INFECTIOUS DISEASE (1)

GERMAN MEASLES / RUBELLA

Contagious disease that is caused by an unrelated virus of the togavirus family

Measles / Rubeola

• Caused by a Paramyxovirus

• Mode of transmission: respiratory droplets, airborne

• Contagious (4 days before until 4 days after the onset of the body rash or exanthema)

Measles / Rubeola

Early Signs (before the skin rash)

• Mouth signs:

  • Tiny elevations on the soft palate

  • Bright redness on the pharynx (back of throat)

  • Herman spots

  • Pregnancy warning: If a pregnant woman gets measles, it can cause congenital defects in the baby.

Herman spots

bluish-gray area on tonsils

Measles / Rubeola

CLINICAL FEATURES:

• Usual on children

• Fever, malaise, coryza, conjunctivitis, photophobia, cough

• Koplik spots

Herpangina

• Type of infection: An acute viral infection (sudden onset, caused by a virus).

• Virus responsible: Coxsackie virus, mainly:

  • Type A1–A6, A8, A10, A22

  • Occasionally type B3

• Who gets it: Usually young children and adolescents.

• How it spreads: Through fecal-oral route (contaminated hands, surfaces, or food).

• Epidemiology: Often occurs endemic in certain regions and is more common in summer.

Herpangina

General symptoms:

• Malaise (feeling tired or unwell)

• Fever

• Dysphagia (difficulty swallowing)

• Sore throat

Herpangina

• Mouth signs:

  • Small vesicles (blister-like spots) on:

    • Soft palate

    • Faucial pillars (sides of the throat)

    • Tonsils

  • Diffuse erythematous pharyngitis: widespread redness in the throat

• Duration: Usually short, less than a week

Hand-Foot-and-Mouth Disease (HFMD)

• Virus responsible:

  • Mainly Coxsackie virus A16 or Enterovirus 71

  • Occasionally: Coxsackie A5, A9, A10, B2, B5

• How it spreads:

  • Airborne droplets (from coughs/sneezes)

  • Fecal-oral route (contaminated hands, surfaces, food)

• Contagiousness: Highly contagious

Hand-Foot-and-Mouth Disease (HFMD)

• Mostly children below 5 years old

• Short incubation period: symptoms appear quickly

• Self-limiting: usually resolves in 1–2 weeks

Hand-Foot-and-Mouth Disease (HFMD)

General symptoms:

• Low-grade fever

• Malaise (feeling unwell)

• Lymphadenopathy (swollen lymph nodes)

• Sore mouth / painful oral lesions

Hand-Foot-and-Mouth Disease (HFMD)

• Oral lesions:

  • Favored sites: palate, tongue, buccal mucosa

  • Vesicles (blisters) → rupture → ulcers

  • Ulcers: yellowish fibrinous membrane with red halo

  • Pain is a common complaint

• Skin lesions (hands & feet):

  • Multiple maculopapular lesions on: hands, fingers, feet, toes

  • Progression: vesicle → ulcer → minimal encrustation

  • Usually heals without scarring

  • Appear shortly after oral lesions

Sodium bicarbonate in warm water

treatment for Hand-Foot-and-Mouth Disease (HFMD) for mouth ulcers

Varicella (Chickenpox)

• Primary infection in people who have never had chickenpox before (seronegative individuals).

• Transmission:

  • Inhalation of contaminated respiratory droplets

  • Direct contact with infected lesions or secretions

• Incubation period: ~2 weeks (time from exposure to symptoms)

• Latency: Virus can remain dormant in sensory ganglia (nerve clusters) after infection

Varicella (Chickenpox)

• Systemic symptoms: fever, chills, malaise (feeling unwell), headache

• Rash progression:

  • Appears on trunk, head, neck first

  • Goes through stages: macule → vesicle → pustule → ulcer

• Oral lesions: multiple shallow ulcers, often start as brief vesicles

• Pruritus: itching can lead to secondary bacterial infection

• Duration: usually self-limiting, resolves in 2–3 weeks

• Complications: pneumonitis (lung infection), encephalitis (brain inflammation), involvement of other organs, fetal abnormalities if infection occurs during pregnancy

