Hepatitis E virus (HEV) infection is endemic in Cambodia. However, little relevant data were available and there is no clue if HEV is an emerging or decreasing pathogen in that setting. The aim of our study was to describe temporal trends of anti-HEV IgG and IgM prevalences during the last two decades (1996–2017) in the context of population growth and urbanisation in Cambodia. A total of 2004 human plasma samples collected between 1996 and 2017 were tested for anti-HEV IgG and IgM using the commercial Wantai anti-HEV assays. Overall, the prevalences of anti-HEV IgG and IgM were 41.1% and 2.7%, respectively. Analysis by calendar period showed a decreasing trend of anti-HEV IgG prevalence over the last 21 years. After age- and gender-standardisation, the anti-HEV IgG prevalence rates decreased from 61.3% during the 1996–2000 period to 32.3% during the 2016–2017 period, but no trends were observed for anti-HEV IgM rates, which fluctuated around the overall one. In conclusion, our results suggest that HEV is not an emerging pathogen, but rather seems to circulate less in Cambodia, in particular, in Phnom Penh, since the prevalence of anti-HEV IgG has been significantly decreased during the past two decades.

We studied the association that exists between the epidemiological type clustering of isolates of Mycobacterium tuberculosis and certain clinical, epidemiological and socio-economic characteristics of tuberculosis patients in the Elche health district of Spain. A total of 144 patients diagnosed between 1993 and 1999 and whose isolates had been genotyped by IS6110–RFLP in an earlier study were included. Multivariate analysis showed that the independent variables associated with clustering of strain types were: age (1–25 years, OR 2·92, 95% CI 0·83–10·3), a high percentage of infection in the first circle of contacts (OR 2·89, 95% CI 0·96–8·68), urban dwelling (OR 2·12, 95% CI 0·73–6·2), use of bronchoscopy to obtain samples (OR 16·3, 95% CI 2·3–11·5) and working contact with many people (OR 2·81, 95% CI 0·94–8·3). These data contribute to a better understanding of the epidemiology of tuberculosis and improved systems of control.

One hundred and eighteen Neisseria meningitidis isolates were recovered from patients with invasive meningococcal disease in Portugal, over one year. Our study was undertaken to evaluate antimicrobial susceptibility, serogroup, serotype and genotype of isolates. One quarter (24·6%) of the isolates showed moderate resistance to penicillin and 47·4% were resistant to sulphadiazine. The two most common serosubtypes were C:2b:P1.5,2 (31·3%) and B:4:P1.15 (3·4%). Half (53·6%) of the isolates with moderate resistance to penicillin were phenotype C:2b:P1.5,2 (n=14), C:2b:P1.2 (n=1) or C:2b:NST (n=1); Pulsed-field gel electrophoresis (PFGE) showed that all these isolates were genetically related. Multilocus sequence typing (MLST) analysis of representative clones from each PFGE pattern showed the predominance of the ST-8 complex/cluster A4 among N. meningitidis with moderate resistance to penicillin. This clonal complex has been principally found in Southern Europe. The apparent emergence and dissemination of the hypervirulent ST-8 complex/cluster A4 among serogroup C strains increases the need for a continued surveillance of antimicrobial susceptibility of meningococci and of genotypic markers in Portugal.

Thirty-seven isolates of cytomegalovirus (CMV) were obtained from a group of 20 promiscuous homosexual men, either suffering from the acquired immunodeficiency syndrome (AIDS) at the time of CMV isolation, or who developed AIDS subsequently. The isolates of CMV were characterized by the method of DNA restriction analysis. All epidemiologically unrelated strains of CMV exhibited different fragment migration patterns and no one strain appeared to be associated with AIDS or any particular disease pattern in these patients.

Sequential isolates of CMV were obtained from nine patients in the study group either from different sites at the same time or from the same site on different dates. In the case of seven of the men, viruses with minor differences in restriction profile were obtained, possiblyrepresenting sub-populations of an endogenous strain of CMV. In two of the patients, reinfection with different strains was apparent. We conclude that reinfections with CMV in AIDS patients can occur, but the isolation of strains exhibiting major differences in genome structure seen by restriction enzyme analysis was uncommon.

