We assessed evidence of exposure to viruses and bacteria in an unmanaged and long-isolated population of Soay sheep (Ovis aries) inhabiting Hirta, in the St Kilda archipelago, 65 km west of Benbecula in the Outer Hebrides of Scotland. The sheep harbour many metazoan and protozoan parasites but their exposure to viral and bacterial pathogens is unknown. We tested for herpes viral DNA in leucocytes and found that 21 of 42 tested sheep were infected with ovine herpesvirus 2 (OHV-2). We also tested 750 plasma samples collected between 1997 and 2010 for evidence of exposure to seven other viral and bacterial agents common in domestic Scottish sheep. We found evidence of exposure to Leptospira spp., with overall seroprevalence of 6·5%. However, serological evidence indicated that the population had not been exposed to border disease, parainfluenza, maedi-visna, or orf viruses, nor to Chlamydia abortus. Some sheep tested positive for antibodies against Mycobacterium avium subsp. paratuberculosis (MAP) but, in the absence of retrospective faecal samples, the presence of this infection could not be confirmed. The roles of importation, the pathogen–host interaction, nematode co-infection and local transmission warrant future investigation, to elucidate the transmission ecology and fitness effects of the few viral and bacterial pathogens on Hirta.

The Limulus test detected endotoxins in the plasma of burned and unburned mice infected with different species of gram-negative bacteria. Individual strains of different species of gram-negative bacteria produced different amounts of endotoxin in the plasma of infected mice. Plasma from mice given lethal infections showed very high concentrations of endotoxin. Low concentrations of endotoxin in the plasma were tolerated by mice but high concentrations were invariably fatal. A polyvalent pseudomonas vaccine reduced endotoxin in the plasma of mice given lethal infections of Pseudomonas aeruginosa.

Vitamin D (VD) deficiency has been linked to increased incidence and morbidity of tuberculosis (TB). Chile has large variations in solar radiation (SR; a proxy of VD status) and high prevalence of VD deficiency in its southernmost regions with low SR. We investigated the correlation between regional SR and rates of TB incidence, admissions and deaths in Chile by reviewing national records on prospectively collected mandatory disease notifications, admissions and mortality between 2001 and 2011. Over the study period, 26 691 new TB notifications were registered. The TB incidence rate was 14·77 (95% confidence intervals (CIs) 14·60–14·95), admission rate was 12·12 (95% CI 11·96–12·28) and mortality rate was 1·61 (95% CI 1·55–1·67) per 100 000 population per year. Multivariable linear regressions adjusting for significant demographic TB risk factors in Chile (regional prevalence of HIV infection, rates of migration from TB-endemic countries and rates of imprisonment) revealed an independent and highly statistically significant inverse association between SR and TB incidence rate (β −1·05, 95% CI −1·73 to −0·36, P = 0·007), admission rate (β −1·58, 95% CI −2·23 to −0·93, P < 0·001), and mortality rate (β −0·15, 95% CI −0·23 to −0·07, P = 0·002). These findings support a potential pathogenic role of VD deficiency in TB incidence and severity.

Dishoeck (1935) confirmed the claim for the discovery of nose “opening” rays made by L. Hill (1932), a discovery denied by Dufton and Bedford (1933) and Winslow, Greenburg and Herrington (1934). By means of a blower fan and a well-fitting tube Dishoeck sends a stream of air through one nasal orifice and out through the mouth while the subject holds his breath. The input pressure of the air, meanwhile, is measured by a water manometer which is connected with the air tube just before this enters the nasal orifice. A few seconds suffices to secure such a reading. He calibrates the instrument by measurements made with glass tubes, each about the length of the nasal passage, viz. 6 cm., and fitted with varying diaphragmatic holes.

(1) Our experiments support the view that influenza is casued by B. influenzae, and that pneumococci and certain streptococci are the most important agents of secondary infections. No new type of bacterium was discovered, and no evidence was obtained of the presence of an ultra-micrascopic virus.

(2) B. influenzae appears more toxic for rabbits and mice when grown on fresh liver or kidney media than when grown on blood agar or in blood broth, and this is especially so when the kidney or liver is obtained from an animal of t he same species that has previously been inoculated with a culture of the influenza bacillus.

(3) Three fairly distinct special forms have been isolated from cultures of B. dysenteriae. They are probably not sexual units or stages in a true life cycle. Special large forms have also been obtained from cultures of B. influenzae, but these reverted back to the normal small type after several sub-cultures.

