6. ****LO 4B: Common Bacterial And Viral Diseases

What is the focus of the "Oral Diseases" section in this lesson (other than caries and periodontal diseases)?

Diseases that may be spread in a dental office

What is a key aspect of the potential for the spread of respiratory diseases in the dental office regarding patients?

Dental patients (and many other persons) are asymptomatic carriers of a variety of pathogens present in their oral or respiratory fluids

What specific infections are caused by Human Herpes Virus type 1 (simplex) (AKA cold sore)?

Infections of mouth, skin, eyes, genitals

How can Human Herpes Virus type 1 spread?

By direct contact with vesicles (BLISTERS) at any site of the body that may contain the virus

What is the protocol for treating a client with an active herpes lesion?

DO NOT treat a client with active herpes lesion

Where, besides vesicles, may Herpes Virus type 1 also be present?

Saliva

What is primary herpetic gingivostomatitis caused by?

Initial infection with the herpes simplex virus Type 1

Which areas of the mouth can primary herpetic gingivostomatitis appear?

keratinized AND non keratinized tissue at INITIAL INFECTION ONLY 

What is the term for the entrance of the herpes virus through breaks in the skin?

Herpetic whitlow

What percentage of genital herpes infections are caused by Human Herpes Virus Type 2?

90%

What is the effect of treating HHV Type 2 with acyclovir?

Will reduce severity and duration, but will not prevent recurrence

What percentage of adults have been infected with human herpesvirus 1 (HHV-1)?

About 90%

Human herpesviruses (HHV) cause several diseases, which are most common?

Type 1 and 2 are most commonly diagnosed and treated (symptoms)

What yeast causes Oral Candidiasis?

Candida albicans

In what fraction of adults does Candida albicans occur asymptomatically in the mouth?

One third of adults

Why is Candida albicans considered an opportunistic pathogen?

It usually causes a harmful infection only under special circumstances

What are the whitish lesions of Oral Candidiasis called?

Thrush

What are the reddish areas of Oral Candidiasis called?

Stomatitis

Name the 3 antifungal agents used to treat Oral Candidiasis.

Nystatin, Ketoconazole, Clotrimazole (-azole is typically an antifungal)

What spirochete is the cause of syphilis?

Treponema pallidum

In what percentage of syphilis cases does the first lesion occur in the mouth?

5-10% of cases

What is the name for the open ulcer caused by syphilis that appears on the lip or tongue?

Chancre (open ulcer on lip or tongue)

What Gram-negative bacteria causes gonorrhea?

Neisseria gonorrhoeae

How is Neisseria gonorrhoeae spread to the mouth?

From sex practices with an infected person

What characteristic do oral syphilis and gonorrhea share regarding the dental team?

They are oral disease-causing agents that have some potential for spread to the dental team

What are the characteristics of Herpangina lesions?

Vesicles on the soft palate that break down to ulcers that last for a week

What is a key feature that differentiates Herpangina from herpes lesions?

Rarely appear on gingiva, buccal mucosa or tongue

What virus causes Herpangina?

Coxsackievirus

How long do the ulcers from Hand-Foot-and-Mouth Disease last in the mouth?

About 1 week

Hand-Foot-and-Mouth Disease is classified as what type of disease?

Viral disease

When does Secondary Syphilis occur?

2-10 weeks after the initial lesion, if primary syphilis goes untreated

What lesion characterizes Secondary Syphilis in the mouth?

Mucous patches in the mouth

Why are the mucous patches of Secondary Syphilis spread by direct contact?

They contain live spirochetes

What medication is used to treat Secondary Syphilis?

Penicillin

What virus causes Chickenpox?

Human herpesvirus type 3 (varicella-zoster virus)

Chickenpox is the primary disease in which age group?

Young children

What is the recurrent disease caused by HHV-3, and when does it usually occur?

Shingles; usually 50 years or older

Although chickenpox produces skin lesions and sometimes oral lesions, how is the disease classified?

As a respiratory disease

How is the varicella-zoster virus spread, in addition to contact with skin lesions?

Through saliva and nasal secretions

What virus causes Infectious Mononucleosis?

Human herpesvirus type 4 (Epstein-Barr virus)

What symptoms does HHV-4 usually cause in young children?

Mild symptoms, if any

In which demographic does HHV-4 cause infectious mononucleosis?

Adolescents and young adults

What is the common name for Infectious Mononucleosis?

‘Kissing disease’

What is the mode of transmission for Infectious Mononucleosis?

