Eurosurveillance - Volume 9, Issue 11, 01 November 2004

In the past 20 to 30 years, methicillin-resistant Staphylococcus aureus (MRSA) strains have been present in hospitals and have become a major cause of hospital-acquired infection. Methicillin resistance rates of S. aureus vary considerably between countries, with a high prevalence in the United States, and southern Europe (>20%) and a low prevalence in northern Europe (< or =5%). Community-acquired MRSA emerged worldwide in the late 1990s. There has been great confusion in the literature between healthcare-associated MRSA infections occurring in the community in patients who are at risk of acquiring hospital MRSA (such as those with past history of hospital admission, immunocompromised status, etc.), and true CA-MRSA infections due to strains that are present in the community only.

Analysis of methicillin-resistant Staphylococcus aureus (MRSA) isolates in the Netherlands in 2003 revealed that 8% of the hospital isolates carried the loci for Panton-Valentine leukocidin (PVL). Molecular subtyping showed that most Dutch PVL-MRSA genotypes corresponded to well-documented global epidemic types. The most common PVL-MRSA genotypes were sequence type ST8, ST22, ST30, ST59 and ST80. MRSA with ST8 increased in the Netherlands from 1% in 2002 to 17% in 2003. It is emphasised that PVL-MRSA might not only emerge in the community, but also in the hospital environment.

Infections by community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) have been reported worldwide. Here we present characterisation of the first CA-MRSA isolated in Latvia. A PVL-positive ST30-MRSA-IV strain was isolated from a nasal swab and the central venous catheter of a patient with fever and multiple organ failure. The PFGE pattern of this strain was identical to pattern SE00-3 of MRSA isolated in Sweden from 29 patients during 2000-2003. This strain is related to the South Pacific area, and its appearance in Sweden and Latvia demonstrates its global spread.

Salmonella enterica serotype Enteritidis is the predominant salmonella serovar identified by the Enter-net national reference laboratories in western Europe. As it is the most commonly recognised serotype, it is important that phage typing is carried out so that outbreaks can be recognised and confirmed, and trends in infections identifed. Data from the Enter-net salmonella database show that there has been a dramatic shift between phage types identified in Europe from 1998-2003. In 1998, the proportion of phage type (PT) 4 was 61.8%, making it the most frequently identified phage type in humans (21 630 cases), whereas by 2003 the proportion of PT4 had fallen to 32.1% (8794 cases) with other strains increasing, both in proportion and numbers. This paper identifies the emerging strains that are becoming more relevant in public health terms.

One of the objectives of any surveillance activity is to monitor trends in infections. The international surveillance network for human enteric infections, Enter-net, has been collecting and reporting data on laboratory-confirmed human salmonella infections since 1993. The number of cases identified rose in the mid-1990s, with the peak being in 1997. This paper describes the subsequent decline in salmonella serotypes being reported by the national reference laboratories participating in the Enter-net surveillance network between 1998-2003. The total number of human cases of salmonellosis reported by the Enter-net participating countries has fallen from 220 698 to 142 891 during this period. Even at these reported levels salmonellosis remains a major cause of morbidity in humans.

Routine notification of invasive meningococcal disease has a long tradition in the Czech Republic: mortality data are available from 1921 and morbidity data from 1943. The collection of Neisseria meningitidis strains kept in the NRL for Meningococcal Infections in Prague dates from 1970 onwards, and represents more than 3500 strains isolated from invasive disease and their contacts, from healthy carriers and from respiratory infection. Analysis of these strains showed that the Czech meningococcal population is different from that seen in western Europe. In 1993, the incidence serogroup C meningococcal disease increased and was associated with the emergence of the hypervirulent complex Neisseria meningitidis C, ST-11, ET-15/37, and caused an increase in the incidence of invasive meningococcal disease which peaked in 1995 (2.2/100 000). A vaccination strategy targeting the part of the population at highest risk of invasive meningococcal disease was adopted in the country.

The Eighth International Meeting of the European Laboratory Working Group on Diphtheria (ELWGD) and the Diphtheria Surveillance Network (DIPNET) was held and co-organised with the WHO Regional Office for Europe, Copenhagen, Denmark, in June 2004. This article provides an international updated review of progress in clinical, epidemiological and microbiological aspects of diphtheria in the European region as presented at the meeting. It highlights the need for improved immunisation coverage, surveillance and epidemiological studies to sustain control of diphtheria in European Region.