2. Infectious Diseases Flashcards
LOs
• Define what is an infection
• Understand what are the common infectious diseases in dental practice
• To choose the most appropriate investigations
• Enumerate common viral, bacterial and fungal infections, clinical features and treatment
• Understand the main differences between passive and active immunity
infection?
- process of tissue invasion by microorganisms,
characterized by multiplication of these microorganisms in body of host to produce disease
cross infection?
transmission of infection between patients as well as patient and health care professionals
infection classifications?
COMMUNITY ACQUIRED INFECTION
- manifesting or diagnosed within 24 hr of admission to hospital w/out previous healthcare encounters
- ie. present @ time of admission or hospital visit
HEALTH CARE ASSOCIATED INFECTIONS
- induced from source within the patients body (autogenous)
- or outside the patients body (exogenous after a visit to a hospital or healthcare centre
what to consider when making a diagnoses?
history (re: transmission of disease)
- foreign travel
- domestic pets
- tattooing
- immigrants
- sexual activity
- injections
- occupation
- drug addiction
- transfusions
infection investigation techniques/ procedures
4 categories of infectious disease?
- Viral infection
- Bacterial infection
- Fungal infection
- Parasitic infection
EG of common viral infections?
HERPES SIMPLEX
1- types (spread by?)
- incubation
2- pathogenesis
3- diagnoses/ infection
4- clinical features
5- complications
6- treatment
2- Pathogenesis
a. DNA targets epithelial cells
b. Replication causes cell lysis
c. Clusters of these infected cells come together and from vesicles
d. Infected cells fuse with healthy adjacent cells spreading infection and forming multinucleate cells
e. Full thickness of the epithelium lost and a well defined ulcer forms
3- Diagnosis/investigation
- Herpetic stomatitis may be visible -> Pale vesicles and ulcers are visible on the palate and gingiva, especially anteriorly, and the gingivae are erythematous and swollen.
- Histology of a smear can be tested and virus damaged cells will be visible.
4- CLINICAL FEATURES
- Orolabialis infection
- Sore throat, fever
- Vesicles on pharynx, buccal mucosa, gingiva and tongue -> spreads to lips and face
- Lymphadenopathy
- Recurrence
Skin infections
• hsv-1 or hsv-2
• herpetic whitlow
• primary infections
Eye infections
• usually hsv-1
• corneal involvement is serious since it may cause
blindness
Genital / anal infections
• usually hsv-2
- Complications
- Encephalitis -> inflammation of the brain
-> affects temporal lobes
- Neonatal -> baby born with herpes ->
60% mortality rate
- Usually occurs due to transfer of hsv-2
during (parturition) birth - Potential
indication for a caesarian section
- Erythema multiforme -> red skin due to deposition of immune complexes, unknown cause
- Eczema herpeticum -> viral infection characterized by itchy blisters and fever - Treatment
- May heal by itself
- Acyclovir
- Valacyclovir
- Chlorhexidine mouthwash is sometimes used in an attempt to reduce pain by controlling
secondary infection of ulcers. It also helps maintain gingival health while tooth brushing is
impossible.
- The saliva is infectious, and transfer to the eye must be avoided because ocular herpes infections
may develop into encephalitis by direct spread along the optic nerves.
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