According to the World Health Organisation, mosquito bites result in more than a million deaths worldwide, largely due to Malaria, it has been over a hundred years since this discovery of mosquitoes causing malaria and yet the disease is still largely prevalent, especially in developing countries.
They are the leading vectors for a large number of diseases, namely:
The female anopheles mosquito is known to cause protozoal disease Malaria.
The Aedes aegypti mosquito causes
- Dengue fever
- Chikungunya fever
- Yellow fever
- Zika virus
The culex mosquito causes
- Japanese Encephalitis
- West Nile Virus
Out of these, Malaria, chikungunya, Dengue and Japanese Encephalitis are prominent in India and South East Asia and are clinically relevant.
LIFE CYCLE OF MOSQUITO
The life cycle of the mosquito happens in 4 stages, namely
- The egg
- Adult form
The first three stages occur in water and the adult stage exists on land. Thus, water is a famous breeding ground for mosquitoes.
HOW TO ELIMINATE MOSQUITOES?
A. ANTI LARVAL MEASURES
- Anopheles mosquitoes: filling and drainage of stagnant water, keeping tanks clean
- Culex mosquito: proper disposal of sewage and waste
- Aedes mosquito: water-holding containers (eg, pots, tins, coolers, etc.) should be removed to prevent breeding
- Mansoniodes mosquito: Remove any aquatic plants
- Paris green and larvicides can also be used to eliminate the larva.
- Using Gambusia or guppy fish in water containing mosquito larvae is beneficial as these fish prey on them, thus making it a biological method of control.
B. ANTI ADULT MEASURES
Use of Insecticides such as:
PERSONAL PROTECTION TO AVOID MOSQUITO BITES.
- Use of mosquito nets: make sure the net is well tucked into the mattress all around and ensure that it does not have holes.
- Screens and wire mesh for windows in order to prevent the entry of mosquitoes.
- Repellents: Compounds such as oil of citronella and Diethytoluamide (DEET is present in the popular product Odomos in India) repel the mosquitoes when applied to the exposed surface.
- Use of mosquito coils or pyrethrum coils.
- Use of fan at a high-speed.
- Wearing full-sleeved clothes that cover a high surface area of the body helps in preventing mosquito bites.
- Maintaining a clean and hygienic environment, free of stagnant water, and exposed sewage and waste.
INTERESTING FACTS ABOUT MOSQUITOES
- World mosquito day is on 20th August, it commemorates the discovery of the causation of malaria due to mosquitoes by Sir Ronald Ross in 1897.
- Iceland is the only country in the world that is mosquito-free.
- Having sickle cell trait, that is when you carry a sickle cell gene, which can cause abnormal hemoglobin formation has a protective advantage over malaria, this is seen predominantly in Africa.
FREQUENTLY ASKED QUESTIONS
Q) Why do mosquitoes bite?
A) Mosquitoes require the human body to reproduce and complete their life cycle; they replicate in the red blood cells and liver cells.
Q) Why do mosquitoes bite me more than others?
A) The hotter you are, the more mosquitoes you attract, the body heat generated as an inherent property of being a warm-blooded creature attracts mosquitoes, therefore in conditions where your body temperature is higher, like in pregnancy, fever, post-exercise, etc, the more likely you are to be bitten by mosquitoes! In addition, mosquitoes also detect the carbon dioxide exhaled along with the chemicals in your sweat. Basically, it’s not easy to avoid them.
Q) What happens when mosquitoes bite?
A) Only the Female Anopheles bite humans. Upon biting, it deposits its sporozoites, which is the infective form, along with its saliva in your blood. The body recognized the saliva as a foreign substance and produces a chemical to fight against it thus causing the red swelling.
Q) Does your blood group matter?
A) Yes, research has shown that mosquitoes are more attracted to the blood group O, which is the most common blood group, followed by the blood group A.