CHATSHAALA SUMMARY 
FROM TINY VECTORS TO MAJOR DISEASES: EXPLORING THE HIDDEN WORLD OF VECTOR BIOLOGY 
Date: 12 June 2026
Today’s Chatshaala session was an exciting journey into the fascinating field of Vector Biology. We were joined by students Rishabh Ojha from Acharya Narendra Dev College*, University of Delhi, who are pursuing B.Sc. (Hons.) Zoology and working on projects related to vectors and vector-borne diseases.
Through this interaction, we learned how some of the smallest organisms on Earth can have a tremendous impact on human health and how scientists investigate these organisms to understand, prevent, and control diseases.
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A QUESTION THAT OFTEN ARISES
Do mosquitoes actually cause diseases?
Many people believe that mosquitoes themselves are the cause of diseases.
COMMON MISCONCEPTION: Mosquitoes do not create diseases.
SCIENTIFIC FACT: Mosquitoes act as vectors, carrying disease-causing organisms from one host to another.
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UNDERSTANDING VECTORS THROUGH A SIMPLE ANALOGY
Imagine a passenger travelling in a vehicle.
Passenger= Pathogen (Virus, Parasite, or Bacterium)
Vehicle = Vector (Mosquito, Flea, Tick, Fly, etc.)
Destination= Human Host
Just as a vehicle transports passengers to their destination, a vector transports pathogens to humans or animals where they may cause disease.
SCIENTIFIC CHAIN
Pathogen ➜ Vector ➜ Host ➜ 
Disease
This simple concept forms the foundation of Vector Biology.
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WHAT IS VECTOR BIOLOGY?
Vector Biology is the branch of science that studies organisms capable of transmitting pathogens from one host to another.
Scientists study:
Vector behaviour
Vector life cycles
Disease transmission pathways
Host-vector interactions
Disease prevention and control strategies
Understanding vectors helps scientists and healthcare workers reduce disease outbreaks and improve public health.
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COMMON DISEASE VECTORS
Mosquitoes are not the only vectors.
Mosquitoes
Transmit malaria, dengue, chikungunya, and filariasis.
Ticks
Transmit Lyme disease and other infections.
Fleas
Transmit plague and murine typhus.
Houseflies
Mechanically transfer disease-causing microbes from contaminated surfaces to food.
Other Arthropods
Various insects and mites can also act as vectors.
KEY LEARNING: Vector Biology is much broader than simply studying mosquitoes.
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THREE IMPORTANT MOSQUITO VECTORS
ANOPHELES MOSQUITO
Identification
Wings usually have dark spots.
Body rests at an angle to the surface.
Disease Transmitted
Malaria
Pathogen Carried
Plasmodium parasite
Scientific Route
Plasmodium ➜ Anopheles ➜ Human ➜ Malaria
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AEDES MOSQUITO
Identification
Black body with distinctive white stripes.
Commonly called the “Tiger Mosquito”.
Diseases Transmitted
Dengue
Chikungunya
Zika
Yellow Fever
Pathogen Carried
Viruses
Scientific Route
Dengue Virus ➜ Aedes ➜ Human ➜ Dengue
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CULEX MOSQUITO
Identification
Brownish appearance.
Commonly breeds in polluted stagnant water.
Diseases Transmitted
Lymphatic Filariasis
Japanese Encephalitis
West Nile Fever
Pathogen Carried
Viruses and parasitic worms
Scientific Route
Pathogen ➜ Culex ➜ Human ➜ Disease
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COMPARISON OF MAJOR MOSQUITO VECTORS
Anopheles → Causes Malaria → Active mainly at night → Breeds mostly in clean water
Aedes → Causes Dengue & Chikungunya → Active mainly during the day → Breeds in clean stagnant water
Culex → Causes Filariasis & Encephalitis → Active during evening/night → Breeds in polluted stagnant water)
DISEASES DISCUSSED DURING THE SESSION
MALARIA
Cause
Plasmodium parasite
Transmission
Female Anopheles mosquito
Target
Red Blood Cells (RBCs)
Symptoms
Fever
Chills
Fatigue
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DENGUE
Cause
Dengue Virus
Transmission
Aedes mosquito
Symptoms
High fever
Severe headache
Body pain
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TYPHOID
Cause
Salmonella Typhi
Transmission
Contaminated food and water
Important Difference
Unlike malaria and dengue, typhoid is generally not spread by mosquito bites.
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DIAGNOSING MALARIA
Scientists use different diagnostic techniques to identify malaria infections.
BLOOD SMEAR TEST
A blood smear is one of the most reliable methods for malaria diagnosis.
Procedure
Blood sample collection
Thin smear preparation
Staining using special dyes
Microscopic examination
Detection of malaria parasites
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RAPID DIAGNOSTIC TEST (RDT)
RDTs detect malaria-specific antigens directly from blood samples.
Advantages
Fast results
Easy to perform
Useful in remote areas
Does not require a microscope
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WHAT CAN WE OBSERVE UNDER THE MICROSCOPE?
During a blood smear examination, we can observe:
Red Blood Cells (RBCs)
White Blood Cells (WBCs)
Platelets
Malaria Parasites (if present)
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WHITE BLOOD CELLS: THE GUARDIANS OF IMMUNITY
Neutrophils
First responders against infections.
Eosinophils
Defend against parasites and participate in allergic responses.
Basophils
Release histamine during inflammation.
Lymphocytes
Responsible for specific immune responses through B-cells and T-cells.
Monocytes
Transform into macrophages and remove pathogens and cellular debris.
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IMPORTANCE OF THE BLOOD CELL DIAGRAM
The diagram drawn during the session helped us visualize and compare the morphology of different blood cells, including:
RBCs
Neutrophils
Eosinophils
Basophils
Lymphocytes
This made microscopic identification easier and improved our understanding of blood cell morphology and disease diagnosis.
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KEY SCIENTIFIC INSIGHT
VECTOR TRANSMISSION PATHWAY
Pathogen ➜ Vector ➜ Host ➜ Disease
A mosquito may appear insignificant, but studying its behaviour, ecology, and interaction with pathogens provides valuable information that can save millions of lives.
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DISCUSSION QUESTION
If vectors are only carriers and not the actual cause of disease, what sustainable methods can we develop to interrupt disease transmission while maintaining ecological balance?
This question encourages us to think like scientists and explore solutions that protect both human health and the environment.
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FINAL REFLECTION
Today’s session demonstrated that some of the biggest discoveries in biology begin with the smallest observations. By studying vectors, blood cells, pathogens, and disease transmission pathways, we learned how microscopic organisms influence global public health. The world beneath a microscope may be tiny, but the knowledge it provides is enormous. Every mosquito, flea, tick, blood cell, and parasite tells a scientific story that helps us better understand life, disease, and the importance of prevention.
Screenshots during Chatshaala -
@manali ,@Arunan sir ,@KiranKalakotiR mam
