LAB 1 Glo germ chains & chain of infection

PUERPERAL FEVER

  • Childbed fever as a bacterial infection of the uterus.

  • By the mid-19th century, mortality rates were alarming—1 in 8 women died in Vienna hospitals post-childbirth.

  • Likely caused by Streptococcus pyogenes (Group A).

  • Ignaz Semmelweis Father of Hand Hygiene & Early Epidemiologist :

    • Observed differing mortality rates in sections run by medical students versus midwives (2x higher for medical students).

    • Noted that a friend died from symptoms resembling puerperal fever after a scalpel injury during an autopsy.

    • Concluded that the 'poison' transferring to women during childbirth was from medical students.

    • Prior to Pasteur and Koch, linked to germ theory of disease.

    • Instituted handwashing protocols with strong disinfectants before entering the maternity ward.

    • Result: Mortality rate dropped from 16% to 2.4%.

  • Semmelweis recognized as the Father of Hand Hygiene and an early epidemiologist.

EPIDEMIOLOGY

  • Definition: The study of distribution and causes of diseases in populations.

  • Epidemiologists engage in various critical activities:

    1. Collecting and compiling data on disease sources and risk factors.

    2. Designing strategies to prevent and predict the spread of diseases.

    3. Necessitates expertise in ecology, microbiology, sociology, statistics, and psychology.

    4. Daily habits, like handwashing and waste disposal, stem from epidemiological studies.

CHAIN OF INFECTION

  • Understanding the chain is pivotal to stopping disease spread.

  • Any break in the chain can stop the transmission of infection.

RESERVOIRS OF INFECTION

  • Definition: The natural habitat of a pathogen (source).

  • Types of reservoirs:

    1. Humans: Infected individuals or carriers.

    2. Animals: Both wild and domestic species.

    3. Environment: Soil, water.

  • Control complexity increases with various reservoirs, affecting disease extent.

MONKEYPOX CASE STUDY

  • Despite its name, rodents are believed to be the actual reservoir for monkeypox.

  • Discovered in 1958 in an imported monkey, with the first human case identified in 1970.

  • The 2003 outbreak in the U.S. raised awareness about the disease.

HUMAN RESERVOIRS

  • Different categories of human infection:

    1. Symptomatic infections: Clear sources of pathogens.

    2. Carriers:

      • Asymptomatic: Infected without symptoms, e.g., certain STIs like Neisseria gonorrhoeae.

      • Pre-symptomatic: Infectious during the incubation period without showing actual symptoms.

PORTALS OF EXIT

  • Routes through which infectious agents leave hosts:

    1. Respiratory: Via droplets or aerosols.

    2. GI Tract: Oral-fecal route, including saliva and feces.

    3. Urogenital Tract: Via sexual fluids and urine.

    4. Skin: Through cells and open lesions (pus and blood).

DISEASE TRANSMISSION

  • Direct Transmission: Close proximity/contact between infected person and susceptible host:

    1. Person-to-person contact: Methods like touch and sexual intercourse.

      • Effective prevention: handwashing (key measure).

    2. Droplet transmission: Respiratory diseases conveyed by inhaling droplets from coughs or sneezes.

  • Indirect Transmission:

    1. Fomites: Inanimate objects that harbor pathogens (e.g., keyboards).

    2. Vehicle-borne transmission: Non-living materials (air, food, water).

    3. Airborne transmission: Small droplets or aerosols (e.g., whooping cough).

VECTOR TRANSMISSION

  • Transmission via living organisms, especially arthropods (e.g., mosquitoes).

PORTAL OF ENTRY

  • Specific entry points for pathogens:

    1. Skin penetration: Through wounds or animal bites.

    2. Mucosa: Most common entry route (respiratory, digestive, genitourinary).

NOSOCOMIAL INFECTIONS (HAIs)

  • Defined as healthcare-associated infections occurring during or after medical treatment.

  • Reasons for HAIs:

    1. High population density in healthcare settings.

    2. Weakened patient populations.

    3. Antibiotic resistance issues.

    4. Invasive medical procedures.

    5. Lack of aseptic techniques.

CURRENT STATS ON HAIs

  • Incidence: 0.1 - 20% of patients, averaging 4%.

  • Estimated 750,000 cases annually leading to 75,000 deaths.

  • Septicemia has a high fatality rate (30-40%).

STAPHYLOCOCCUS AUREUS

  • Commonly found on the skin and nasal passages (microbiota).

  • Most frequent cause of wound infections, and can be fatal if it becomes systemic.

IMPROVEMENTS IN HAND HYGIENE

  • Healthcare providers now consistently use soap and water or alcohol-based rubs before and after patient care.

  • Legacy of Ignaz Semmelweis emphasized handwashing to prevent infections.

ENGAGING PATIENTS IN HAND HYGIENE

  • Introduce hand hygiene focus in patient conversations.

  • Explain the rationale behind cleaning hands to patients.

  • Encourage questions and provide reassurance regarding hygiene practices.

  • Promote collaborative efforts for effective hand hygiene.

OTHER MEASURES

  • Limit catheter use and ensure prompt removal when unnecessary.

  • Clean skin prior to catheter insertion and surgical sites.

  • Employ proper PPE usage among healthcare providers during treatments.

STUDENT HAND HYGIENE EXPERIMENTS

  • Instructions for conducting experiments to assess handwashing effectiveness:

    1. Utilize nutrient agar plates for samples (labeling protocols included).

    2. Incubate and store Petri dishes upside down to minimize contamination.

EXPERIMENTAL ORDER OF EVENTS

  • Detailed steps for labeling, incubating, and conducting experiments on bacterial growth post-handwashing.

GLO-GERM EDUCATION

  • Instructions for using Glo-Germ to visualize germs in practice.