July 20, 2000. Copyright 2000. Graphic News. All rights reserved.

POP BOTTLES CUT RIVER BLINDNESS

LONDON, July 20, Graphic News: A CHEAP low-tech trap made from a couple of old plastic pop bottles and some animal dung has led to the development of an effective fly trap that is helping control trachoma Ð the worldÕs leading cause of preventable blindness.

The simple homemade device was invented by a retired professor from the Institute of Child Health in London. 

Trachoma, also known as river blindness, affects approximately 150 million people worldwide, with a further 540 million -- 10 percent of the worldÕs population, mainly in developing countries -- at risk of getting it, according to World Health Organisation estimates.

The infection is spread in part by flies and inflames the eye, filling it with sticky mucus. Over years, multiple infections tighten the rim of the upper eyelid, forcing it to curl in on itself and prod the eye with its own lashes. This scars the cornea, turning it white, until the sufferer can no longer see.

Trachoma is usually treated with tetracycline, an antibiotic eye ointment, oral antibiotics such as azithromycin or a simple 10-minute operation which turns the eyelid back round the right way, but a cheaper, simpler option is prevention at source through effective fly control. 

In AfricaÕs Rift Valley, for example, there could be as many as 32,000 flies buzzing around a single home.

 Studies have suggested that simply by killing the flies, the risk of transmission of the infection could also be reduced. 

Professor David Morley, a retired specialist in tropical child health at Great Ormond Street Hospital in London, developed a fly trap which can be built simply from two transparent plastic bottles, based on his observation that flies, following feeding, tend to fly upwards towards the light. 

The lower bottle is plastered with mud to make it dark inside, and then filled with a mixture of goat droppings and cow urine -- guaranteed to prove irresistable to flies. 

After dining, the flies pass up a plastic tube into a second bottle, left transparent to lure them. Here they die from exhaustion and exposure to UV light. 

A one-year trial of the bottle-trap in 300 Masai homes in Kenya reduced the fly population by an estimated 40%, and more importantly, the number of trachoma cases fell by more than a third.
/ENDS

Sources: New Scientist, Reuters, BBC World Service