pathogens and the oral cavity wilkins ch 4 concorde career college preclinical sciences dh101 lisa...
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Pathogens and the Oral CavityWilkins CH 4
Concorde Career College
Preclinical Sciences DH101
Lisa Mayo, RDH, BSDH
Virginia Carrillo, RDH, BSDH
Pathogens Transmissible by the Oral CavityWilkins CH4
Tuberculosis p.44-45
Viral hepatitis p.45-50
HIV p.54-58
Herpetic infections p.50-54
Tuberculosis
Tuberculosis: special consideration when sterilization and disinfection methods are selected and administered
Types of TB: drug-resistant, multidrug resistant TB, extensively drug-resistant
Transmission: Inhalation of fresh droplets containing tubercle bacilli disseminated from sputum & saliva of infected individual by coughing, sneezing, or breathing heavily
Factors affecting transmission Degree to which infected individual produces infectious
droplets & amount and duration of exposure and susceptibility of the recipient
Maximum communicability is just before the disease is diagnosed
Tuberculosis
Areas of infection: lungs (most common), lymph nodes, meninges, kidneys, bone, skin, & oral cavity.
Clinical management: official CDC recommendations 1.Annual risk assessment2.Screening of all newly employed DHCP3.Taking and updating medical history 4.Referral of patients with suggestive TB history or symptoms5.Deferral of elective dental treatment6.Urgent dental care be provided in a facility that can offer isolation7.A separate reception area for suspected or confirmed TB patients
is preferred, and appointment scheduling should be arranged to prevent a waiting period.
(Source: McInnes ME. Essentials of communicable disease. 2nd ed. St. Louis: The C.V. Mosby Co.; 1975).
Review
Tuberculosis infection occurs most commonly in which area?
A) Lymph nodes
B) Lungs
C) Kidneys
D) Liver
Answer
B) Lungs is the correct answer.
Tuberculosis infection occurs most commonly in the lungs, although it can occur in lymph nodes, kidneys, bone, skin, & the oral cavity.
Viral Hepatitis
Inflammation of the liver Causes
Viral & bacterial infections Toxins & certain medications Heavy alcohol use
Viral Hepatitis
Categories A & E: Oral-fecal route. Unsanitary food & water B, C, & D: Blood-borne route. Impacts DH F & G: New, transfusion-transmitted
HEPATITIS B
Hepatitis B HBV is a serious, endemic, worldwide disease Use of strict sterilization of equipment & materials, aseptic
techniques, & self-protection measures is mandatory Transmission (cont’d next slide)
• Blood & other body fluids
• Percutaneous (intravenous, intramuscular, & subcutaneous) & Perimucosal exposure
• Accidents with needle stick & other sharps
• Exchanging contaminated needles, syringes, & other IV drug paraphernalia
1.) Sexual exposure
2.) Infection from blood transfusion & blood products
Hepatitis B
Transmission (cont’d) Perinatal transmission• During fetal stage, at birth
• Infected infant at high risk for chronic infection, which can lead to chronic liver disease or cancer later in life
Carrier state or chronic hepatitis B• All HBsAg-positive persons are potentially infective
• chronic carrier is defined as individual with the HBsAg marker found in the blood on @ least 2 occasions at least 6mo apart
Hepatitis B
Prevention: critical occupational hazard for DH due to close association with potentially infected body fluids of patients. Preventive measures Prenatal testing of all pregnant women for HBsAg Universal immunization of infants & children; immunization of
adolescents & adults (especially those at high risk) Enforce blood bank control measures (screening of donors,
strict testing for all donated blood) Enforce use of disposable syringes & needles Education of public
Active immunization: the vaccines, available since 1982 for pre-exposure & post exposure prophylaxis; stimulate antibodies & convey immunity.
Hepatitis C
General facts: Serologic test for antibody to HCV was developed in 1991, and routine blood screening was implemented in 1992.
Transmission: primarily parenteral; rarely occurs from mucous membrane exposures to blood No documentation of transmission from intact or non-intact
skin exposures to blood Sexual contact with infected partner most common
Prevention & control: No vaccine is available for HCV Education & behavior modification are essential Standards precautions in dental office
Hepatitis D
Delta hepatitis virus, also called the delta agent, causes infection ONLY in the presence of HBV infection (B BEFORE D)
Transmission Delta infection is superimposed on HBsAg carriers Multiple exposures to HBV, especially those with hemophilia
and IV drug use Transmission similar to that of HBV, by direct exposure to
contaminated blood and serous body fluids, contaminated needles and syringes, sexual contacts, and perinatal transfer
Prevention: all measures used to prevent HBV prevent HDV since delta is dependent on presence of HBV.
