, respectively, for goats. With sheep, the likelihood of an animal testing positive increased with total flock size (P = 0·002) and number of breeding ewes in the flock (P = 0·021). It also increased with number of goats within a 10 km radius (P = 0·038). There was no evidence for spatial clustering of positive herds above that expected by chance alone. No analysis of risk factors was attempted for goats because of the paucity of positives.

Eighteen strains of Campylobacter sputorum bv. paraureolyticus (isolated over a 12-month period from seven dairy cows contained in a single herd) were examined by resistotyping, and macrorestriction profiling using pulsed field gel electrophoresis (PFGE). The resistotypes of these strains were identical, although repeat testing indicated resistance to metronidazole was not a reliable trait for typing purposes. Five SmaI-derived genotypes were identified among the 18 strains. In 5 of 7 cows, isolates obtained from the same animal, but from different time periods, were genotypically indistinguishable, indicating persistence of infection. Macrorestriction profiles of 5 strains representing the 5 SmaI genotypes and 8 other strains of C. sputorum from various sources, were prepared using 4 endonucleases (SmaI, SalI, BamHI and KpnI). The only other strain of C. sputorum bv. paraureolyticus examined (a Canadian isolate from human faeces), was found to have a SmaI macrorestriction profile identical with one of the five clones isolated from the cattle. Moreover, SalI and BamHI profiles of all bv. paraureolyticus strains were similar, while digestion with KpnI was not observed. By contrast, the seven strains of C. sputorum bv. sputorum yielded various macrorestriction profiles with all the enzymes used, and features distinguishing the two biovars studied could be identified. This study indicates that C. sputorum can persist in cattle for at least 12 months and exhibits a clonal population genetic structure.

By using neutralization, complement fixation and immunogel-diffusion tests, it has been demonstrated that cross-reactions occur between various avian pox viruses and between sheep pox and goat pox viruses. No such reactions were demonstrated between avian pox viruses and vaccinia virus or between avian pox and sheep pox and goat pox viruses. Furthermore, no serological relationship was demonstrable between vaccinia virus and sheep pox and goat pox viruses.

Aboriginal communities in Northern Australia with high rates of group A streptococcal (GAS) skin infection in childhood also have high rates of renal failure in adult life. In a cross-sectional study of one such high risk community, albuminuria was used as a marker of renal disease. The prevalence of albuminuria increased from 0/52 in subjects aged 10–19 years to 10/29 (32·9%) in those aged 50 or more (P<0·001). Antibodies to streptococcal M protein, markers of past GAS infection, were present in 48/52 (92%) at ages 10–19 years, 16/32 (50%) at ages 30–39, and 20/29 (69%) in those aged 50 or more. After allowing for the age-dependencies of albuminuria and of M protein antibodies (P<0·001) albuminuria was significantly associated with M protein antibodies (P<0·01). Thus, 72% of adults aged 30 or more with M protein antibodies also had albuminuria, compared with only 21% of those who were seronegative. More detailed modelling suggested that although most Aboriginal people in this community developed M protein antibodies following GAS infection in childhood, the development of proteinuria was associated with the persistence of such seropositivity into adult life. The models predicted that proteinuria developed at a mean age of 30 years in seropositive persons, at 45 years in seronegative persons who were overweight, and at 62 years in seronegative persons of normal weight. We demonstrated a clear association between evidence of childhood GAS infection and individual risk of proteinuria in adult life. This study provided a strong rationale for prevention of renal disease through the more effective control of GAS skin infections in childhood and through the prevention of obesity in adult life.

Antibiotic susceptibilities of large cohorts of Enterobacteriaceae isolated from urine collected in the community are scarce. We report the susceptibilities of Enterobacteriaceae isolated from urine of non-selected community populations in a metropolitan area (Leeds and Bradford, UK) over 2 years. Isolates (n = 6614) were identified as follows: Escherichia coli (n = 5436), Klebsiella spp. (n = 525), Proteus mirabilis (n = 305), and 15 other species (n = 290); 58 isolates were unidentified. Ampicillin resistance was observed in 53% E. coli and 28% P. mirabilis; ⩾34% E. coli and P. mirabilis were non-susceptible to trimethoprim compared to 20% Klebsiella spp.; nitrofurantoin resistance was observed in 3% E. coli and 15% Klebsiella spp. The occurrence of extended-spectrum β-lactamases (ESBL) was low (6%), as was non-susceptibility to carbapenems, cefipime and tigecycline (<2%). Further surveillance is required to monitor this level of resistance and additional clinical studies are needed to understand the impact on the outcome of current empirical prescribing decisions.