(4) A filter-passing material has been found associated with certain micro- cocci from vaccinia and in pure cultures of members of the dysentery-typhoid- coli group of bacteria. This material breaks down and dissolves the bacteria of the cultures, and the “infection” can be carried to fresh normal cultures. The evidence is against its being a living ultra-microscopic virus infecting the bacteria, but it may have some connection with the special forms. No definite evidence of a similar dissolving material has been found associated with cultures of the influenza bacillus.

(5) There is some indication that one or more of the forms isolated from pure cultures of dysentery bacilli may be special toxin-producing units, also that this function is at its maximum when the bacilli are first produced by the normal small forms or by sexual units of a normal culture. This may possibly be the case also with special forms that have been found in cultures of the influenza bacillus.

(6) It is believed that non-pathogenic wild varieties of ultra-microscopic viruses must exist in nature, and that they should present less difficulty in cultivation than the pathogenic varieties. Cultivations were made from filtrates of soil, faeces and water on various special media, and the tubes incubated in various gases. The chief gases tested either alone or mixed were oxygen, nitrogen, carbon dioxide and sulphuretted hydrogen. All the results were negative, but some interesting deposit colonies were obtained on media con taining a small quantity of sodium sulphide.

(7) The influenza bacillus grows in symbiosis with amoebae on blood agar, and in such cultures the bacillus lives considerably longer.

(8) The influenza bacillus grows in symbiosis with a small spirillum that was isolated from a grass emulsion, and in symbiosis with an extremely minute and delicate bacterium isolated from garden soil; after passing the emulsions through a Berkefeld filter. With these delicate bacteria the influenza bacillus will grow on media containing no blood, and if an egg medium is used the mixed growth is dense, heaped up and brownish in colour. In such cultures the in fluenza bacillus may live for months.

(9) The influenza and other bacilli will grow in an atmosphere of pure oxygen or pure carbon dioxide under diminished pressure.

The virulence of Pseudomonas aeruginosa appears to depend on both its ability to grow in the serum of animals and its ability to produce various types of extra-cellular toxins. No strain of Ps. aeruginosa lacking either of these qualifications was ever found to be virulent to animals.

The ability of various sera of animals to inhibit growth of Ps. aeruginosa appears to depend largely on their content of specific antibodies to each serological type of the surface antigens (the slime layer) and, therefore, susceptibility of animals to the infections of Ps. aeruginosa, even within one species, varies considerably from one individual to another.

This work was supported by a research career development award of the U.S. Public Health Service to the senior author (GM-K3–15).

The aim of this study was to assess the effects of reductions in the number of isolates tested by phage-typing on the recognition of outbreaks of salmonellosis. Five outbreaks (categorized as ‘small’, ‘medium’ or ‘large’) which occurred in England in 2005 were used as examples. The outbreaks were caused by serotypes which were subdivided by phage-typing. Results indicated that reducing the number of isolates phage-typed would have an impact on the surveillance system, with one outbreak likely to have been missed altogether. However, this does not have a great effect on the ‘time-to-detection’ for the other outbreaks. Assuming no testing for phage-typing was undertaken it is likely that two out of five outbreaks would not have been detected. Assessing the value of phage-type information is important not only in deciding on the efficiency of the current surveillance system but also in providing a basis upon which to assess more detailed typing methodologies such as an antibiogram of molecular profile.

Salmonella enterica commonly colonizes the intestinal tract of cattle and is a leading cause of foodborne illness. A previously described investigation into the prevalence of S. enterica on a dairy farm revealed an 8-year-long asymptomatic S. enterica epidemic caused by serotypes Cerro and Kentucky in the lactating herd. To investigate the source of the S. Kentucky strains, the genomes of two S. Kentucky isolates were sequenced; one collected prior to the epidemic (2004) and one collected during the epidemic (2010). Comparative genomic analysis demonstrated significant polymorphisms between the two strains. PCR primers targeting unique and strain-specific regions were developed, and screening of the archived isolates identified the index case of the asymptomatic S. Kentucky epidemic as a heifer that was raised off-site and transported onto the study farm in 2005. Analysis of isolates collected from all heifers brought onto the farm demonstrated frequent re-introduction of clones of the epidemic strain suggesting transmission of pathogens between farms might occur repeatedly.

