Week #10: Healthcare Associated Infection

Nosocomial

Nosocomial refers to a disease or infection that a patient acquires while receiving medical care in a hospital or healthcare facility, which was not present or incubating at the time of admission. These are more broadly known as healthcare-associated infections (HAIs).

Roman Hospitals 

Roman Military hospitals

• Kept sick people and wounded people, and etc seperate 

Roman aqueducts and sewers

• Clean water and sanitation 

Paris Hospitals

• Hotel dieu - longest operating hospital that we know

• Bad

  • Wounds were washed daily with a sponge that went from patient to patient.

  • Mortality after amputation was ~60%.

  • Only the maternity and surgical wards were heated.

  • Drinking water came directly from the Seine (which the hospital spanned).

  • Puerperal fever was common (the maternity ward was located in the basement and frequently the Seine would empty water and garbage onto the floor).

British hospitals

• Every patient had clean sheets on admission.

• Patients given clean sheets every three weeks.

• Only one patient per bed unless there were no spare beds

Development of Specialty Hospitals

• Leprosarium

• Lazaretto (first used in Venice for confining plague victims)

• Fever hospitals in England (originally developed for smallpox victims, also used for other diseases such as typhus)

Puerperal fever

Puer: child or boy

Childbed fever

Major killer of women in hospitals

Ignaz Semmelweis: 1818 –1865

Allgemeines Krankenhaus – Vienna general hospital

• Wards run by: Nurses/midwives and MDs switch 

• Ignaz Semmelweis: noticed that mortality rate for MD deliveries was 3x higher (9%) than midwives (3%)

  • Found that the practice of dissections correspond with mortality rates during delivery 

  • Proposed people start washing their hands: incidence dropped 

Why midwifery care decreased chances of puerperal fever?

• Because MDs start their day with a dissection of a woman that died of puerperal fever, wouldn’t wash their hands, and then go into the delivery suite 

• Doctors performing both autopsies and patient exams

• Doctors examining multiple patients without hand washing

• Patients being examined by multiple doctors

Louis Pasteur: 1822 - 1895

1879: announced that streptococcus was the cause of puerperal sepsis.

Florence Nightingale: 1820 – 1910

Crimean War - 1854

Nightingale at Hospital in Scutari

• Noticed

  • Built on an open sewer

  • Untreated soldiers laid on unsanitary floor 

  • lack of medical equiptment and medicine

  • Overworked and tired staff

• She raised a lot of hell and got change 

James Simpson: 1811–1870

• Realized hospitals are much more likely to transmit harmful bacteria to patients 

  • Comparing survival rates for people who have serious surgery in a major hospital to rural hospitals 

• Shock and (pyemia) sepsis

Joseph Lister (1827 –1912)

• introduced antiseptic approaches

• Penicillin: antibiotic for sepsis 

What is considered a HAI:

• Most infections that become clinically evident after 48 hours of hospitalization are considered an HAI.

•  Infections that occur after the patient is discharged from the hospital can be considered an HAI if the organisms were acquired during the hospital stay

Where do HAIs occur

• Not just hospitals: HAIs occur in all types of facilities, including:

  • Long-term care facilities

  • Dialysis facilities

  • Ambulatory surgical centers

  • Hospitals

Endogenous source of HAIs

• Normal flora of humans

  • Present on: skin, URT, oral cavity, intestine (esp large), vaginal tract 

  • Very little flora in eyes and stomach 

• ex) Strep - women’s normal flora

Exogenous source of HAIs 

• Other people

• Hospital appliances 

Common HAI sites

Big 5 sites for infection

• Surgical site infections (SSIs)

• Central line infections (CLABSIs)

• Ventilator associated events (VAEs)

• Catheter associated UTIs (CAUTIs)

• Clostridioides difficile infections (CDIs)

• Majority is urinary tract (40%), surgical (19%), respiratory (15%) 

HAI Organisms

Staphylococcus spp. (Staph and Strep)

Gram negative rods

Clostridioides difficile

Other Gram-positive cocci

Fungi including Candida

Candida auris 

emerging multidrug resistant fungi

7 strategies to prevent healthcare-associated infections

1. Hand hygiene

2. Environmental hygiene

3. Screening and cohorting patients

4. Surveillance

5. Antibiotic stewardship

6. Following guidelines

7. Safety culture 

Bundle

a grouping of evidence-based practices that individually improve care

HAI prevention research

Prevention approach unknown ; need identify new strategies to prevent the remaining HAIs

Preventable: need for complete implementation of practices known to prevent HAIs