Eurosurveillance - Volume 11, Issue 4, 01 April 2006

People can catch diarrhoeal diseases from contamination of both natural and man-made environments with human or animal faeces. Young children are more likely to be susceptible to the agents and to be exposed. While some diarrhoeal diseases acquired in childhood can be relatively mild and give some protection as an adult, others are more severe. The two papers presented in this issue of Eurosurveillance describe, on the face of it, unremarkable small outbreaks; one, from Chikwe Ihekweazu et al, linked to exposure to a stream contaminated with Escherichia coli from animal faeces [1]; the other, from Melanie Jones et al, to exposure to a water feature contaminated with Cryptosporidium parvum from either animal or human faeces [2].

A need for national guidelines relating to interactive water features was highlighted following three outbreaks of cryptosporidiosis in the United Kingdom, all of which were related to public water features. In August 2003 the Health Protection Agency South West of England was notified of an outbreak of cryptosporidiosis associated with an interactive water feature designed for water play within an adventure park. The water feature was implicated following samples with a high coliform count and the presence of faecal coliforms. A case was defined as any child (younger than 16 years of age) who had visited the park during August and who subsequently had gastrointestinal symptoms and a faecal sample positive for cryptosporidium. Seventy one children were identified in the cohort. This outbreak of cryptosporidiosis was characterised by a very high attack rate (89%), relatively severe in duration (median 8 days) and had a relatively high hospital admission (16% of cases). The epidemic curve was consistent with a point source of infection, which corresponded to the date 80% of the cohort visited the park. This outbreak has similarities to two other cryptosporidiosis outbreaks reported in England in 2003 that involved public water features. These outbreaks raise issues about the operation and maintenance of water-based recreational attractions that very often involve children. The paper reflects on the basic control measures that can be taken and highlights the need for guidelines, especially since such attractions are becoming increasingly common. The Pool Water Treatment Advisory Group in United Kingdom has now produced guidelines.

In August 2004 seven cases of Escherichia coli O157 infection were identified in children on holiday in Cornwall, southwest England, all of whom had stayed at different sites in the area. Isolates from all seven cases were confirmed as E. coli serogroup O157 phage type 21/28. We carried out a case-control study among holidaymakers who visited the beach. A standardised questionnaire was administered by telephone to parents. They were asked where on the beach the children had played, whether they had had contact with the stream that flowed across the beach, and about their use of food outlets and sources of food eaten. Cases were more likely to have played in the stream than controls (OR [1.72- undefined]). The time spent in the stream by cases was twice spent there by controls. Cases and controls were equally exposed to other suspected risk factors. PFGE profiles for all the cases were indistinguishable. Increased numbers of coliforms were found in the stream prior to the outbreak. Cattle were found grazing upstream. We suggest that the vehicle of infection for an outbreak of acute gastrointestinal illness caused by E. coli O157 was a contaminated freshwater stream flowing across a seaside beach. The onset dates were consistent with a point source. Heavy rainfall in the days preceding the outbreak might have lead to faeces from the cattle potentially contaminated by E. coli O157 contaminating the stream, thereby leading to the outbreak. Control measures included fencing off the part of the stream in which children played, and putting up warning signs around the beach.

In 2001 Germany implemented a new electronic reporting system for surveillance of notifiable infectious diseases (SurvNet@RKI). The system is currently being used in all 431 local health departments (LHD), the 16 state health departments (SHD) and the Robert Koch-Institut (RKI), the national agency for infectious disease epidemiology. The SurvNet@RKI software is written in MS Access 97 and Visual Basic and it supports MS Access as well as MS SQL Server database management systems as a back-end. The database is designed as a distributed, dynamic database for 73 reporting categories with more than 600 fields and about 7000 predefined entry values. An integrated version management system documents deletion, undeletion, completion and correction of cases at any time and entry level and allows reproduction of previously conducted queries. Integrated algorithms and help functions support data quality and the application of case definitions. RKI makes the system available to all LHDs and SHDs free of charge. RKI receives an average of 300 000 case reports and 6240 outbreak reports per year through this system. A public web-based query interface, SurvStat@RKI, assures extensive and timely publication of the data. During the 5 years that SurvNet@RKI has been running in all LHDs and SHDs in Germany it has coped well with a complex federal structure which makes this system particularly attractive to multinational surveillance networks. The system is currently being migrated to Microsoft C#/.NET and transport formats in XML. Based on our experiences, we provide recommendations for the design and implementation of national or international electronic surveillance systems.

