[Infection prevention in secondary immunodeficiencies].

Over one million people in The Netherlands are estimated having an immunodeficiency, of which the majority has an acquired immunodeficiency due to immunosuppressive medication. These patients are at risk for a more severe course of common infections, and also for opportunistic infections and viral reactivations. The following topics are discussed: types of immunodeficiency and how to estimate its severity; commonly seen infections in immunocompromised patients; recommended screening before start of immunosuppressive medication; pitfalls in clinical clues and diagnostics, and safety and immunogenicity of vaccination in these patients.

The High Impact of Penicillin Allergy Registration in Hospitalized Patients.

Background: Suspected penicillin allergy (Pen-A) is often not verified or excluded by diagnostic testing.

Objective: To assess the prevalence and impact of Pen-A registration in a Dutch University Medical Center.

Methods: In a prospective matched cohort study, all admitted patients (July 2013-July 2014) who underwent a pharmacotherapeutic interview were selected.

Cost-effectiveness of preoperative screening and eradication of Staphylococcus aureus carriage.

Background: Preoperative screening for nasal S. aureus carriage, followed by eradication treatment of identified carriers with nasal mupirocine ointment and chlorhexidine soap was highly effective in preventing deep-seated S. aureus infections.

[The Dutch MRSA policy can and should be different].

The methicillin-resistant Staphylococcus aureus (MRSA) infection rate in the Netherlands is low thanks to a nationwide 'search and destroy' MRSA policy. This policy is based on two factors: MRSA in the community was rare and all patients at risk for MRSA are isolated until culture results are negative. However, in 2005, livestock-associated MRSA emerged.

The nosocomial transmission rate of animal-associated ST398 meticillin-resistant Staphylococcus aureus.

The global epidemiology of meticillin-resistant Staphylococcus aureus (MRSA) is characterized by different clonal lineages with different epidemiological behaviour. There are pandemic hospital clones (hospital-associated (HA-)MRSA), clones mainly causing community-acquired infections (community-associated (CA-)MRSA, mainly USA300) and an animal-associated clone (ST398) emerging in European and American livestock with subsequent spread to humans. Nosocomial transmission capacities (R(A)) of these different MRSA types have never been quantified.

Quantifying cost-effectiveness of controlling nosocomial spread of antibiotic-resistant bacteria: the case of MRSA.

Background: The costs and benefits of controlling nosocomial spread of antibiotic-resistant bacteria are unknown.

Methods: We developed a mathematical algorithm to determine cost-effectiveness of infection control programs and explored the dynamical interactions between different epidemiological variables and cost-effectiveness. The algorithm includes occurrence of nosocomial infections, attributable mortality, costs and efficacy of infection control and how antibiotic-resistant bacteria affect total number of infections: do infections with antibiotic-resistant bacteria replace infections caused by susceptible bacteria (replacement scenario) or occur in addition to them (addition scenario).