DH-Preclinic: Wilkins Ch 2 Transmission of Diseases (Q & A)

Wilkins- Ch 2 p.22

Purpose of INFECTION CONTROL-is to PROTECT
(1) Patients
(2) DHCP
(3) Other in dental office

Wilkins- Ch 2 p.22

the ENTIRE dental team is responsible for ORGANIZING/MAINTAINING a system for

(1) sterilization
(2) disinfection
(3) care of instruments
(4) care of equipment

Wilkins- Ch 2 p. 22

Dental must prevent DIRECT & INDIRECT CROSS-CONTAMINATION

(1) b/w dental personnel & pts
(2) one pt to another

Wilkins- Ch 2, p.22

Standard Precautions-
(1) NEW term that recognizes
(2) BODILY FLUIDS + blood as infectious agents

Wilkins - Ch 2, p.22

"Universal Precautions" came before Standard Precautions

Wilkins- Ch 2, p.22

"Universal Precautions"
(1) OLD term
(2) only recognized BLOOD as infectious agent
(3) Treat everyone as if they had AIDS

Wilkins- Ch 2, p.22

Standard Precautions-contact with
(1) blood
(2) ALL BODY FLUIDS-secretions/excretions ***except sweat
(3) nonintact skin
(4) mucous membrane

Wilkins - Ch 2, p. 22

Other precautions
(1) Transmission-based (Ex: TB)
(2) Transmission via airborne droplets
(3) Skin contact transmission

Wilkins - Ch 2, p.24

Microorganism originate:

(1) few hours -1 day after birth
(2) with dev. of oral flora

Wilkins - Ch 2, p. 24

Salivary bacteria originates
(1) dorsum of tongue
(2) mucous membrane
(3) gingival/periodontal tissues

Wilkins -Ch 2, p.24

Infection Potential = High
Because....
(1) Pathogen organisms are TRANSIENT (travel)
(2) Pts may be CARRIERS of diseases
(3) Inappropriate work practices
(ex: careless hand washing)
(2)

Wilkins -Ch 2, p.24

"Cross-Contamination"

SPREADING of microorganism from one source to another
(1) DIRECTLY-person to person
(2) INDIRECTLY- inanimate object to person

Wilkins -Ch 2, p.24-25

"Infectious Process"

is a chain of events req'd for the SPREAD of an infectious agent

Wilkins -Ch 2, p.25

Essential Features = 6 LINKS

(1) Infectious Agent
(2) Reservoir (home)
(3) Port of Exit = (Escape)
(4) Mode of Transmission
(5) Port of Entry =(Invasion)
(6) Susceptible Host = (Victim)

Wilkins -Ch 2, p.25

Infection is SPREAD by :

(1) at least ONE BREAK in the chain of 6 major links
(2) Oftentimes by not following STANDARD PRECAUTIONS and other reasons

Wilkins- Ch 2, (p.25)

"infectious agent"

= the INVADING organism

Wilkins- Ch 2, (p. 25)

"reservoir"

= WHERE the invading organism LIVES

Examples
(1) inanimate object
(2) insect
(3) human cells or blood

Wilkins- Ch 2, (p. 25)

"port of exit"

=HOW the invading organism ESCAPES from the "reservoir"

Wilkins- Ch 2, (p. 25)

"mode of transmission"

(1) DIRECT = person to person
Ex: contaminated hands
Ex: Droplet from sneezing to persons mouth

(2) INDIRECT = obj. to person
Ex: hypodermic needle
Ex: Sneezing into hands and touching a pt

Wilkins- Ch 2, (p. 25)

"port entry"

= HOW the invading organism ENTERS the new host

Examples
(1) respiratory tract
(2) mucous membranes
(3) break in skin

Wilkins- Ch 2, (p. 25)

"Susceptible Host"

= DOES NOT have IMMUNITY to the invading infectious agent

Wilkins- Ch 2, (p. 25-26)

"FACTORS" influencing dev. of infection:

(1) # of organisms
(2) DURATION of exposure
(3) VIRULENCE of organism (ability to survive)
(4) IMMUNE STATUS of host
(5) General phys.& nutritional status of host

Wilkins- Ch 2, (p. 25)

Just b/c an infectious agent is PRESENT it MAY NOT necessarily lead to infection.

