The journal that is now Epidemiology & Infection was founded in 1901 as the Journal of Hygiene ‘to fulfil a definite purpose by serving as a focus to English-speaking investigators for works in physics, chemistry, physiology, pathology, bacteriology, parasitology and epidemiology in relation to hygiene and preventive medicine’. In 1987 the name of the journal was changed to Epidemiology & Infection. The reasons for this change were articulated by John Pattison [1] on one of the few occasions that the Editor has directly addressed the readership and formalized the historic shift towards microbiology and epidemiology.

The likelihood of airborne spread of foot-and-mouth disease at the start of the 1967–1968 epidemic is re-assessed in the light of current understanding of airborne disease spread. The findings strongly confirm those made at the time that airborne virus was the most likely cause of the rapid early development of the disease out to 60 km from the source. This conclusion is reached following a detailed epidemiological, meteorological and modelling study using original records and current modelling techniques. The role played by ‘lee waves’ as the mechanism for the spread is investigated. It is thought that they played little part in influencing the development of the epidemic. A number of lessons learned from the work are drawn, identifying the need for further research on the quantity and characteristics of airborne virus. The results are also used to illustrate what advice would have been available to disease controllers if the outbreak had occurred in 2004.

Infections caused by Vibrio vulnificus were first reported in 1979 by Blake et al. of the US Centers for Disease Control. At that time described as a ‘rare, unnamed halophilic lactose-fermenting Vibrio species’, V. vulnificus has emerged as the most virulent foodborne pathogen in the United States with a hospitalization rate of 0·910 and a case-fatality rate of 0·390. It is in addition a significant cause of potentially life-threatening wound infections. Infections following ingestion of raw or undercooked seafood, commonly raw oysters, can lead to a primary septicaemia with a fatality rate of 50–60%. An unusual symptom, occurring in 69% of 274 cases reviewed by Oliver, is the development of secondary lesions, typically on the extremities, which are generally severe (often a necrotizing fasciitis) and require tissue debridement or amputation. These cases occur almost exclusively in males over the age of 50 years. Interestingly, this gender specificity has been found to be due to the female hormone oestrogen, which in some manner provides protection against the lethal V. vulnificus endotoxin. Further, most cases occur in persons with certain underlying diseases which are either immunocompromising or which lead to elevated serum iron levels (e.g. liver cirrhosis, chronic hepatitis, haemochromatosis). V. vulnificus infections resulting in primary septicaemia have been extensively studied, and the subject of several reviews. This review concentrates on the wound infections caused by this marine bacterial pathogen, including the more recently described biotypes 2 and 3, with brief discussions of those caused by other marine vibrios, and the increasingly reported wound/skin infections caused by Mycobacterium marinum, Erysipelothrix rhusiopathiae, and Aeromonas hydrophila.

The free movement of people and foodstuffs between countries are effective ways of distributing disease internationally. There is a requirement for a mechanism whereby data and information on potential outbreaks of foodborne pathogens can be disseminated rapidly to those who need to know. The Enter-net dedicated surveillance network provides this mechanism, complemented by the Salm-gene molecular typing network. Data on epidemiological and microbiological features on current cases, as well as background levels of infections are immediately available within the Enter-net databases. The Salm-gene network with its database of harmonized salmonella PFGE patterns from the participating European countries provides immediate, and electronically exchangeable, DNA fingerprints of outbreak strains. This prompt electronic dissemination of information regarding unusual events with international implications ensures that public health interventions can be implemented and cases of foodborne disease prevented.

From 2000 to May 2004 there has been a marked increase in illness resulting from spore-forming bacteria in injecting heroin users in the United Kingdom. Clostridium novyi caused 63 cases of severe illness in 2000 and seven further cases from 2001. Wound botulism first occurred in 2000 (six cases) with 51 further cases to March 2004. Tetanus occurred in 20 cases between late 2003 and March 2004. Infections with C. histolyticum (nine cases), C. sordellii (one case) and Bacillus cereus (one case) were also reported. The reasons for the increase in illness are unclear. The major risk factor was skin- or muscle-popping. The problem appears to be here to stay. This review describes the causative organisms, pathogenesis, clinical presentation, epidemiology and treatment of cases. Clinical vigilance and a high standard of anaerobic microbiology are essential. Clinicians and laboratories must report such cases (or likely cases) rapidly so that clusters can be rapidly identified, in order to control disease. Prevention relies on tetanus immunization.

Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 ‘definite’ and 32 ‘probable’ cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia.

Epidemiology and Infection became 100 years old in 2001. Its powers and influence however do not appear to have diminished, and, as the Senior Editor appointed in its 101st year, I am greatly honoured to be so closely associated with it. Just over 100 years after it was founded, Epidemiology and Infection is ‘going electronic’. To mark both occasions we have put together a small selection of some of the most important or thought-provoking papers published in our first century, and have invited eminent epidemiologists and microbiologists to assess and comment on them critically in the light of modern knowledge. Naturally, to mark our coming of age in terms of modern methods of communication also, all the papers chosen for our centenary edition will be available – free – online. I am most grateful to my predecessor, Professor Bo Drasar, for putting together this unique tribute to Epidemiology and Infection, its Editors, its Editorial Board, and, not least the authors of our papers. Enjoy and marvel at our predecessors' wisdom, perspicacity and scientific rigour.

For over two centuries yellow fever (YF) had terrorized those visiting and living close to endemic areas. Prompted by continued imports and its impact on US troops in the Spanish–American War of 1898, US Surgeon-General George Sternberg sent a small Commission to investigate the problem in US-occupied Cuba. It comprised James Carrol, Jesse Lazear and Aristide Agramonte; its leader was Surgeon-Major Walter Reed. Whilst in Cuba they collaborated with Cuban Juan Guitéras of Havana's Sanitary Department and Surgeon-Major William Gorgas, American chief of the island's Sanitary Department.

The Danish meningococcal disease laboratory surveillance system was established in 1974, based on close collaboration between local Departments of Clinical Microbiology and the Reference Laboratory at Statens Serum Institut. The completeness of the clinical notification system integrated with the laboratory surveillance system has been estimated to be more than 95%. Overall 4257 (79%) of 5356 cases of meningococcal disease notified during 1974–1999 were confirmed by culture of Neisseria meningitidis. The proportion of culture-confirmed cases ranged from 70% in 1989 to 89% in 1980. Only 26 patients (0·6%) with culture-confirmed meningococcal disease were not notified. Serological phenotype and susceptibility to penicillin and sulphonamide were determined for all isolates. Multilocus enzyme electrophoresis and/or DNA-based analyses were used for the assessment of clusters and outbreaks. Meningococcal antibody tests and counter-immunoelectrophoresis were used for the ascertainment of suspected cases. These combined systems allowed timely and reliable management of outbreaks and identification of clusters.

Between 1996 and 2000, rates of cryptosporidiosis in North West England were significantly higher than overall in England and Wales, particularly during the first half of each year. In addition, during the second quarter of each year in this period, up to 40% of all cases recorded in England and Wales were from the North West Region. In 2001, cryptosporidiosis dramatically decreased throughout the United Kingdom and the springtime excess of cases formerly seen in the North West was no longer apparent. This changed epidemiology was due to a decline in cases of Cryptosporidium parvum (formerly genotype 2), associated with zoonotic transmission. Although the initial loss of a spring peak of infection corresponded with the outbreak of foot-and-mouth disease throughout the United Kingdom, its continued absence relates to major structural changes in the North West public water supply. This study highlights the far-reaching public health benefit of local working relationships in addressing re-occurring disease issues.

As a major foodborne pathogen, Campylobacter jejuni receives much attention in quantitative risk assessment. To date, all dose–response assessments have been based on a single human feeding study which unfortunately provides incomplete and possibly biased information on the dose–response relation. An incident at a dairy farm, where several children from a school class became ill as a result of drinking raw milk contaminated with C. jejuni, appeared to show a very clear dose–response relation between the amount of milk consumed and the attack rate. This relation was very nearly exponentially shaped and, therefore, seemed to conflict with the rather slowly rising dose–response relation established in the feeding study. Here we show that both datasets can be reconciled when illness and infection are considered separately. This not only provides new information on the illness dose–response relation for Campylobacter, but also amends the infection dose–response relation because of their conditional dependence.

