1. Introduction

The Insect That Spreads Disease in Humans

Mosquitoes are delicate insects with six legs and two wings that allow them to fly. They spread diseases like malaria, dengue, and yellow fever in humans. Only female mosquitoes are responsible for transmitting diseases to humans.

1. Female Anopheles Mosquito

The female Anopheles mosquito spreads malaria in humans through a parasite called Plasmodium.

2. Female Aides Mosquito

The female Aides mosquito spreads dengue fever in humans through the dengue virus.

Geographical Distribution of Mosquitoes

Mosquitoes are commonly found in tropical and subtropical regions of the world, such as Pakistan, India, Sri Lanka, Bangladesh, Malaysia, and Indonesia. For their survival and reproduction, a warm and humid climate along with rainfall is essential. Temperatures between 28°C and 35°C are ideal for mosquitoes.

In extremely hot and dry weather—like in May and June, when temperatures exceed 40°C—the number of mosquitoes decreases due to their high mortality. Similarly, in the extreme cold of December, January, and February, when the temperature drops below 15°C, the mosquito population significantly reduces.

In Pakistan, the monsoon season—July, August, and September—brings a sharp increase in the mosquito population.

1. Identification of Aedes Mosquito

The Aedes mosquito has stripes on its body and legs. These white stripes help in its identification.

Identification of Anopheles Mosquito

The Anopheles mosquito rests at a vertical angle against walls. It does not have body stripes. Its body hairs are uniquely arranged. It is generally smaller in size compared to the Aedes mosquito.

Diet

All female mosquitoes feed on flower nectar. However, to lay eggs, female mosquitoes feed on human blood (as well as the blood of mammals and birds). Male mosquitoes do not feed on blood as they lack the anatomical parts needed to suck blood.

Lifespan

The average lifespan of a mosquito is 2 to 3 weeks.

Biting Time

The Aedes mosquito is most active in the early morning after sunrise and in the evening around sunset. The Anopheles mosquito mostly bites at night.

Habitat of the Aedes Mosquito

The Aedes mosquito lives in clean but stagnant water found in drains and puddles. Examples include drains and dirty water ponds.

During the day, Aedes mosquitoes hide in utensils and containers, as well as in grass, bushes, and tree leaves. They also hide indoors in dark and humid places, such as behind cupboards, behind curtains, under beds, and inside bathrooms, kitchens, and storage areas. These mosquitoes tend to live close to human populations.

Breeding Places of the Aedes Mosquito
The female Aedes mosquito lays between 50 to 300 eggs on the surface of clean, stagnant water. Common breeding places include:

Flower pots, Tin cans, Old tires, Water tanks, Ponds and pools, Rainwater collected in tree holes

Life Cycle of the Aedes Mosquito
Eggs

The eggs are elongated and black in color. They are laid individually and float on the surface of water.

Larvae

The larvae hatch from the eggs within 2 to 7 days. They are very small and feed on particles in the water, such as bacteria, bits of algae, and tiny organisms. Larvae can grow up to 10 millimeters in length. They breathe using a siphon and remain vertically oriented in the water, with their breathing tube above water and their head submerged.
They often dive deep into the water to feed at the bottom.
Larvae shed their skin four times. Within 2 to 4 days, they transform into pupae.

Pupa

The pupa is comma-shaped (like the Urdu letter ‘و’) and is also known as “kalabad”. Although fast swimmers, they do not eat.
Within 1 or 2 days, they attach themselves to a solid surface.
When their outer skin splits, new adult mosquitoes emerge. They spread their wings, rest for a while on the water’s surface, and then fly away to begin a new life cycle.

Habitat of the Anopheles Mosquito

This mosquito lives in dirty but either flowing or stagnant water, such as drains and sewers.

Anopheles mosquitoes also hide during the day in grass, bushes, and on tree leaves. They can also hide indoors in dark and humid areas, such as behind furniture or in corners. These mosquitoes may be found both near and far from human populations.

Breeding Places

The female Anopheles mosquito lays between 40 to 100 eggs on dirty water surfaces such as ponds, drains, and slow-moving streams.

Life Cycle
Egg

The eggs of the Anopheles mosquito are boat-shaped. They are laid individually, not in clusters, and float on the surface of water.

Larva

The larvae hatch from the eggs within 1 to 5 days and are very small in size. They feed on particles in the water, bacteria, algae, and tiny aquatic organisms. These larvae can grow up to 10 millimeters in length.

They breathe through tiny holes located on their bodies. Unlike Aedes larvae, they do not dive deep and instead remain at the surface to feed. They do not hang vertically, but lie parallel to the water surface.

The larvae molt (shed their skin) four times. Within 2 to 4 days, they transform into pupae.

Pupa

The pupa is comma-shaped (like the Urdu letter “و”). It swims quickly, but does not eat. Within 1 or 2 days, it attaches itself to a solid surface. When its outer layer splits open, a new mosquito emerges.

