About the study
In the study, the parasites that cause the disease (sporozoites) were injected directly into the mice's blood stream. At the same time they were also treated with the antibiotics clindamycin or azithromycin.
Normally the parasites enter the liver where they replicate rapidly and mature before then entering the blood cells causing the disease. The antibiotics did not prevent the parasites from growing, but they did prevent them from infecting the blood cells. It is this infection that results in the symptoms of malaria and ultimately death. Thus the antibiotics protected the mice from the effects of the parasite.
But as well as preventing the disease, the treatment also gave the mice immunity from further infection. When re-infected at periods of 40 days, 4 months and 6 months the mice were found to be protected from the disease even though they were not given any more antibiotics.
Limitations of the treatment
Although the treatment worked very well in mice, more work needs to be done before it can be considered of benefit to humans. This is because in the "real world" humans tend to be subjected to continual low concentrations of the parasite caused by mosquito bites.
When this scenario was replicated in mice, only 30% of them were protected by the treatment, but for those mice that were infected the malaria did not affect the brain in 85% of cases, showing that there are still benefits to be had.
The study also helped identify a section of the parasite, called the apicoplast, which is used to infect other cells in the body. Study leader Dr. Johannes Friesen commented: "Even if our results cannot be confirmed in a field trial, the apicoplast is a promising target for future medication."
The study is published in the journal Science Translational Medicine and was carried out by teams at Heidelberg University Hospital and the Max Planck Institute for Infection Biology.