In 1989–91 anti-measles vaccination campaigns were conducted in several Italian regions to vaccinate all children aged between 13 months and 10–12 years without a history of measles or measles vaccination. This study was conducted to evaluate serological status after the mass vaccination campaigns. In 1994, capillary blood samples were collected from randomly selected children, aged 2–14 years, living in 13 local health units. Antibody titres were determined by ELISA. Blood spot samples were analysed for 4114 (75·6%) of 5440 selected children. Among the 835 that reported measles before 1990, 806 (96·5%) were immune and of the 2798 vaccinated, 2665 (95·2%) were immune. The Edmoston–Zagreb (E–Z) strain vaccine was associated with a lower level of immunity than the Schwarz (SW) strain. A history of measles identified almost all immune children. Vaccination with the SW strain conferred persistent immunity (at least 5 years) in 98% of vaccinees. The strategy was able to unite natural and induced immunity.

Injections of virus in calves up to about 5 weeks of age caused either the production of both IgM and IgG, or the production of only IgG, or no detectable antibody. In all but one case priming for a secondary response occurred even in the absence of a detectable primary response. These results suggest that in the young calf immunological memory is more readily induced than IgG synthesis. IgM appeared by the 7th or 10th day, which was similar to the response in older calves. IgG was more variable in its appearances but was usually considerably delayed relative to the response in older calves. In general only low levels of IgM were formed in the primary response and it was virtually absent from the secondary responses. Higher levels of IgM were formed after reovirus inoculation than after Murray Valley encephalitis virus or Getah viruses. The delay in appearance of IgG was more pronounced in response to Getah than to reovirus or Murray Valley encephalitis virus. High levels of maternally derived passive antibody inhibited the development of an active response, although in one animal a response occurred in the presence of low levels of passive antibody.

Tick-borne encephalitis is a serious arboviral infection with unstable dynamics and profound inter-annual fluctuations in case numbers. A dependable predictive model has been sought since the discovery of the disease. The present study demonstrates that four superimposed cycles, approximately 2·4, 3, 5·4, and 10·4 years long, can account for three-fifths of the variation in the disease fluctuations over central Europe. Using harmonic regression, these cycles can be projected into the future, yielding forecasts of sufficient accuracy for up to 4 years ahead. For the years 2016–2018, this model predicts elevated incidence levels in most parts of the region.

Beijing–Tianjin–Hebei is the largest urban agglomeration in northern China, but the spatiotemporal patterns and risk factors concerning hepatitis B virus (HBV) incidence in this area have been unclear. The present study aimed to reveal the spatiotemporal epidemiological features of HBV infection and quantify the association between HBV infection and socio-economic risk factors. The data on HBV cases in Beijing–Tianjin–Hebei from 2007 to 2012 was collected for each county. The Bayesian space–time hierarchy model and the GeoDetector method were used to reveal spatiotemporal patterns and detect risk factors. High-risk regions were mainly distributed in the underdeveloped rural areas in the north and mid-south of the study region, while low-risk regions were mainly distributed in the urban and western areas. The HBV annual incidence rate decreased substantially over the 6-year period, dropping from 7.34/105 to 5.51/105. Compared with this overall trend, 38.5% of high-risk counties showed a faster decrease, and 35.9% of high-risk counties exhibited a slower decrease. Meanwhile, 29.7% of low-risk counties had a faster decrease, and 44.6% of low-risk counties exhibited a slower decrease. Socio-economic factors were strongly associated with the spatiotemporal patterns and variation. The population density and gross domestic product per capita were negatively associated with HBV transmission, with determinant powers of 0.17 and 0.12, respectively. The proportion of primary industry and the number of healthcare workers were positively associated with the disease incidence, with determinant powers of 0.11 and 0.8, respectively. The interactive effect between population density and the other factors exerted a greater influence on HBV transmission than that of these factors measured independently.

This study aimed to determine the prevalence of serological markers for HIV-1/2, HBV, HCV, Treponema cruzi and T. pallidum infections. The association of these infections with risk factors in a population from Salvador, Bahia, Brazil was also analysed. Of the 780 enrolled individuals, 545 (70%) were female and 235 (30%) were male. Seroprevalence of 0·8% (6/702), 1·3% (9/678), 1·5% (10/684), 3·5% (23/663) and 11·5% (77/668) for HIV-1/2, HBV, HCV, T. cruzi and T. pallidum infections, respectively, was observed. The seroprevalence of T. pallidum was higher in males 20% (43/210) than in females 7% (34/458) (P < 0·01). An association between age and seroprevalence for T. cruzi (P = 0·02) and T. pallidum (P < 0·01) was observed. HBsAg was associated with having tattoos (3/37 vs. 6/623, P = 0·01) and not having a steady sexual partner (5/141 vs. 4/473, P = 0·04), while anti-HIV-1/2 was associated with having tattoos (2/39 vs. 4/647, P = 0·04); however, larger studies are needed to categorically state the relationship of these risk factors with infectious agents. The prevalence of serological markers for HIV-1/2, HBV, HCV and T. cruzi was consistent with other studies.

