What is a healthcare-associated infection and how prevalent are they?

Healthcare-Associated Infections: Definition and Prevalence

Healthcare-associated infections (HAIs) are infections that develop during hospitalization or within 7 days of discharge from a healthcare facility, and were not present or incubating at the time of admission. 1 These infections represent a significant patient safety concern, causing substantial preventable morbidity and mortality worldwide.

Definition and Classification

Healthcare-associated infections can be categorized as:

1. Hospital-onset: Infections that develop during hospitalization (typically >48 hours after admission)
2. Community-onset healthcare-associated: Infections that develop within 7 days after discharge from a healthcare facility 1

For an infection to be considered healthcare-associated, it must meet specific criteria:

• Not present or incubating at admission
• Develops during hospitalization or within 7 days post-discharge
• No other obvious source of transmission outside the healthcare setting 1

Prevalence and Impact

HAIs represent a major public health burden:

• Incidence: Approximately 2 million patients develop HAIs annually in the United States 2
• Mortality: These infections result in approximately 75,000-90,000 deaths per year 2, 3
• Economic burden: HAIs cost billions of dollars in preventable healthcare expenses 2
• Global variation: The WHO estimates that in acute care hospitals, approximately 7% of patients in high-income countries and 15% in low-income countries acquire at least one HAI 1
• Regional differences: More recent studies found HAI prevalence of 12.5% in Eastern Mediterranean countries, 27.0% in African countries, and 8.0% in European countries 1

Common Types of Healthcare-Associated Infections

The most prevalent HAIs include:

1. Central line-associated bloodstream infections (CLABSI)
2. Catheter-associated urinary tract infections (CAUTI) - the most common device-related HAI 3
3. Surgical site infections (SSI)
4. Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) - together represent the most common HAIs 2
5. Clostridium difficile infections (CDI)
6. Methicillin-resistant Staphylococcus aureus (MRSA) infections
7. Other multidrug-resistant organism (MDRO) infections 2, 4

Contributing Factors

Multiple factors contribute to the development and spread of HAIs:

• Inadequate hand hygiene by healthcare workers
• Inappropriate antibiotic use leading to antimicrobial resistance
• Increasing prevalence of multidrug-resistant organisms
• Suboptimal disinfection and cleaning of hospital rooms and equipment
• Use of invasive medical devices (catheters, ventilators, etc.)
• Hospital overcrowding
• Inadequate isolation precautions 2, 5

Prevention Strategies

Evidence-based prevention strategies include:

1. Basic Prevention Measures

• Administrative support and visible leadership
• Education of healthcare personnel
• Hand hygiene - simple alcohol-based hand rubs can significantly reduce HAIs 6
• Isolation precautions for infected patients 3

2. Device-Related Infection Prevention

• Avoid unnecessary insertion of central lines and catheters
• Adhere to aseptic technique during insertion
• Remove devices when no longer necessary
• Maintain closed drainage systems for urinary catheters
• Position ventilated patients semi-recumbent with antiseptic oral care 3

3. Multimodal Implementation Strategies

The WHO recommends using multimodal strategies (combining at least three elements) for implementing infection prevention interventions:

• System change
• Education and training
• Monitoring and feedback
• Reminders/communications
• Culture change 1

4. Environmental Controls

• Enhanced cleaning protocols for patient rooms and equipment
• Proper disinfection of shared medical equipment
• Avoidance of tap water in certain procedures (particularly with immunocompromised patients) 1

5. Antimicrobial Stewardship

• Review antibiotic therapy every 48-72 hours
• De-escalate therapy when appropriate
• Document indications for initiating and continuing antibiotics 4

Surveillance and Outbreak Management

Continuous surveillance is essential for early detection of potential outbreaks:

• Distinguish between true outbreaks and pseudo-outbreaks (positive laboratory results without clinical disease) 7
• Establish case definitions with specific clinical and laboratory criteria
• Create epidemic curves to analyze temporal patterns
• Implement immediate control measures when outbreaks are identified 7

Conclusion

Healthcare-associated infections represent a significant but largely preventable cause of morbidity and mortality. Through systematic implementation of evidence-based prevention strategies and continuous surveillance, healthcare facilities can significantly reduce the burden of these infections and improve patient outcomes.