We describe recent epidemiological changes in salmonellosis. Linking 1968–2000 National Salmonella Surveillance System to census data, we calculated population-based age- and sex-stratified rates of non-urinary salmonellosis for the top 30 non-typhoidal serotypes. Using 1996–1997, 1998–1999, and 2000–2001 population-based FoodNet surveys, we compared reported diarrhoea, medical visits, and stool cultures. Despite an overall female-to-male incidence rate ratio (FMRR) of 0·99, the sex-specific burden of salmonellosis varied by age (<5 years FMRR 0·92; 5–19 years 0·85; 20–39 years 1·09; 40–59 years 1·23, and ⩾60 years 1·08) and serotype (FMRR range 0·87 for Mississippi to 1·25 for Senftenberg). Serotype-specific FMRRs and median age (range 2 years for Derby to 29 years for Senftenberg) were related (correlation 0·76, P<0·0001). Recently, the relative burden of salmonellosis in women has increased. FoodNet data suggest that this change is real rather than due to differential reporting. Excess salmonellosis in women may reflect differences in exposure or biological susceptibility.

In August 2008 an outbreak of Salmonella Typhimurium DT104 occurred in South West London. Sixteen cases were identified with a particular multilocus variable number tandem repeat analysis (MLVA) pattern. In a matched case-control study 14 primary cases were included. These were defined as individuals with gastrointestinal symptoms and Salmonella Typhimurium DT104 isolated from a stool specimen, with a characteristic antibiotic resistance profile and MLVA pattern, and diagnosed in a local laboratory. Four controls per case were matched on age, gender and area of residence. Cases were 26 times more likely than controls to have eaten beef biltong, a South African speciality meat product (odds ratio 25·83, 95% confidence interval 4·92–135·59, P < 0·01). Although environmental investigation failed to identify Salmonella in the food product we conclude that beef biltong consumption led to this outbreak. This conclusion has importance in informing the ongoing risk assessment relating to uncontrolled foodstuffs.

All seven series give answers in the same sense, and we may conclude that we have definite experimental evidence that fatness increases the susceptibility to death from caisson disease. The regularity of the results in the guinea-pig experiments suggests that fatness is here the predominant influence in individual susceptibility. The difference in weight between the “survived” and ‘died” is not always in the same sense, and is in no case very large. The weight factor may therefore be relatively excluded in considering these results : indirectly it is of influence in that rats, like men, tend to become fatter as they grow older. Our results show pretty clearly that females are fatter than males, and, in the guinea-pig series, much more susceptible. Femality, like age, is not a quality which can per se have any influence on susceptibility. The increased susceptibility of females is probably simply due to their increased fatness, which tends to further increase during pregnancy. With regard to symptoms other than death our evidence is very meagre. Some symptoms, e.g. bends, may be presumed to be independent of fatness.

The Philippines confirmed local transmission of COVID-19 on 7 March 2020. We described the characteristics and epidemiological time-to-event distributions for laboratory-confirmed cases in the Philippines recorded up to 29 April 2020 and followed until 22 May 2020. The median age of 8212 cases was 46 years (IQR 32–61), with 46.2% being female and 68.8% living in the National Capital Region. Health care workers represented 24.7% of all detected infections. Mean length of hospitalisation for those who were discharged or died were 16.00 days (95% CI 15.48–16.54) and 7.27 days (95% CI 6.59–8.24). Mean duration of illness was 26.66 days (95% CI 26.06–27.28) and 12.61 days (95% CI 11.88–13.37) for those who recovered or died. Mean serial interval was 6.90 days (95% CI 5.81–8.41). Epidemic doubling time prior to the enhanced community quarantine (ECQ; 11 February and 19 March) was 4.86 days (95% CI 4.67–5.07) and the reproductive number was 2.41 (95% CI 2.33–2.48). During the ECQ (20 March to 9 April), doubling time was 12.97 days (95% CI 12.57–13.39) and the reproductive number was 0.89 (95% CI 0.78–1.02).

