Thirty-five E. coli strains belonging to O-serogroups associated with enteroinvasive types of Escherichia coli (EIEC) isolated in Germany between 1989 and 1995 were investigated for invasivity-associated DNA sequences. Only 11 strains were positive for ipaH and thus confirmed as EIEC. All 11 EIEC isolates originated from human infections which were imported to Germany from Eastern Europe. EIEC O124 were most frequent and originated from asymptomatic Romanians arriving at Rostock, Germany in 1992 and 1993. In January 1993, EIEC O124 were isolated from faeces of a laboratory technician with diarrhoea working at the enteric pathogen department of the Institute of Hygiene in Rostock. By comparing her E. coli O124 isolate with recently imported O124 strains for Xba I restriction fragment length polymorphisms (RFLP) the probable source of infection could be determined. Four major RFLP patterns were found in the group of O124 strains. O124 strains with identical RFLP patterns were found in the group of O124 strains. O124 strains with identical RFLP patterns were isolated from people who were in close contact to each other.

Between 23 August and 15 December 1990 an epidemic of cholera affected Mozambican refugees in Malawi causing 1931 cases (attack rate=2·4%); 86% of patients had arrived in Malawi <3 months before illness onset. There were 68 deaths (case-fatality rate=3·5%); most deaths (63%) occurred within 24 h of hospital admission which may have indicated delayed presentation to health facilities and inadequate early rehydration. Mortality was higher in children <4 years old and febrile deaths may have been associated with prolonged IV use. Significant risk factors for illness (P<0·05) in two case-control studies included drinking river water (odds ratio [OR]=3·0); placing hands into stored household drinking water (OR=6·0); and among those without adequate firewood to reheat food, eating leftover cooked peas (OR=8·0). Toxigenic V. cholerae O1, serotype Inaba, was isolated from patients and stored household water. The rapidity with which newly arrived refugees became infected precluded effective use of a cholera vaccine to prevent cases unless vaccination had occurred immediately upon camp arrival. Improved access to treatment and care of paediatric patients, and increased use of oral rehydration therapy, could decrease mortality. Preventing future cholera outbreaks in Africa will depend on interrupting both waterborne and foodborne transmission of this pathogen.

Group B streptococci (GBS) were isolated from bovine bulk milk and from vaginas and throats of antenatal and postnatal women using TKT and rapid GBS media. Sixty-three of 529 (12%) bovine bulk milk samples, 9 of 48 (19%) vaginal and 3 of 48 (6%) throat samples were positive. Both bovine and human beta haemolytic isolates were characterized biochemically and serologically. Pigment production was a characteristic of both human and bovine beta haemolytic isolates. The majority (88%) of human isolates fermented salicin and not lactose and most bovine isolates were either lactose positive/salicin positive (41%) or lactose positive/salicin negative (38%). Human and bovine isolates were 100% and 85% typable respectively. Serotype distribution was similar in the bovine and human populations with serotype la, lc and lll being most common in both. Fermentation of sugars showed major differences between bovine and human isolates but similarity in serotype distribution suggests some genetic relationship.

This study assessed accuracy of (a) recording Vibrio vulnificus infection on death certificates and (b) International Classification of Disease (ICD)-9 codes for V. vulnificus. Patients with microbiologically confirmed V. vulnificus infection were identified as part of co-ordinated surveillance in four USA Gulf Coast states between 1989 and 1993. Of 60 deaths, 51 death certificates were reviewed and V. vulnificus was recorded as the immediate cause of death on 11 (22%). There was no ICD-9 code for V. vulnificus infection, thus no patients had an ICD-9 code indicating V. vulnificus infection. Of 23 certificates where V. vulnificus was recorded on the death certificate, only 5 (22%) were coded for Gram-negative, septicaemia. This study highlights the importance of teaching physicians how to provide epidemiologically meaningful data on death certificates and the need for accurate ICD mortality codes.

To obtain insights into the pathogenic mechanisms involving Mycobacterium paratuberculosis in Crohn's disease (CD) we questioned if the strains of M. paratuberculosis isolated from CD are distinguishable from those involved in Johne's disease (JD), a chronic granulomatous enteritis in cattle. Accordingly we compared human and animal strains at the DNA level, both by the analysis of restriction fragment length polymorphism (RFLP) in and around the insertion sequence IS 900 and by the arbitrarily primed polymerase chain reaction (AP-PCR). Results are in favour of a common clonal origin for the 4 strains isolated from CD and for 8 of the 11 strains isolated from cattle and sheep JD.

