iCliniq logo

Ask a Doctor Online Now

HomeHealth articlescontagious diseaseWhat Are Communicable Diseases?

Communicable Diseases- Transmission, Symptoms and Treatment

Verified dataVerified data

4 min read


Communicable diseases are diseases that spread from one person to another through blood, bodily fluids, skin, sexual contact, and droplets. Read to know more.

Medically reviewed by

Dr. Kaushal Bhavsar

Published At December 20, 2022
Reviewed AtMarch 28, 2024


A communicable disease is a medical condition that spreads from one person to another through many routes that include: contact with blood, exchange of bodily fluids through sexual contact or kisses, droplets (airborne virus), being bitten by an insect, fecal-oral, food, contact with contaminated fomites, skin contact, surface or object contamination, through the host animal, etc.

What Are the Most Common Communicable Diseases?

The most common communicable diseases are:

  • COVID-19 infection.

  • Monkeypox.

  • Zika virus.

  • Enterovirus D68.

  • MRSA (Methicillin-resistant Staphylococcus aureus).

  • Pertussis.

  • Toxoplasmosis.

  • Chickenpox or Shingles.

  • Tuberculosis.

  • Ebola.

  • Flu.

  • Hepatitis A.

  • Measles.

  • Influenza A.

  • H1N1 (swine flu).

  • Hepatitis B.

  • Hepatitis C.

  • HIV (human immunodeficiency virus) or AIDS (acquired immunodeficiency syndrome).

  • Sexually transmitted diseases.

  • Influenza.

  • Mumps.

What Are the Most Common Routes of Transmission of Infection in Communicable Diseases?

Physical contact with an infected person, for example, through touch (Staphylococcus), sexual contact (gonorrhea, HIV), fecal/oral transmission (hepatitis A), or droplet (influenza), contact with contaminated surfaces or objects (Norovirus), food (Salmonella, E. coli), blood (HIV, hepatitis B), or water (botulism).

What Are the Differences Between Communicable Diseases and Non-Communicable Diseases?

  • Nature: Non-communicable diseases are non-contagious, which means they are not transmitted from one person to another, whereas communicable diseases are contagious and spread from one person to another through various transmission routes.

  • Inheritance: Communicable diseases cannot be inherited from one generation to the next. On the contrary, non-communicable diseases can be inherited from one generation to another.

  • Causative Agents: The causative agents in communicable diseases are the pathogens that are highly infectious and are transmitted by vectors through different routes like transmission through blood, bodily fluids, fecal-oral, sexual contact, skin, surface contamination, droplet, etc. The causative agents in non-communicable diseases are lifestyle changes, environmental changes, allergies, abnormalities in cell proliferation, malnutrition, nutrient deficiency, etc.

  • Type: Communicable diseases can develop over a short period of exposure (or almost immediately) to the causative agents; thus, they have an acute onset. Whereas non-communicable diseases develop over a period of time and last for a long duration; thus, they are chronic diseases.

  • Infecting Agent: The agents causing communicable diseases are bacteria, viruses, fungi, and parasites. Non-communicable diseases have no causative agents in the development and progression of the disease.

  • Treatment Modality: Communicable diseases are treated with conventional methods. Non-communicable diseases are treated and monitored through conservative measures or surgical methods.

  • Preventive Measures: Vaccination (with regular dosing and scheduling), wearing a mask, maintaining social distancing, maintaining personal hygiene, and frequent and thorough handwashing are the essential preventive measures to protect from communicable diseases. Whereas routine evaluation and monitoring of health and lifestyle interventions like diet, physical activity, and good personal hygiene are preventive measures in avoiding or reducing the risk of developing non-communicable diseases.

  • Examples: Examples of communicable diseases include AIDS, COVID-19, Ebola, tuberculosis, ringworm, etc. Non-communicable diseases include diabetes, hypertension, allergies, cancer, heart disease, pneumonia, etc.

What Are the Types of Transmission of Communicable Diseases?

Communicable diseases can spread through:

1. Direct Transmission - Infectious diseases can be spread through direct contacts, such as:

  • Person to Person: The most common ways that communicable diseases are transmitted are through infected blood, the interchange of bodily fluids during sexual activity, skin-to-skin contact, surface or item contamination, and droplets from the infected person's cough or sneeze.

