World Mosquito Day was first started in 1897 because of British doctor Sir Ronald Ross’s who found that female mosquitoes transmit malaria between humans, and was celebrated annually on 20th August. It aims to raise awareness about the causes of mosquito borne diseases and how it can be prevented, and the achievements of research into mosquitoes and how to prevent the disease they carry.

Mosquitoes are one of the deadliest insect in the world. They are able to carry and spread diseases to humans and cause millions of deaths every year. Mosquitoes have been around for over a hundred million years and spread diseases which led to many losses of lives. In fact around 6 million deaths occur every decade owing to malaria. There are several different mosquitoes that can carry many different diseases. Aedes, Anopheles, Culex mosquitoes act as vectors (living organisms that can transmit infectious diseases between humans or from animals to humans) for the following diseases-

Aedes: Chikungunya, Dengue fever, Lymphatic filariasis, Rift Valley fever, Yellow fever.
Anopheles: Malaria, Lymphatic filariasis (in Africa)
Culex: Japanese encephalitis, Lymphatic filariasis, West Nile fever

Global Data epidemiologists reported that approximately 70% of malaria deaths are of children under five. Malaria is a huge financial burden on African countries, costing the African economy $12 billion every year, slowing the economic growth of these countries.

Facts about mosquito borne diseases:

• Female Anopheles culicifacies is the main vector of malaria and commonly feeds on cattle as well as humans.
• Anopheles (Vector of malaria) breeds in rainwater pools and puddles, borrow pits, river bed pools, irrigation channels, seepages, rice fields, wells, pond margins, sluggish streams with sandy margins.
• Anopheles mosquito mostly bites between dusk and dawn.
• Female Aedes aegypti transmits dengue, chikungunya and yellow fever to humans.
• Aedes aegypti bites most frequently during daytime, and peak biting periods are early in the morning and in the evening before dusk.
• Aedes aegypti mosquito breeds in any type of manmade containers or storage containers having even a small quantity of water.
• Eggs of Aedes aegypti can live without water for more than one year.
• Aedes aegypti usually fly an average of 400 meters, but it can be transported accidently by humans from one place to another.

Only female mosquitoes require a blood meal and bite animals while male mosquitoes do not bite but feed on the nectar of flowers or other suitable sugar source. Actually, female mosquitoes suck blood in order to help with the development of their eggs prior to laying them. Although at times mosquitoes are dangerous because of their ability to carry and transmit diseases. Mosquitoes play an important role in the ecosystem because they serve as a food source for many organisms.

Rapid urbanization, increases in international trade and travel, climate change and changing agricultural practices are all contributing to the increases in mosquito and other vector-borne diseases. History shows that vector control efforts need to be continuously supported by all countries to maintain expertise and capacity. This is essential to detect threats, prevent resurgence of deadly diseases and cope with new outbreaks of diseases.

Prevent mosquito borne diseases by ‘Integrated vector management (IVM)’.

(a) Vector surveillance- Larval surveys and adult surveys are important for early detection of mosquito population so that proper control measures can be initiated at an early stage.

(b) Vector management– It includes methods to eliminate mosquito breeding and adult mosquito population. These are –

(i) Environment management:
It includes efforts to reduce actual or potential larval (immature stages of mosquitoes) habitats in and around houses by:

• Covering all water containers in the house to prevent fresh egg laying by the vector.
• Emptying and drying water tanks, containers, coolers, bird baths, pets’ water bowls, plant pots, drip trays at least once each week.
• Removing discarded items that collect rainwater from open spaces.
• Regularly checking for flat roofs that may have poor drainage.

(ii) Biological control–

• Introducing larvivorous fishes (Gambusia/ Guppy) in ornamental water tanks/garden.
• Using bacteria, Bacillus thuringiensis (Bt H-14) as biological larvicide in stagnant water. It poses no danger to humans, non-targeted animal species, or the environment when used according to directions.

(iii) Chemical control-

• Chemical larvicides (such as temephos) – Used in permanent big water containers where water has to be conserved or stored because of scarcity of water or irregular water supply.
• Adulticide- In areas where cases of dengue, chikungunya infection are detected pyrethrum spray or malathion fogging spray are recommended for the control of adult mosquitoes. Indoor residual spraying with insecticides is used to control malaria.

(c) Personal protective/preventive measures-

• Using insect repellent – Mortein, Good Night, All Out, Odomos, Himalaya Herbal, Kavach, Hit, Bug Off.
• Wearing clothes (preferably light-colored) that cover as much of the body as possible
• Using physical barriers such as screening the windows and doors.
• Sleeping under mosquito nets even during day time.