Viral infections are caused by viruses—tiny infectious agents that multiply only inside living host cells. These infections can affect almost any part of the body, from the respiratory tract to the liver, blood, skin, and nervous system. Some viral infections are mild and self-limiting, while others can become severe or chronic. Early diagnosis, supportive care, vaccination, and antiviral therapy play a major role in managing viral diseases.
Common Viral Infections
1. Respiratory Viral Infections
- Influenza
- Common cold (rhinovirus)
- Respiratory syncytial virus (RSV)
- Coronaviruses
2. Herpes Virus Infections
- Herpes simplex (cold sores, genital herpes)
- Varicella-zoster (chickenpox, shingles)
- Epstein–Barr virus
3. Viral Hepatitis
- Hepatitis A
- Hepatitis B
- Hepatitis C
4. Gastrointestinal Viral Infections
- Rotavirus
- Norovirus
5. HIV Infection
- Causes immune suppression and opportunistic infections
Modes of Transmission
- Airborne droplets (coughing or sneezing)
- Contaminated food and water
- Sexual contact
- Blood transfusion or shared needles
- Mother-to-child transmission
Symptoms
Symptoms vary depending on the virus and organ involved.
- Fever
- Fatigue
- Cough or sore throat
- Headache
- Skin rashes
- Diarrhea or vomiting
- Muscle aches
- Neurological symptoms in severe cases
Diagnosis
- PCR tests: detect viral genetic material
- Antigen tests: rapid detection
- Serology: detects antibodies
- Viral culture: rarely used today
Treatment of Viral Infections
Most viral infections require supportive care, but some have specific antiviral treatments.
Antiviral Drugs
1. Herpes Virus Infections
- Acyclovir
- Valacyclovir
- Famciclovir
2. Influenza
- Oseltamivir
- Zanamivir
3. Hepatitis B and C
- Tenofovir
- Entecavir
- Direct-acting antivirals (DAAs) for Hepatitis C
4. HIV
- Combination antiretroviral therapy (ART)
Supportive Treatment
- Rest and hydration
- Paracetamol for fever
- Antihistamines for cold symptoms
- ORS for gastrointestinal infections
Complications
- Pneumonia
- Organ damage (liver, brain, lungs)
- Dehydration
- Secondary bacterial infections
- Chronic viral diseases (HIV, hepatitis)
Prevention
- Vaccination (measles, hepatitis B, influenza, HPV)
- Hand hygiene
- Safe sexual practices
- Safe food and water intake
- Avoid sharing needles
- Use masks in viral outbreaks
Patient Counseling
- Take antiviral medicines as prescribed
- Stay hydrated and rest adequately
- Avoid self-medication with antibiotics
- Isolate during contagious phases
- Get recommended vaccinations
Detailed Notes:
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