A comparison of five methods of cleaning Formica surfaces contaminated with bacteria dried in milk has been carried out. A standardized procedure was developed, and impression plates were found to be at least as sensitive as a swab-rinse method for detecting bacteria on the surfaces. The most satisfactory results were obtained with one type of disposable alcohol-impregnated wipe and with a detergent/hypochlorite solution applied with paper. A reusable cloth impregnated with disinfectant initially performed well against all test organisms, but was less reliable against Staphylococcus aureus and Streptococcus faecalis after the cloth had been used and rinsed several times. The importance of introducing methods to reduce the high risk of cross–contamination presently associated with the use of wiping cloths in catering premises is stressed.

To characterize the association between county-level risk factors and the incidence of mumps in the 2006 Iowa outbreak, we used generalized linear mixed models with the number of mumps cases per county as the dependent variable. To assess the impact of spring-break travel, we tested for differences in the proportions of mumps cases in three different age groups. In the final multivariable model, the proportion of Iowa's college students per county was positively associated (P<0·0001) with mumps cases, but the number of colleges was negatively associated with cases (P=0·0002). Thus, if the college students in a county were spread among more campuses, this was associated with fewer mumps cases. Finally, we found the proportion of mumps cases in both older and younger persons increased after 1 April (P=0·0029), suggesting that spring-break college travel was associated with the spread of mumps to other age groups.

The results just described for Greater London compare very favourably with those of similar surveys carried out in the United States by Hopkins & Kelly (1919), Smith (1923), and Layson, Huffer & Brannon (1936) (see also Report, 1934). The figures recorded in Table 7 show that approximately 50% of bottles from the large, the small rotary, and the steam sterilization plants conformed to a standard of less than 600 colonies per pint bottle, or approximately 1 colony per ml. capacity.

The figures for the small rotary plants were not so good as for the large plants, there being a greater proportion of high counts among these. The same was even truer of the steam sterilization plants, in which about a quarter of the bottles were grossly contaminated. The results with the plants using hand-washing only were bad, none of them falling below the 2500 mark.

The general conclusions to be drawn from this survey are that equally good results may be obtained in large or in small rotary plants relying on treatment with hot caustic detergent as in plants employing steam sterilization, and that the uniformly best results are obtained in properly designed and operated plants of the spray type.

Seroconversion illness is known to be associated with more rapid HIV disease progression. However, symptoms are often subjective and prone to recall bias. We describe symptoms reported as seroconversion illness and examine the relationship between illness, HIV test interval (time between antibody-negative and anibody-positive test dates) and the effect of both on time to AIDS from seroconversion. We used a Cox model, adjusting for age, sex, exposure group and year of estimated seroconversion. Of 1820 individuals, information on seroconversion illness was available for 1244 of whom 423 (34%) reported symptomatic seroconversion. Persons with a short test interval ([les ]2 months) were significantly more likely to report an illness than people with a longer interval (OR 6·76, 95% CI 4·75–9·62). Time to AIDS was significantly faster (P=0·01) in those with a short test interval. The HIV test interval is a useful replacement for information on seroconversion illness in studies of HIV disease progression.

The use of a gamma radiation process for the elimination of Salmonella from frozen meat is considered with particular reference to the treatment of boned-out horsemeat and kangaroo meat imported into the UK and intended for use as pet meat.

Examination of dose/survival curves produced for several serotypes of Salmonella in frozen meat shows that a radiation dose of 0·6 Mrad. will reduce a population by at least a factor of 105. The influence on the radiation resistance of salmonellas of such factors as preirradiation growth in the meat and temperature during irradiation have been examined and considered. It is also demonstrated with both preinoculated and naturally contaminated meat that postirradiation storage in the frozen state does not lead to the revival of irradiated salmonellas.

The properties of Salmonella survivors deliberately produced in meat using conditions of irradiation designed to simulate a commercial process are studied after six recycling treatments through the process. There were no important changes in characteristics normally used for identification of Salmonella but radiation resistance was lowered. Survivors grown in situ in meat after irradiation showed an abnormally long lag phase, and removal of competitive microflora in meat by the radiation treatment can influence the growth of salmonellas.