Firemen have been considered at occupational risk of hepatitis (HBV) infection, but proof is lacking. The aim of this study was to assess the degree of risk by determining the prevalence of serological markers of past infection with HBV in members of the West Yorkshire Fire Service. Sera from 173 firemen, 9·3% of the brigade, were tested for antibodies to HBV surface antigen and to core antigen. Those containing anti-HBs≥10 IU/L or anti-core antibody, were also tested for antibody to HBe antigen. The presence of more than one marker was used to define past infection. One sample satisfied this criterion, giving a prevalence rate of 0·6%. This compares with a rate of 1% in London blood donors. We conclude that the group shows no evidence of having been at increased risk of HBV infection. A comprehensive vaccination policy for firemen might be questionable

This paper compares strains of foot-and-mouth disease (FMD) serotype SAT (South African Territories) 2 viruses isolated from Zimbabwe and other African countries using monoclonal antibodies (MAb). A sandwich-ELISA was used to examine the relative binding of anti-SAT 2 MAb to the various viruses. The MAb-binding profiles of viruses isolated from field samples were compared using hierarchical cluster analysis. Viruses were obtained from game animals, mainly African buffalo (Syncerus caffer) which is the natural host and reservoir for SAT serotypes in Africa, and from cattle showing clinical signs of FMD, as well as from animals suspected of carrying the virus subclinically. Some isolates have been adapted for use as vaccine strains. The results showed that most of the Zimbabwe isolates collected between 1989 and 1992 were an antigenically closely-related group. Although differences were observed between Zimbabwe isolates collected between 1989 and 1992 and those collected in 1987, there was no correlation with the different MAb binding patterns within the 1987 group and the epidemiological information received from the field. Similar profiles were observed for many SAT 2 viruses, including viruses isolated over a 50-year period and from geographically distant areas. This indicates an inherent stability in antigenic profiles of SAT 2 viruses. The MAb panel was capable of assessing antigenic variation, since very different profiles were obtained for some isolates. The work also allowed comparison and characterization of anti-type SAT 2 MAb from different laboratories. The findings are discussed with reference to selection of vaccine strains.

COVID-19 impacts population health equity. While mRNA vaccines protect against serious illness and death, little New Zealand (NZ) data exist about the impact of Omicron – and the effectiveness of vaccination – on different population groups. We aim to examine the impact of Omicron on Māori, Pacific, and Other ethnicities and how this interacts with age and vaccination status in the Te Manawa Taki Midland region of NZ. Daily COVID-19 infection and hospitalisation rates (1 February 2022 to 29 June 2022) were calculated for Māori, Pacific, and Other ethnicities for six age bands. A multivariate logistic regression model quantified the effects of ethnicity, age, and vaccination on hospitalisation rates. Per-capita Omicron cases were highest and occurred earliest among Pacific (9 per 1,000) and Māori (5 per 1,000) people and were highest among 12–24-year-olds (7 per 1,000). Hospitalisation was significantly more likely for Māori people (odds ratio (OR) = 2.03), Pacific people (OR = 1.75), over 75-year-olds (OR = 39.22), and unvaccinated people (OR = 4.64). Length of hospitalisation is strongly related to age. COVID-19 vaccination reduces hospitalisations for older individuals and Māori and Pacific populations. Omicron inequitably impacted Māori and Pacific people through higher per-capita infection and hospitalisation rates. Older people are more likely to be hospitalised and for longer.

Owing to the somewhat contradictory results which have been obtained by various investigators as to the nature of the Micrococcus neoformans and the relation which this organism bears to malignant disease, we have thought it advisable to place on record our observations in a large number of cases of carcinomata, sarcomata and certain cases of anaemia which are known to run a fatal course. Doyen (1886), in a preliminary note communicated to the Academy of Sciences of Paris, stated that he had found small spherical bodies in malignant and other growths which he regarded as micro-organisms. In 1902, at the Surgical Congress, at Berlin, he stated further that he had isolated a micro-organism from simple and malignant growths which, when inoculated into animals, gave rise to neoplastic formations. To this organism he gave the name M. neoformans. In his opinion new growths resulted from an infection of the body with this organism. Since then he has published a number of observations showing the beneficial effects which may be obtained by the employment of a vaccine or serum against the M. neoformans in malignant disease.

In these studies it is shown that the common ‘British’ and ‘American’ adult cockroaches can survive exposure to formaldehyde fumigation carried out at double the strength and for four times as long as is recommended for disinfection of rooms.

It is further reported that vaccinia virus ingested prior to the fumigation survives in the cockroach gut and may be excreted up to 5 days later.

Since cockroaches are ubiquitous and are to be found in most hospitals, laboratories and animal houses, these findings should be considered whenever fumigation is called for.

