In order to study the prevalence of antibody to hepatitis E virus (HEV) among hemodialysis patients and to evaluate whether chronic hemodialysis is associated with an increased risk of exposure to HEV in developed countries, the IgG anti-HEV was determined in serum samples obtained from 182 patients on chronic hemodialysis and 349 statistically selected, healthy Swedish control subjects. Serum specimens from 11 of the 182 (6.0%) hemodialysis patients and from 18 of the 349 (5.2%) control subjects were repeatedly positive for HEV antibodies (the difference was not significant: P = .67). Analysis of serial serum samples obtained at the initiation of hemodialysis and consecutively during follow-up periods of several years demonstrated no IgG anti-HEV seroconversion during chronic hemodialysis. The seroprevalence of anti-HEV antibody in the adult Swedish population was associated significantly with age. In persons younger than 40 years, the percentage of seropositive individuals was 2.5%, whereas the seroprevalence rate of anti-HEV was 7.4% in subjects older than 40 years (P < .05). This study indicates that nosocomial transmission of HEV to patients on maintenance hemodialysis was non-existent in three dialysis centers in Sweden (a developed country) and that chronic hemodialysis is not associated with an increased risk of exposure to HEV infection in this region.

The nasopharyngeal carriage rate of potential respiratory pathogens was studied in 36 index children with a pneumococci nonsusceptible to penicillin (PNSP), in 595 healthy children, and in 123 personnel at 16 day-care centers (DCCs) with index cases in the Stockholm area, an urban area with a low incidence of antibiotic resistant pneumococci, during the winter of 1997-1998. The spread and clonality of PNSP, Haemophilus influenzae and Moraxella catarrhalis, were studied by analyzing antibiotic susceptibility and serotype, and for PSNP also by using pulsed-field electrophoresis (PFGE) and multilocus sequence typing (MLST). In contrast to the low carriage rate found among the adult contacts (2%), 40% of the children harbored pneumococci, of which 20% were PNSP. Nasopharyngeal colonization decreased with age. The 49 PNSP isolates consisted of 20 clones, of which 10 could be identified in more than one child attending the same or different DCCs. In five DCCs, we observed a spread of PNSP from the index case. A novel PNSP clone of type 35B, found to cause invasive disease in several states in the United States, was found to emerge among several carriers at two DCCs . A high proportion of PNSP isolates were multiresistant to antibiotics (34%), which has implications for treatment regimens, even in a country like Sweden where the proportion of PNSP currently is low (3-4%). One PNSP clone of type 9V found among the carriers, has been shown to cause invasive disease in Sweden as well as in other countries, suggesting that one reason for the occurrence of invasive PNSP clones may be their ability to colonize and spread among healthy carriers. Other internationally spread antibiotic resistant pneumococcal clones found were of types 9V, 19F, and 23F.

To determine the prevalence of the asymptomatic carriage of drug-resistant Streptococcus pneumoniae (DRSP) by children attending day-care centres in the Stockholm area, nasopharyngeal swabs were cultured from 1129 children and 308 day-care personnel in 36 day-care centres during a 3-week period, from March to April 1995. Approximately 36% of the children were asymptomatic carriers of S. pneumoniae sensitive to penicillin and other antibiotics. The highest prevalence of nasopharyngeal carriage was found in the 2-year-old group (50%), whereas among the 4-year-old children colonization was observed in 42%, and among the 7-year-old children 21% were asymptomatic carriers of penicillin-sensitive S. pneumoniae. In 2 day-care centres, 4 and 5 children, respectively, were found to have DRSP strains in the nasopharynx. The same serotype of DRSP strain was found among the children attending the same day-care centre. During the same period, none of the staff were found to harbour DRSP in the nasopharynx, but 3% were asymptomatic carriers of penicillin-sensitive S. pneumoniae. The patterns of nasopharyngeal colonization by Haemophilus influenzae, Moraxella catarrhalis and Group A streptococci were also studied in 635 children during the same period. 42% of the nasal cultures yielded Moraxella, 32% H. influenzae and 2% Streptococcus pyogenes.

The total number of persons infected or colonised with vancomycin-resistant enterococci mandatorily reported to the Swedish Institute for Infectious Disease Control increased dramatically during 2007 and 2008. During a period of twenty months from 1 July 2007 to 28 February 2009, a total of 760 cases were reported compared with 194 cases reported during the entire period from 2000 to 2006. This rise was mainly attributed to a wide dissemination of vancomycin resistant enterococci which started in a number of hospitals in Stockholm in the autumn of 2007 and was followed by dissemination in various healthcare facilities (hospitals and homes for the elderly) in a further two Swedish counties in 2008. The majority of the cases (97%) were acquired in Sweden and among these, healthcare-acquired E. faecium vanB dominated (n=634). The majority of these isolates had identical or closely related pulsed-field gel electrophoresis patterns indicating clonal dissemination in the affected counties. The median minimum inhibitory concentration of vancomycin was 32 mg/L (ranging from 4 to >128 mg/L) and of teichoplanin 0.12 mg/L (ranging from 0.06 to 0.25 mg/L). Particular emphasis was placed on countermeasures such as screening, contact tracing, cleaning procedures, education in accurate use of infection control practices as well as increasing awareness of hygiene among patients and visitors. With these measures the dissemination rate decreased substantially, but new infections with the E. faecium vanB strain were still detected.

Background: The present prospective study was conducted from [2003][2004][2005], among all individuals 65 years and older in Uppsala County, a region with 300 000 inhabitants situated close to the Stockholm urban area.