Issue 7
Monday, 22 May 2017
Charles Darwin University
Patients wait outside a health centre in Ethiopia to enrol in the malaria study. Photo Lorenz Von Seidlein
Patients wait outside a health centre in Ethiopia to enrol in the malaria study. Photo Lorenz Von Seidlein

Study stresses need for vivax malaria radical cure

By Melody Song

A study into the treatment of the difficult-to-cure Plasmodium vivax malaria in Ethiopia has emphasised the need to include the drug primaquine to reduce the risk of relapsing infection, further transmission and, potentially, loss of life.

The clinical study was a collaborative effort by Menzies School of Health Research, US President’s Malaria Initiative and ICAP Columbia University’s Mailman School of Public Health in Addis Ababa, with support from the Ethiopian Public Health Institute. It was funded by the US President’s Malaria Initiative and the Bill and Melinda Gates Foundation.

The co-lead author from Menzies, Dr Kamala Thriemer, said the findings of the radical cure study would influence malaria treatment policy in Ethiopia and other malaria-endemic countries.

“Vivax malaria can remain dormant in the liver, and successful treatment requires treatment for both the blood stages and liver stages. Treating just the blood stages of the infection is like pulling weeds out of the garden without taking steps to prevent them growing back,” Dr Thriemer said.

“During the study, we found evidence of resistance to chloroquine, which is traditionally used to treat the blood stages of vivax malaria; almost 20 per cent of patients failed treatment within 42 days.

“Surprisingly, artemether-lumefantrine, the drug used to treat the more commonly diagnosed Plasmodium falciparum malaria, was not much better than chloroquine unless it was administered in combination with primaquine, which is used to treat the liver forms of malaria.

“The conclusion we arrived at was the administration of the combination treatment significantly reduced the risk of relapse.”

Ethiopian lead author on the study, Dr Tesfay Abreha acknowledged additional work needed to be done in treating vivax malaria, which accounted for around 40 per cent of reported malaria cases in the country.

The findings of this study have implications for other malaria-endemic regions, including Australian tourist hotspots such as South-east Asia, where a spreading resistance to commonly prescribed treatment is on the rise.

The results of the study were published recently in the PLoS Medicine journal.