TB across the globe (3). Tuberculosis in Russia

This paper was presented in place of one that was to have been given by the late Professor A.G. Khomenko, Director of the Central Tuberculosis Research Institute, Moscow. Professor Khomenko had a long and distinguished career and with his death Russia has lost one of its finest and most active workers in the fight against TB.

Continuous source outbreak of campylobacteriosis traced to chicken

Poultry is a source of human campylobacteriosis, but a large continuous source outbreak, heretofore, has not been attributed to both a single source of poultry and single serotype of Campylobacter. Here we report an outbreak of C. jejuni affecting 6 catering college trainees and 13 patrons of a restaurant in southern England. An epidemiological investigation successfully tracked the outbreak source to the farm of origin. Frequency of occurrence of campylobacters and outbreak serotype distribution were determined in index cases, the local population, and local chicken suppliers. The source farm was investigated and the effect of interventions assessed. A single outbreak serotype of C. jejuni was isolated from trainee chefs, patrons, and chicken supplied to the college by Wholesaler A. The Campylobacter isolation rate for Wholesaler A was 89% (98% outbreak serotype), compared to 40% for non-Wholesaler A (10% outbreak serotype). The isolation rate for 14 months averaged 85% (99% outbreak serotype) in chickens grown on two farms (X and Y) supplying Wholesaler A, contributing approximately 40% to all local cases. In the research reported here, a specific strain and hygiene practice were found to be important for understanding transmission of Campylobacter from poultry to humans in this outbreak.

Microbial ecology of Campylobacter jejuni in a United Kingdom chicken supply chain: intermittent common source, vertical transmission, and amplification by flock propagation

A study of Campylobacter jejuni on a broiler chicken farm between 1989 and 1994 gave an estimated isolation rate of 27% (3,304 of 12,233) from a 0.9% sample of 1.44 million broiler chickens from six to eight sheds over 32 consecutive rearing flocks comprising 251 broiler shed flocks. During the study, C. jejuni was found in 35.5% of the 251 shed flocks but only 9.2% (23 of 251) had Campylobacter isolates in successive flocks, with 9 of those 23 sheds having the same serotype between consecutive flocks, indicating a low level of transmission between flocks. Analysis of a systematic sample of 484 of 3,304 (14.6%) C. jejuni isolates showed that 85% were of 10 serotype complexes but 58% were of 3 serotype complexes, indicating a high degree of strain similarity throughout the entire study. The three commonest types were detected in 8 of 32 flocks during the 5-year study period, suggesting an intermittent common external Campylobacter source. This hypothesis was tested by a retrospective cohort analysis of C. jejuni rates and types by reference to hatchery supplier of the 1-day-old chicks. Isolation rates of C. jejuni and frequency distribution of types were determined in 6-week-old broiler chickens identified by the hatchery supplying the original chicks. The isolation rate of C. jejuni in broilers, supplied by hatchery A, was 17.6%, compared to 42.9% (P < 0.0001) for broilers reared from chicks supplied by hatchery B. In two instances, when both hatcheries were used to stock the same farm flock, Campylobacter isolates were found only in those sheds with chicks supplied by hatchery B. Thus, the frequency distribution of Campylobacter types for chickens supplied by the two hatcheries over the 5-year period showed marked dissimilarity. These findings suggest that the isolation rate and type of Campylobacter isolates in broiler chickens was associated with the hatchery supplying chicks. The lack of diversity of types and the intermittent high positivity of sheds is evidence for a common source of C. jejuni introduced by vertical transmission rather than contamination at the hatchery or during transportation.

Waterborne cryptosporidiosis associated with a borehole supply

From 1 April to 31 May 1993, 64 cases of cryptosporidiosis were diagnosed within one district health authority. Forty were classified as primary cases, 35 of whom were clustered in an area supplied by a discrete public water supply that supplied the majority of homes in a large town. Most of the water in this supply is abstracted from boreholes and some is filtered before distribution. Households that received mains water from this supply were 15 times more likely to be affected than households nearby that received water from other sources. A case control study demonstrated a dose response relationship between consumption of water obtained from the town supply and risk of illness. Very low concentrations of cryptosporidial oocysts were detected in the water supply on four occasions several weeks after the outbreak. Environmental investigation failed to reveal a likely mechanism for contamination of the water supply.

