How the mosquito net came into our lives

I learnt something interesting while watching an interview with Dr. Himmatrao Bawaskar, who was awarded the Padma Shri for his research on scorpion stings in rural Konkan. In the initial days, he found that one community was stung by scorpions while another was not. Intrigued, he visited the villages and discovered that the second group slept under mosquito nets, which not only protected them from scorpions but also from the deadly bite of the Common Krait. The humble net saved users from threats well beyond mosquitoes.

But it was not always so. Early forms of mosquito nets were used exclusively by the royalty in ancient civilisations such as Egypt and Rome. In India, mosquito nets are mentioned in the poetry of 15th century Telugu poet Annamayya, though their usage may have been older. The British probably picked up the use of mosquito nets during the initial phase of colonising India. As awareness of insect-borne diseases grew, these nets became essential household items. Improvements in weaving and textile production offered finer mesh, better airflow, and greater comfort.

The often re-invented humble mosquito net seems to be coming back into fashion
| Photo Credit:
Surachet99

Creating a mesh

However, the true mosquito net revolution began in 1983 in Bobo-Dioulasso, Burkina Faso, West Africa. The fight against malaria was in full swing. A team of Franco-African medical entomologists dipped nets in a water-insecticide (pyrethroid) mix. They found that, apart from protecting humans inside the nets, this significantly reduced malaria transmission. However, the scientific community was sceptical, pinning its hopes on the “impending” discovery of a malaria vaccine that, incidentally, is still pending.

Further testing and wide-ranging studies firmly established the effectiveness of this method. So, in the 1990s, industrial companies started manufacturing Long-Lasting Insecticidal Nets (LLINs) in which the insecticide is incorporated into the net fibre during manufacturing. This allowed them to remain effective for several years without re-treatment. The insecticides used (deltamethrin or permethrin) are generally safe for humans but toxic to mosquitoes. Today, LLI nets are distributed in malaria-infected countries. At the same time, regular mosquito nets remain available and popular, especially in areas that are mosquito-infested but relatively free of malaria.

While mosquito nets are popular in India, the surge in dengue and chikungunya has seen nets being replaced by coils, vapourisers, creams, and agarbatti repellents that often contain pyrethroids. Though considered safer than DDT, the recommended use in well-ventilated areas is rarely followed. Recently, the government discontinued certain agarbatti-based repellents due to the use of banned ingredients. DDT, once used widely, has been banned in the U.S. since 1972. All this has raised concerns about the risk of using repellents. So, the often re-invented humble mosquito net seems to be coming back into fashion, as it not only protects from mosquitoes but also from scorpions and snakes.