Wilkins 5: Infection Control: Transmissible Diseases

For healthcare providers, ________ and ______ disease can lead to illness, disability, and loss of work time.

infection, communicable

Standard Precautions

A strict form of infection control that is based on the assumption that all blood and other body fluids are infectious.

Droplet precautions

respiratory or mucous membrane contact transmitted through airborne droplets

- mycobacterium tuberculosis

- influenza virsus

- chickenpox virus

contact precautions

Reduce the risk of transmission of serious diseases such as respiratory syncytial virus (RSV), herpes simplex, wound infections, and others through direct or indirect contact

- vancomycin-resistant enterococci

- methicillin-resistant staphylococcus aureus (MRSA)

airbone precautions

reduce risk of airborne transmission of infectious agents by droplet nuclei

- special air handling and ventilation required

- legionella pneumophila, M. tuberculosis

sharp precautions

reduce risk of bloodborne pathogen transmission and infection by percutaneous sharps injury

- hep B/C

- HIV

asymptomatic carrier

someone who is infected with a disease organism but is not experiencing symptoms

cross-contamination

spread of microorganisms from one source to another: person to person, or person to an inanimate object and then to another person

Essential features for disease transmission (6)

infectious agent, reservoir, port of exit, mode of transmission, port of entry, susceptible host

infectious agent

- bacteria, viruses, fungi, rickettsia, protozoa

- each infectious agent has its own specific reaction in an infected host

reservoir

- where the agent live and grow.

- people, equipment, instruments, dental unit waterlines

port of exit

mode of escape from the reservoir

- body fluids, skin + mucous membrane, droplets + splatter

mode of transmission

- transmission by droplet may be directed from the respiratory tract of one person to the oral cavity of the receiving host by coughing or sneezing

- or indirect by transfer to hands/instruments and then to receiving host

port of entry

modes of entry may be similar to modes of escape

- body fluids, skin + mucous membranes, droplets + spatter, needle stick, and inhalation

susceptible host

- someone who does not have the immunity or defense to the invading infectious agent

- immunosuppressed, medically compromised, elderly, pre-existing transmissible disease, non-vaccinated

among the infectious agents that may travel in dust brought from in from outside and move in and about dental treatment areas

clostridium tetani (tetanous bacillus) + enteric bacteria

airborne particles

aerosol + spatter

aerosol

solid or liquid particle that may remain suspended in air.

- range from 1-100um

- 10um or smaller can be breathed into the longs

spatter

composed of particles greater than 50um in diameter that usually fall within 2 feet of origin.

prevention of transmission

- elimination/limitation of infectious agents at the source

- interruption of transmission

- protection of the potentially susceptible recipient

- carefully monitored procedures for all patients with or without a known communicable disease

Planktonic

Describes bacteria that are freely floating in water.

incubation periods

the time between exposure to a disease and the appearance of symptoms

M. tubercolosis

etiologic agent in TB, is a resistant organism requiring special consideration when sterilization and disinfection methods are selected and administered

- contracted when a vulnerable person inhales aerosolized droplet nuclei containing tubercle bacilli from sputum and saliva

serious, endemic, worldwide disease

every healthcare individual requires this immunization

Heb b virus (HBV)

HBV can cause

liver cancer, acute/chronic hepatitis, cirrhosis

HBsAg

hepatitis B surface antigen

- prenatal testing

When did the serologic test for antibody to HCV become available

1991

CDC recommended that everyone born between these years should be tested for HCV

1945-1965

not a significant risk for transmission in the healthcare setting

Hepatitis C Virus (HCV)

Cannot cause infection except in the presence of HBV (Hep B) infection:

Hepatitis D Virus (HDV)

95 % of the adult population have this

Human herpesvirus disease

HHVs travel along sensory nerve pathways to specific ganglia where they remain latent and become reactivated to produce

recurrent infection after certain stimuli or when the Boyds immunity is significant lowered

HHVs are among the _______ in HIV/AIDS, and several have been implicated as copathogens in HIV transmission and progression

opportunistic infectious agents

usually occurs in children but may occur at an age, especially in the immunocompromised

primary infection

50-90% of people worldwide have this

HHV-1 (HSV-1)

over 150 viruses considered to be

human papilloma viruses (HPVs) and each is identified by a number

- everyone will be infected by an HPV at some point in their lives

HIV/AIDS attacks

body's immune system

CD4+T lymphocyte cells (T-cells)

Opportunistic infections (OIs)

diseases that take advantage of a weakened immune system

parenteral

sharing needles or other injection equipment

What do antigen/antibody tests look for when testing for HIV

HIV antibodies and antigens

p24 antigen that is produced before antibodies develop

HIV CD4+ lymphocyte count

normal: 500-1500 cells

HIV stage 1

Acute HIV Infection

- 2-4 weeks flu like symptoms

- no aids OIs

- cd4+ t lymphocyte at 29%

HIV stage 2

Clinical latency

- active, replicating at a slow rate, still transmissible

- no aids OIs

- cd4+ t lymphocyte at 14%-28%

HIV stage 3

AIDS

- immune system is damaged

- OIs present

- cd4+ t lymphocyte at 14%

most common pathogen

Candida albicans