General Basics of Infection and Oral Manifestations of Bacterial Infectious Diseases PDF

General basics of Infection & Oral manifestation of bacterial infectious diseases Dr/ Heba Elhendawy Associate professor of Oral Pathology Faculty of Dentistry- Mansoura University  Infections Definition: Invasion of the body by pathogenic micro-organisms which may b...

General basics of Infection & Oral manifestation of bacterial infectious diseases Dr/ Heba Elhendawy Associate professor of Oral Pathology Faculty of Dentistry- Mansoura University  Infections Definition: Invasion of the body by pathogenic micro-organisms which may be Bacteria, Viruses, Fungi, protozoa. The body has both non-specific (e.g. inflammation) and specific (immunity) defense mechanisms to protect against infection.  Routes of infection 1. Exogenous: Via skin or mucous membrane Ingestion Inhalation Injection and blood transfusion Sexual Transmission Transplacental 2. Endogenous: Septic focus. Commensals.  Spread of Infections Local spread to surrounding structures Natural passages …trachea, ureters, Lymphatic spread …to the draining lymph nodes. Neural spread …along nerves as varicella zoster virus. Hematogenous spread …in plasma (bacteria) or within cells as monocytes (HIV).  Blood spread Bacteremia and Viremia: Passive circulation of small numbers of bacteria (or viruses) without growth in the blood stream. Toxemia: Circulation of bacterial toxins in the blood with production of clinical and pathological manifestation as: Constitutional signs and symptoms, Degeneration of parenchymatous organs. Anemia and necrosis  Septicemia: Circulation and multiplication of large number of virulent microorganisms with their toxins in the blood also with production of clinical and pathological manifestation as toxemia. Pyemia: Circulation of septic emboli (detached septic thrombi) with their localization in the organs→ pyemic abscesses. Oral Bacterial Infections Dental caries Periodontal disease Pharyngitis and tonsillitis Tuberculosis –Mycobacterium TB Syphilis -Treponema pallidum Leprosy-Mycobacterium lepra Actinomycosis –Actinomyces Osteomyelitis -Staphylococcus NUG – Borrelia vencenti Tuberculosis: Infectious granulomatous disease affecting lung primarily, but can affect any organ.  Caused by Mycobacterium tuberculosis. Positive to Ziehl-Neelsen stain. Mode of infection: Inhalation, ingestion, contact. Clinically: Fever, weight loss, fatigue, malaise, persistent cough with hemoptysis. Formation of TB granuloma in different sites. Sites: 1. Pulmonary. 2. Extrapulmonary tuberculosis Intestinal tract, tonsils, skin and intraoral sites (posterior third of tongue, palate, lips, buccal mucosa and gingiva. Central in bone of maxilla, mandible and periapical tissues. Spread: Miliary TB (spread though out the body, life threating condition). Scrofula Submaxillary and cervical LNs (cold abscess). Tuberculous gingivitis Ulcer Tuberculoma in gingival tissue  Oral findings: Tongue ulcers. Tuberculous osteomyelitis. Periapical tuberculoma. Tuberculous gingivitis Microscopically (M/E) Granulomatous inflammation with central caseation necrosis.  Syphilis Caused by: Treponema pallidum (a spirochete). Identified by silver stains Mode of infection: Sexual, Contact, Blood. Clinically: 1. Acquired: 3 clinical stages (primary, secondary, tertiary). 2. Congenital syphilis. histopathology: 1ry and 2ry $→ non-specific inflammatory reaction rich in plasma cells, thickened wall blood vessels. 