  • Animal to Person: It occurs by being bitten or scratched by insects or infected animals. The other most common example is toxoplasmosis, an infection caused by the Toxoplasma gondii parasite, which usually develops by consumption of undercooked and contaminated meat, being exposed to infected cat feces, or transmission from the mother to the child during pregnancy.

  • Congenitally: It is also known as mother-to-unborn child transmission, where contagious infections, including toxoplasmosis, HIV, hepatitis B, syphilis, Chagas, rubella, herpes simplex virus, etc., are vertically transmitted from mother to baby during pregnancy, childbirth, or breastfeeding. The route of transmission is through the placenta, breast milk, or from the infected causative pathogens present in the vagina exposed to the baby during childbirth.

2. Indirect Transmission -This can spread through transmission from infected air, water, food, surface, or object contamination.

What Are the Common Symptoms of Communicable Diseases?

Some of the common symptoms of infectious communicable diseases include:

  • Flu-like-symptoms.

  • Fatigue.

  • Headache.

  • Nausea and vomiting.

  • Dysentery.

  • Diarrhea.

  • Cough.

  • Runny nose.

  • Rashes.

  • Itching.

  • Muscle aches.

  • Joint pain.

  • Reduced sensory function.

What Are the Risk Factors for Developing Communicable Diseases?

  • While anyone can contract a communicable disease, it is more likely that individuals who have issues with their immune system or have low immunity are more prone to develop or contract communicable diseases. This is because their body’s immune system can not fight foreign invaders or disease-causing organisms (bacteria, viruses)

  • Individuals taking steroids or other medications that suppress their immune system, such as anti-rejection drugs for transplanted organs, are also prone to communicable diseases.

  • Individuals with certain types of cancer or other medical conditions can hamper their immune systems.

  • In addition, other medical conditions may also predispose an individual to transmissible infections, including implanted medical devices, malnutrition in childhood, and old age.

What Are the Communicable Diseases That Are Prevalent Now?

In the recent past, COVID-19 disease, monkeypox, Zika, dengue, Middle East respiratory syndrome coronavirus (MERS-CoV), Ebola, cholera, H1N1, measles, yellow flu, avian flu, influenza A, Lassa fever are the most common emerging and re-emerging communicable disease outbreak prevalent in the world.

How Can Communicable Diseases Be Treated?

Some communicable diseases simply produce mild symptoms that subside on their own. Others could result in serious symptoms or complications that could be fatal. Treatment for various communicable diseases includes the following:

  • Bacterial Infections: A course of antibiotics may be necessary for someone with a bacterial infection to help control the infection. These drugs can help kill the disease-causing bacteria or inhibit bacterial growth so the immune system can fight them.

  • Viral Infections: Several viral infections can be prevented with the use of vaccines. A weakened form of the virus is given to the patient as a vaccine. In response, the immune system creates antibodies that can later kill a strong or active virus. However, an individual who is already affected by a viral infection will require antiviral drugs to treat the infection.

  • Fungal Infection: Antifungal drugs in the form of pills and topical ointments can be prescribed to treat various fungal infections.


Communicable diseases, also known as infectious diseases, contagious diseases, or transmissible diseases, are illnesses that result from the spread of infection from one person to another via an array of susceptible routes like blood, fluids from the body, sexual contact, skin, surface contamination, presence and growth of pathogenic and biologic agents (that have the potential to cause infections) in an individual human or an animal host.

Source Article IclonSourcesSource Article Arrow
Dr. Kaushal Bhavsar
Dr. Kaushal Bhavsar

Pulmonology (Asthma Doctors)


contagious diseasecommunicable disease
Community Banner Mobile
By subscribing, I agree to iCliniq's Terms & Privacy Policy.

Source Article ArrowMost popular articles

Ask your health query to a doctor online

General Medicine

*guaranteed answer within 4 hours

Disclaimer: No content published on this website is intended to be a substitute for professional medical diagnosis, advice or treatment by a trained physician. Seek advice from your physician or other qualified healthcare providers with questions you may have regarding your symptoms and medical condition for a complete medical diagnosis. Do not delay or disregard seeking professional medical advice because of something you have read on this website. Read our Editorial Process to know how we create content for health articles and queries.

This website uses cookies to ensure you get the best experience on our website. iCliniq privacy policy