In a multi-laboratory trial, lauryl tryptose mannitol broth (LTMB) and minerals-modified glutamate medium with added tryptophan (MMGM + T) were compared as single tube tests for the confirmation of Escherichia coli in water; the confirmed results were also compared with the production of gas from minerals-modified glutamate medium without added tryptophan (MMGM). LTMB and MMGM + T gave similar gas and indole results with about 90% of the water samples in most of the laboratories. When compared with the ‘correct’ results as judged by acid and gas production from lactose peptone water and indole from tryptone water, the difference in the rate of false positive reactions between LTMB and MMGM + T was insignificant; but LTMB gave a significantly lower rate of false negative reactions than MMGM + T. Gas production from MMGM without added tryptophan gave significantly higher rates of both false positive and false negative reactions. Lauryl sulphate is therefore a suitable inhibitory surfactant for use in single tubemedia for the confirmation of E. coli, which can be recommended.

1. Over 450 naturally infected or wild flies (Musca domestica) were caught in Liverpool during September and the first part of October 1911 from different parts of the city. The number and kinds of bacteria carried and contained by them have been investigated.

2. The number of bacteria coming from house-flies whilst struggling in liquid may be very large, varying from 2000, the lowest figure in 5 minutes, to 350,000, the highest figure in 30 minutes. This number may be taken as a measure of their capacity to pollute liquid with their vomit or excrement, or by wallowing in it. The number of bacteria carried inside the fly is very much greater.

3. Flies caught either in insanitary or congested areas of the city carry and contain far more bacteria than those from the more sanitary, less congested or suburban areas. The number of aerobic bacteria from the former varied from 800,000 to 500,000,000 per fly, and from the latter from 21,000 to 100,000.

4. The number of intestinal bacteria as indicated by glucose bile salt fermenters is also greater in the insanitary or congested areas, the numbers varying from 10,000 to 333,000,000, than in the more sanitary areas where they carried from 100 to 10,000.

5. Pathogenic bacteria and those allied to the food poisoning group were only obtained from the congested or moderately congested areas and never from the suburban areas.

6. We have examined the morphological characters and cultural reactions of 123 strains. Among those identified were two Streptococci, and several Staphylococci and Sarcinae. 106 were small Gram negative non-spore bearing bacilli, and have been grouped as follows:

Chromogenic group. Two strains of B. pyocyaneus were isolated from a knacker's yard; for the first time, we believe, from wild flies.

Colon group. 41 colonies of this group were picked off haphazard and classified according to McConkey as follows:

B. acidi lactici type 19·5%

B. coli communis type 12·2 %

B. neapolitanus type 19·5 %

B. lactis aerogenes type 46·4 %

Salmonella group. One bacillus gave identical reactions to B. enteritidis of Gaertner except that serological tests were negative.

Morgan's infantile diarrhoea group. One identical to Morgan's No. 1, and many others closely resembling it and Morgan's Nos. 2 and 3 were obtained.

Others fall into Proteolytic, Acid lactose-sucrose (saccharose), and Miscellaneous groups.

7. Flies caught in milk shops apparently carry and contain more bacteria than those from other shops with exposed food in a similar neighbourhood. The reason of this is probably because milk when accessible, especially in the summer months, is suitable culture medium for bacteria, and the flies first inoculate the milk and later reinoculate themselves, and then more of the milk, so establishing a vicious circle.

8. On one occasion we compared the number of bacteria carried by house-flies caught in an eating house opposite the slaughter houses with the number carried by blue-bottles; the latter, as might be expected, was far larger.

9. In cities where food is plentiful flies rarely migrate from the localities in which they are bred, and consequently the number of bacteria they carry depends upon the general standard of cleanliness in that locality. This is well indicated by the fact that flies caught in a street of modern fairly high class workmens' dwellings forming a sanitary oasis (Hornby Street) in the midst of a slum area, carried far less bacteria than those caught in the adjacent neighbourhood.

10. It is clear that flies from the suburbs where infantile diarrhoea is rare carry far less bacteria than those in the city where it is common. It was, nevertheless, impossible in the time at our disposal to correlate exactly the number or varieties of bacteria carried by flies in the city with the number of cases and deaths from infantile diarrhoea in individual streets.

