2. Candidiasis and Immunity Quiz

Upper GI Tract Infections: Oral Cavity/Esophagus

• Expert: Dr. Javier Adan Castaneda Moreno, Board-certified Otolaryngologist by the Mexican Society of Otolaryngology-Head and Neck surgery, and Professor of the UAG International Students program.
• Contact: [email protected]

Objectives

• Identify common oral cavity and upper esophagus infections and their causative agents.
• Describe characteristics of common upper esophagus and mouth infections.
• Analyze definitions, characteristics, pathology, clinical manifestations, diagnostic methods, complications, and treatments for each infection.

Coxsackie A Virus Infection

• Coxsackie viruses (RNA viruses) have over 20 serotypes divided into groups A and B, based on viral characteristics.

Herpangina

• A seasonal acute infection.
• Symptoms include fever, sore throat, and herpes-like lesions on the posterior oropharynx and tonsils.
• Most common in children aged 3-10 years, primarily during summer and fall.

Clinical Features (of Coxsackie-associated infections)

• High fever and sore throat
• Herpes-like oral lesions
• Multiple 1-mm vesicles on the posterior oropharynx and tonsils
• Redness of the pharynx and tonsils
• Fibrin-covered ulcerations in later stages

Candida Infections

• Organisms: Yeasts, fungi existing predominantly in unicellular forms.
• Size: Small (4-6 µm), thin-walled, and ovoid cells (blastospores), reproducing by budding.
• Yeast forms: Pseudohyphae and hyphae.
• Staining: Gram-positive
• Species: More than 150 species of Candida, but only a few are frequent human pathogens (e.g., C. albicans, C. guilliermondii, C. krusei, C. parapsilosis, C. tropicalis, etc.).

Candida Infections: Epidemiology and Ecology

• Environment: Found in soil, animals, hospital environments, inanimate objects, and food.
• Non-albicans species: Can also live in animal and non-animal environments.
• Contaminants: Rarely a laboratory contaminant.
• Normal commensals: Found on skin, the gastrointestinal (GI) tract, sputum/bronchoalveolar lavage fluid, and the female genital tract.

Candida Infections: Pathogenesis and Immunology

• Iatrogenic factors: The most important predisposing factors to Candida infections.
• Factors: Antibiotics, myeloablative chemotherapy, and intravenous catheters.
• Immune response: Innate immunity (phagocytes) is critical for controlling systemic candidiasis, while adaptive immunity (T lymphocytes) is important for mucosal candidiasis.

Candida Infections: Mucous Membrane Infection (Thrush)

• Definition: Oral thrush describes a specific form of oral candidiasis, characterized by creamy white, curd-like patches on the oral mucosa, especially the tongue.
• Removable: The patches are removable by scraping and leave a raw, bleeding, and painful surface.
• Asthma treatment: Inhaled steroids are strongly associated with oral thrush, especially in children.

Candida Infections: Other Manifestations

• Acute atrophic candidiasis: A nonspecific atrophy of the tongue, often a consequence of acute pseudomembranous candidiasis.
• Chronic atrophic candidiasis (denture sore mouth): A chronic inflammatory reaction, characterized by epithelial thinning under dental plates.
• Angular cheilitis: Inflammatory reaction at the corners of the mouth, not exclusively due to Candida.
• Candida leukoplakia: Firm, white plaques on cheeks, lips, and tongue, potentially precancerous.

Candida Esophagitis

• Associated conditions: Frequently associated with treatments for malignancies of the hematopoietic or lymphatic systems and in AIDS patients.
• Diagnosis: Clinical settings, associated with endoscopic appearance of white patches.
• Co-occurring conditions: Can occur simultaneously with herpes simplex virus or cytomegalovirus infection in severely immunocompromised patients.
• Diagnostic procedure: Endoscopy is the preferred method for definitive diagnosis.
• Symptoms: Painful swallowing, feeling of obstruction on swallowing, and substernal chest pain. Nausea and vomiting may also occur.

Diagnostics

• Initial test: Potassium hydroxide (KOH) smear on scrapings or smears.
• Confirmation tests: Blood or tissue cultures.
• Growth conditions: Candida spp. forming yeast cells and pseudohyphae at 20-25°C; Candida albicans forming germ tubes at 37°C.

Herpetic Esophagitis and Glossitis

• Co-occurrence: Can concurrently occur with herpes simplex virus or cytomegalovirus infection in severely immunocompromised patients.
• Diagnostic method: Endoscopy is frequently the preferred procedure for definitive diagnosis.