Certain factors MUST BE PRESENT

Wilkins- Ch 2, (p. 26)

FACTORS that ALTER normal defenses:

(1) ABNORMAL Phys. conditions
(2) SYSTEMIC Diseases
(3) DRUG Therapy
(4) PROSTHESIS & Transplants

Wilkins- Ch 2, (p. 26)

"ABNORMAL Phys. Condition"
Ex: Defective Heart valve

ALTERS Normal Defenses by:
(1) susceptible to infective endocarditis from bacteria during a cleaning

Wilkins- Ch 2, (p. 26)

SYSTEMIC DISEASES examples
(1) diabetes mellitus
(2) alcoholism
(3) leukemia
(4) glomerulonephritus
(5) AIDS

ALTER Normal defenses by:
(1) causing IMMUNOSUPPRESSION;
(2) increasing risk of INFECTION

Wilkins- Ch 2, (p. 26)

DRUG THERAPY used to treat "systemic diseases"
Examples
(1) steroids
(2) chemotherapeutic agents

ALTER Normal defenses by:
(1) SUPPRESSING immune system
(2) higher risk of INFECTION

***May require antibiotic premed

Wilkins- Ch 2, (p. 26)

PROSTHESIS & TRANSPLANTS
Examples
(1) joint replacement
(2) cardiac prosthesis
(3) VA shunt for hydrocephalus
(4) Organ transplant

ALTER Normal defenses by:
(1) SUPPRESSING immune system
(2) higher risk of INFECTION

***May require antibiotic premed

Wilkins - Ch 2, (p.26)

AIRBORNE INFECTIONS- start from infectious agents traveling in
(1) dust particles
(2) aerosols

Wilkins - Ch 2, (p.26)

DUST-BORNE Organisms
(1) Clostridium tetani
(2) Staphylococcus aureus
(3) enteric bacteria

TRAVEL through DUST that:
(1) lands on instruments
(2) hands of DHCP
(3) Surfaces in dental office

Wilkins - Ch 2, (p.26)

AEROSOLS -

are AIRBORNE PARTICLES w/contaminants that are occur in (1) SOLID (2) LIQUID form (3) are invisible (4) suspended in air long time

Classified by size
(1) aerosols <50 (smaller)
(2) spatter > 50 (larger)

Wilkins - Ch 2, (p.26)

AEROSOLS are dangerous b/c:

(1) they're SO SMALL we can breathe them DEEP into lungs
(2) remain airborne LONGER

THEY CONTAIN:
(1) resp. disease producing organisms
(2) traces of mercury or amalgam

Wilkins - Ch 2, (p.26)

SPATTER is dangerous b/c:

(1) Drop or Spatter on obj. & people

Wilkins - Ch 2, (p.26)

AEROSOLS & SPATTER are created:
(1) breathing
(2) speaking
(3) coughing
(4) sneezing
(5) intraoral procedures

Wilkins - Ch 2, (p.26)

AEROSOLS- produced by equipment:
(1) air/water syringe tips
(2) handpieces
(3) ultrasonic scalers

Wilkins - Ch 2, (p.27)

MICROORGANISMS (Ultrasonic scalers)

(1) Staphylococcus aureus
(2) albus
(3) pyogene
(4) Streptococcus viridans
(5) Lactobacilli
(6) actinomyces
(7) pneumococci
(8) diptheroids
***also VIRUSES

Wilkins - Ch 2, (p.27)

PREVENTION (Airborne infections)

(1) ELIMINATION / LIMITATION
ex: brushing & flossing; mouthrinses

(2) INTERRUPTION of Transmission
ex: rubber dam, HVE, manual scaling, vacuuming

(3) PROTECTION of susceptible recipient
ex: Clean water, running water lines, PPE for DHCP; eyewear for pt

Wilkins - Ch 2, (p.27)

WATER LINES must be run
(1) Start of day = 2 min.
(2) After each pt = 20-30 sec.