Mice of strain TO, in groups of ten, were inoculated intravaginally with Mycoplasma pulmonis organisms. Seven mice became infected after inoculation of organisms with strong haemadsorptive capacity, four after inoculation of organisms with diminished adsorptive capacity following ten passes in medium, and none after inoculation of apparently non-adsorbing organisms which had been passed 50 times. There appeared to be a correlation, therefore, between the ability to infect and the cytadsorptive capacity of the organisms. There was only a minimal vaginal polymorphonuclear leucocyte (PMNL) response in the infected mice and most of them had ceased to be infected by 35–42 days. In contrast, mice treated with progesterone had enhanced infections; all those given strongly haemadsorbing organisms, and organisms passed ten times, became infected and remained so for at least 42 days. Furthermore, at least ten fold more organisms were recovered from progesterone-treated than from untreated mice, and the PMNL response was much greater. Most of the progesterone-treated mice given organisms passed 50 times did not become infected, but some did, and the organisms recovered from them were fully cytadsorptive. It is postulated that a few cytadsorbing organisms in this inoculum were induced to infect under the enhancing effect of progesterone.

Dengue haemorrhagic fever (DHF) is caused by dengue virus transmitted by Aedes mosquitoes; mean age of patients varies temporally and geographically. Variability in age of patients may be due to differences in transmission intensity or demographic structure. To compare these two hypotheses, the mean age of DHF patients from 90 districts in northern Thailand (1994–1996, 2002–2004) was regressed against (i) Aedes abundance or (ii) demographic variables (birthrate, average age) of the district. We also developed software to quantify direction and strength of geographical gradients of these variables. We found that, after adjusting for socioeconomics, climate, spatial autocorrelation, the mean age of patients was correlated only with Aedes abundance. The geographical gradient of mean age of patients originated from entomological, climate, and socioeconomic gradients. Vector abundance was a stronger determinant of mean age of patients than demographic variables, in northern Thailand.

Single and multi-jet liquid impingers and membrane-filters were found to be efficient sampling devices for aerosols generated from suspensions of the virus of foot-and-mouth disease (FMD). Concentration of the aerosol samples with an adsorbent, Attaclay, facilitated the detection of small amounts of virus. Sodium dodecyl sulphate could be used for elution as the virus of FMD is resistant to this anionic detergent.

The penetration of these aerosols through various air filtration media was determined using impinger samplers. A glass fibre paper was found to be the most efficient with a virus penetration of less than 0·001%.

We wish to thank Dr D. W. Henderson and Dr H. M. Darlow, of M.R.E. and Mr R. G. Dorman of C.D.E. Porton for valuable prefatory discussions and advice. We are also indebted to Miss S. Cartwright for inoculating mice, to Miss M. Shoobridge and Mr S. Taylor for technical assistance, and to Vokes Ltd. for supplying materials.

Meningococcal disease is a rare, rapidly progressing condition which may be difficult to diagnose, disproportionally affects children, and has high morbidity and mortality. Accurate incidence estimates are needed to monitor the effectiveness of vaccination and treatment. We used linked notification, hospital, mortality and birth data for all children of an Australian state (2000–2007) to estimate the incidence of meningococcal disease. A total of 595 cases were notified, 684 cases had a hospital diagnosis, and 26 cases died from meningococcal disease. All deaths were notified, but only 68% (466/684) of hospitalized cases. Of non-notified hospitalized cases with more than one clinical admission, most (90%, 103/114) did not have meningococcal disease recorded as their final diagnosis, consistent with initial ‘false-positive’ hospital meningococcal disease diagnosis. After adjusting for false-positive rates in hospital data, capture–recapture estimation suggested that up to four cases of meningococcal disease may not have been captured in either notification or hospital records. The estimated incidence of meningococcal disease in NSW-born and -resident children aged 0–14 years was 5·1–5·4 cases/100 000 child-years at risk, comparable to international estimates using similar methods, but lower than estimates based on hospital data.

(a) This paper is a study of a poliomyelitis epidemic in the Central Auckland Health District which commenced in November 1947, and by the end of April 1949 had produced 345 cases in a population of about 350,000.

(b) Incidence per 10,000 reached 8·0 in the city, 15·4 in the country districts, and 21·5 in certain urban areas lying between city and country.

(c) In general, incidence was inversely related to population density. Abnormally high incidences in some urban areas was attributed to influx of rural dwellers in recent years. Unusually low incidence in one city area may have been related to the periodic effect of race meetings in increasing the local density.

(d) The three previous Auckland epidemics showed a successively declining incidence, and were linked by periods of grumbling activity. The present epidemic was preceded by a lull, and its toll has approached that of the 1916 epidemic. It is probable that a new cycle has begun which will imitate the first, but on a lower scale.

(e) Spot maps showed that the disease was already widespread before the first positive cases revealed its presence. Some ebb and flow, but no actual movement from one area to another, occurred during its course. An interesting feature was the comparative rarity of cases in the neighbourhood of the city's sewage-polluted bathing beaches.

(f) An inverse correlation was noted between the ratios of ‘suspect’ to positive cases established in a previous inquiry, and the incidence of cases with paralysis or paresis in various age/sex groups. High ratios indicated lower severity.

