Yersinia enterocolitica is a recognized cause of gastroenteritis in northern Europe. During October 1988-January 1990, a prospective case-control study was performed to address risk factors associated with sporadic. Y. enterocolitica infections in southeastern Norway. Sixty-seven case-patients (mean age 23.4 years, range 8 months-88 years) and 132, age-, sex- and geographically-matched controls were enrolled in the study. Multivariate analysis of the data showed that persons with Y. enterocolitica infection reported having eaten significantly more pork items(3.79 v. 2.30 meals, P = 0.02) and sausage (2.84 v. 2.20 meals, P = 0.03) in the 2 weeks before illness onset than their matched controls; only one patient had eaten raw pork. Patients were also more likely than controls to report a preference for eating meat prepared raw or rare (47 v. 27%, P = 0.01), and to report drinking untreated water (39 v. 25%, P = 0.01) in the 2 weeks before illness onset. Each of these factors was independently associated with disease, suggesting a link between yersiniosis and consumption of undercooked pork and sausage products and untreated water. Efforts should be directed towards developing techniques to reduce Y. enterocolitica contamination of pork and educating consumers about (1) proper handling and preparation of pork items and (2) the hazards of drinking untreated water.

Experimental data suggest a role for the microflora in Systemic Lupus Erythematosus (SLE). Anti–ds–DNA antibodies may be pathogenic in SLE by forming immune complexes with DNA. Foreign bacteria in the intestines could constitute the stimulus for anti–ds–DNA antibody production in SLE. Colonization Resistance (CR) is the defence capacity of the indigenous microflora against colonization of the intestines by foreign bacteria. A low CR implies increase of translocation of bacteria and a higher chance of subsequent, possibly DNA–cross–reacting antibacterial antibody production.

We measured CR by a comprehensive biotyping technique in healthy individuals and patients with inactive and active SLE. CR tended to be lower in active SLE patients than in healthy individuals (P = 0.09, Wilcoxon one sided, with correction for ties). This could indicate that in SLE more and different bacteria translocate across the gut wall due to a lower CR. Some of these may serve as polyconal B cell activators or as antigens cross-reacting with DNA.

Water was cultured from 39 of 48 hospitals (7 Halifax hospitals and 32 non-Halifax hospitals) in the province of Nova Scotia and from 90 residences (74 private dwellings, 16 apartments) in Halifax to determine the frequency of legionella contamination. Six of seven Halifax hospitals had Legionellaceae isolated from their potable water compared with 3 of 32 non-Halifax hospitals (P < 0.0001). Overall. 19 of 59 (32%) of the water samples from Halifax hospitals were positive for legionellae compared with 5 of 480 (1%) samples from non-Halifax hospitals (P < 0.0000). Five of the six positive Halifax hospitals had Legionella pneumophila serogroup 1 and 1 had L. longbeachae serogroup 2 recovered from their potable water. Legionella contamination was associated with older, larger (> 50 beds) hospitals with total system recirculation. These hospitals also had water with a higher pH and calcium content but lower sodium, potassium, nitrate, iron and copper content.

Fourteen of the 225 (6.2%) water samples from Halifax residences were positive for legionellae – 8% (6/74) of the single family dwellings were positive, compared with 25% (4/16) apartments. The positivity rate of 15.7% for the 19 electric hot-water heaters in Halifax homes was not significantly different from the 32% positivity for Halifax hospitals. L. longbeachae accounted for 2 of the 14 isolates of legionellae from Halifax homes.

Attempts were made to identify the causative organism of Lyme disease in Australia from possible tick vectors.

Ticks were collected in coastal areas of New South Wales, Australia, from localities associated with putative human infections. The ticks were dissected; a portion of the gut contents was examined for spirochaetes by microscopy, the remaining portion inoculated into culture media. The detection of spirochaetes in culture was performed using microscopy, and immunochemical and molecular (PCR) techniques. Additionally, whole ticks were tested with PCR for spirochaetes.