The mosquito spreads its wings, rests briefly on the water’s surface, and then flies away to begin its new life cycle.

Note:

Anopheles larvae remain parallel to the water surface; they do not hang vertically like Aedes larvae.

Mosquito – A Harmful Insect

Many types of mosquitoes spread various diseases among humans, animals, and birds.
The dengue virus enters female Aedes mosquitoes when they bite a dengue-infected person. The virus develops inside the mosquito, specifically in its saliva and salivary glands.

Whilst an inflamed mosquito bites a healthy man or woman, it transmits the virus through its saliva into the character’s bloodstream, doubtlessly causing dengue fever.

further, the woman Anopheles mosquito acquires the Plasmodium parasite after biting a person infected with malaria. The parasite additionally develops inside the mosquito, and whilst it bites a healthful man or woman, the Plasmodium parasite is transmitted via its saliva, which can result in malaria.

via eliminating mosquitoes, we can protect ourselves from illnesses like dengue and malaria.

Insecticide Spraying

Insecticide spray must be applied within the house, especially in areas where mosquitoes have a tendency to hide, such as:

• At the back of curtains
• In the back of cabinets and sofas
• below beds
• In corners of rooms
• In toilets and kitchens

The quality time to spray is one hour before sunset.

After spraying, maintain the rooms closed for 2 hours in order that the mosquitoes die and those are covered from the harmful consequences of the chemical substances.
Spraying need to be accomplished at the least as soon as every week.

Insecticide Fogging

In public locations such as: Playgrounds, Gardens, Streets and roads, Railway stations, Bus stands, Airports places of work, stores, faculties, colleges, and cinemas

Insecticide spraying and fogging have to be finished every week to manipulate mosquito populations and decrease the hazard of disease.

Drainage

Water accumulated in homes, streets, markets, fields, and gardens should be immediately dried or drained.

Cleanliness

Cleanliness is half of faith.

Do not throw tin cans, old tires, broken bottles, or garbage inside or outside homes, as these can become breeding grounds for mosquitoes.

Spraying Larvicides and Kerosene Oil

In ponds, pools, marshy areas, and lakes, spray larvicide and kerosene oil on the surface of the water to eliminate mosquito larvae.

Use of Electric Mosquito Repellents

At night, use electric mosquito repellents in homes and shops to keep mosquitoes away.

Precautionary Measures to Prevent Mosquito Bites
Install wire mesh/screens on doors, windows, and ventilators.

Sleep under a mosquito net.

Apply mosquito repellent oil or lotion on exposed parts of the body.
Light mosquito coils or repellent mats in rooms before sleeping at night.
Wear long-sleeved shirts and clothing that fully covers the body.
Isolate Dengue and Malaria Patients

Dengue and malaria patients should be kept inside mosquito nets so that mosquitoes do not bite them and spread the disease to healthy individuals.

This is an important step in preventing the spread of these diseases.

Symptoms of Dengue Fever

• Symptoms of dengue fever usually appear 5 to 7 days after being bitten by an infected dengue mosquito.
  
• The symptoms of dengue fever include:
  
• The patient’s body temperature can exceed 102°F (39°C), and the fever tends to be continuous.
  
• The patient does not experience chills.
  
• Severe headache, especially behind the eyes.
  
• Red rashes may appear on the skin.
  
• Intense pain in bones, joints, and muscles, which is why it is also known as “breakbone fever”.
  
• The patient may experience diarrhea and vomiting.
  

 

Treatment

• Use Paracetamol (as prescribed by a doctor) to reduce fever and pain.
  
• Always follow the doctor’s advice for treatment and medications.
  

Dengue Patient Care

• The patient should be admitted to a hospital after proper dengue tests and on a doctor’s recommendation.
  
• The patient needs complete bed rest for more than 15 days.
  
• Medications should be taken strictly according to the doctor’s instructions.
  
• The patient should be given plenty of fluids, such as:
  Fresh fruit juices ORS (Oral Rehydration Solution), Shikanjabeen (lemon drink)
• These help restore the body’s energy and prevent dehydration.
  
• Do not stress the patient; instead, provide encouragement and ensure complete rest.
  
• Within 7 to 15 days, the patient usually recovers fully and develops natural immunity against the disease.

Symptoms of Malaria Fever

1. Symptoms of malaria fever usually begin to appear 7 to 10 days after being bitten by an Anopheles mosquito.
2. The symptoms of malaria include:
3. The patient’s body temperature can exceed 102°F (39°C).
4. After a certain interval, the fever subsides on its own through heavy sweating.
5. The patient experiences intense chills and shivering.
6. The patient suffers from a severe headache and profuse sweating.
7. Red rashes do not appear on the body.
8. If left untreated, malaria fever reoccurs at regular intervals, which is why it is commonly referred to as “intermittent fever.”
9. The patient usually does not experience diarrhea or vomiting.
10. Treatment
    Malaria medication must be taken strictly according to the doctor’s instructions.
11. With proper treatment, malaria fever can be completely cured.