Herpesviridae Infections

• Virus Type: Double-stranded DNA virus; 120-260 nm in diameter.
• Symptom association: Symptomatic disease in herpesviruses is frequently associated with lytic virus replication.
• Orofacial infection: Gingivostomatitis and pharyngitis are common initial manifestations of HSV-1 infection.
• Recurrent infection: Recurrent lesions (herpes labialis) on the lip vermilion border commonly indicate latent infections.
• Epidemiology: Most human herpesvirus encounters are asymptomatic or induce very mild symptoms; many persons infected with HSV-1 or HSV-2 are asymptomatic, and young children and infants infected with CMV and EBV are usually asymptomatic; infections are rarely fatal, except in highly immunocompromised persons.

Herpesviridae Infections 134.1 (Table)

• Viral characteristics: Table outlining various Herpesviruses, including subfamilies, size, receptors, and latency sites.

Herpesviridae Infections: Epidemiology

• Transmission: Spread through saliva, vaginal secretions, contact with lesion fluid (mucous membrane contact).
• Infections: Nearly all adults are infected with HSV-1/VZV/EBV/HHV-6/HHV-7; various percentages for each.
• Spread method: Direct contact. Most herpesviruses do not survive long in the environment (except VZV).

Herpesviridae Infections: Clinical Syndromes

• Clinical manifestations: Clinical syndromes associated with herpesviruses including vesicular lesions, skin lesions, retinitis, hepatitis, encephalitis, and mononucleosis.
• Impaired Immunity: Patients with impaired T-cell immunity (HIV as an example) frequently exhibit more severe herpes virus infection.

Orofacial Herpes Simplex Virus Infection

• Frequent manifestations: Gingivostomatitis and pharyngitis are common clinical manifestations of initial HSV-1 infection.
• Infection type: Usually results from primary infection.
• Common in: Mostly common in children and young adults.
• Symptoms: Malaise, myalgias, inability to eat, irritability, and cervical adenopathy.

Therapy in Immunocompromised Patients

• Treatment regimen variance: Treatment regimens vary for initial episodes and recurrent episodes and differ in immunocompromised patients (IV acyclovir).

Therapy in Immunocompetent Patients

• Typical treatment: Oral acyclovir (or other antiviral drugs) may be used; frequency and dosage depend on the specific condition and individual patient.

Infectious Mononucleosis (Epstein-Barr Virus)

• Cause: EBV (human herpesvirus 4) is a gamma-1 herpesvirus.
• Genome/structure: Has a double-stranded DNA genome embedded with viral glycoproteins, a lipid envelope, and an amorphous protein layer (tegument).
• Clinical traits: Acute illness characterized by sore throat, fever, and lymphadenopathy.
• Diagnosis: Diagnosed serologically (heterophile antibodies).

Infectious Mononucleosis (EBV) Hematologic Complications

• Hematologic abnormalities: Mononuclear leukocytosis (atypical lymphocytes or Downey cells)

Infectious Mononucleosis: Dermatologic Complications

• Rare association: Rash; skin eruptions; associated with maculopapular eruptions.
• Antibiotic association: Maculopapular eruptions often occur in response (secondary to) antibiotic administration

Infectious Mononucleosis: Other Complications

• Rare manifestations: Splenic rupture, encephalitis, Guillain-Barré syndrome, Bell’s palsy, transverse myelitis, hepatic manifestations (elevated liver enzymes), and renal manifestations (hematuria and/or proteinuria).

Oral Hairy Leukoplakia (Epstein-Barr Virus)

• Associated condition: Caused by unchecked lytic replication of EBV, especially in immunodeficient conditions such as AIDS.
• Lesion type: Typically manifests as a corrugated or "hairy" white lesion on the lateral tongue, although it can occur elsewhere.
• Alternative diagnoses: Differential diagnosis includes oral candidiasis.

Human Herpesvirus 8 (Kaposi Sarcoma-associated Herpesvirus)

• Opportunistic infection: Kaposi's sarcoma is an opportunistic infection commonly associated with AIDS.
• Target cells: Primary target of HHV-8 is B cells, along with endothelial cells, monocytes, and nerves (epithelial and sensory nerve cells).

Human Herpesvirus 8 (Kaposi Sarcoma-associated Herpesvirus) Epidemiology

• Geography: HHV-8 is more prevalent in certain geographic areas like Italy, Greece, and Africa.
• High prevalence: Kaposi's sarcoma is the most common cancer in Sub-Saharan Africa.

Test your knowledge about candidiasis, its types, and associated conditions. This quiz covers important aspects of immunity related to systemic and mucosal candidiasis, as well as visual characteristics of oral thrush. Dive deep into the implications of Candida infections and their clinical significance.