Wilkins - Ch 2, (p.27)

PATHOGENS (Trans. by Oral Cavity)
(1) Tuberculosis
(2) Viral Hepatitis
(3) AIDS
(4) Herpetic Infections

Wilkins - Ch 2, (p.27)

ETIOLOGY - the study of the CAUSE of diseases/disorders

ETIOLOGIC AGENT - disease causing

Wilkins - Ch 2, (p.27)

NO !!!!!!!!!!!!!!!!!!!!
Sometimes pathogens are dormant

Wilkins - Ch 2, (p.27)

INFECTIOUS AGENT (TB) = Mycobacterium tuberculosis

Wilkins - Ch 2, (p.27)

TUBERCULOSIS is
(1) a serious disease
(2) common communicable disease
(3) AIDS-defining illness--b/c it's often found in HIV+ people

Wilkins - Ch 2, (p.30)

TRANSMISSION of TB:
(1) Inhalation of DROPLETS
(2) Sputum
(3) Saliva

Wilkins - Ch 2, (p.30)

STANDARD PRECAUTIONS are NOT ENOUGH to protect the DHCP

REASON--Droplet Nuclei:
(1) are SMALL enough to pass though >95% of surgical masks
(2) remain suspended in air for HOURS

Wilkins - Ch 2, (p.30)

FACTORS affecting transmission (TB)
(1) AMOUNT of droplets produced by TB infected person
(2) AMOUNT & DURATION of exposure
(3) SUSCEPTIBILITY of recipient

Wilkins - Ch 2, (p.30)

COMMUNICABLE PERIOD (TB)
(1) As long as viable BACILLI are discharged in sputum

MOST Communicable
(1) Just BEFORE the disease is diagnosed !!!!

Wilkins - Ch 2, (p.30)

TUBERCLE BACILLI can enter by:
(1) Ingestion
(2) direct inoculation

OTHER AFFECTED AREAS
(1) lymph nodes
(2) meninges
(3) kidneys
(4) bone
(5) skin
(6) oral cavity

Wilkins - Ch 2, (p.30)

PREDISPOSING FACTORS (TB)
(1) Suppressed immune system
(2) Systemic conditions

Wilkins - Ch 2, (p.30)

INCUBATION PERIOD (TB)
(1) as long as 10 weeks

Wilkins - Ch 2, (p.30)

EARLY SYMPTOMS (TB)
(1) low-grade fever
(2) loss of appetite
(3) weight loss
(4) fatigue
(5) SLIGHT COUGH
(6) SPUTUM

Wilkins - Ch 2, (p.30)

LATE SYMPTOMS (TB)
(1) spikes in temp. (ex: night sweats)
(2) weakness
(3) PERSISTENT COUGH

DIAGNOSED by:
(1) chest X-ray
(2) TB testing

Wilkins - Ch 2, (p.30)

REACTIVATION (TB)

(1) Remains INACTIVE, then reoccurs
(2) INCOMPLETE treatment of primary infection
(3) Suppressed immune system
(4) LATENT TB infection--shows up years later

Wilkins - Ch 2, (p.31)

MULTIDRUG RESISTANT TB-resists:
(1) isoniazid
(2) rifampin
(3) requires use of SECOND LINE drugs for treatment

BECOMES RESISTANT to DRUGS:
(1) Pt not taking meds as prescribed
(2) Meds NOT properly prescribed

Wilkins - Ch 2, (p.31)

PREVENTION OF MULTIDRUG RESISTANT TB
(1) EARLY diagnosis
(2) DOT- directly observed therapy
(3) LOCATE & treat persons w/ latent TB

Wilkins - Ch 2, (p.31)

TB-MEDICATIONS:
(1) Isoniazid
(2) pyrazinamide
(3) rifampin
(4) ethambutol

Wilkins - Ch 2, (p.31)

XDR Tuberculosis = "Extensively Drug-Resistant TB"

Discovered to be ESPECIALLY SEVERE in HIV+ patients

Wilkins - Ch 2, (p.31)

CLINICALLY MANAGING (TB)
(1) Periodic ASSESSMENT
(2) Reviewing MEDICAL HISTORY
(3) REFERRING suspected pt w/TB for med.eval
(4) DEFERRING elective treatment who may have TB
(5) URGENT DENTAL CARE done in hospitals
(6) DHCP---getting med. eval.
(7) SEPARATING TB pts /suspected TB pts.

Wilkins - Ch 2, (p.31)

HISTORY OF TB:
(1) Consult w/physician for current status and clearance

Wilkins - Ch 2, (p.31)

PT UNDERGOING TB TREATMENT
(1) After several weeks on meds
(2) With physician clearance

Wilkins - Ch 2, (p.31)

POSITIVE TB SKIN TEST PT
(1) consult physician to determine ABSENCE OF DISEASE
(2) Pt may be placed on Isoniazid for 6 -12 month to prevent clinical disease

Wilkins - Ch 2, (p.31)

DO NOT TREAT PT!!!!

