Eurosurveillance - Volume 12, Issue 2, 01 February 2007

Eurosurveillance was created in 1995 to support exchange and dissemination of authoritative scientific information within the part of public health community involved in the field of infectious disease surveillance and control, at a time when European surveillance networks were at an early stage of growth. Now part of a large network, the publication is entering a new stage: the editorial function will now be hosted at the European Centre for Disease Prevention and Control (ECDC) in Stockholm. This will strengthen the platform for the next stage in Eurosurveillance’s development as the major home of peer-reviewed European information on infectious disease surveillance and control.

The problem of methicillin resistant Staphylococcus aureus (MRSA) is increasing worldwide, and the spread of MRSA in the community challenges infection control since it is no longer restricted to hospital settings but involves private homes, places of work and kindergartens [1]. Furthermore, community acquired (CA)-MRSA may circumvent existing hospital infection control, since patients are rarely screened at admission. In the United States, the predominant CA-MRSA is defined by the Center for Disease Control (CDC) as the USA300 (ST8) clone. USA300 primarily causes skin and soft tissue infections (SSTI) in the community [2], but healthcare acquired infections with USA300 are rapidly emerging in the United States [3,4]. Comparison of the Danish collection of MRSA from 1997-2005 with the USA300 reference strain showed that USA300 has been introduced into Denmark on several occasions. Between 2000 and 2005, we identified 44 isolates which in addition to identical pulsed-field gel electrophoresis (PFGE) pattern shared other molecular characteristics with USA300: spa type t008 or closely related variants, Panton-Valentine leukocidin (PVL) positive and Staphylococcal Cassette Chromosome mec (SCCmec) type IVa. The isolates primarily caused SSTI, but cases of invasive infections were also encountered. The number of USA300 has increased several-folds in Denmark from 2003 to 2005 (2, 11 and 28 new cases, respectively) and with the experience from the US in mind, this is of great concern, especially as it is observed in a country with a long reputation for controlling MRSA.

In October/November 2005, the largest outbreak of verotoxin-producing Escherichia coli (VTEC) ever recorded in Ireland occurred. Eighteen E. coli O157 culture-positive cases, phage type 32, verotoxin 2 positive, were identified in a small rural area of mid-west Ireland. Half of these patients were asymptomatic. Two children were admitted to hospital with haemolytic uraemic syndrome, one of whom required peritoneal dialysis, and both recovered. All 18 culture-positive patients had indistinguishable or closely related pulsed field gel electrophoresis (PFGE) patterns. Nine of the VTEC O157 culture-positive individuals were in preschool children attending two local crèches. Several culture-positive individuals apparently had exposure to a vulnerable private group water scheme (GWS) in an agricultural area. No microbiological evidence of VTEC was found in food or water. One veterinary sample (an animal rectal swab) was positive for E. coli O157 and the PFGE strain was indistinguishable from the outbreak strain. A case control study showed analytical epidemiological evidence of risk related to potential exposure to the GWS but not related to reported consumption of that water. Selection of cases and controls proved challenging. Transmission occurred primarily in childcare and family settings, with significant person-to-person spread. Control measures included voluntary closure of the crèches, exclusion of culture-positive individuals in risk groups until microbiological clearance was achieved and the issuing of a ‘boil water’ advisory for drinking water pending upgrading of disinfection facilities.

