Infectious Diseases

What Are Infectious Diseases?

Infectious diseases are illnesses caused by pathogens such as bacteria, viruses, fungi, or parasites. These diseases can be mild or life-threatening, and may spread from person to person, through contaminated food or water, insect bites, or contact with infected animals.

Thanks to modern medicine, many infectious diseases are preventable or treatable, especially when diagnosed early.

Types of Infectious Agents

Bacteria – Single-celled organisms 

Can cause illnesses like:

• Tuberculosis (TB)
• Strep throat
• Urinary tract infections (UTIs)
• Bacterial pneumonia

Viruses – Tiny particles that hijack host cells 

Causes:

• Influenza (flu)
• COVID-19
• Dengue fever
• HIV/AIDS
• Hepatitis A, B, and C

Fungi – Includes yeasts and molds 

Causes include:

• Ringworm
• Athlete’s foot
• Candida infections

Parasites – Organisms that live off a host 

Examples:

• Malaria
• Giardiasis
• Toxoplasmosis
• Tapeworm infections

How Infections Spread

• Direct contact: Skin-to-skin, sexual contact, droplet inhalation
• Indirect contact: Contaminated surfaces, shared items
• Food and water: Contaminated or undercooked food
• Animal or insect bites: Mosquitoes (dengue, malaria), ticks (Lyme disease)
• Blood transfusions or needles: Hepatitis, HIV

Common Symptoms of Infectious Diseases

Symptoms vary by infection but often include:

• Fever or chills
• Fatigue and weakness
• Cough or sore throat
• Diarrhea or vomiting
• Body aches
• Skin rashes
• Swollen glands
• Breathing difficulties (in severe cases)

Note: Some infections may remain asymptomatic in early stages.

Diagnosis

Infectious diseases are diagnosed using:

• Physical examination and symptom history
• Blood tests (e.g., CBC, culture, PCR tests)
• Urine and stool analysis
• Swab tests (throat, nasal, wound)
• Imaging (X-ray, CT scan) for internal infections
• Serological tests (antibody detection)
• Molecular tests (RT-PCR) for viral infections like COVID-19 or flu

Treatment Options

Treatment depends on the type of infection:

Antibiotics

For bacterial infections (e.g., pneumonia, UTI, strep throat)

Important: Misuse of antibiotics can lead to resistance—take only when prescribed.

Antivirals

For viral infections like HIV, hepatitis, influenza, COVID-19 (in some cases)

Antifungals

For fungal infections like candidiasis or ringworm

Antiparasitics

For parasites like malaria or giardiasis

Supportive Care

• Hydration, rest, fever management
• Oxygen support in severe cases
• Isolation in highly contagious diseases

Prevention Tips

• Wash hands frequently with soap
• Avoid close contact with sick individuals
• Cook food thoroughly and drink clean water
• Use insect repellents and nets to avoid bites
• Get vaccinated for preventable diseases (e.g., flu, hepatitis, measles, COVID-19)
• Practice safe sex and avoid sharing needles
• Travel wisely with appropriate precautions for endemic diseases

When to See a Doctor

Seek medical care if you experience:

• High or persistent fever
• Breathing difficulty
• Rash with fever
• Dehydration (especially in children or elderly)
• Sudden confusion or drowsiness
• Worsening symptoms after initial improvement
• Exposure to someone with a contagious illness

Why Choose Aster Hospitals for Infectious Disease Care?

Aster Hospitals provides expert diagnosis and treatment for a broad spectrum of infectious diseases through a team of experienced infectious disease specialists and internal medicine experts. Our advanced diagnostic labs and rapid testing services ensure timely and accurate identification of infections. We offer specialized care units for conditions such as COVID-19, tuberculosis, and dengue, along with travel medicine consultations and vaccination services. With dedicated isolation facilities and robust infection control teams, we prioritize safety and containment. Our multidisciplinary care approach extends to immunocompromised patients, including those with HIV or cancer, supported by comprehensive post-infection recovery and follow-up. At Aster, we focus on early detection, evidence-based treatment, and prevention to help you stay safe, recover fully, and maintain long-term health.