Refer to physician
(1) dry, unexplained cough
(2) chest pain
(3) fatigue fever
(4) dyspnea
(5) weight loss

Wilkins - Ch 2, (p.32)

LYMPHODENOPATHY-

enlargement of regional lymph nodes

Wilkins - Ch 2, (p.32)

TB EXPRESSIONS IN EO/IO EXAMS
(1) enlarged lymph nodes
(2) oral lesions (ulcers) on soft, hard palate, tongue

Wilkins - Ch 2, (p.32)

TB INFECTED PTS RECEIVE
(1) Chemotherapy--to reduce contagiousness

Wilkins - Ch 2, (p.32)

HEPATITIS -
means inflammation of the liver

TYPES ********NO "F"
(1) Hepatitis A
(2) Hepatitis B
(3) Hepatitis C
(4) Hepatitis D
(5) Hepatitis E
(6) Hepatitis G

1. living the gospel before / toward all people (3:1-2)
2. the gospel transforms... "we ourselves were once foolish..." (3:3-8)
3. Avoiding foolish controversies, genealogies etc and people who continue in them when warned (3:9-11)
4. Personal instructions and Final Greetings (3:12-15)

Wilkins - Ch 2, (p.32)

TRANSMISSION OF HEPATITIS A:
(1) fecal-oral route
ex: unwashed hands

(2) waterborne and food-borne
ex: contaminated water/food

(3) Blood
ex: blood transfusion---but rare***

Wilkins - Ch 2, (p.32)

INCUBATION PERIOD (HEP. A):

(1) 15-50 days

Wilkins - Ch 2, (p.32)

COMMUNICABLE PERIOD (HEP.A):

(1) 2-3 weeks BEFORE the onset of jaundice

Wilkins - Ch 2, (p.32)

SIGNS & SYMPTOMS (HEP. A)
(1) jaundice


preicteric = BEFORE jaundice appears

icteric = while jaundice is present

Wilkins - Ch 2, (p.32)

IMMUNITY
(1) immunity occurs after 2nd exposure
(2) Vaccine is available

Wilkins - Ch 2, (p.32-34)

HEPATITIS A PREVENTION:
(1) sanitation
(2) personal hygiene-hand washing
(3) cooking food above 185 degrees

Wilkins - Ch 2, (p.34)

AT RISK FOR HEPATITIS A

(1) Travelers
(2) Men who have sex with men (anal sex)
(3) Drug users (injecting & non)
(4) People w/clotting disorders (blood)
(5) People w/chronic LIVER disease
(6) Children where Hep A is prevalent

Wilkins - Ch 2, (p.34)

HEPATITIS B VIRUS (HBV)
aka "Serum hepatitis"

(1) Most SERIOUS occupational hazard for HCP
(2) occurs in any age

Wilkins - Ch 2, (p.34)

HEPATITIS B DIFFERS FROM HEP A
(1) mode of transmission
(2) period of incubation
(3) onset
(4) existence of chronic carrier state

Wilkins - Ch 2, (p.34)

TRANSMISSION OF HEP. B
by percutaneous + permucosal exposure

(1) Blood
ex: drug users sharing needles; accidental needle stick; blood transfusion
(2) Saliva + other bodily fluids
(3) Sexual contact
(4) Perinatal Transmission
ex: during pregnancy/after birth

Wilkins - Ch 2, (p.35)

(1) HCP
(2) Drug users
(3) Those who don't practice safe sex
(4) Pts w/chronic liver diseases
(5) Male prisoners
(6) Travelers/ Military abroad
(7) Infants of HIV+ mothers

Wilkins - Ch 2, (p.35)

INCUBATION PERIOD (HEP B.)
(1) 2-6months

***longer than HepA

Wilkins - Ch 2, (p.35)

COMMUNICABLE PERIOD (hEP B)
(1) before, during and after clinical signs

CARRIER STATE = indefinite

Wilkins - Ch 2, (p.35)

CHRONIC CARRIER OF HEP B

= HBsAg marker in the blood serum for more than 6 months

Wilkins - Ch 2, (p.35)