Immunization with HBV vaccine also protects the recipient from delta hepatitis infection (NBQ)
(Source: Hoofnagle JH. Type D hepatitis and the hepatitis delta virus. In: Thomas HC, Jones EA, editors. Recent advances in hepatology. Edinburgh: Churchill Livingstone; 1986).
Diagram shows the delta antigen surrounded by HBsAg.
Herpes1. Description
2. HSV1 & 2: Primary Herpetic Gingivostomatitis, Herpes Labialis, Herpetic Whitlow, Ocular/Opthalmic Herpes, Genital herpes
3. HSV3: Varicella-Zoster Virus
4. HSV4: Epstein-Barr Virus
5. HSV5 Cytomegalovirus
6. HSV8 Kaposi’s Sarcoma
Herpes Virus Diseases Description
Endemic worldwide, each virus causing many disease entities that are highly infectious
Public health problem due to lack of effective therapeutics & vaccines 8 strains are known to infect humans Herpes viruses produce diseases with latent, recurrent, and sometimes
malignant tendencies HS type 2 has been implicated in cervical cancer HS type 1 in oral cancer, & Epstein-Barr virus with various types of
cancer After infection, the virus has the ability to remain latent in the
individual and only become reactivated to produce recurrent infection • Certain stimuli • Immune response lowered/altered
Herpes Virus Description
Relation to periodontal disease Human herpes viruses occur in periodontitis, found in
pocket flora with relatively high prevalence Infection with herpes viruses can suppress a patient’s
immunity, and as a result, subgingival overgrowth of opportunistic periodontal pathogens can occur, making periodontal disease symptoms more severe
Herpes Virus Description
HSV-1: primary infection usually occurs in children, but may occur at any age
Antibodies (anti-HSV) are produced, but do not guarantee immunity to recurrent herpes or other herpes virus infections
Sulcular epithelium can serve as reservoir for the viruses, Anti-HSV is present in gingival sulcus fluid The possibility exists that trauma to oral tissues during
dental or DH appointment may bring about herpetic recurrence
Herpes Virus DiseasesPrimary Herpetic Gingivostomatitis
Primary infection with HSV-1 Full-blown case presents with widespread oral ulcers that may
involve pharyngeal areas Fever, malaise, inability to eat, swollen lymph nodes Reactivation may also lead to herpetic ulcerations of the lip,
the typical “cold sore”
Herpes Virus Diseases: Labialis
Herpes labialis (cold sore, fever blister) HSV-1 & HSV-2 cause genital & oral-facial infections (cannot
distinguish between the 2) Reactivation of oral-facial HSV-1 infections are more frequent than
oral-facial HSV-2 Recurrent triggers: stress, sunlight, illness, trauma (dental appts) Prodromal: prior lesion appearance, burning, stinging, tingling
sensations with slight swelling may appear Clinical characteristics
Group of vesicles form and eventually ruptures & may coalesces Crusting follows and healing may take up to 10 days The lesions are infectious, with viral shedding Care must be taken by the patient because autoinfection (to eye,
nose, or genitals) is possible, as is infection of other people Laser dentistry
Herpes Virus Diseases Labialis
Clinical management: Use patient-friendly terms such as “cold sore” or “fever blister” or “ulcer” NEVER SAY HERPES LESION!!
POSTPONE appointment for patient with active lesion Explain problems: contagiousness, may spread around
their oral cavity Irritation to the lesion(s) can prolong the course and
increase severity of the infection Prodromal state MOST contagious!!
Latent infection of herpes simplex virus. Path of the virus traced from point of viral penetration on lip to establishment of latent infection in the trigeminal ganglion
Herpes Virus Diseases: Whitlow
Herpetic whitlow HSV-1 infection of the fingers that results from viral entry
through minor skin abrasions Most frequently found around a fingernail Prevention is with use of protective gloves during dental
procedures Extinct in dentistry with standard precautions
Herpes Virus Diseases Ocular/Ophthalmic Herpes
Can be primary or recurrent infection in the eye from HSV-1 or HSV-2
Transmission from splashing saliva or fluid from a vesicular lesion directly into an UNPROTECTED eye
Prevention: PPE
Herpes Virus Diseases HSV2
Herpes simplex virus type 2 (HSV-2) Commonly known as genital herpes, but can also
occur as an oral and ocular infections Antiviral therapy can suppress HSV-2 lesions, but
the latency of the virus can never be eradicated
Herpes Virus HSV3 Varicella-Zoster Virus
Varicella-zoster virus 1. Chicken pox caused by varicella virus: highly
contagious, may be transmitted by direct contact, droplet (possibly air-borne), or indirect contact with articles soiled by discharge from vesicles and the respiratory tract.