11. As the amount of dirt carried by flies in any particular locality, measured in terms of bacteria, bears a definite relation to the habits of the people and the state of the streets, it demonstrates the necessity of efficient municipal and domestic cleanliness, if the food of the inhabitants is to escape pollution, not only with harmless but also with occasional pathogenic bacteria.

In the Netherlands, case histories of 160 patients aged more than 1 month, with meningitis due to bacteria other than Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae were reviewed in order to look for associations between the bacteriological data and the course of disease.

The incidence of such cases was about 0·8/100000/year. Escherichia coli and Listeria monocytogenes each accounted for about 15% of the cases. The case-fatality rate was 18·8% (Gram-negative bacteria, 25%; Gram-positives, 15%) and sequelae occurred in 13·3% of the surviving patients (14 and 13% Gram-negative and Gram-positive, respectively). Hearing loss was the most prevalent sequela (50%). Predisposing factors were present in 70% of patients (69 and 71% respectively), especially in meningitis due to enteric Gram-negative bacteria (except for salmonella) and due to staphylococci.

Surveillance is important because the incidence of meningitis due to these micro-organisms is likely to increase and because the problems in antibiotic treatment have not yet been solved.

A total of 193 sera were examined for antibody to Mycoplasma pneumoniae by three techniques – complement fixation (CF), haemagglutination (HA) and immunofluorescence (IF), the last method being used to assess IgM, IgG and IgA antibodies. The most reliable single test for diagnosis was HA, and the most useful combination of tests was HA with IF (IgM and IgG). The IgA IF was not found to be diagnostically helpful.

The diagnosis and control of Mycobacterium bovis infection (bovine tuberculosis: TB) continues to present huge challenges to the British cattle industry. A clearer understanding of the magnitude and duration of immune response to M. bovis infection in the European badger (Meles meles) – a wildlife maintenance host – may assist with the future development of diagnostic tests, and vaccination and disease management strategies. Here, we analyse 5280 diagnostic test results from 550 live wild badgers from a naturally-infected population to investigate whether one diagnostic test (a gamma interferon release [IFNγ] assay, n = 550 tests) could be used to predict future positive results on two other tests for the same disease (a serological test [n = 2342 tests] and mycobacterial culture [n = 2388 tests]) and hence act as an indicator of likely bacterial excretion or disease progression. Badgers with the highest IFNγ optical density (OD) values were most likely to subsequently test positive on both serological and culture tests, and this effect was detectable for up to 24 months after the IFNγ test. Furthermore, the higher the original IFNγ OD value, the greater the chance that a badger would subsequently test positive using serology. Relationships between IFNγ titres and mycobacterial culture results from different types of clinical sample suggest that the route of infection may affect the magnitude of immune response in badgers. These findings identify further value in the IFNγ test as a useful research tool, as it may help us to target studies at animals and groups that are most likely to succumb to more progressive disease.

Foodborne pathogen Listeria monocytogenes may cause serious, life-threatening disease in susceptible persons. We combined data from Finnish national listeriosis surveillance, patient interview responses, and laboratory data of patient samples and compared them to listeria findings from food and food production plants collected as part of outbreak investigations during 2011–2021. The incidence of invasive listeriosis in Finland (1.3/100000 in 2021) is higher than the EU average (0.5/100000 in 2021), and most cases are observed in the elderly with a predisposing condition. Many cases reported consuming high-risk foods as well as improper food storage. Since ongoing patient interviews and whole genome sequencing were introduced, several listeriosis outbreaks were detected and food sources identified. Recommendations about high-risk foods for listeriosis and proper food storage should be better communicated to susceptible people. In Finland, patient interviews and typing and comparing listeria isolates in foods and patient samples are crucial in solving outbreaks and determining measures to control invasive listeriosis.

Knowledge, attitudes and practices (KAP) of the population regarding severe fever with thrombocytopenia syndrome (SFTS) in endemic areas of Lu'an in China were assessed before and after an intervention programme. The pre-intervention phase was conducted using a sample of 425 participants from the 12 selected villages with the highest rates of endemic SFTS infection. A predesigned interview questionnaire was used to assess KAP. Subsequently, an intervention programme was designed and applied in the selected villages. KAP was re-assessed for each population in the selected villages using the same interview questionnaire. Following 2 months of the programme, 339 participants had completed the re-assessed survey. The impact of the intervention programme was evaluated using suitable statistical methods. A significant increase in the KAP and total KAP scores was noted following the intervention programme, whereas the proportion of correct knowledge, the positive attitudes and the effective practices toward SFTS of respondents increased significantly. The intervention programme was effective in improving KAP level of SFTS in populations that were resident in endemic areas.