From 1990 to 1992, approximately 12000 ticks were processed for spirochaetes. No evidence of Borrelia burgdorferi or any other spirochaete was recovered from or detected in likely tick vectors. Some spirochaete–like objects detected in the cultures were shown to be artifacts, probably aggregates of bacterial flagellae.

There is no definitive evidence for the existence in Australia of B. burgdorferi the causative agent of true Lyme disease, or for any other tick–borne spirochaete that may be responsible for a local syndrome being reported as Lyme disease.

A mixed vaccination strategy against rubella is proposed. We describe how the vaccination strategy was designed with the help of mathematical techniques. The strategy was designed for application in a non-immunized community of the State of São Paulo, Brazil, and was implemented by local health authorities in 1992. This strategy comprises a pulse vaccination campaign, covering the age interval between 1 and 10 years, followed by the introduction of the vaccine in the immunization calendar at 15 months of age. The expected impact of the proposed strategy is discussed.

The introduction of screening for hepatitis C virus (HCV) by the National Blood Transfusion Service identified donors who had acquired HCV infection. We undertook a case-control study amongst blood donors in the Trent Region to determine risks for HCV infection. A total of 74 blood donors confirmed positive for hepatitis C infection and 150 age, sex and donor venue matched controls were included in the study. Fifty-three percent of hepatitis C infected blood donors reported previous use of injected drugs compared to no controls; relative risk (RR) not estimatable (lower limit 95% CI = 20). Other risk factors were a history of: receipt of a blood transfusion or blood products RR = 3·6 (95% CI 1·5–8·3), having been a ‘health care worker’ RR = 2·8 (95% CI 1·1–7·6), tattooing RR = 3·3 (95% CI 1·2–8·7), and an association with having been born abroad RR = 3·2 (95% CI 1·1–9·5). No risk was shown for a history of multiple sexual partners, ear piercing or acupuncture. Injecting drug use explains more than 50% of hepatitis C infections in blood donors, a group who are less likely to have injected drugs than the general population.

Botulism due to Clostridium botulinum type C causes considerable mortality in gulls in the UK, and refuse disposal sites are suspected as a major source of toxin. C. botulinum types B, C and D were each found in 12 (63.2%) of 19 landfill sites examined. Type E was detected in only one (5.2%) and types A, F and G were not found. The prevalence of type C spores was much higher than that demonstrated in the UK environment by earlier surveys. The presence of these spores, together with the rotting organic matter and generated heat associated with landfill sites, undoubtedly leads to bacterial proliferation and toxigenesis. This is likely to result in botulism in scavenging gulls unless skilled landfill management prevents the ingestion of toxic material. Type D spores were previously shown to be rare in the UK environment and their high prevalence on landfill sites was therefore surprising. Four composite samples of refuse collected before distribution on a landfill gave negative results for C. botulinum and it seems likely that the gulls themselves play a major role in introducing contamination.

The gastric-adapted bacterium Helicobacter pylori plays an important role in gastritis and ulcer disease, but no phenotypic typing scheme presently exists for this organism. With a view to the development of genotypic typing, we have compared isolates of H. pylori from gastritis or ulcer patients with those from subjects exhibiting no disease. Variation was analysed at the urease genes, ureA and ureCD, by employing PCR-generated probes in genomic Southern blot hybridizations. Whilst ureA restriction fragments provided a fourfold subgrouping of strains, ureCD fragments were considerably more discriminatory. Twenty-four combined ureACD profiles were generated with Hind III, subdividing the 64 strains into 11 types and 13 single profiles. The most prevalent profile (UI) was found in 33% of strains, almost all from gastritis or ulcer patients. On the other hand strains isolated from asymptomatic individuals had the most diverse ureACD profiles. A key finding from this set of isolates was that strains of H. pylori associated with general gastroduodenal disease were genetically more homogeneous than strains carried by people without disease symptoms.

