India health alert after 'brain-eating' amoeba rise

India has issued a health alert after infections and deaths caused by a rare water-borne "brain-eating" amoeba doubled compared to last year in Kerala.

Numbers are still tiny but Altaf Ali, a doctor who is part of a government task force to arrest the spread, told AFP that officials were "conducting tests on a large scale across the state to detect and treat cases".

Officials reported 19 deaths and 72 infections of the Naegleria fowleri amoeba this year, including nine deaths and 24 cases in September alone. Last year, the amoeba killed nine people out of 36 reported cases.

The US Centers for Disease Control and Prevention (CDC) says it is often called a "brain-eating amoeba" because it can "infect the brain and destroy brain tissue".

If the amoeba reaches the brain, it can cause an infection that kills over 95 percent of those affected. Infections are "very rare but nearly always fatal", the CDC notes.

The amoeba lives in warm lakes and rivers and is contracted by contaminated water entering the nose. It does not spread from person to person.