Malaria is fighting back against efforts to eliminate it

THESE SHOULD be hopeful days for those battling malaria. Deaths from the disease have fallen to around 435,000 a year, from perhaps five times that number a century ago. On May 22nd the World Health Organisation (WHO) declared Algeria and Argentina malaria-free, bringing to 38 the number of countries now officially rid of the disease. Algeria will be regarded as a particular success because it is in Africa. The continent suffered 90% of an estimated 219m cases worldwide in 2017. But two big clouds darken the outlook. One is the stubborn persistence of malaria south of the Sahara. The other is the emergence of new strains of the disease resistant to the available treatments.