Thu | Nov 15, 2018

Zero tolerance on mosquitoes

Published:Monday | February 8, 2016 | 12:09 AMMichael Abrahams
In this January 30, 2016 photo, Jose Wesley, who was born with microcephaly and screams uncontrollably for long stretches, is attended to in Bonito, Pernambuco state, Brazil. The Zika virus is drawing worldwide attention to a devastating birth defect that until now has got little public notice. Regardless of whether the mosquito-borne virus really causes babies to be born with abnormally small heads, a variety of other conditions can trigger it.

When we think about dangerous animals that kill people, many creatures initially come to mind, especially large intimidating carnivorous predators such as sharks, lions and tigers. We also think of scary-looking critters that poison us, like venomous snakes and spiders.
The most deadly animal in the world, however, is the mosquito, causing more misery and death than any other family of creatures.
The word ‘mosquito’ is Spanish for ‘little fly’ (mosca + ito). According to the World Health Organization (WHO), mosquito bites result in the deaths of more than one million people every year. The majority of these deaths are caused by malaria, an infection caused by a parasite. The insects also transmit the parasites responsible for filariasis or elephantiasis, a condition which can cause gross swelling deformities of the lower limbs and genitalia, in addition to transmitting the yellow fever, West Nile, dengue, chikungunya and Zika viruses. Mosquitoes, not surprisingly, have been referred to as ‘flying syringes’ and ‘bioterrorists’.
The first confirmed human case of malaria dates from 450 AD, diagnosed in 2001 when British researchers recovered traces of the parasite's DNA from a children's cemetery on the outskirts of Rome, Italy. It has been estimated that malaria may have killed half of all the people that ever lived, and an estimated 300-600 million people suffer from the infection each year. More than 40 per cent of the world's population lives in malaria-risk areas.
Humans have been fighting mosquitoes for years, from using pesticides such as DDT (dichlorodiphenyltrichloroethane), to genetic modification to breed sterile males and flightless females, to infecting them with fungi, or with harmful or genetically modified bacteria. These efforts have met with varying degrees of success. Unfortunately, mosquitoes are still breeding and terrorising us.
Some have suggested that we should just attempt to eradicate mosquitoes from the planet. It sounds like a good idea, but apart from being extremely difficult to pull off, it may be unnecessary to kill off all of the insects.
More than 3,500 species of mosquitoes exist, present on every continent except Antarctica. Not all species suck blood, and in the groups that do, only females engage in the practice, and not all transmit disease. Also, eradication could also bring about ecological turmoil. Mosquitoes are important food sources for fish (who eat their larvae), and many species of birds, insects, spiders, reptiles and amphibians. If mosquitoes were to disappear off the face of the earth, all of these animals would be adversely affected, possibly resulting in a number of deleterious ecological effects.
The Aedes aegypti mosquito (the name aēdēs means ‘unpleasant’ or ‘odious’ in ancient Greek), however, is a notorious vector of disease and unfortunately lives in Jamaica and has given no indication that it is likely to leave any time soon. This mosquito transmits dengue and chikungunya, which are now endemic to this country, and now the Zika virus. It loves to live among people, and is as domesticated as our pet cats and dogs.

So, in order to protect ourselves against this perennial pest, we must develop a culture of zero tolerance regarding mosquitoes. We must become ninja/gladiator warriors with a take-no-prisoners attitude towards these critters, and inculcate this mindset in our children.

Attention must be paid to our environment, especially with respect to the disposal of garbage. Littering is an excellent way to provide mosquitoes with breeding sites. Carelessly discarded open bottles, and Styrofoam and plastic containers, are excellent reservoirs for water after rainfall. These objects will also block drains and gullies.
But, even more importantly, we must pay attention to our immediate surroundings. The Aedes aegypti mosquito does not fly farther than about 400 metres, so if it is in your home, it is breeding in your community or in an adjoining one. So we must perform regular inspections. Tyres must be discarded, and those used for swings punctured with multiple holes to prevent water collection and stagnation. Wheelbarrows must be turned over. Outdoor containers should also be turned over, or covered, or perforated so that water will not settle in them.
Water in flower vases, birdbaths and feeding bowls for pets should be changed regularly. Flower pot saucers should be emptied of residual water, and unused toilet bowls flushed regularly or treated with pesticides. Female mosquitoes can lay up to 1,000 eggs, which, after prolonged periods of dormancy, up to 10-15 years, can hatch after contact with water. So, the above-mentioned containers should also be scrubbed and cleaned weekly. Swimming pools and garden ponds must also be properly maintained.
Prevention of breeding is one thing, but protection against being bitten is of equal importance, and the use of nets and screens, and the wearing of appropriate clothing (long-sleeved, light-coloured, thick fabric and wearing shoes and socks) is of immense value, as is the use of appropriate repellents, the most effective being those containing DEET (N,N-diethyl-meta-toluamide). Even if we do not fear mosquito-borne illnesses ourselves, if we get infected, we become reservoirs and sources of infections for others, so we must protect ourselves.
There is only so much that the Government and other authorities can do to protect us against these insects and the potentially debilitating diseases that they carry. Much of the responsibility lies with us, the populace. We must develop a ‘mosquito-unfriendly’ culture.

- Michael Abrahams is an obstetrician and gynaecologist, comedian and poet. Email feedback to and, or tweet @mikeyabrahams.