Communicable Diseases

Etiology: The cause or set of causes of a disease.
Pathogenesis: The origination and development of a disease.
Diagnostics: Tests including laboratory methods and imaging used to confirm diseases.
Treatment: Medications and procedures to treat diseases.
Prevention: Measures taken to prevent disease occurrence.

Etiology: Primarily caused by viral strains A and B.
- Mechanism involves the virus binding to respiratory epithelial cells.
- Surface proteins: Hemagglutinin (HA), Neuraminidase (NA)
- Antigenic Drift: Minor mutations leading to seasonal epidemics.
- Antigenic Shift: Major mutations leading to novel strains.
Pathogenesis: Viral infection starts in the upper respiratory tract, damaging cells and inducing apoptosis.
Signs and Symptoms: Cough, cold, fever, body weakness.
Diagnostics: Influenza tests, CBC, Chest X-Ray (CXR).
Treatment: Symptomatic management, increased oral fluid intake, antiviral medications.
Prevention: Vaccination, cough etiquette, handwashing.

Etiology: Can be caused by bacteria, viruses, fungi, and parasites. Higher risk in those with chronic lung conditions, immune suppression, and smoking.
- Pathogen entry via inhalation or aspiration.
Pathogenesis: Infection proliferates in lower airways and alveoli leading to local inflammation.
- Immune response varies; may present as lobar pneumonia (localized) or interstitial pneumonia (diffused).
Signs and Symptoms: Cough, fever, chills, dyspnea, pleuritic chest pain, fatigue.
Diagnostics: CXR showing consolidation, CBC, sputum analysis.
Treatment: Antibiotics, symptomatic management, pneumonia vaccine.
Prevention: Proper cough etiquette, hand hygiene, vaccination.

Etiology: Caused by the bacterium Vibrio cholerae, typically transmitted through contaminated water.
Pathogenesis: Alters the intestinal brush border, leading to loss of fluids and electrolytes.
- Major symptom is profuse watery diarrhea.
Signs and Symptoms: Abdominal pain, diarrhea, fever, nausea/vomiting.
Diagnostics: Stool culture, hydration status assessment.
Treatment: Antibiotics for severe cases, prompt rehydration, zinc supplementation.
Prevention: Access to clean water, boiling water, hand hygiene.

Etiology: Caused by Mycobacterium tuberculosis, primarily inhaled in airborne droplets.
Pathogenesis: The bacilli evade destruction by macrophages leading to complex immune responses.
Signs and Symptoms: Cough, fever, night sweats, weight loss.
Diagnostics: Sputum smear microscopy, culture, chest X-ray.
Treatment: HRZE regimen (isoniazid, rifampicin, pyrazinamide, ethambutol).
Prevention: BCG vaccine, proper cough etiquette, hand hygiene.

Etiology: Caused by Mycobacterium leprae, primarily affects skin and peripheral nerves.
Pathogenesis: Infection in Schwann cells leads to nerve damage and granuloma formation.
Signs and Symptoms: Hypopigmented skin lesions, nerve damage, and numbness.
Diagnostics: Skin biopsy for microscopic examination.
Treatment: Dapsone, rifampicin, clofazimine.
Prevention: Avoiding contact with lesions and infected bodily fluids.

Etiology: Caused by Schistosoma species, transmitted through skin contact with contaminated water.
Pathogenesis: Schistosoma eggs cause hypersensitivity reactions leading to inflammatory responses.
Signs and Symptoms: Cough, abdominal pain, diarrhea, and eosinophilia.
Diagnostics: Stool examination for eggs, serological tests.
Treatment: Praziquantel.
Prevention: Avoid contact with infected water sources.

Etiology: Caused by various helminths, including Ascaris, Trichuris, and hookworms.
- Transmitted through contamination of soil with feces.
Signs and Symptoms: Abdominal pain, diarrhea, fever, cough, eosinophilia.
Diagnostics: Stool examination.
Treatment: Mebendazole, albendazole.
Prevention: Handwashing, proper sanitation, wearing protective footwear.

Etiology: Caused by the measles virus, contagious before and after rash appears.
Signs and Symptoms: Fever, cough, rash, conjunctivitis.
Diagnostics: Serological testing, RT-PCR.
Treatment: Supportive care, vaccination is key to prevention.