(g) It was estimated that by the end of April 1949, all boys 10–15 years in Auckland had been affected by poliomyelitis, either ‘suspect’ or positive. Less than half the girls of this age had been affected. Estimates are given for the other age groups.

(h) Families of cases showed no significant difference in composition from the average in the area.

(i) No correlation, whether inverse or direct, was found between sanitary conditions in schools and the incidence of positive cases.

(j) The cycle of poliomyelitis in the community is discussed in the light of these findings.

During the period 1968–85 shigella organisms were isolated from stool specimens of 1562 patients attending Tygerberg Hospital, situated in the south-western province of the Cape of Good Hope of the Republic of South Africa. Shigella flexneri (72% of patients) was the commonest subgroup identified. Sh. sonnei was the second-commonest isolate (20%), with smaller number of Sh. boydii (5%) and Sh. dysenteriae (3%). Sh. dysenteriae has not been isolated since 1979. In 1985 30% of isolates were resistant to ampicillin and 52% to trimethoprim-sulphamethoxazole. During this period 12 cases of shigellaemia were seen, 11 in young infants less than 13 months of age who were malnourished in 6 cases. The single adult had had a previous gastrectomy and splenectomy.

Vaccines are the cornerstone of influenza control policy, but can suffer from several drawbacks. Seasonal influenza vaccines are prone to production problems and low efficacies, while pandemic vaccines are unlikely to be available in time to slow a rapidly spreading global outbreak. Antiviral therapy was found to be beneficial during the influenza A(H1N1)pdm09 pandemic even with limited use; however, antiviral use has decreased further since then. We sought to determine the role antiviral therapy can play in pandemic and seasonal influenza control using conservative estimates of antiviral efficacy, and to assess if conservative but targeted strategies could be employed to optimize the use of antivirals. Using an age-structured contact network model for an urban population, we compared the transmission-blocking ability of a conservative antiviral therapy strategy to the susceptibility-reducing effects of a robust influenza vaccine. Our results show that while antiviral therapy cannot replace a robust influenza vaccine, it can play a role in reducing attack rates and eliminating outbreaks, and could significantly reduce public health burden when vaccine is either unavailable or ineffective. We also found that antiviral therapy, by treating those who are infected, is naturally a highly optimized strategy, and need not be improved upon with expensive targeted campaigns.

In Serbia, modern pork production systems with implemented control measures, including the detection of Trichinella larvae in meat (ISO18743), have eliminated farmed pork from pigs slaughtered at abattoirs as a source of trichinellosis. Epidemiological data from 2011 to 2020 indicate that the number of human cases and the number of infected domestic pigs has decreased significantly. Over the years, pork was the most frequent source of human infection. Cases generally occurred in small family outbreaks, and the infection was linked to consumption of raw or undercooked pork from backyard pigs. In most of the outbreaks, T. spiralis was the aetiological agent of infection, but in 2016, a large outbreak was caused by consumption of uninspected wild boar meat containing T. britovi larvae. To achieve safe pork, it is important that consumers of pork from animals raised in backyard smallholdings and of wild game meat are properly educated about the risks associated with consumption of untested meat. Laboratories conducting Trichinella testing should have a functional quality assurance system to ensure competency of analysts and that accurate and repeatable results are achieved. Regular participation in proficiency testing is needed.

We have assessed the effect of house-cleaning procedures on changes in airborne dust and bacteria counts and correlated these with respiratory function tests in 14 children with bronchial asthma who were known to have developed attacks at home, and who had positive skin tests to house dust and the house-dust mite.

We have demonstrated that after cleaning procedures a positive and statistically significant correlation exists between the increase in the numbers of small particles, 2 μm. and less in diameter, in the environment, and reduction in mean peak flow. This indicates that particles of this size penetrate the bronchial tree and are the causative factor in the genesis of bronchospasm.

In an inter-laboratory survey, 148 samples of cooked prawns and shrimps were obtained at the point of sale to the consumer. Salmonellae and Vibrio parahaemolyticus were not detected. Yersinia enterocolitica was isolated from three samples. Results for total viable count and presence of Escherichia coli and Staphylococcus aureus complied well with available guidelines for imported cooked prawns, suggesting that the risk of food poisoning from retail samples of these foods in the South of England is minimal.

At present the coli titre of water is almost universally determined by fermentation tests in sugar-containing media; the fermentation method of Eijkman (glucose-peptone solution at 46°2) and that of Bulir (neutral-red mannite bouillon at 46°) are current in many European countries, while in America fermentation in lactose bouillon at 37° is the standard test. Fermentation tests at 37° in lactose-containing media with the addition of bile and bactericidal dyes are also widely used (Great Britain, America).