Zoster (Shingles)

• Reactivation of latent varicella-zoster virus from sensory ganglia

• Triggers: immunosuppression, certain medications, radiation, spinal surgery, trauma

• Prodrome: pain, tingling, or abnormal sensation (paresthesia) before rash

cingulum

girdle → belt-like rash around torso

zoster

warrior’s belt → describes rash appearance

Zoster (Shingles)

• Population affected: older adults, immunocompromised individuals

• Incidence increases with age

• Location: usually unilateral, affecting sensory nerves of trunk, head, neck

• Rash progression:

  • Prodromal symptoms: pain, paresthesia

  • Maculopapular rash → vesicles → pustules → ulcers

    • Macules = flat lesions

    • Papules = raised lesions

• Duration: usually self-limiting, resolves in several weeks

Zoster (Shingles)

• Secondary infection of skin ulcers

• Post-herpetic neuralgia: persistent sharp or burning pain, especially in people in their 50s

• Motor paralysis (rare)

• Ocular involvement: if trigeminal nerve ophthalmic branch is affected → eye inflammation

• Ramsay Hunt syndrome:

Ramsay Hunt syndrome

• Involves facial and auditory nerves

• Causes facial paralysis, ear vesicles, tinnitus, deafness, vertigo

Recurrent HSV infection

DD of zoster

Tuberculosis (TB)

Caused by Mycobacterium tuberculosis
Causes granulomatous inflammation and caseous necrosis

Tuberculosis (TB)

Main transmission: Inhalation

• Infected person coughs → droplets released

• Small droplets → evaporate → bacteria float in air → inhaled

• Large droplets → fall to ground

Secondary transmission:

• Ingestion (contaminated milk – usually M. bovis)

• Patient coughs infected sputum → infects oral tissues → oral TB lesion

Ghon Complex

combination of a primary granulomatous lung lesion and an infected hilar lymph node

Purified Protein Derivative

PPD

Miliary Tuberculosis

Widespread infection with multiple organ involvement

Primary Pulmonary Tuberculosis

• Seen most often in infants and children

• Cavitation is rare

• Lymph node involvement and lymphohematogenous spread are not prominent features

Secondary / Reinfection Tuberculosis

• Adults

• Occurs with delayed reactivation of persistent dormant viable bacilli and probably represents relapse of a previous infection

• Usually is confined to the lungs

• Cavitation is common

• Inadequate treatment of the primary infection and the influences of illness

• Immunosuppressive agents

• Immunodeficiency disease (as in AIDS)

• Age

Reasons for relapse for TB

1. Progressive Primary Tuberculosis

2. Cavitary Disease

3. Pleurisy and Pleural Effusion

4. Meningitis

5. Disseminated or Miliary Tuberculosis

Sequelae (Complications) of TB

Cough

• Most common in pulmonary TB (may appear late in the course of the disease)

• Common in cavitary disease

• Sputum produced is characteristically scanty and mucoid; becomes purulent with progressive disease

• Hemoptysis (blood in sputum) is infrequent, occurring in about 20% of cases

• Dyspnea is a feature of advanced disease

1. Cough

2. Lassitude and Malaise

3. Anorexia

4. Unexplained Weight Loss

5. Night sweats

6. Fever

Signs and Symptoms of Tuberculosis

3 consecutive morning sputum specimens

Definitive Diagnosis of Tuberculosis obtained for culturing to ensure positive results

Radiographic Appearance for TB

• Patchy or lobular infiltrates in the apical posterior segments of the upper lobes or in the middle or lower lobes

• With cavitation and hilar adenopathy in active “progressive primary” TB

• Healed primary lesions leave a calcified peripheral nodule associated with a calcified hilar lymph node (Ghon complex)

isoniazid, rifampin, ethambutol, pyrazinamide for two months

four drugs, initial phase regimen for treatment of TB

isoniazid, rifampin for four months

two drug continuation phase for tx of TB

pyrazinamide, fluoroquinolone, ethionamide, cycloserine, para- aminosalysilic acid

five agent regimen for multidrug resistant TB

• mucosal lesion

• jaw (osteomyelitis)

