3. Healthcare-associated Infections

• infections acquired while in the healthcare setting with a lack of evidence that the infection was present or incubating at the time of entry into the healthcare setting
• also known as nosocomial infections
• 1/20 patients hospitalized contract

• noticed mothers giving birth in ward were less likely to develop puerperal fever if delivered by nurses instead of med students
• instituted hand washing measures and brought down level of fever

• pioneer of antiseptic surgery
• used carbolic acid for wounds and to sterilize surgical equipment
• had surgeons wear masks and gloves to prevent infection

• bloodstream infections - central line-associated bloodstream infection
• urinary tract infections - catheter-associated urinary tract infection
• pneumonia - ventilator-associated pneumonia
• surgical site infection
• clostridium difficile infection

• staphylococcus species
• enterococcus species
• candida species
• escheriscia coli
• pseudomonas aeruginosa
• klebsiella pneumoniae
• enterobacter species
• acinetobacter baunmannii
• clostridium difficile

• survive for long periods on environmental surfaces
• remain virulent after environmental exposure
• ability to colonize patients
• transiently colonize hands of HCW and be transmitted
• small inoculating dose
• resistance to disinfectants

self-infection from another site in the body

• from another person
• from the environment
• IV fluids

• 20-40% of HAI from infection via hands
• can result from = direct patient contact, indirectly touching contaminated surfaces
• patients can also become colonized by direct contact with a surface

• direct contact: hands, fomites
• airborne: droplets, droplet nuclei

• hospitalization for more than 2 days
• residence in long-term care facility
• home infusion therapy
• long-term dialysis within 30 days
• home wound care
• family member with multidrug-resistant pathogen

• antimicrobial therapy in preceding 90 days
• current hospitalization >5 days
• high frequency of antibiotic resistances in the community
• immunosuppression

• infections are so common considered a routine complication
• ~>50% are preventable

• one of the most common HAI in US
• risk factors - extremes of age, underlying disease, immunosuppression, cardiopulmonary disease
• those with ventilator are at highest risk

• 14-16% of HAI
• increasing number caused by antimicrobial resistant pathogens
• sometimes skin only, others involve organs and are more serious

• most common HAI
• infection from catheterization most common
• many preventable with proper management of catheter

• only use catheters when needed
• follow antiseptic technique when inserting catheter and central lines, performing surgery
• disinfect equipment and hospital surfaces
• surveillance
• wash hands

• infection control can be cost effective
• insure surveillance uses are valid
• improve design of invasive devices
• forestalling the post-antibiotic era
• newer microbiologic methods
• successful collaboration

• quality report to congress
• medicare payments to hospitals reduced for preventable readmissions and for certain infections that can usually be prevented with good care
• american recovery and reinvestment act included money to assist states

• produces spores - can survive for many years in an aerobic environment
• leading cause of nosocomial-acquired diarrhea - usually after completing antibiotics
• reservoir in humans
• transmission with hands, fomites
• toxin mediated

• antibiotics changes normal flora
• colonization with virulent strain
• host predisposition

• culture - often not performed
• toxin assay - poor sensitivity and specificity
• cepheid Xpert - automated machine performs PCR test to detect organism

• diarrhea
• colitis - diarrhea, blood and pus in stool
• toxic megacolon - paralysis of peristaltic movement, feces can consolidate in hard masses in colon

initial - discontinue antibiotics, supportive care (hydration and electrolyte replacement), avoid anti-diarrheals, antibiotics

relapse - antibiotics, probiotics, bile sequestration, passive immunization

• contact precautions when diarrhea present
• environmental disinfection
• timely diagnosis and isolation
• decrease unnecessary antibiotic use
• vaccine