In 2002, in The Netherlands a national study of gastroenteritis outbreaks was performed. Epidemiological information was collected by the Public Health Services (PHS) and the Food Inspection Services (FIS) using standardized questionnaires. Stool samples were collected for diagnostic testing. For foodborne outbreaks, food samples were taken. In total, 281 gastroenteritis outbreaks were included, mainly from nursing homes and homes for the elderly (57%), restaurants (11%), hospitals (9%) and day-care centres (7%). Direct person-to-person spread was the predominant transmission route in all settings (overall 78%), except for restaurant outbreaks where food was suspected in almost 90% (overall in 21% of outbreaks). The most common pathogen was norovirus (54%), followed by Salmonella spp. (4%), rotavirus group A (2%), Campylobacter spp. (1%) and only incidentally others. In conclusion, most outbreaks were reported from health and residential institutions, with norovirus as the dominant agent. Control should aim at reducing person-to-person spread. In foodborne outbreaks norovirus was common, due to contamination of food by food handlers. Salmonella, as the second foodborne pathogen, was mainly associated with raw shell eggs. These results stress the continuous need for food safety education, complementary to governmental regulation.

A recent European Union Directive required member states to put monitoring and control programmes in place, of which vaccination is a central component. Live Salmonella vaccines generally confer better protection than killed vaccines, because the former stimulate both cell-mediated and humoral immunity. Administering Salmonella bacteria orally to newly hatched chickens results in extensive gut colonization and a strong adaptive immune stimulus but broiler chickens are immunologically immature. However, colonization exerts a variety of rapid (within 24 h) protective effects. These include specific colonization-inhibition (competitive exclusion) in which the protective bacteria exert a profound resistance to establishment and colonization by other related bacteria. This is thought to be primarily a metabolic attribute of the vaccinating bacteria but may also involve competition for attachment sites. The presence of large numbers of bacteria originating from a live Salmonella vaccine in the intestine can also induce infiltration of polymorphonuclear cells into the intestinal wall, which confers resistance to invasion and systemic spread by virulent Salmonella strains. This opens new perspectives for vaccine usage in broilers, layers and breeding poultry but also in other animals which show increased susceptibility to infection because of their young age or for other reasons, such as oral chemoprophylaxis or chemotherapy, where the lack of established normal gut flora is an issue. We recommend that all live vaccines considered for oral administration should be tested for their ability to induce the two protective effects described above. Further developments in live Salmonella vaccines are, however, currently hindered by fears associated with the use and release of live vaccines which may be genetically modified.

The aim was to establish the prevalence of large pericardial effusions in the Western Cape Province of South Africa, and to determine the incidence of various types of effusions. A total of 233 patients presented with large pericardial effusions. Each patient underwent tests for HIV, sputum smear and culture, blood culture, blood biochemistry and serological testing. Tuberculous pericardial effusions were diagnosed according to pre-determined criteria. Eighty-four patients (36·1%) were found to be HIV positive; 81 of these (96·4%) had tuberculous pericarditis. More than 65% of the study population was aged between 15 and 39 years. The prevalence of HIV amongst unemployed individuals was 49·0% compared to 30·0% amongst employed individuals. Tuberculous pericarditis was the most common cause of pericardial effusions (69·5%, n=162). It was concluded that tuberculosis (TB) is a leading cause of pericarditis in this province of South Africa. The prevalence of TB confounded by HIV co-infection is steadily increasing, burdening the health-care facilities.

‘The opportunities of a pathologist at a large Eastern Hospital are many; but his time for research work is short, and his conveniences are few.’ So begins this landmark paper written by Alfred Whitmore and published in the journal in 1913 [1]. He goes on to demonstrate just how well that short time can be used by someone with the energy, intelligence and scientific rigour in order to make the most of those opportunities. I first read this paper 15 years ago and have re-read it many times since, usually reflecting on how remarkably little our knowledge of melioidosis has advanced since 1913. I notice something new each time I read it and, most importantly of all, each time it is an absolute pleasure to read. How many modern scientific papers leave one feeling the same way?

