Washington (AFP)

The massive distribution of antibiotics to children in Niger has reduced mortality in their villages, without apparently creating the resistance to antibiotics so feared by public health experts, according to a study released Wednesday in the United States.

But this study does not settle definitively the question, because other work showed a more mitigated impact of these distributions.

A team of researchers from the University of California at San Francisco and Berkeley and the Carter Center conducted a first major trial a few years ago in Niger and other African countries, MORDOR I, to see if the massive distribution of the antibiotic azithromycin to children under five, twice a year, reduced overall mortality.

This antibiotic is effective against several bacteria, including E. coli and the one that causes trachoma, a serious contagious disease that has blinded nearly two million people worldwide, according to the World Health Organization. WHO runs a huge program that has distributed hundreds of millions of doses of azithromycin to the most affected countries.

For the MORDOR I trial, funded by the Bill and Melinda Gates Foundation, researchers found after two years that mortality was reduced by 18% in the villages treated in Niger, compared to control villages, where children received placebos.

But scientists were asking themselves several questions: could continuing distribution from year to year reduce mortality more? Or, could it have the perverse effect of strengthening strains of antibiotic-resistant bacteria?

They then realized the continuation of MORDOR I, during a third year, baptized MORDOR II. This time, all children under five in the 594 villages received the antibiotic, oral solution, twice a year.

The results are clear, according to the study: the effect has not increased, but it "has not faded," write the researchers. Resistance was observed in laboratories, but without consequences on mortality.

And the effect was almost immediate: whether the villages received the antibiotic for the first time, or whether they were treated for the third consecutive year, mortality was reduced in similar proportions.

It remains to be seen whether resistance could develop in the longer term. The researchers will continue the experiment for another three years, says lead author Tom Lietman of the University of California at San Francisco.

"We will start to know more next year," the professor told AFP.

? 2019 AFP