Dengue is regarded as the most important arboviral disease. Although sporadic cases have been reported, serotypes responsible for outbreaks have not been identified from central India over the last 20 years. We investigated two outbreaks of febrile illness, in August and November 2012, from Korea district (Chhattisgarh) and Narsinghpur district (Madhya Pradesh), respectively. Fever and entomological surveys were conducted in the affected regions. Molecular and serological tests were conducted on collected serum samples. Dengue-specific amplicons were sequenced and phylogenetic analyses were performed. In Korea and Narsinghpur districts 37·3% and 59% of cases were positive, respectively, for dengue infection, with adults being the worst affected. RT–PCR confirmed dengue virus serotype 1 genotype III as the aetiology. Ninety-six percent of infections were primary. This is the first time that dengue virus 1 outbreaks have been documented from central India. Introduction of the virus into the population and a conducive mosquitogenic environment favouring increased vector density caused the outbreak. Timely diagnosis and strengthening vector control measures are essential to avoid future outbreaks.

The development of the molluscum body and of the molluscum contagiosum virus is described. All cells of the molluscum lesion do not form molluscum bodies, but those which do probably show cytoplasmic abnormality prior to the appearance of virus particles within the cytoplasm. Such abnormal cells may reflect the activity of some infective precursor of the morphologically observable virus particle; they may alternatively represent cells which have successfully resisted invasion by the infective precursor.

Cells which have failed to resist invasion gradually become filled with virus particles and the nucleus becomes eccentric. The molluscum body thus formed is virtually a bag of virus particles, the wall of the bag being the peripheral cytoplasm, which seems to resist invasion and in which the nucleus remnant can readily be detected.

There appear to be two kinds of viruses. Development of the commoner virus is compared and contrasted with studies by Morgan and his colleagues of vaccinia and fowl pox. It is akin to fowl pox in its origin from foci of finely dispersed cytoplasm, here called cytoplasmic clouds; it is akin to vaccinia in that no evidence can be found of a denser, finely granular, pre-nucleoid material; it is like both in that the virus does not observably develop within the nucleus; and it is unlike both in that a nuclear change—the appearance of rather unspecific dense bodies—is seen. The structural changes seen in the virus particles during development are similar to those described by Morgan et al., but a slightly different interpretation is given of the behaviour of the transient ‘nucleoid’: they believe that it expands to form a central viroplasm, whereas in this paper it is believed to disperse through an already present central viroplasm.

The second type of virus is of uncertain origin. It may develop from, or at least it seems to be related to, a double-membrane structure seen in abnormal lesion cells.

Globally, twice as many men as women are being diagnosed with tuberculosis (TB) annually. Little is known about gender differentials in TB in Africa. A retrospective cohort analysis of routine data was conducted on adult TB patients treated between 2011 and 2012 in two large healthcare facilities in Nigeria. Gender differences in their demographic characteristics and treatment outcomes were analysed accordingly. Of 1668 TB patients enrolled, the male:female ratio was 1·4:1. The mean ages of males and females were 40·2 ± 14·7 and 36·1 ± 14·6 years, respectively (t test 6·62, P < 0·001). Male gender was associated with a higher failure to smear convert after 2 months (21·8% vs. 17·5%, P = 0·06) and 5 months (4·3% vs. 1·5%, P = 0·02) of treatment for smear-positive TB patients. Moreover, men were more likely than women to fail treatment (2·2% vs. 0·7%, P = 0·01). No significant differences exist in the treatment success rates between women and men (78·2% vs. 74·5%, P = 0·08). Adjusted analyses showed significant association between being an urban male and a HIV-infected female with unsuccessful outcome adjusted by socio-demographic and clinical factors. We found that gender disparities exist in TB profile and treatment outcomes in Nigeria and gender-specific strategies are needed to optimize TB management.

Phylogenetic analyses of bartonella have suggested divergence between bartonellae that infect mammals native to the Old and New Worlds. We characterized bartonella isolated from Eastern grey squirrels (Sciurus carolinensis) in the United States and from grey and red squirrels (Sciurus vulgaris) in the United Kingdom by nucleotide sequence comparison (gltA and groEL). Isolates from grey squirrels in the United States and the United Kingdom were identical, and most similar to Bartonella vinsonii, a species associated with New World rodents. A single and novel bartonella genotype was obtained from all 12 red squirrel isolates. Although grey squirrels were first introduced into the United Kingdom over 125 years ago, they continue to be infected solely by the bartonella associated with grey squirrels native to the United States. These results illustrate that exotic species may be accompanied by the introduction and maintenance, over many generations, of their microparasites.