Healthcare-associated infections (HAIs) are defined as an infection acquired during the course of hospitalization and exclude infections that were either present or incubating at the time of admission. HAIs are a leading cause of death in hospitalized populations and are associated with an increased length of stay and high cost.

It is estimated that HAIs affect over 2 million patients per year with an approximate cost of over $4.5 billion annually in the United States.

There are multiple factors influencing HAIs. These include microbial agents and virulence, patient susceptibility, environmental factors, and bacterial resistance.

Evidence-based guidelines for infection control and prevention were created with the intention to decrease rates of HAIs and assure maximal adherence to these guidelines by healthcare workers (HCWs).

This chapter highlights infection prevention strategies and interventions that reduce rates of HAIs in modern healthcare settings.

HORIZONTAL VERSUS VERTICAL INFECTION CONTROL STRATEGIES

In the last decade, a significant paradigm shift in infection prevention has occurred. First, although all infections are not preventable by the current state of science, there is a growing emphasis on implementation of evidence-based infection interventions. There are currently two major infection control strategies, horizontal versus vertical infection control interventions.

A horizontal infection control strategy is defined as interventions attempting to decrease the rates of all infections produced by pathogens similarly transmitted. This approach is broad based and favors multipotent, common sense evidence-based infection prevention interventions such as robust hand hygiene (HH) practices, chlorhexidine (CHG) patient bathing, CHG impregnated central line dressings, central line checklists, and head of bed elevation in ventilated patients.

A vertical infection control strategy focuses on specific organisms such as methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE). This is considered a narrow infection prevention approach and may not impact the rates of all infections produced by pathogens similarly transmitted.

Notwithstanding some overlap between the two strategies, financial and personnel constraints prohibit full-scale implementation of all components of vertical and horizontal strategies broadly and simultaneously. Consequently, a horizontal infection prevention strategy may be the more effective approach. Wenzel et al. suggested that outcomes of horizontal programs outweigh those of programs with a vertical focus in terms of reduced mortality, years of life lost, and cost. Under this paradigm, a vertical, or pathogen based, focus should be adopted only when the approach demonstrates a significant, incremental benefit atop a horizontal infection prevention strategy.