Simple "dipstick" test could save millions from blindness

May 15 2006

A Cambridge University team have developed a simple "dipstick" test to detect the eye infection trachoma, a disease spread by flies, which could potentially help save the sight of millions around the world.

The novel, inexpensive, sensitive and simple rapid test for trachoma, was created by Dr. Helen Lee and her team at Cambridge's diagnostics development unit.

Trachoma is caused by the Chlamydia trachomatis bacteria, and results in the eyelid folding inward and the lashes scarring the cornea.

As many as 84 million people, mainly in the developing world, have the infection.

In a study involving more than 600 Masai children in Tanzania, the test proved to be more than twice as effective as traditional methods and produced results in less than half an hour.

It can be used in remote areas by staff who have been trained on-the-spot and have access to only the most basic facilities.

The results were able to be evaluated without electricity or running water and by just using such basic furniture as tables as makeshift lab benches.

Claude-Edouard Michel, one of the programme leaders, says they have demonstrated that the test can work in the most difficult circumstances without even the most basic of laboratory equipment.

The test is simple to use and it took just one hour to train local health workers to carry out the tests.

It involves a wafer-thin, 8cm long trachoma dipstick which is in fact an adaptation of a test first developed to diagnose the sexually-transmitted form of chlamydia.

It is possible to cure the infection with a single dose of a drug called azithromycin.

Professor David Mabey, from the London School of Hygiene and Tropical Medicine, who was involved in the trial says the test is an important advance in the fight against trachoma and will enable programme managers to ascertain which communities still harbour the infection and then focus treatment on communities which really need it.

It seems much of the drug is wasted in treating communities which no longer need it.

Dr. Paul Courtright, co-director of the Kilimanjaro Centre for Community Ophthalmology at Tumaini University in Moshi, Tanzania says the findings from the study will probably lead to a major re-think on how trachoma control is carried out in Africa and help towards a more targeted approach, saving both time and money.