3ry $→Syphilitic granuloma with central coagulative necrosis, end arteritis obliterans, and excess plasma cells. Acquired syphilis: (Chancre). Highly infectious. Ulcer (chancre) appears 1-3 weeks after contact. Site: genital (95% of cases). Oral: lip, tongue, palate, tonsil, buccal mucosa. Chancre is indurated ulcer, painless. Heals within few weeks. B. Secondary syphilis (skin rash and mucous patches) 1-3 months after primary lesion. Skin rash: macules and papules. Oral: mucous patch and “snail track” ulcers. Mucous patches are highly infectious. Heals in few weeks Mucous patches Condyloma latum C. Tertiary syphilis 1-3 or more years after secondary. Manifestations: Gumma (necrotic tumor-like mass exhibiting granulomatous inflammation). Gummatous perforation of the hard palate. Syphilitic glossitis. Not infectious. Syphilitic glossitis(atrophic, fisssuring) Congenital syphilis: In-utero from infected mother. Rare today because of routine serologic tests. Features: frontal bossing of skull. Saddle nose. Sabre tibia Hypoplastic teeth (Hutchinson’s incisors). Mulberry molar Rhagades: fissures around mouth. Skin rash and desquamation. Hutchinson’s triad: hypoplasia of incisors. 8th cranial nerve deafness. interstitial keratosis in cornea.  Important questions: 1. Enumerate different routes of infection spread. 2. Define Toxemia, septicemia, pyemia. 3. Discuss oral findings of TB infection. 4. Microscopy of TB infection. 5. Discuss clinical stages of acquired syphilis. 6. Features of congenital Syphilis. End Leprosy: Granulomatous inflammation of nerves. Caused by: Mycobacterium leprae Identified by: Ziehl-Neelsen stain Mode of infection: Droplet, Contact Mycobacterium leprare multiplies very slowly. Symptoms can take as long as 20 years to appear. Clinically: Hypopigmented patches, partial or total loss of cutaneous sensation. multiple macular erythematous eruptions. Advanced disease: nodules, ulcers, loss of fingers and toes. Skin lepromas & loss of sensation, loss fingers Macular erythematous rash Leproma in palate Oral findings: Nodules called lepromas on the tongue, lips, or hard palate that may ulcerate. Dental manifestations: Odontodysplasia leprosa: hypoplasia, shortening of roots, pinkish discoloration of crowns. M/E: Granuloma formation sheets of foamy macrophages containing numerous acid-fast bacilli (lepra cells). epithelioid cells and lymphocytes in a fibrous stroma. Langhans giant cells Odontodysplasia leprosa  Actinomycosis: Acute or chronic granulomatous suppurative and fibrosing disease.  Caused by: Actinomyces (A. bovis, israeli). Mode of infection: Actinomyces are one of the normal oral flora that attacks the host when resistance decreased or in combination with staph. Or streptococci. Site: Cervicofacial (66%), abdominal, pulmonary. Clinically: Indurated swelling then fluctuation→ abscess containing Sulphur granules→ healing and appearance of new sinus result in disfigurement. Specific osteomyelitis affect maxilla that may spread to meninges and brain. No pain or mild pain, no fever  (M/E) Suppurative granulomatous inflammation which includes central colonies of the organism surrounded by excess neutrophils, epithelioid histiocytes and lymphocytes. Acute necrotizing ulcerative gingivitis Sever acute non-suppurative inflammation characterized by marked gingival tissue necrosis, pain, and bleeding. Caustive organism: fusiform bacilli, Borrelia vincenti and spirochetes. Different naming: Vincent’s disease, Trench mouth, Acute necrotizing ulcerative gingivitis, Fuso-spirochetal gingivitis.  C/P: Young adults. Psychologically stressed. Ulcerated, necrotic papilla (punched out). Sever pain. Foul odor, metallic taste, fever, lymphadenopathy. Profuse gingival bleeding with gentle touch.  Cancrum oris (NOMA) Gangrenous necrosis with rapid tissue destruction of the face, mouth, cheek. Causative organism: Borrelia vencentii superimposed by staphyloccus aureus. Predisposing factors include: Malnutrition or dehydration Poor oral hygiene Poor sanitation Unsafe drinking water Recent illness Malignancy An immunodeficiency disorder, including AIDS Important questions: 1. Clinical picture and oral findings of leprosy. 2. Clinical picture of actinomycosis. 3. Difference between the microscopic pictures of actinomycosis, TB granuloma, and Syphilitic granuloma. 4. Clinical picture of ANUG. Thank you