Surveillance of infections in long-term care facilities (LTCFs): The impact of participation during multiple years on health care-associated infection incidence.

We studied trends in the incidence of health care-associated infections (HAIs) in LTCFs between 2009 and 2015 and determined the effect of participation in our network. Elder-care physicians reported weekly the number of cases of influenza-like illness, gastroenteritis, (probable) pneumonia, urinary tract infections (UTIs) and all-cause mortality. Trends in the incidence of infection and mortality in relation to LTCF characteristics were calculated using multilevel univariate and multivariate logistic regression. Thirty LTCF participated for 3 years or more, 16 for 2 years and the remaining 12 LTCF for 1 year. During the study period, the median number of beds decreased from 158 to 139, whereas the percentage of residents with private bedrooms increased from 14% to 87%. UTIs were the most frequently reported infections, followed by (probable) pneumonia and gastroenteritis. Adjusted for calendar year and season, we observed a statistically significant decrease in the incidence of influenza-like illness (odds ratio (OR) = 0.8, P < 0.01) and (probable) pneumonia (OR = 0.8, P < 0.01) for each extra year an LTCF participated. Although there are other likely contributors, such as more private rooms and enhanced infection control measures, the decreasing trend of HAI in LTCFs participating in surveillance implies that surveillance is a valuable addition to current strategies to optimise infection control.

Assessing potential introduction of universal or targeted hepatitis A vaccination in the Netherlands.

In many industrialized countries, hepatitis A incidence rates have declined steadily in the past decades. Since future cohorts of non-vaccinated elderly will lack protection against disease and the burden of hepatitis A is higher with increasing age, this could be an argument in favour of taking preventive measures such as including hepatitis A vaccine into the National Immunisation Program, or offering hepatitis A vaccine to the elderly only. Using a vaccination evaluation scheme, we assessed the potential benefits and drawbacks of introducing hepatitis A vaccine in the National Immunisation Program in the Netherlands. The average number of annual hepatitis A notifications is declining, from 957 in the period 1991 to 1995 to 211 over the period 2006 to 2010. The direct health care costs and costs due to productivity losses per patient are rising, because the age at infection increases and older patients require a relatively higher number of hospitalizations. Initiating a vaccination program would most likely not be cost-effective yet. The annual costs of mass-vaccination are large: about €10 million for infants and €13 million for older people (and only in the first year €210 million), based on current retail prices. The annual effects of mass-vaccination are small: the cost-of-illness in recent years attributed to hepatitis A infection is estimated to be €650,000 per year, and the disease burden is on average 17 DALYs. Given the current low hepatitis A incidence, and the continuing decline in incidence, targeted preventive measures such as vaccinating travellers and other high-risk groups and timely vaccination of close contacts of hepatitis A patients are adequate. However, because susceptibility to hepatitis A is increasing in the group with the highest risk of developing severe complications upon infections, careful monitoring of the epidemiology of hepatitis A remains important.

Genotypic comparison of clinical Legionella isolates and patient-related environmental isolates in The Netherlands, 2002-2006.

This study investigated the hypothesis that the genotype distribution of Legionella isolates from sporadic patients with Legionnaires' disease differs from that of Legionella strains in the environment. An amplified fragment-length polymorphism (AFLP) assay was used to genotype patient-derived and environmental Legionella isolates. The three Legionella pneumophila genotypes isolated most frequently from human respiratory secretions were AFLP types 004 Lyon, 010 London and 006 Copenhagen. These genotypes were cultured significantly less frequently from environmental samples (50% vs. 4%; p <0.001). The most frequently observed L. pneumophila serogroup 1 genotype among patient-derived isolates was 004 Lyon (32%). This genotype was cultured from only one of 6458 environmental samples. The positive sample contained 1.26 x 10(6) CFU/mL and originated from a whirlpool spa that had not been disinfected and had been maintained at 36 degrees C for several months. Overall, the distribution of genotypes differed significantly among patient and environmental isolates. A possible explanation is that virulent strains may exist in potential environmental sources at undetectable concentrations.

Legionnaires' disease and gardening.

Legionella longbeachae was cultured from the sputum of a patient suffering from Legionnaires' disease. Source identification efforts included analysis of samples of potting soil from the patient's garden, and a genotypically indistinguishable strain of L. longbeachae was cultured from this material. Following examination of a national collection of Legionella isolates, two more patients with indistinguishable genotypes were identified. One of these patients had visited a garden centre in the same municipality in which the index patient had acquired his potting soil. The study demonstrated the value of systematic collection of identification data and patient isolates over a prolonged period.