Tuberculosis (TB)
Airborne transmission: Mycobacterium tuberculosis in respiratory droplet nuclei. Latent TB (LTBI): infected, not infectious, no symptoms. Active TB: infectious, symptomatic (cough >3 weeks, hemoptysis, night sweats, weight loss, fever). Testing: TST (Mantoux) or IGRA (QuantiFERON Gold). Isolation: negative pressure room, N95 respirator. Treatment: RIPE therapy (Rifampin, Isoniazid, Pyrazinamide, Ethambutol) × 6–9 months. DOT (directly observed therapy) for adherence.
HIV/AIDS
Transmission: blood, sexual contact, breast milk, vertical (mother-to-child). Pathophysiology: destroys CD4+ T cells → immunodeficiency. Diagnosis: HIV antibody test (ELISA → Western blot confirmation); CD4 count and viral load for staging. AIDS: CD4 <200 cells/mm³ OR AIDS-defining illness. Treatment: antiretroviral therapy (ART) — all HIV+ patients; undetectable = untransmissible (U=U). PrEP (pre-exposure prophylaxis): for high-risk HIV-negative individuals.
Viral Hepatitis (B & C)
Hep B: DNA virus; transmission = blood, sexual, vertical. Vaccine-preventable. Chronic HBV → cirrhosis and hepatocellular carcinoma. Treatment: antivirals (tenofovir, entecavir) for chronic HBV. Hep C: RNA virus; primarily bloodborne (IVDU, transfusions pre-1992). No vaccine. Most common blood-borne infection in US. Now curable: DAAs (direct-acting antivirals) — 8–12 weeks, >95% cure rate. Screen: all adults born 1945–1965 (baby boomers), all pregnant women, IVDU.
Sexually Transmitted Infections
Chlamydia: most common bacterial STI; often asymptomatic; screen sexually active women <25 annually; treat with azithromycin or doxycycline. Gonorrhea: increasing antibiotic resistance; treat with ceftriaxone. Syphilis: stages (primary chancre, secondary rash on palms/soles, latent, tertiary); treat with penicillin G. HPV: most common STI; vaccine prevents high-risk strains (16, 18 → cervical cancer). Herpes (HSV): lifelong; antiviral suppression reduces outbreaks and transmission. Partner notification is essential.
Mandatory Reporting
Nurses have a legal obligation to report notifiable diseases to local/state public health authorities. Reportable diseases include: TB, HIV, syphilis, gonorrhea, chlamydia, hepatitis A/B/C, measles, pertussis, meningococcal disease, Salmonella, E. coli O157:H7, and others (list varies by state). Process: complete the appropriate form; submit within required timeframe (immediately for urgent diseases; within 1–7 days for others). Public health investigates contacts.
Important Notes
- TB isolation: airborne precautions with N95 (not surgical mask) — negative pressure room required until 3 negative AFB smears.
- HIV: all positive results must be reported; also offer partner services (contact notification) — may be legally required.
Clinical Tips
- Isoniazid (INH) for TB: always give with pyridoxine (Vitamin B6) to prevent peripheral neuropathy.
- U=U (Undetectable = Untransmittable) for HIV: people on effective ART with undetectable viral load cannot sexually transmit HIV.
Summary
Communicable disease nursing requires knowledge of transmission, prevention, screening, and treatment. Mandatory reporting, contact tracing, and public health collaboration are essential components of infection control and community protection.