Measles re-emerged in some counties in Germany in 2005, despite increasing vaccination coverage rates in children at school entry in recent years, which had led to decreasing incidence (with the lowest incidence ever recorded, 0.2 cases per 100 000 inhabitants in 2004). Regional outbreaks have been detected by the mandatory reporting system in the states of Hesse and Bavaria. Although both outbreaks led to similar incidences in the affected areas (14 and 12 cases respectively per 100 000 inhabitants) they differed in age distribution, transmission patterns and measles virus genotype. In Hesse, 223 cases were submitted, from which 160 belonged to 41 clusters mainly defined by family or household contacts. Attack rate was highest in children aged between 1-4 years (102 cases per 100 000). Results of measles virus diagnosis showed genotype D4 and identical nucleotide sequences for all analysed cases from Hesse. In Bavaria, 279 cases were submitted, most of which had occurred in schools and preschool facilities. Age-specific attack rate was highest in children aged between 5-9 years (129 per 100 000). Laboratory diagnosed viruses were identified as genotype D6 and were identical at the nucleotide level. In both outbreaks the vast majority of cases (95% in Hesse and 98% in Bavaria) were in unvaccinated children, but vaccination coverage differed in the affected areas and was slightly lower in Bavaria than in Hesse. Local accumulation of unvaccinated children and their concentration in schools and kindergarten preceded the outbreak in Bavaria. Despite high average vaccination coverage levels, local variations may lead to regionally limited outbreaks.

The first HIV/ AIDS cases in Poland were diagnosed in the mid-1980, and the outbreak in injecting drug users was first observed in 1989. For many years the HIV epidemic in Poland was driven by injecting drug use. In this study we examine the trends in the HIV/ AIDS epidemic based on the surveillance data for 1999-2004. During this period, 3561 new HIV infections (annual rate of 15.4 per 1 000 000 inhabitants) were reported and 803 incident AIDS cases (incidence 3.5 per 1 000 000) were diagnosed. Both the annual number of newly detected HIV infections and the AIDS incidence showed a slight increasing trend. In particular, the vertically transmitted AIDS incidence increased from 0.46 in 1999 - 2000 to 0.91 per 1 000 000 children under 15 years in 2003 - 2004. Approximately 36% of AIDS patients aged 15 years or above had not been previously diagnosed with HIV. The annual number of the late presenters increased markedly between 1999 and 2004 and was higher amongst individuals infected through sexual transmission (51.0%) than those infected by injecting drug use (20.1%) . Injecting drug users made up 78.6% of new HIV infections with known transmission route, but for 47.9% of all cases the route of transmission was not reported. In order to generate more accurate data, HIV surveillance must be enhanced. Nevertheless, there is clear evidence for implementation of a comprehensive programme of prevention of vertical transmission and encouraging more extensive HIV testing especially in the groups at risk for sexual transmission. An effort is needed to enhance HIV surveillance and prevention in the framework of programmes for STI.

Six hundred and fifty five cases of travel-associated legionnaires’ disease with onset in 2004 have been reported to the EWGLINET surveillance scheme by 25 countries. A total of 84.9% of cases were diagnosed by the urinary antigen test, and 37 cultures were obtained. Thirty seven deaths were reported, giving a case fatality rate of 5.6%. Eighty six new clusters were detected, 45% of which would not have been detected without the EWGLINET scheme. Ninety four accommodation sites were investigated and the names of four sites were published on the EWGLI website. Fifteen sites were associated with additional cases after a report was received to say that investigations and control measures had been satisfactorily carried out. Further improvements could be made in the data collected on deaths due to travel-associated legionnaires’ disease, and on the number of samples taken for culture throughout Europe.