Infection Infection Control:Control:Transmissible DiseasesTransmissible Diseases

Infection Control:

• Objectives: Protect patients, dental professional, and others from exposure to acquired infection in dental environment.

Standard Precautions• Definition: Blood, all body fluids, secretions, and

excretions (except sweat) are treated as if known infection.

Microorganisms of the Oral Cavity

• Infection potential- bacteria come from dorsum of tongue, dental biofilm, periodontal pockets, caries.

• Cross-contamination occurs: – Person to person– Person to inanimate object– Inanimate object to another person

ReviewCross-contamination refers to the spread of microorganisms

from one source to another; this may include which of the following?

A) Person to person, person to inanimate object, and inanimate object to person

B) Person to inanimate object onlyC) Inanimate object to person onlyD) Person to person onlyE) Person to inanimate object and inanimate object to person

only

AnswerA) Person to person, person to inanimate object, and

inanimate object to personPerson to person, person to inanimate object, and

inanimate object to person are all possible sources of cross-contamination.

Infectious Agent

Factors Influencing the Development of Infection

• Number of organisms, duration of exposure

• Virulence of the organism: strength of pathology

• Immune status of host: ability to resist infection

• Host general physical health and nutritional status

Factors That Alter Normal Defenses

• Abnormal physical conditions: defective heart valve as congenital or acquired condition

• Systemic diseases: diabetes mellitus, alcoholism, leukemia, AIDS

• Drug therapy: Steroids and chemotherapeutic agents

• Prostheses and transplants: joint replacement, cardiac prosthesis, shunts, organ transplant

Air-borne Infection• Dust-borne organisms• Aerosol production

– Aerosols: less than 50um in diameter, invisible, suspended in air for long periods, may contain respiratory disease organisms

– Spatter: Spatter-heavier, larger particles greater than 50um, air-borne shorter time, may be visible

– Origin: Produced during all intraoral procedures, including examination and treatment

– Contents: single or clumps of mo adhere to dust or debrie particles from mouth

Prevention of Transmission• Pre-procedural oral hygiene measures: biofilm removal;

brushing, flossing, mouthrinse• Interruption of transmission: rubber dam, high evacuation,

manual instrumentation, ventilation, filtration

• Clean water: EPA standards. Run water lines 2 minutes before and after patient in clinic

• Protection of the clinician: PPE’s

• Protection of the patient: Eyewear

Pathogens Transmissible by the Oral Cavity

• Tuberculosis

• Viral hepatitis

• AIDS

• Herpetic infections• Table 2-1 p 28

Active TB InfectionActive: incubation as long as 10 weeks• Usually has a skin or blood test result indicating TB infection• May have an abnormal chest x-ray or positive sputum smear• Has active TB bacteria in body• Usually feels sick with coughing, fever, and weight loss• May spread TB to others• Needs treatment to treat active disease

Latent TB Infection

Latent:• Usually has a skin or blood test result indicating TB

infection• Has a normal chest x-ray or negative sputum smear• Has inactive TB bacteria body• Does not feel sick, cannot spread to others• May need treatment for latent TB infection to

prevent active TB disease

How is Active TB Spread?• Most communicability just before diagnoses• Spread by inhalation, inoculation and mucous

Who is at risk for Active TB?• Born in country with high TB burden (Asia, India,

Latin America, Soviet Union)• Child of parents born in country with endemic TB• Close contact to person with active TB• Living and working in congested settings (shelters,

long term care)• Medically underserved (low income, uninsured, drug

abuse)

HIV and TB• HIV testing is recommended for all TB suspects or

confirmed cases• HIV + persons with TB disease have higher HIV viral

loads that HIV + persons without TB disease• HIV disease can mask TB symptoms and vice versa• HIV + person who are skin test+ have an increased

annual risk of TB disease

Active TB TreatmentStandard Drug Regimen; RIPE taken for several months• Rifampin• Isoniazid• Pyrazinamide• EthambutolIs a drug resistant illness

Droplet Nuclei

Viral Hepatitis• Inflammation of the liver• Strains of hepatitis

– Hepatitis A, B, C, D, E– Non-ABCDE– G (HGV)

Hepatitis A(HAV)• Jaundice, influenza type symptoms, not a chronic infection

• Water and food borne, poor food handling, unwashed hand, fecal/oral route. Best defense is handwashing

• No carrier state . May treat in clinic. May use the ultrasonic scaler.