This study documents the changes in mortality in England and Wales over the last 100 years as a possible explanation for our increasingly allergy-prone Western society. A total of 53 million computerized recorded deaths, which occurred from 1901 to 2000 were analysed retrospectively. Childhood mortality decreased by 98%, from 40·6% of total annual deaths in 1901 to 0·9% in 2000. In 1901, 36·2% of all deaths and 51·5% of childhood deaths were from infectious diseases. By contrast in 2000, 11·6% of all deaths and only 7·4% of childhood deaths were from infectious diseases. Infectious diseases were a significant cause of childhood mortality in British cities until about 40 years ago. Several factors, including vaccination, antibiotics and improved sanitation have contributed to this trend. Survival of individuals with heightened immunity to infections may have led to natural selection of allergy-prone individuals in England and Wales. However, the relationship between changes in rates of infection and allergy is complex and not fully understood.

In August 1998, an outbreak of campylobacteriosis occurred in one municipality in northern Finland. A 10% random sample of residents (population 15000) was selected through the National Population Registry for a survey conducted by using postal questionnaires. Cases were defined as residents of the municipality with onset of acute gastroenteritis from 1 to 20 August 1998. Of 1167 respondents (response rate 78%), 218 (18·7%) met the case definition. Drinking non-chlorinated municipal tap water was strongly associated with illness (OR 34·4). The estimated total number of ill persons was 2700. Campylobacter jejuni was isolated from stool samples of 45 (61%) out of 74 patients tested. All five isolates tested had indistinguishable PFGE patterns. Water samples were negative for campylobacter and coliforms. Epidemiological and environmental evidence suggested mains repair as the source of contamination. Non-chlorinated ground-water systems may be susceptible to contamination and can cause large outbreaks.

Based on 92537 blood samples received from 7365 patients with a request for a meningococcal antibody test (MAT) during a 10-year period (1986–1995), the usefulness of the test in the diagnosis of meningococcal disease was assessed. Of 635 patients with culture-confirmed meningococcal disease, 88% were seronegative on admittance to hospital and 90% were seropositive 10–15 days after onset of disease. The humoral immune response in children <2 years of age was weaker than in older children and adults. Among 893 MAT-positive patients without culture-confirmed meningococcal disease, 261 (29%) had been notified as cases of meningococcal disease. Among 228 patients notified as serologically confirmed the MAT results were consistent with the clinical diagnosis in 86%. MAT is a reliable tool for establishing a diagnosis in patients with suspected meningococcal disease. Key factors facilitating appropriate interpretation of negative as well as positive test results were: time(s) of sampling(s) after onset of disease, age of the patient and clinical features.

Foodborne outbreaks of Salmonella enterica serovar Enteritidis phage type 4 (PT4) infection (n=497), reported to the Health Protection Agency Communicable Disease Surveillance Centre between 1992 and 2002, were compared with other pathogens (n=1148) to determine factors (season, setting, food vehicles, food safety faults) associated with this pathogen. Logistic regression was applied to control for potential confounding. Foodborne general outbreaks of S. Enteritidis PT4 infection were more likely to occur in the spring and summer, and were more often linked to schools, private residences and residential institutions. Eggs, egg products and the use of raw shell egg were strongly associated with this pathogen. Most outbreaks were linked to cross-contamination and inadequate heat treatment. This paper describes the decline in the S. Enteritidis PT4 epidemic, providing evidence that control measures introduced, e.g. improved biosecurity and vaccination, have worked. Continued surveillance of human and veterinary salmonellosis is essential to detect future problems.

Sporadic outbreaks of cyclosporiasis, a common cause of protracted diarrhoea in underdeveloped countries, are often undetected and undiagnosed in industrial countries. In May 2001, an outbreak of Cyclospora cayetanensis gastroenteritis was identified in British Columbia, Canada, with 17 reported cases. We conducted a case-control study involving 12 out of the 17 reported and confirmed case patients. Eleven (92%) of the patients had consumed Thai basil, an essential ingredient in Vietnamese cuisine, compared to 3 out of 16 (19%) of the control patients (P=0·003). Trace-back investigations implicated Thai basil imported via the United States as the vehicle for this outbreak. This is the first documented sporadic outbreak of cyclosporiasis linked to Thai basil in Canada, and the first outbreak of cyclosporiasis identified in an ethnic immigrant population. This outbreak provides the opportunity to increase our understanding of this emerging pathogen and improve on our prevention and control for future outbreaks.