A sentinel surveillance system for the control of sexually transmitted diseases (STD) among foreigners was developed in Italy in 1991. From January 1991 to June 1995, 4030 foreigners with a new STD episode were reported. More than one-third of them were North-Africans. The most frequent STDs were non-specific urethritis and genital warts among men, and non-specific vaginitis and latent syphilis among women. The overall HIV prevalence was 5%, with large differences in rates in people from different continents. Very high HIV-positivity rates were observed among homosexuals and homosexual IDUs from Central–South America, with 39·1% and 77·8% seropositive individuals respectively.

These data stress the need for increased knowledge of both the spread of and risk factors for STDs among immigrants. Particular attention should be paid to counselling procedures focused on the prevention of risk behaviours for acquiring STDs and HIV infection.

An Hasidic Jewish community has experienced recurrent hepatitis A outbreaks since 1980. To assess risk factors for illness during a 1985–6 outbreak, the authors reviewed case records and randomly selected 93 households for an interview and serologic survey. In the outbreak, 117 cases of hepatitis A were identified, with the highest attack rate (4·2%) among 3–5 year olds. Among the survey households, the presence of 3–5 year olds was the only risk factor that increased a household's risk of hepatitis A (indeterminant relative risk, P=0·02). Furthermore, case households from the outbreak were more likely to have 3–5 year olds than were control households from the survey (odds ratio=16·4, P<0·001). Children 3–5 years old were more likely to have hepatitis A and may have been the most frequent transmitters of hepatitis A in this community. Hepatitis A vaccination of 3–5 year olds can protect this age group and might prevent future outbreaks in this community.

An outbreak of rubella in April 1996 involved four male British soldiers deployed to Bosnia–Herzegovina. All were helicopter ground crew who were members of the same unit and who periodically travelled to and worked at forward air refuelling stations in Bosnia. There was a potential for spread of the infection to adjacent British units, to troops of other nations in the peacekeeping force, and also to the local civilian population. The British force included 620 female personnel, some of whom may have been non-immune to rubella. One pregnant British servicewoman was repatriated to UK for her own protection. There was a potential health risk, including the possibility of congenital rubella syndrome, in the non-immune wives and partners of deployed male personnel, as a result of contact during the mid-tour home leave of the husbands or partners. The outbreak was monitored through a medical surveillance system known as ARRC 97, and was contained by prompt and rigorous control measures. This outbreak shows the importance of effective surveillance and of good microbiology laboratory support during military operations. The role of immunization against rubella during future military deployments is discussed.

The relationship, in 539 individuals infected with the human immunodeficiency virus (HIV), between two prognostic markers, the CD4 count and beta-2-microglobulin (B2M), and the development of the acquired immunodeficiency syndrome (AIDS) and death was investigated. Cox proportional hazards models were used to determine the risk of AIDS or death. In a multivariate model which adjusted for demographic factors and treatment, the most recent measurements of B2M (relative hazard (RH) 1·37 per g/l higher) and CD4 count (RH 2·17 per log-unit lower) were both significantly associated with the development of AIDS. Similarly, in a multivariate model which additionally adjusted for the development of AIDS as a time dependant covariate, there was a strong relationship with risk of death for the most recent measurements of B2M (RH 1·34 per g/l higher), and CD4 lymphocyte count (RH 1·91 per log-unit lower). A difference in the level of B2M could be used among patients with similar CD4 counts as an indicator of increased risk of progression to AIDS or death. Using the most recent values of these markers provides a better estimate of the risk of AIDS or death, compared to the more common method of analysis, where baseline values of the markers are used.

A prospective longitudinal study of diseases of lambs born in December and January and housed through to slaughter was carried out on three flocks (A, B and C) between 1989 and 1991. In the first year of the investigation (1989–90) three cohorts of approximately 80 lambs were examined in detail on a regular (weekly or fortnightly) basis. This involved over 2000 examinations and at least one clinical abnormality was observed in each lamb. In the second year (1990–1) the farmers were asked to present sick lambs for treatment on the farm. Farmers from flocks A and B participated in this part of the study; a total of 97/1295 lambs that were slaughtered received at least one treatment.

The carcases and visceral organs of lambs from each flock were observed after slaughter. There was no association between the abnormalities observed during routine examination of the cohort lambs (year 1) and those observed at post mortem meat inspection. However, in year 2, in lambs from flock A, there was a significant association between lambs treated for arthritis or pneumonia on the farm and the presence of arthritic or pleuritic lesions, respectively, post mortem. In both years of the study lambs which were older when slaughtered were significantly more likely to have pleuritic, pneumonic or arthritic lesions at meat inspection.

It was concluded that routine examination of groups of lambs is an inefficient and possibly ineffective method to identify lambs with lesions at slaughter. However, lambs which have been treated for disease, and the older lambs in a flock, had an increased prevalence of lesions post mortem and hence more detailed inspection of these animals would increase the efficiency of meat inspection.