In June 2004, three confirmed cases of typhoid fever were reported to the health authorities in Leipzig, Germany. The patients had been admitted to hospital with unexplained fever and otherwise mild symptoms. All were members of the same pony club, none had been abroad. A retrospective cohort study among pony club members was performed to identify the source of infection. A suspected case was defined as unexplained fever >=38.5°C over three or more days since 1 May 2004. Additional positive serology defined a probable case and Salmonella Typhi isolation from blood or stool cultures a confirmed case. All hospitals, paediatricians and general practitioners in Leipzig and surroundings were contacted to identify additional cases. In total, six cases were identified, all among pony club members: four confirmed, including the three originally reported cases, one probable and one suspected. The only exposure common to all cases during the probable time of infection was consumption of sandwiches with herb dressing from a snack bar on 25 or 26 May (May 25: RR=5.7; 95% CI 0.9-37.9; both days: RR=, P=0.007). Foods and workers from the snack bar tested negative. However, one worker, not previously registered with the health authorities, was identified during a site visit. It cannot be excluded that further unregistered individuals worked at the snack bar between May and June 2004. Despite intense case-finding activities, no further cases were identified among the population. The most likely vehicle in this outbreak was sandwiches with herb dressing, though the source of contamination remains unknown. Even without history of travel to endemic countries, physicians should consider typhoid fever when managing patients with unexplained fever.

The 7-valent anti-pneumococcal conjugate vaccine (PCV), anti-meningococcal C-conjugate vaccine (MenC) and varicella vaccine have been recently introduced in EU. In Italy, these vaccines have so far been recommended for use in specific groups. Since the health system is decentralised, the Regional Health Authorities (RHAs) can decide to recommend vaccination for other target populations. We conducted a survey to describe the recommendations on these vaccines currently in place in the 21 Italian regions. In November 2005, a standardised questionnaire was sent to RHAs, including information on the existence of regional recommendations, vaccination target population, and whether vaccines were provided free of charge, or at a reduced cost compared to pharmacies. Information reported in the questionnaires were followed up in May 2006. All 21 regions completed and returned the questionnaire and were contacted for follow-up. Recommendations about at least one of the three vaccines were present in 20 out of 21 regions. All included free of charge PCV offering to specific groups, while MenC and varicella immunisations were recommended in 17 and 19 regions, respectively. Recommendations for other individuals varied greatly by area: free of charge PCV and MenC vaccinations targeting all infants have been recommended in nine regions, and varicella vaccination targeting children in the second year of life in three regions. These different recommendations can lead to marked variation in vaccination coverage rates observed through the country, with a consequent different level of disease control. It is thus crucial to properly monitor vaccination coverage rates for PCV, MenC and varicella, as these are not routinely collected at the national level.

Rotavirus infection is one of the main causes of acute gastroenteritis and has an important impact on hospitalisation. There is no homogeneous surveillance system for rotavirus infections in Europe. The aim of this study is to develop a predictive model in order to estimate the expected rotavirus infections in the population covered by a hospital. A five year study (2000-2004) was developed in a Spanish university hospital. A correlation test between the notifications reported to the Microbiological Information System (SIM) and hospitalisations was carried out, as well as a time series analysis, obtaining the trend and the cyclical components. The predictive model was adjusted using the least squares method. A direct relationship between the microbiological isolations and the hospitalisations was established (=0.925; p<0.001). A significant annual cycle was observed, with the peak of cases occurring in February. The two principal outbreaks that occurred in the study period would have been detected with the predictive model. Expected rotavirus cases and hospitalisations for 2005 and 2006 were obtained. The notifications of rotavirus infections reported to SIM are adequate in order to establish a hospital surveillance system, but a predictive model which provides expected cases is also necessary. Therefore, this tool will be useful to evaluate preventive measures such as rotavirus vaccines, which will soon be available in Europe.

In Slovenia, varicella and herpes zoster infections are case-based mandatorily notifiable diseases. We present surveillance data for a period of ten years (1996 - 2005). Incidences of varicella ranged from 456 to 777 per 100 000 population in all age groups. As many as 75% of varicella cases reported were in pre-school children, with children aged three and four years being most affected. The incidence of varicella increased between October and January and was lowest in August and September; the seasonal pattern matches patterns in the school calendar. Herpes zoster was declared a reportable disease in 1995. In 2005, 1627 cases were notified (81.3/100 000). Female cases outnumbered male. The highest incidence of herpes zoster was noted in elderly individuals over 70 years of age. Complications, such as zoster meningitis and meningoencephalitis, were rarely reported (3.05/1 000 000).