The infection hazards of human cadavers

Cadavers may pose infection hazards to people who handle them. None of the organisms that caused mass death in the past--for example, plague, cholera, typhoid, tuberculosis, anthrax, smallpox--is likely to survive long in buried human remains. Items such as mould spores or lead dust are much greater risks to those involved in exhumations. Infectious conditions and pathogens in the recently deceased that present particular risks include tuberculosis, group A streptococcal infection, gastrointestinal organisms, the agents that cause transmissible spongiform encephalopathies (such as Creutzfeldt-Jakob disease), hepatitis B and C viruses, HIV, and possibly meningitis and septicaemia (especially meningococcal). The use of appropriate protective clothing and the observance of Control of Substances Hazardous to Health regulations, will protect all who handle cadavers against infectious hazards.

Infection in the deceased: a survey of management

Funeral directors, control of infection officers, chief environmental health officers, and consultants in communicable disease control were surveyed to identify the sources and nature of advice about infectious hazards from the deceased available to undertakers. They were asked about management responsibilities, policies, particular activities (viewing, hygienic preparation, bagging, embalming, and final disposal by burial or cremation), specific diseases (hepatitis B, HIV infection, tuberculosis, meningitis, septicaemia, and salmonellosis), and repatriation. A wide range of opinions and advice was received on each topic. Medical personnel need a greater understanding of the work of funeral directors. Policies based on a realistic assessment of risk should be agreed.

An outbreak of Campylobacter infection associated with the consumption of unpasteurised milk at a large festival in England

Seventy-two laboratory confirmed cases of Campylobacter infection were identified in people who attended a large festival in England. A case-control study was undertaken to identify the vehicle of infection. Potential risk factors included the water supply to the site, and food, bottled spring water and unpasteurised milk sold at the event. Only the consumption of unpasteurised milk showed a statistical association with having a Campylobacter infection, strongly suggesting that this was the vehicle of infection.

Communicable diseases in former Yugoslavia and in refugees arriving in the United Kingdom

The war in the republics of former Yugoslavia has created the largest number of European refugees since the Second World War. Over 40,000 people from the republics arrived in the United Kingdom before visa restrictions were applied in September 1992, although not all of these were refugees. In November 1992, permission was given for about 4000 Bosnian ex-detainees and their dependents to come to the UK, about 700 of whom had arrived by the end of April 1993. The pre-war health care system in the republics is breaking down and the reporting and control of communicable diseases has been disrupted. Tuberculosis, lice and scabies are likely to affect refugees from former Yugoslavia. Suggestions are given for the management of refugees arriving in the UK, as well as travel health advice for aid workers and others going to the region.

Colonization of broiler chickens by waterborne Campylobacter jejuni

Chickens on a broiler farm in southern England were found to be colonized with Campylobacter jejuni of a single serotype, Lior 1 Penner 4. The farm was the sole supplier of a local slaughterhouse associated with a campylobacter outbreak in 1984 caused by this serotype. The serotype persisted on the farm for at least 18 months after the outbreak; its prevalence in the human population served by the farm remained high until it disappeared from the farm in 1986. The possible sources and routes of transmission of C. jejuni to the broilers on the farm were investigated. The results showed that vertical transmission, feed, litter, small mammals, and environmental or airborne cross-contamination between sheds or successive crops could be excluded as persistent sources of C. jejuni. The predominant source of C. jejuni on the farm was shown to be the water supply. Direct microscopy and fluorescent antibody methods revealed presumptive campylobacters throughout the farm's water system. Campylobacter-free chickens raised in an animal house and given water from the farm supply became colonized with the serotype of C. jejuni endemic on the farm (Lior 1 Penner 4). An intervention program based on water chlorination, shed drinking system cleaning and disinfection, and withdrawal of furazolidone from feed reduced the proportion of birds colonized with campylobacter from 81 to 7% and was associated with a 1,000- to 10,000-fold reduction in campylobacters recoverable from the carcasses. Two months after the end of the intervention program colonization of the birds returned to high levels (84%), indicating that there was a temporal association between intervention and reduced colonization with C. jejuni. Investigations continue to establish the general applicability of these findings.

The surveillance and control of campylobacter infection

Campylobacter jejuni and C. coli are the most commonly reported bacterial causes of enteritis in man in the United Kingdom. The reported incidence of campylobacter infection varies with place and time. Its epidemiology differs from that of salmonella: campylobacters do not multiply on food, secondary spread is rare, and infections peak at the end of May (salmonellas peak in July). Known sources of infection include poultry, milk, water, pets and other domestic animals. Campylobacters are widespread in the environment, and in domestic and wild birds and mammals. About 10% of infections reported in the UK are acquired abroad. The application of preventive measures can be effective in reducing the incidence of infection and its not inconsiderable financial burden.

