Rapid Malaria Tests Change Medical Diagnoses in Africa

By Phuong Tran

Dakar

25 April 2008

　



What started out as Africa Malaria Day was being observed worldwide for the first time on Friday. Health organizations have long said that most of the one million deaths every year attributed to malaria happen in Africa. But a newly-introduced malaria test that gives results in 15 minutes shows not every case of fever means malaria, which is how many health workers have previously diagnosed the disease. Phuong Tran has more VOA's West Africa Bureau in Dakar.

　

Nurse Khany Faye Sougou recently examined an 18-month-old baby at the district health center in Pikine, a suburb of Senegal's capital Dakar. His mother says she was worried he had malaria because he had not eaten the previous day and had a fever, common signs of malaria.

The nurse pricked the child's finger to draw blood that she dropped into a small white stick to test for the malaria parasite, spread through infected mosquitoes.

Fifteen minutes later, Sougou looked at the white stick and announced the child did not have malaria.

Senegal's health centers in cities started using rapid diagnostic tests last September. Pikine's medical chief, Karim Diop, says the tests have completely changed how his workers treat fevers.

　

"Before the rapid tests, every case of fever was assumed to be malaria," said Diop. "None of the other 21 health centers in my district have labs to test for malaria. We could not take the risk and wait for lab results from the region's only lab. So every child, pregnant woman, and most others with fevers got anti-malarial medication just to be safe."

Malaria can kill within days, especially pregnant women, children and patients with weak immune systems, like those with the Human Immunodeficiency Virus, HIV, which causes AIDS.

Most suspected cases are not tested in Senegal because of a lack of good quality microscopes.

Malaria rapid tests do not require lab analysis and are given for free. The international donor group, the Global Fund, covers the 50 cent cost for each test, and recently funded one million tests in Senegal.

Since using the test, medical chief Diop says less than 30 percent of 10,000 suspected malaria cases have been positive. He says all 10,000 patients would have been given malaria medication if workers did not have the rapid test.

Scientist David Bell with the World Health Organization says anti-malarial drugs become ineffective when people without malaria take it and develop resistance.

Rapid tests have been introduced worldwide in recent years, as countries face more pressure to improve diagnosis because of growing drug resistance.

While most countries in West Africa are switching over to more effective anti-malarial drugs, only a few are widely offering rapid tests, such as Liberia, Ghana, and Senegal.

The World Health Organization estimates up to 80 million rapid tests were used last year, mostly in Africa.

But scientist Bell says rapid tests are not a guarantee against future drug resistance.

"Someone can have a rapid diagnostic test done on them, but if it is negative, they still have a fever; they are still sick," said Bell. "Programs need to give some other way for the health worker to help that person, otherwise there is still a danger they will be given anti-malarial drugs if the health worker has nothing else to give them."

Deadly illnesses that share symptoms with malaria include meningitis and respiratory infections. Bell adds that if the tests are not stored and transported properly, they will not work. When possible, World Health Organization officials encourage microscope testing where available.

"Because of the technology which the tests are made of, they are often sensitive to heat," said Bell. "If you are using a rapid test in a remote village in somewhere like Sudan or West Africa, the temperatures can get up to 40 degrees [Celsius], then it has been shown that the tests can deteriorate under those conditions."

Bell says though there have been studies showing some malaria rapid tests are as effective as microscope tests, not all studies are reliable.

For six years, the World Health Organization has been gathering malaria samples from across the world to test more than 40 different rapid tests. Next month, the World Health Organization is expected to launch product testing. Scientist Bell says results are expected by year end.