Thiruvananthapuram: A 34-year-old woman from Edava in Varkala has tested positive for amoebic meningoencephalitis, a rare but often fatal brain infection. A routine laboratory test of the woman’s cerebrospinal fluid confirmed the presence of amoeba.

The patient had undergone clinical examination at the neurology department of the Government Medical College Hospital here, after she suffered diplopia or “double vision” for a long time. 

However, identifying the specific strain of amoeba that infected her brain requires a PCR (polymerase chain reaction) test, health officials said.

On Monday, a native of Kodumon in Attingal also tested positive for the brain-eating amoeba. According to official reports, the district currently has three active cases of brain fever.

The amoeba comes in two forms.One, primary amoebic meningoencephalitis (PAM). This is caused by 'naegleria fowleri', a microscopic amoeba commonly called the "brain-eating amoeba", and whose mortality rate is near absolute, above 98 per cent. The second is granulomatous amoebic encephalitis (GAE). This is caused by many kinds of amoeba like Acanthamoeba, Sappinia and Balamuthia. Its mortality rate is 60 per cent.

Apart from Thiruvananthapuram, Kozhikode, Malappuram and Palakkad districts also reported the disease. According to the official data published by the state surveillance unit on September 12, a total of 17 people died of the infection.