• Traveling to at risk areas, homosexual men, iv drug uses, hemophiliacs, liver disease

• Immunization available

Hepatitis B (HBV)• Very serious, prolonged illness, liver cancer, significantly

increased occupational hazard of healthcare workers

• 5-10% carrier state. Virus remains in blood and can be found in blood products during prophylaxis, body fluids and saliva. Do not treat patients with active Hepatitis B.

• Needlesticks , sexual and perinatal exposure, blood transfusion occupation, lifestyle, drug abuse

• Immunization available

Hepatitis C (HCV)

• Flu-like symptoms. 50-80% chronic carries, 70% liver disease . Most reason for liver transplants.

• Do not use ultrasonic scaler with previous history.

• Male, alcoholism, HIV or HBV, blood transfusion before 1991, IV drug abuse, tattooing, piercing, organ transplantation

• No Immunization. Behavior modification, infection control

Hepatitis D(HDV)

• Signs and symptoms resemble HBV. Patients with Hepatitis D also have Hepatitis B

• Do not use ultrasonic scaler with previous history

• Immunization with HBV vaccine also protects the recipient from delta hepatitis infection.

Hepatitis E• HEV formerly known as enterically transmitted non-A, non-B

hepatitis. Water-borne epidemics.

• No carrier state. May use ultrasonic scaler. Patient fully recovers and does not carry the virus in the bloodstream.

• Transmitted by contaminated water, person to person, and fecal oral route.

• No Immunization: sanitary disposal of wastes; handwashing, especially before handling food.

Tips for Remembering Types of Hepatitis

• Consonants refer to the blood-born strains B, C, D• Vowels refer to fecal-oral transmission A, E

Herpes Virus Diseases

• Highly contagious, eight are known to infect humans.

• Relation to periodontal infections: opportunistic periodontal pathogens can occur, making periodontal disease symptoms more severe.

Latent Infection

Triggers:•Ultraviolent light•Stress•Dental treatment

Types of Herpes Infection • Herpetic whitlow: infection of fingers contacted via skin abrasions from

lesion

• Ocular herpes: HSV 1 or HSV 2 infection of eye

• Herpes simplex type 1 (HSV-1): Oral herpes. HSV 1 and HSV 2 cannot be distinguished clinically

• Herpes simplex type 2 (HSV-2): Genital herpes. Antiviral therapy can suppress lesion, but latency can never be erased. Most common STD

• Postpone appointment for active lesions. Acyclovir, an antiviral drug of choice for treatment for HSV2

Types of Herpes Infection

Varicella-herpes zoster virus (HZV):• Chickenpox: Varicella; highly contagious, acute infection

• Shingles: Herpes zoster; lantent in dorsal root ganglia. Unilateral eruptions, may occur intraoral

Epstein-Barr virus EBV: • Infectious mononucleosis: flu-like symptoms, transmitted by saliva or

droplets, last carrier state

• Hairy leukoplakia: associated with AIDS, white, lesion on lateral borders of tongue

Types of Herpes Infections• Cytomegalovirus (HCMV HHV-5): Adult infection; immunodeficient or

immunosuppressed patients

• Herpes lymphotrophic virus (HHV-6): Childhood infection (6 months to 2 years), roseola infantum, with accompanying high temperature and rash

• Human herpes virus-7 (HHV-7): prevalent in general population, detected in both healthy gingiva and diseased periodontal tissues.

• Kaposi sarcoma-related virus (KSRV)(HHV-8): immunocompromised host, a major cofactor in production of Kaposi sarcoma, an AIDS-defining lesion.

HIV Infection• Slow, progressive, lethal pandemic caused by infection with the human

immunodeficiency virus.

• Found in most body fluids; transmitted via blood, semen, vaginal secretions, and breast milk.

• Obtain permission to treat from physician. Do not use the ultrasonic scaler. Legally need to treat patient

• Unprotected sexual contact with infected person, IV drug users (sharing needles), transplantation of organs and tissues, occupational exposure, perinatal transmission, hemophiliacs

When HIV becomes AIDS

• http://www.youtube.com/watch?v=68I7JlVhuhY