Difference Between Emerging and Re-emerging Diseases

Emerging vs Re-emerging Diseases: Key Differences & Examples 

Emerging and re-emerging diseases pose significant public health challenges worldwide. While both affect global health systems, they differ in origin and spread. Understanding these distinctions is crucial for planning prevention strategies and improving disease management across healthcare systems and communities.

Comparison Between Emerging and Re-emerging Diseases  

This table provides a detailed comparison between the two types of diseases:

Understanding Emerging Diseases

Emerging diseases are caused by newly discovered or previously unrecognised pathogens. These diseases often originate from zoonotic sources, where pathogens jump from animals to humans. They may be viral, bacterial, parasitic, or fungal in nature. Factors such as global travel, urbanisation, environmental changes, and closer human-animal interactions contribute significantly to the emergence of these diseases.

Some examples of emerging diseases include:

• Candida Auris : It is a fungal infection that occurs in the bloodstream and causes life-threatening conditions. Symptoms may include low blood pressure, lethargy, and increased heart rate.   
• Mpox (Monkeypox) : An emerging viral infection occurs in animals and humans and spreads through physical contact. It causes fever, cold problems, enlarged lymph nodes and rashes on the face, hands, chest, genitals and feet.  
• COVID-19 : It is an emerging contagious respiratory infection caused by the SARS-CoV-2 virus. It affects the lungs and, with symptoms like breathing issues, sore throat, fever, runny nose, dry cough and loss of smell and taste.     

Understanding Re-emerging Diseases

Re-emerging diseases are those that were once major health threats, controlled through public health interventions such as vaccines and sanitation but have started to resurface. This resurgence can be due to various reasons, including antimicrobial resistance, waning vaccination rates, or environmental changes.

Examples of some re-emerging diseases include:

• Measles : It is a re-emerging, extremely contagious viral infection that spreads through air droplets from sneezes or coughs. Measles causes fever, rash, fatigue, conjunctivitis and Koplik's spots inside the mouth.
• Whooping Cough : It is a bacterial infection that is rising among people who have not been vaccinated yet. Whooping cough causes intense coughing, vomiting, breathing issues and exhaustion.  
• Tuberculosis : This is re-emerging as a worldwide public health concern. Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. It mainly affects the lungs and causes persistent coughing, fatigue, fever, weight loss, and phlegm with blood.   

Factors Driving Emerging and Re-emerging Diseases

Certain factors driving emerging and re-emerging diseases are:

1. The evolution of microorganisms, such as bacteria, fungi, viruses, and pathogens stops responding to medication due to drug resistance.
2. Human Behavioural changes, including food habits, travel patterns, etc.
3. A poor healthcare system may respond to the re-emergence of the worst infection outbreaks.

Understanding the difference between emerging and re-emerging diseases is essential for effective disease surveillance and public health preparedness. Vigilance, scientific research, and coordinated health care efforts are key to identifying, controlling, and preventing future outbreaks and minimising their impact.