The surveillance of communicable disease in the European Community

This article summarises the existing international structures in Europe which collate data produced by surveillance systems in individual countries. The surveillance of influenza, tuberculosis, and other infections in Europe is undertaken by the World Health Organisation (WHO), the European Community (EC), and national and international organisations set up to study specific diseases. The surveillance of foodborne infections, rabies, travel-associated legionellosis and AIDS/HIV is undertaken by WHO collaborating centres or WHO/EC programmes. Research into immunisation and sexually transmitted diseases other than HIV is carried out through EC concerted action programmes. The Maastricht treaty, if ratified, may lead to changes in the way communicable disease surveillance is undertaken in the EC.

Salmonella in rodents: a risk to man?

Studies of salmonella infections in rodents in the United Kingdom have focused particularly on rats and house mice. Only rarely were more than 10% of animals found to carry salmonella. The organisms were mostly cultured from spleen or liver and less than 3% of animals were found to carry these organisms in the intestine. The extensive use of 'virus' rodenticides (consisting of salmonella cultures) in the first half of this century increased the prevalence of salmonella carriage in rodents and was a hazard to human health. Whilst rodents certainly acted as sources of human salmonella infection in the UK in the past, their role has probably never been great.

Frequency of isolation of campylobacter spp., Yersinia spp. and salmonella spp. from small mammals from two sites in Southern Britain

Small wild mammals were trapped at two sites in the United Kingdom: Skomer Island, Dyfed and a farm in Dorset. Faecal samples were collected from 43 rodents of two species on Skomer and tested for the presence of Yersinia. Samples of faeces and of material from the terminal ileum were collected from 141 animals of eight species in Dorset and tested for Campylobacter, Yersinia and Salmonella. In addition some samples of spleens from the Dorset animals were tested for Campylobacter. Four typable isolates of Campylobacter were obtained from the Dorset site, two from spleens from shrews and two from intestinal contents from a bank vole. Nineteen isolations of Yersinia were made from the Skomer animals and seventeen from animals in Dorset. No isolations of Salmonella were made from any of the animals sampled.

Infections with blood parasites in the small British rodents Apodemus sylvaticus, Clethrionomys glareolus and Microtus agrestis

Three populations of small wild British rodents were studied by capture-recapture methods over a period of 3 years, a fourth group was studied for 1 year and a fifth was sampled annually for 4 years. Blood smears were taken from 3 species of rodents: the woodmouse Apodemus sylvaticus, the bank vole Clethrionomys glareolus (and an island sub-species C.g. skomerensis) and the short-tailed vole Microtus agrestis. The smears were examined microscopically. Four genera of haemoparasites Babesia, Hepatozoon, Trypanosoma and Grahamella were detected. Babesia was absent from C.g. skomerensis, Hepatozoon was rarely found in A. sylvaticus and M. agrestis and Trypanosoma was rare in A. sylvaticus. More males were infected than females but the difference was only statistically significant for the infection with Hepatozoon in adult C.g. skomerensis. Infections with Babesia and Hepatozoon were more prevalent in adult animals and infections with Trypanosoma were more prevalent in younger individuals. Only in C.g. skomerensis was there a significant difference between age classes in the prevalence of infection with Grahamella--there being more adults infected. Concurrent infections were detected, Hepatozoon being the parasite most commonly involved. The prevalence of infections was found to be approximately proportional to the number of animals known to be alive, regardless of the season.

Etomidate: a valuable anaesthetic for mice

Etomidate, a new nonbarbiturate short-acting hypnotic agent, was effective in anaesthetizing laboratory mice at a dose of 23.7 +/- 1.5 mg/kg bodyweight ip. Surgical anaesthesia developed which permitted the performance of operations upon the animals for at least 20 minutes after induction. In these mice (LACA-2 and C57-BL strains), doses up to 33 mg/kg were tolerated. Recovery from anaesthesia was uncomplicated.

A note on some Enterobacteriaceae from the faeces of small wild British mammals

Over a four-year period 878 samples of faeces were collected from five species of small wild rodents and two species of shrews at sites in England, Scotland and Wales. A search was made for Salmonella in these samples but no isolations of this genus were made. Several other genera of Enterobacteriaceae were identified.

Evidence of infection by viruses in small British field rodents

Four populations of small wild British rodents were studied by capture--re-capture methods over a period of three years. Samples of blood were taken from these animals and tested for antibodies to nine viruses. Animals were removed from another 11 sites around the UK, and immunosuppressed. Samples of tissue from these animals were tested for the presence of viruses by passage in laboratory mice and serum samples from some of them were tested for antibody to the nine viruses. Indications were found of the possible influence of epizootic outbreaks of certain diseases on animal populations.