IMMUNITY OF HEP B

= presence of anti-HBs in serum

REASONING: b/c person has been previously exposed and is now
immune to reinfection)

VACCINE = available

Wilkins - Ch 2, (p.36)

PREVENTION OF HEP B
(1) ELIMINATE trans. during Infancy/Childhood
(2) ENFORCE Blood Bank Control Measures
(3) ENFORCE sterilization
(4) USE of disposable Syringes/Needles
(5) Get vaccinations

Wilkins - Ch 2, (p.36)

PRE- & POST-EXPOSURE HEP B
(1) at onset
(2) 1 month
(3) 6 months

GIVEN: deltoid muscle of adults
LASTS: up to 15 years after successful immunization

Wilkins - Ch 2, (p.36)

POST-PROPHYLAXIS HEP B
(1) newborn of HBsAg positive mother
(2) significant exposure to HBsAg positive blood

Wilkins - Ch 2, (p.37)

PRIMARY USE OF (HBIG)
(1) for postexposure prophylaxis
(2) it is HIGH-TITER vs IG that is "low-titer" , less effective

Wilkins - Ch 2, (p.37)

IG reccomended for:
(1) Hep C
(2) Hep E

Wilkins - Ch 2, (p.37)

HEPATITIS C VIRUS (HCV)
aka "non-A, non-B"

(1) MOST CHRONIC BLOOD-BORNE infection in US
(2) freq. indication of for LIVER TRANSPLANT
(3) serologic tests have been dev. for blood donors

Wilkins - Ch 2, (p.37)

TRANSMISSION OF HEP C
(1) percutaneous exposure
ex: contaminated needles, transfusion
(2) found in SALIVA
(3) SEXUAL transmission
(4) Perinatal exposure

Wilkins - Ch 2, (p.37)

DISEASE PROCESS
(1) May not have clinical signs at onset
(2) 50-80% become chronic carriers
(3) 70% dev. serious liver disease
(4) may progress first 20 yrs w/o symptoms

Wilkins - Ch 2, (p.37)

PEOPLE AT RISK (HEPATITIS C)
(1) 40 yrs or older
(2) MALES
(3) Mod.-heavy ALCOHOL intake
(4) HIV+ and those with HBV

Wilkins - Ch 2, (p.37)

RISK FACTORS FOR HEPATITIS C
(1) Blood transfusion (before 1991)
(2) injection drug use
(3) cocaine users
(4)tattooing, ear/body piercing
(5) perinatal transmission
(6) sexual transmission
(7) Hemodialysis
(8) Organ transplantation

Wilkins - Ch 2, (p.37)

PREVENTION OF HEPATITIS C
(1) follow measures rec. for Hep B
(2) behavior modification
(3) standard infection control procedures

Wilkins - Ch 2, (p.37)

NO VACCINE FOR HEP C

Wilkins - Ch 2, (p.37)

DELTA HEPATITIS VIRUS or (HDV)
aka "Delta agent"

(1) can only cause infection in the PRESENCE OF HBV

Wilkins - Ch 2, (p.37)

TRANSMISSION OF HEPATITIS D
(1) Co-infection with HBV
(2) Blood
ex: hemophiliacs , IV drug users
(3) Sexual contacts

***similar transmission as Hep B
(4) Perinatal

Wilkins - Ch 2, (p.38)

DISEASE PROCESS-HEP D
(1) mortality rate is GREATER than Hep B
(2) onset= abrupt
(3) signs & symptoms resemble Hep B
(4) Coinfection/Superinfection w/ HBV

Wilkins - Ch 2, (p.38)

PREVENTION -HEPATITIS D
(1) use measure to prevent Hep B
(2) Hep B vaccines

Wilkins - Ch 2, (p.38)

HEPATITIS E VIRUS (HEV)
aka "enterically trans. non-A, non-B"

SIMILAR TO: ***Hepatitis A

Wilkins - Ch 2, (p.38)

TRANSMISSION - HEPATITIS E:
(1) fecal-oral route
(2) contaminated water

Wilkins - Ch 2, (p.38)

HERPES VIRUS
(1) are HIGHLY infectious
(2) many exist---8 infect humans

Wilkins - Ch 2, (p.38)

