MALARIA: Historical aspects

Kicking off proceedings was LSHTM’s Professor Brian Greenwood, a legend in malaria research, who painted a picture of how malaria treatment used to be – and how much it has changed.
Forty years ago almost every African child had malaria, with an estimated prevalence of 95 per cent (though Greenwood reckoned it was nearer to 100 per cent in reality). Yet, at the time, confidence in malaria treatments was high. The front-line anti-malaria drugs such as chloroquine were effective and anti-malarials for prophylaxis were widely sold. “We didn’t have seminars about malaria,” said Greenwood, “People didn’t feel there needed to be [any]”.
But that was before the spectre of anti-malaria drug resistance emerged. Following the first report in 1968, resistance spread rapidly through the continent, rendering many of the front-line treatments ineffective and forcing a major rethink of treatment strategies.
A serious barrier was changing doctors’ behaviour. Despite the fact that resistance was widely acknowledged, chloroquine continued to be (mis-)used. Why?
“Everyone liked chloroquine,” said Greenwood, “Doctors had confidence in it from years of effective use, and doctors are very conservative by nature. Getting them to change their minds was a hard task.”
Moreover, chloroquine had benefits beyond malaria. It is an effective anti-inflammatory, one of the reasons the drug was always prescribed, even if the patient didn’t have malaria. Said Greenwood, “It was thought to be fine to do so as they were always likely to benefit”.
Furthermore, there was a widespread (erroneous) belief that having a few parasites circulating in the body ‘stimulated the immune system’. It was common practice in many places to give patients just one day of a three-day course of chloroquine.
We now know that many of these practices are detrimental to health and a boon to increasing the resistance of the parasite to the drug. The patient could develop anaemia or the parasite could recover and cause another bout of malaria.
By the 1990s the malaria community had learnt that treatment should eliminate all parasites. This was in no small part due to pioneering research by scientists such as Professor Nick White from the Wellcome Trust’s Major Overseas Programme in Thailand (in South-east Asia the idea of leaving parasites around for immunity was never fully accepted). Also, from treating tuberculosis, researchers and healthcare workers soon realised that the use of mono-therapies – and overuse of them at that – was helping to increase drug resistance.
We now know the importance of diagnosing and only treating those who really have malaria, yet the relative slowness with which the community recognised these dangers was disastrous. Even today the idea of leaving a few parasites in the body has not completely been dispelled. As Greenwood said, it’s taken a long time to learn those messages and we are mostly there now, but the message must continue to be broadcast.
http://wellcometrust.wordpress.com/2010/04/26/counting-malaria-out-malaria-treatment-as-it-used-to-be/