Large-scale surveys of immunity to vaccine-preventable diseases may be limited by the inconvenience and expense involved in collection of blood by venepuncture. An alternative method of collecting blood on filter paper for measurement of immunity to diphtheria and tetanus is described. The precut filter disks (Elisadiscs), originally developed for serological diagnosis of disease in pigs, have advantages over previously described methods in that they allow safe handling of minimal volumes of blood (5 μl) which can be conveniently quantified.

To compare values obtained by venepuncture and fingerprick, paired samples were collected from 60 subjects and diphtheria and tetanus antitoxin concentrations were measured by ELISA. There was no significant difference detected between samples collected by the two methods.

The results suggest that Elisadiscs are a reliable alternative to venepuncture for monitoring immunity to diphtheria and tetanus and would be useful for sample collection in remote areas and from children.

The distribution of adenovirus types in faecal samples of patients with suspected viral gastroenteritis from South Australia was determined during the 12-month period, July 1991–June 1992. There were 3299 samples tested and 226 (6·9%) were positive for adenovirus by enzyme immunoassay. Of these 226 samples. 154 (68%) were typed directly using virus DNA extracted from the faecal samples according to the Sma I, Hind III and BstEII restriction patterns and Southern hybridization analysis with pooled viral genomic DNA probes. In this group, 86% of the samples were from patients who were < 3 years of age. Enteric adenovirus types 40 and 41 accounted for 20 and 40% respectively, of these samples, and types 1, 2, 3, 5, 6, 7 and 31 comprised the remainder. Type 40 was detected mainly in the winter and spring periods, and type 41 predominated in the autumn period. The majority of the non-enteric types were found during the late winter and spring periods.

A cluster of disseminated Candida albicans infections, which occurred at the Intensive Care Unit of the Department of Heart Surgery, was investigated. Ten patients became infected and seven died. A wide microbiological surveillance was carried out. A total of 14 isolates of Candida albicans, four environmental and ten human, were examined using the Restriction Endonuclease Analysis (REA) of DNA. The isolates were classified into five different main groups. Five of the clinical isolates had the predominant pattern Ab and two more clinical strains were very closely related. Two more isolates from the emergency kit desk and the hands of a nurse gave the same REA profile. Such a relationship proved the epidemic nature of the cluster, with most of the patients cross-infected, and strongly suggested transmission on the hands of the staff as a determinant of the epidemic. Thus, REA has the potential to address many important questions in the study of nosocomial epidemiology of Candida albicans.

The presence of six gene 4 alleles (or VP4 genotypes) in human rotaviruses has been recognized. Using 16 representative cultivable human rotavirus strains, we confirmed the specificity of VP4 genotyping by polymerase chain reaction (PCR) using the nested oligonucleotides specific to each of the four representative gene 4 alleles. Using the PCR. we surveyed the gene 4 alleles of 199 human rotaviruses in stools collected in Japan and Thailand. Strains with the gene 4 allele, corresponding to P1A serotype. were shown to be the most prevalent, but two strains with P2 gene 4 allele and one strain with P3 gene 4 allele were detected in Thailand and in Japan, respectively.

Of 41 coagulase-negative staphylococcal isolates from cases of ovine mastitis, 80% were speciated by the ‘API-Staph SYSTEM’ and 90% by a combination of biochemical tests. Staphylococcus simulans and Staph. xylosus were the two most prevalent species.

Current methods to establish the duration of toxoplasma infection in pregnant women and for the diagnosis of toxoplasmosis in the neonate or HIV infected patient have significant limitations. We assessed the precision of a commercial ELISA for the detection of toxoplasma specific IgG and adapted the assay to measure avidity using an elution agent washing step. The sensitivity and specificity of the ELISA were 100 and 75 % respectively and optimal measurement of avidity was achieved using 6 M urea as the elution agent.

Toxoplasma lymphadenopathy of less than 3 months duration was associated with low avidity specific IgG but some discordant findings were recorded. Serial measurement of IgG avidity assisted the distinction between actively produced antibody in infants with congenital toxoplasmosis and passively acquired antibody of maternal origin in uninfected babies. There was no significant difference between avidity levels in HIV infected patients with or without cerebral toxoplasmosis.

