Antibiotic misuse has soared in an African capital as an unforeseen consequence of improving the diagnosis of malaria, according to a study.
A team testing the roll-out of fast, accurate tests for malaria in Dar es Salaam, Tanzania, found that antibiotic prescriptions for fever rose by nearly a quarter, from 49 to 72 per cent, raising fears that the behaviour will contribute to growing antibiotic resistance.
The team was assessing the impact of rapid diagnostic tests for malaria, which replaced the less precise microscope diagnosis in three hospitals and three health facilities in the capital. Eighteen months after the tests were rolled out, prescriptions of antimalarial drugs dropped from being given to three quarters of patients to just a fifth.
The results reflect a success for the tests in reducing the inappropriate prescribing of anti-malarial drugs, a major contributor to the growth in resistance to drugs such as artemisinin, a problem about which there is grave international concern.
But, as a consequence, said Valerie D'Acremont, lead author and a senior scientist at the Swiss Tropical and Public Health Institute, Switzerland, clinicians were handing out antibiotics, instead of anti-malarial drugs, to all patients with fever who tested negative for malaria.
"They do that to avoid putting patients at risk," she told SciDev.Net, "especially as there are no diagnostic tools for other diseases such as typhoid or pneumonia. The increase in absolute use of antibiotics is a mathematical consequence of knowing that fewer patients have malaria."
D'Acremont said that there is a serious risk that the introduction of the malaria tests will lead to a widespread increase in the use of antibiotics across the continent.
"Ideally, with training and the implementation of clinical guidelines, it's possible to reduce antibiotic use from 80 per cent to 25 per cent of patients," she said, citing an earlier study the team conducted, also in Tanzania.
Andreas Heddini, director of Action on Antibiotic Resistance (ReAct), said: "Ideally there would be tests for malaria and for bacterial infections, but these are unlikely to become available for the next years. In the meantime, much can be achieved with training.
"The big challenge is that in countries with weak health systems it is difficult to have a cautious approach to infections. You can't ask someone to come back in a few days if the symptoms get worse."
The team, which included scientists from Tanzania's City Medical Office of Health, the Ministry of Health and Social Welfare, and Ifakara Health Institute, published its results in Malaria Journal last month (29 April).
Malaria Journal doi:10.1186/1475-2875-10-107 (2011)