Salivary Gland Infections Flashcards
What is Sialadenitis?
An inflammation of salivary tracts
Sialadenitis infective causes are …?
- Viral
- Bacterial
- Parotid glands ( more common )
Viral causes of Sialadenitis
- Mumps ( most common )
- CMV
- Rare viruses :
a. Parainfluenza virus types 2 & 3
b. Echoviruses
c. Coxsackie viruses
Important properties of mumps
- Lipoprotein envelope with spikes of 2 transmembrane glycoproteins
- Helical nucleocapsid
- Single-stranded, linear, nonsegmented negative-polarity RNA
- RNA dependent RNA polymerase
- Single serotype
What are the 3 proteins with viral RNA in mumps?
- Nucleocapsid (N) protein:
* forms helical nucleocapsid
* represents major internal protein - P (Phosphoprotein)
- L (Large polymerase) proteins
* L & P proteins & nucleocapsid together has RNA-dependent RNA transcriptase activity
What are the 3 proteins forming the viral envelope?
- Matrix (M) protein:
* underlies viral envelope
* important in virion assembly - Two transmembrane glycoproteins:
a. Hemagglutinin neuraminidase(HN):
* Hemagglutination activities
* Attachment to host cell - Fusion (F) glycoproteins
* Membrane fusion
* Hemolysin activities
How mumps is transmitted?
Respiratory droplets
Explain pathogenesis of mumps virus
- Infects URT —> spreads through blood to infect :
parotid glands, testes, ovaries, pancreas & meninges - Virus ascend from buccal mucosa up Stensen’s duct to parotid gland
Pathogenesis of mumps through vertical transmission
Maternal antibody passes placenta & provides protection during first 6 months of life
Mumps occurs only once; subsequent parotitis caused by :
- Other viruses such as parainfluenza viruses
- Bacteria
- Duct stones
What are the clinical findings of mumps ?
1 Prodromal stage:
- fever
- malaise
- anorexia followed by tender swelling of parotid glands, either unilateral or bilateral ( puffy cheeks)
- Drinking citrus juices increase in parotid pain
- Loss of appetite
- Headache
Incubation period of mumps virus
18 to 21 days
When mumps virus resolves ?
1 week ; disease is benign
Complications of mumps virus
- Orchitis :
* in postpubertal males
* bilateral——-> sterility
* they have fibrous tunica albuginea, which resists expansion ——-> pressure necrosis of spermatocytes
* Unilateral orchitis is painful but does not lead to sterility - Meningitis :
* benign, self-limited & without sequelae
How to diagnose mumps virus ?
- Cell culture :
* isolate virus from saliva, spinal fluid & urine - PCR
- Fourfold rise in antibody titer
- Complement fixation (CF) test :
* both S (soluble) antigen (consists of NP)
& V antigen (consists of HN glycoprotein)
- Antibody to S antigen indicates ——> current infection (appears early & short lived)
- If only V antibody is found——> patient has had mumps in past
Important properties of Actinomyces Israelii
- Anaerobic
* Gram-positive filamentous, branching rods
What is the habitat of Actinomyces Israelii?
Habitat is human mouth
* anaerobic crevices around teeth
Transmission of Actinomyces Israelii
- Occurs during dental disease or local trauma such as broken jaw or dental extraction
- Organism aspirated into lungs, causing thoracic actinomycosis
Explain pathogenesis of Actinomyces Israelii
- Infection is initiated by trauma that introduces these endogenous bacteria into mucosa
- Organisms grow in anaerobic niche, induce mixed inflammatory response ——> spread with formation of sinuses ( contain granules & drain pus to surface through sinus tracts)
- Infection causes hard, non tender swelling that develops slowly & may spread to neighboring organs, including bones
Clinical findings of Actinomyces Israelii
- Cervicofacial disease
- Thoracic actinomycosis
- Abdominal actinomycosis
- Genital actinomycosis
What are the manifestations of Cervicofacial disease of Actinomyces Israelii?
- Swollen, erythematosus process in jaw area “lumpy jaw”
- With progression, mass becomes fluctuant, producing draining fistulas
- Disease extend to contiguous tissue, bone & lymph nodes of head & neck
What are the manifestations of Thoracic actinomycosis?
- resemble those of subacute pulmonary infection:
* mild fever, cough & purulent sputum - Lung tissue is destroyed, sinus tracts may erupt through to chest wall & invasion of ribs
What are the manifestations of Abdominal actinomycosis?
- Follows ruptured appendix or ulcer
* In peritoneal cavity, pathology is same, but any organs involved
What are the manifestations of Genital actinomycosis ?
- Rarely occur in women with retained intrauterine device for long period of time
How to diagnose Actinomyces Israelii ?
- Examining pus:
* from draining sinuses, sputum, or specimens of tissue for presence of sulfur granules - Gram staining : showing Gram-positive branching rods
- Culturing of pus or tissue specimens
* anaerobic conditions - Immunofluorescence (identification)
Describe the structure of sulfur granules
- granules are hard
- lobulated & composed of tissue & bacterial filaments
- club shaped at periphery