Information about the distribution of bluetongue in Turkey during 1978–81 has been obtained by serological surveys in cattle, sheep and goats. The group-specific immunodiffusion test was used to identify the presence of bluetongue virus (BTV) in a given province and the type-specific microneutralization test to decide which virus types had been in circulation. By drawing sera from accurately aged donor animals in May and August 1980. it was possible to draw up a general outline of the distribution of BTV in Turkey between early 1978 and mid 1980. By combining the same technique with spring and autumn field visits it became possible to make detailed inferences about the distribution of BTV serotypes in 1980 and 1981. The results support the conclusion that BTV was widespread in central and western Turkey for a number of years and suggests that overwintering can be a regular occurrence in that country. When compared with contemporaneous results from Syria and Jordan, a unifying and well-defined bluetongue virus ecosystem becomes apparent.

Staphylococcus aureus (n = 75) isolated from mammary secretions of cows with subclinical and clinical mastitis from several geographic locations in the USA were examined using polymerase chain reaction-based DNA fingerprinting. DNA fingerprints were produced using a synthetic oligonucleotide primer (5‘GTAACGCC3’) to produce a distinct spectrum of amplified DNA fragments facilitating a high degree of resolution for differentiating S. aureus strains. PCR-based DNA fingerprinting grouped the 75 S. aureus isolates into 19 distinct profiles. The technique differentiated closely related strains within and between geographic locations. Findings suggest that certain types are found across geographic regions suggesting a common clonal type. Within herd data suggest heterogeneity among subclinical and clinical isolates of S. aureus strains. Compared to existing typing methods, PCR-based DNA fingerprinting is easy to perform and interpret. Use of PCR-based DNA fingerprinting may allow for a more detailed investigation of the epidemiology of S. aureus mastitis in dairy cows.

In 1964, the Medical Research Council undertook a trial of measles vaccine in over 36000 United Kingdom children; 9577 of whom received live vaccine, 10625 received inactivated followed by live vaccine, and 16328 acted as unvaccinated controls. Participants in this study have been followed to determine the long term protection from measles vaccine and follow-up data were available on 4194, 4638 and 274 respectively. During the 5–year period 1986–90, the protective efficacy of live measles vaccine has remained high at 87%, but the 95% confidence interval was wide ( –43 to 99%) due to the small numbers of cases. Between 1976 and 1990, however, the overall efficacy of the live vaccine was 92% (95% confidence interval 86 to 95%) and there was no evidence of a decline in efficacy (P = 0.13) over the 15–year period. This study suggests that the protection from live measles vaccine persists for up to 27 years after vaccination, and that no change in the current United Kingdom measles immunization policy should be made on the grounds of waning immunity.

Results of serotyping on 291 astrovirus-positive stools collected between 1976 and 1992 showed that about two-thirds (64.9%) were serotype 1. Infections were more frequent in the fourth quarter of the year and there was a suggestion that during the past 5 years serotype 1 has occurred with greater frequency in alternate years. Evidence is provided for the existence of two new serotypes, 6 and 7.

A trial of protective efficacy which compared medium–titre Edmonston-Zagreb (EZ) measles vaccine (104.6 p.f.u.) from the age of 4 months with the standard Schwarz (SW) measles vaccine given from the age of 9 months was started in an urban community in Guinea-Bissau in 1985. Because trials of high–titre measles vaccine have found increased mortality among female recipients, we examined whether EZ medium–titre vaccine was associated with any long-term impact on mortality, suppression of T–cells, or growth. The mortality rate ratio over 5 years of follow–up was 1.12 for EZ children compared with children in the standard group (P = 0.63). Seventy–five percent of the children still residing in the area at 5 years of age took part in an immunological and anthropometric examination. There was no difference in T–cell subsets between the two groups. There was no difference in mid–upper–arm circumference, but EZ children were significantly shorter than the children in the standard group. In conclusion, medium–titre EZ was not associated with reduced survival or persistent immunosuppression.