infection control-transmission of disease and pathogens transmitted via the oral cavity

how does an infectious disease occur

when a microorganism in the body multiplies and causes damage to the tissues

pathogenic microorganism

cause infectious diseases

OSHA

mandates that all workplaces that pose a potential risk for transmission of blood-borne diseases establish a written infection control plan that minimizes or eliminates employee exposure-goes by CDC recomendations

CDC

recommends application of standard precautions to protect consumer as well as health care provider

standard precautions

consider all bodily fluids encountered during TX as potentially infectious, no special treatment for any patient “mroe risky”

essential features for disease transmission

an infectious agent, Virus, bacterium, fungi, protozoa, rickettsia,

virus

smallest infectious microorganism must live inside a living host cell to reproduce

how are viruses most commonly spread

blood, saliva, and other bodily secretions

Bacterium

single-celled, live in inside tissues rather than specific cells

what are the types of bacterium

cocci, bacilli, spirilla, vibrios

Fungi

yeasts and molds

protozoa

single celled, often called amoeba

where do protozoa live

live in fluids, in bloodstream, oral cavity, GI tract, stagnant ponds, polluted water

rickettsia

similar to tiny bacteria in appearance, parasites

what are common hosts for rickettsia

lice, ticks, fleas, roaches, rats and mice are common hosts

reservoir

place for the microorganism to live and multiply

mode of escape

port of exit from the reservoir

mode of transmission

1. patient to clinician, clinician to patient, patient to patient

2. direct contact

3. indirect contact

4. blood borne

5. airborne

6. aerosols

7. splatter

splatter

heavier, larger particles, larger than 50 microns. can be visible

mode of entry

can be the same as mode of escape, ex-respiratory track, skin lesions, mucous membranes

susceptible host

unable to resist the pathogenic microorganism

influencing factors of a susceptible host

1. # of organisms, and the length of time of exposure

2. virulence of the organisms

3. immune status of the host

4. general physical health of the host including nutritional status

factors that alter normal defenses

1. abnormal physical conditions

2. systemic disease

3. drug therapy

4. prosthesis and transplants

types of infections

endogenous, autogenous

exogenous

originates from means outside of the body, includes nosocomial

opportunistic

does not usually infect healthy individuals with intact immune system

five stages of infectious disease

1. incubation stage

2. prodromal stage

3. acute stage

4. declining stage

5. convalescent stage

incubation stage

time between exposure and 1st symptoms

prodromal stage

vague or undifferentiated set of symptoms similar to infectious of any number of diseases

acute stage

disease at its peak, fully developed symptoms

declining stage

symptoms begin to subside

convalescent stage

recovery and recuperation

hepatitis

inflammation of the liver

how are Hep. A and E usually transmitted

mainly transmitted through contaminated food and water

how are Hep. B,C,D and G transmitted

bloodborne

Hepatitis A

occurs more frequently in children and young adults, primarily spread through fecal-oral route from contaminated food and water

icteric symptoms of HAV

jaundice present, 85-90% of patients recover completely 

highest occupational risk for unvaccinated dental personnel

hepatitis B

Hepatitis B

endemic, occurs at any age, CDC estimates 1-1.25 million carriers in US

modes of transmission of HBV

1. percutaneous

2. permucosal

3. prenatal exposure

4. infection from blood products rare since 1985

transient subclinical infection of HBV

majority of pts don’t have icteric stage, may remain undiagnosed and develop antibodies and permanent immunity, transient because pts immune system clears the disease before it becomes established

Acute type HBV

can’t be distinguished from other types of hepatitis on the basis of signs and symptoms, period of illness longer than HAV

HBV carrier state

chronic carrier has HBsAG marker in the blood for more than 6 months, many carriers develp cirrhosis of liver or cancer of the liver

Hepatitis C

most chronic bloodborne infection in the US, 80% of infected have no signs or symptoms

Hepatitis D

aka Delta agent, han only cause infection in presence of HBV. more sever and death rates greater than HBV

Hepatitis E

associated with water-borne epidemics. Rare in the US

Herpes Virus diseases

wide variety of infections that are extremely contagious, virus is present in saliva, even in good health. Produce diseases with latent, recurrent, and sometimes malignant tendencies. Characterized by prodromal period followed by formation of vesicles

viral latency

is a persistent infection following a primary infection

where does HSV-1 travel to

trigeminal nerve ganglion

where does HSV-2 travel to

thoracic, lumbar and sacral dorsal root ganglia

where does varicella zoster travel to

sensory ganglia of the vagus, spinal or cranial nerves

types of Herpes viruses

varicella zoster virus, Epstein Barr virus, cytomegalovirus, herpes simplex virus

varicella zoster virus

aka chicken pox. causes maculopapular rash, and lesions anywhere in the body

what are the vaccines for chicken pox

Varivax, Proquad

what does chicken pox cause

maculopapular rash, and lesions anywhere in the body

Shingles

reactivation of latent VZV in dorsal root ganglion

Epstein-Barr Virus

causes one type of mononucleosis, transmitted orally by direct contact by droplet. Can become latent and reactivated

Cytomegalovirus

HHV type 5. mono-like, opportunists infection. most often affects 1-2 year olds and 16-50 year olds.

where has cytomegalovirus been found

in tumor cells of Kaposi’s sarcoma

where is Anti-HSV present

in gingival sulcular fluid

where does HV-1 typically transmit

above the waist, but can be transmitted to the genital area via oral sex with infected partner

where does HV-2 typically transmit

primarily below the waist

primary herpetic gingivostomatitis

sore throat, gingivostomatitis, fever, malaise, inability to eat, lymphadenopathy for 2-7 days

where would painful vesicular lesions occur in herpetic gingivostomatitis

may occur on gingiva, mucosa, tongue and lips

where would recurrent herpes simplex 1 infections occur

vermillion border of the lower lip, sometimes gingiva and hard palate.

are aphthous ulcers (canker sores) herpetic?

no

what are the clinical symptoms of Herpes simplex virus infections

group of vesicles form, then rupture and coalesce

Herpetic whitlow

HSV infection of the fingers

how does the virus enter in herpetic whitlow

enters skin through minor abrasions, mostly around fingernails

ocular herpes

primary or recurrent infection of HSV-1 or HSV-2

how does ocular herpes occur

splashing saliva or fluid from lesion into eye, extension of facial infection into eye

human immunodeficiency virus (HIV)

acquired immunodeficiency virus (aids) caused by infection with HIV. Destroys body’s immune system.

what does HIV primarily infect

T lymphocytes

transmission of HIV

through body fluids, most commonly through unsafe sex and contaminated needles

what is the target/host cell of HIV

T-helper lymphocytes, monocytes, brain tissue cells

what is the CD4+ count of HIV in the early stage

>500 cells/mm

what is the CD4+ count of HIV in the intermediate stage

between 200 and 500 cells/mm

what is the CD4+ count of HIV in the late stage

between 50 to 200 cells/mm

signs of oral manifestations of HIV-1

oral candidiasis, kaposi’s sarcoma and hairy leukoplakia. Gingival and periodontal infections

intra oral examination-HIV-1

unusual severity of gingivitis, and necrotizing gingivitis

how is tuberculosis transmitted

transmitted through aerosols, splatter from sputum and saliva. Can also be transmitted through ingestion or direct inoculation

symptoms of early on TB

low-grade temp, loss of appetite, weight loss, fatigue, slight cough, eventually sputum

signs of later TB

definite increase in temp, night sweats, weakness, persistent cough and sputum

how to diagnose TB 

chest x-ray and tuberculin testing