• cervical and submandibular lymph nodes (scrofula, nodes are enlarge and painful, abcess with drainage)

Oral Manifestations for TB

Mucosal lesion for TB

- Classic: painful, deep, irregular ulcer on the dorsum of the tongue

- Sometimes painless: granular, nodular, or leukoplakia

- May also be affected: palate, lips, buccal mucosa, and gingiva

HEPATITIS

- Inflammation of the liver

Noninfectious Hepatitis

Can result from excessive or prolonged use of toxic substances, including drugs (i.e., acetaminophen, halothane, ketoconazole, methyldopa, and methotrexate) or alcohol

Hepatitis A (HAV)

• Highly contagious

Mode of Transmission

• Fecal–oral route (main)

  • Contaminated food or water

  • Poor sanitary conditions

• Direct person-to-person contact

• Less commonly: contaminated food from fecal matter

Hepatitis A (HAV)

• Jaundice: occurs in ~70% of adults, less in children

• Relapsing cholestatic hepatitis: the most common cause

• Immune response: antibodies rise to high levels and persist for life, providing lifelong immunity

HEPATITIS B

• Parenteral route or by intimate personal contact

• Common in injection drug users, heterosexual persons with multiple sexual partners, and men who have sex with men

• Maternal-infant spread

HEPATITIS B

• Jaundice appears in 1/3 of adults; lesser proportion of children

Hepatitis C (HCV)

• Highly infectious, major concern for dental professionals

Mode of Transmission

• Parenteral route (main) – through blood exposure

  • Injection drug use

  • Needle-stick accidents

  • Multiple parenteral exposures

• Maternal-infant transmission

• Sexual transmission: uncommon

chronic hepatitis

Major complication of acute hepatitis C is the development of

Peginterferon alfa and ribavirin therapy

beneficial for Chronic Hepatitis C

Sofosbuvir and velpatasvir

demonstrated superior viral control

Herpes

- From Greek word "herpein" → to creep

- Signifies the creeping or spreading nature of the skin lesions

Herpes Virus

Characterized by a DNA core surrounded by a capsid and an envelope

HSV 1

Infections above the waist

- Involving oropharyngeal regions, dermatitis, meningoencephalitis

- Mode of transmission: physical contact, body fluids (seronegative)

Primary Herpetic Gingivostomatitis

• Usually in children

- Adults with no previous HSV exposure, or with no appropriate response to previous infection

- Vesicular eruption may appear on skin, vermilion, oral mucous membrane

- Mouth can become sore, burning sensation, difficulty in swallowing

- Gingiva is erythematous, boggy, bleeds spontaneously on slightest of provocation

- Vesicles rupture to form shallow painful ulcers that are usually covered by a grayish colored membrane, bound by an erythematous halo

Secondary / Recurrent Herpes Simplex Infections

- Reactivation of latent HSV1

- Triggered by sunlight, trauma, hormonal changes, stress, drugs, immunosuppression

- Recurrence rate decline with age

Secondary / Recurrent Herpes Simplex Infections

- Prodromal symptoms of tingling, burning or pain at the site where lesions will appear

- Multiple, fragile, short-lived vesicles appear (within hours)

- unroofed, coalesce → form map-like superficial ulcers (after hours-day)

- Most common: herpes labialis → vermillion border

- Hard palate and gingiva can also be affected

- Can be contagious

- Self-limiting, heals without scarring

Herpetic Whitlow

- Primary or secondary HSV infection

- Intense painful infections affecting fingers or toes

- Pain, redness, swelling

- Usually preceded by prodromal symptoms of burning and tingling sensation and pruritus

- Vesicles or pustules → break and becomes ulcers

Vesicle

elevated lesion with water inside

Pustules

elevated lesion with pus inside

HSV 2

- Infections below the waist

- Responsible for anogenital infections

a. Genital herpes