2. Shingles caused by herpes zoster virus: chickenpox leaves lasting immunity, but the VZV remains latent in the dorsal root ganglia. Secondary infection.
Herpes Virus HSV4: Epstein-Barr Virus
EBV virus causes:
1. Infectious mononucleosis• Prevention: minimize contact with saliva by frequent
handwashing, avoiding drinking from a common container, follow standard precautions
2. Oral hairy leukoplakia• High incidence in HIV/AIDS patients
• Tongue lesions appear as white linear lesions along the lateral borders
Infectious Mononucleosis
Oral Hairy Leukoplakia
Herpes Virus HSV5 Cytomegalovirus
Cytomegalovirus (CMV) Common in HIV/AIDS Most severe form developing in infants affected in utero Transmission
• Virus from mother’s primary or recurrent infection may affect infant in utero, in the birth canal, or through breast milk.
• CMV in the fetus can lead to premature birth, anemia, mental retardation, microcephaly, motor disabilities, deafness, and chronic liver disease
• Blood transfusion, post-transplant infection, sexual, respiratory droplet (daycare rate high)
Prevention• Standard precautions, handwashing
HSV8
Kaposi’s sarcoma-related herpes virus in immunocompromised host, a major cofactor in production of Kaposi sarcoma, an AIDS-defining lesion.
HIV
HIV-1 Infection
• General facts• Severe pandemic disease caused by HIV infection • First recognized in 1981 as cluster of diseases characterized by loss
of cellular immunity • Major types: HIV-1 (more prevalent in U.S. & Europe) & HIV-2 Slow,
progressive, & often lethal• Can persist within cells such as macrophages for long periods
Transmission: semen, vaginal secretions, breast milk, blood Serological tests: 1985 (EIA/ELISA)
Confirmation with Western blot or IFA test T-helper cell % marker for progression
Review
The majority of cases of transmission of HIV in adults is due to which of the following?
A) Blood transfusion
B) Needle sharing
C) Sexual contact
D) Contact with saliva
Answer
C) Sexual contact is the correct answer.
Sexual contact is the most common way HIV is transmitted among adults. Transmission via blood transfusions is rare, especially in developed countries. Needle sharing is a method of transmission, but not as common. No cases of transmission via saliva are known.
Clinical Course of HIV-1
Seroconversion = when antibody can be detected 6wks-6mo after exposure
Incubation period: Range from time infection → AIDS symptoms Could be 15+yrs
Clinical Course of HIV-1
Early symptomatic HIV disease
CD4+ T lymphocytes 200-500 cells; continued increase in viremia; systemic symptoms: night sweats, weight loss, diarrhea, fever, malaise, general weakness; opportunistic infections begin; oral lesions become more common
Late-stage disease: AIDS
CD4+ count below 200; pneumonia is presenting feature with other AIDS-defining diseases; presentation of full-blown AIDS is highly variable & affected by host’s prior exposure to chronic infections & treatment.
Symptoms: AIDS-indicating conditions
CD4+ numbers decline, Opportunistic infections become more frequent, extensive, & severe
• AIDS-dementia complex, Tuberculosis infection, Constitutional disease, Neoplasms
• Death in 1 to 3 years (if untreated)
Oral Manifestations of HIV-1
Extraoral examination: Lymphadenopathy, Skin lesions
Intraoral examination
Fungal infections: Candidiasis
Viral infections: Kaposi Sarcoma, Herpes, Oral Hairy Leukoplakia, Chickenpox, Verrucca vulgaris, HPV, Cytomegalovirus
Bacterial infections: Linear Gingival Erythema, NUG/NUP
Dental hygiene management: Refer symptomatic patients, help maintain quality of life, educated on home care
Prevention of HIV Infection
Community education Attitudinal, behavioral changes: increase awareness, modes of
transmission, prevention methods Goals
Primary prevention: lower rate at which new cases of HIV-1 appear. HIV testing is required for all pregnant women, all newborns
Secondary prevention: For seropositive individuals to reduce the rate of transmission and introduce treatment early.
Early intervention may postpone severe clinical manifestations of advanced illness. Counsel HIV-infected individuals to practice safe sex, cooperate with screening programs, and counsel their sexual contacts and families
Postpone visit due to herpes infection Don’t touch/scratch lesion Avoid transferring virus to objects Keeping medical history up-to-date Maintaining oral health
Factors to Teach the Patient