Direct contact person-to-person

Name two symptoms of Infectious Mononucleosis.

Fever, malaise, anorexia, fatigue, sore throat, oral ulcers, enlarged cervical lymph nodes, palatal petechiae, erythema of oral mucosa, swelling of uvula

What bacteria causes Streptococcal pharyngitis (Strep Throat)? - contagious

Streptococcus pyogenes

What condition is characterized by "strep throat" with a skin rash? - contagious

Scarlet fever

What severe infection can some strains of S. pyogenes cause?

Necrotizing fasciitis (spreading damage to muscle tissue, known as "flesh-eating" bacteria)

How are infections caused by S. pyogenes typically treated?

Penicillin therapy

When is a person considered infected with M. Tuberculosis?

If enough M. Tuberculosis reach the lung alveoli and begin to multiply

What is the only evidence of M. Tuberculosis infection?

Tuberculin skin test

Tuberculosis begins with symptoms resembling what other disease?

Pneumonia

What are the tubercles formed in the lung tissue during tuberculosis?

Consolidation of tissue around the lung infection site

What can happen to tubercles as the disease progresses?

They may enlarge, become necrotic and produce open spaces in lung tissue

What are the two names for the Tuberculin Skin Test?

Mantoux test or purified protein derivative (PPD) test

How is PPD administered?

Injection of PPD under skin in forearm

How long is the Tuberculin Skin Test observed for a reaction?

48-72 hours

What indicates a positive reaction to the PPD test?

Induration (hardening) of the injection site, and the diameter is measured

Where does Streptococcus pneumoniae normally exist?

In the nose and throat

Who carries S. pneumoniae asymptomatically?

Preschoolers and adults

S. pneumoniae is the leading cause of which type of infection in children?

Middle-ear infections

What severe disease can S. pneumoniae cause?

Bacterial meningitis

What is Human Herpes Virus type 5 called?

Cytomegalovirus

What congenital disease does HHV-5 cause?

Cytomegalic inclusion disease

Name one potential effect of cytomegalic inclusion disease.

Mental retardation, neurologic problems, deafness, possible damage to internal organs

Where has Human Herpes Virus type 6 been isolated from?

Saliva

What symptoms does HHV Type 6 cause in infants?

High fever and skin rash

Where has Human Herpes Virus type 7 been isolated from?

Saliva

Is HHV Type 7 associated with a particular disease state?

Not associated with any particular disease state

What is Human Herpes Virus type 8 associated with?

Kaposi’s sarcoma in AIDS patients

What are the two types of Influenza (the "flu") that typically infect humans?

Type A and type B

Name two routes of Influenza transmission.

Droplet exposure of mucosal surfaces (coughing, sneezing), direct contact, contact with fomite, self-inoculation

How are many respiratory diseases spread?

By inhalation of infected respiratory/oral droplets

What is heavily contaminated with bacteria inside the dental unit?

The water inside dental units and hoses for water-spray handpieces and the air/water syringes

What forms on the inside of dental water lines?

Biofilm

How many types of bacteria are typically present in water line biofilm?

30-40 types of bacteria

Name the two most prevalent bacteria associated with waterborne disease in dental units.

Legionella pneumophila and Pseudomonas aeruginosa

What is one CDC recommendation for flushing dental water lines?

Flushing water lines between patients or Flushing water line at the start of the day

What is the CDC recommendation regarding using dental unit water lines to irrigate surgical sites?

Do not use dental unit water line to irrigate surgical sites in which bone is exposed

What specific instruction does the CDC give regarding client suction use?

Never ask the client to close their mouth on the suction

What bacteria causes Legionnaires Disease?

L. Pneumophila

What is the Gram stain and shape of L. Pneumophila?

Gram (-) rod bacteria

How is Legionnaires Disease characterized?

Pneumonia-like disease

What antibiotic treats Legionnaires Disease?

Erythromycin

Has person-to-person spread of Legionnaires disease been documented?

Has not been documented

What type of pathogen is Pseudomonas?

An opportunistic pathogen

What is the prevalence of Pseudomonas in nature versus dental unit water?

Occurs widely in nature but low in numbers in water used in a dental unit

What is Methicillin-Resistant Staphylococcus aureus (MRSA) resistant to?

Certain antibiotics like β-lactams (skin infections)

Where do more severe or potentially life-threatening MRSA infections occur most frequently?

Among patients in health care settings

Is MRSA currently prevalent in dentistry?

Fortunately, not prevalent in dentistry yet