THERE ARE 8 HERPES VIRUSES
(1)HHV1=Herpes Simplex Virus Type 1
(2)HHV2=Herpes Simplex Virus Type 2
(3)HHV3=Varicella-Zoster Virus
(4)HHV4=Epstein-Barr Virus
(5)HHV5=Human Cytomegalovirus
(6)HHV6=Herpes Lymphotrophic virus
(7)HHV7=Human Herpes Virus 7
(8)HHV8=Kaposi's Sarcoma related virus

Wilkins - Ch 2, (p.38)

CHARACTERISTICS-HERPES VIRUS
(1) latent-
ex: HSV1 latent in trigeminal ganglion
(2) malignant
ex: HSV2-cervical cancer/HSV1-oral
(3) recurrent- in immunosuppressed
(4) opportunistic org. in AIDS

Wilkins - Ch 2, (p.38)

HERPES & PERIO INFECTIONS
(1) herpes occurs in perio. pockets
(2) herpes suppresses immune system-perio pathogens fluorish

Wilkins - Ch 2, (p.39)

Herpes Simplex Virus Type 1 (HSV1) (aka "oral herpes)

CAUSES THESE INFECTIONS:
(1) Herpetic gingivostomatitis
(2) Herpes labialis
(3) Herpetic Whitlow
(4) Herpetic conjunctivitis (ocular)

Wilkins - Ch 2, (p.40)

PRODROME
refers to burning, stinging sensation w/slight swelling that shows up as a FOREWARNING --before a local [herpes] lesion appears

Wilkins - Ch 2, (p.40)

CHARACTERISTIC- ORAL HERPES
(1) lesion ruptures
(2) crusting follows
(3) healing takes up to 10 days
(4) infectious w/ viral shedding

Wilkins - Ch 2, (p.40)

HERPETIC WHITLOW (HSV-1 or HSV-2)
(1) infection of the FINGERS
(2) virus enters around fingernails,or other cracks in skin

TRANSMITTED BY:
(1) contact w/lesion -pt's lip/saliva
(2) autoinfection-lip/nail biting

PREVENTED BY:
(1) wearing GLOVES!!!!!!!!!

Wilkins - Ch 2, (p.40)

OCULAR HERPES (HSV-1 or HSV-2)
lesions in the eyes

TRANSMITTED BY
(1) splashing of saliva/fluid to eye

PREVENTION:
(1) standard precautions
(2) use of PPE
(3) eyewear for pt

Wilkins -Ch 2, (p.40)

Herpes Simplex Virus Type 2 (HSV2)
aka "genital herpes" although lesions can occur orally

LATENCY of VIRUS can NEVER be eradicated

Wilkins -Ch 2, (p.40)

CLINICAL MANAGEMENT OF HSV2
(1) Postpone tx for active lesions!!!
(2) For future-pt is advised to call ahead to resched. when lesion is dev.
(3) Pt is prescribed Acyclovir (antiviral drug)

Wilkins -Ch 2, (p.41)

HHV3- VARICELLA-ZOSTER VIRUS (VZV)

INFECTIONS:
(1) Chicken pox - (varicella)
Ex: often occurs in childhood; rash over entire body, scabs

(2) Shingles - (herpes zoster)
Ex: intraoral lesions may occur

Wilkins -Ch 2, (p.41)

HHV4=EPSTEIN -BARR VIRUS (EBV)

TRANSMISSION: Saliva

INFECTIONS IT CAUSES:
(1) Infectious Mononucleosis
Ex:afflicts adolescents/young adults

(2) Hairy Leukoplakia
Ex: White linear lesions along border of tongue; assoc w/AIDS

(3) Endodontic Periapical Pathosis
Ex; Apical pain

(4) Periodontal disease severity

Wilkins -Ch 2, (p.41)

HHV5=CYTOMEGALOVIRUS (HCMV)
most severe in infants infected in utero

TRANS. urine, saliva, genital secretions

INFECTIONS IT CAUSES:
(1) Periapical pathosis
(2) Periodontal disease w/EBV, HSV
****serious complication for AIDS pt

Wilkins -Ch 2, (p.42)

HHV6=HERPES LYMPHOTROPHIC VIRUS (HLV)

INFECTIONS IT CAUSES
(1) immune system suppression
Ex: depletes CD4 lymphocytes
(2) in HIV-periodontitis w/EBV