An immigration officer wears a face mask at the Nnamdi Azikiwe International Airport in Abuja, Nigeria Reuters

The Nigerian government has debunked local the rumours of an unidentified disease outbreak, which has killed 19 since 15 April in south-western Nigeria.

This comes just six months after the Nigeria authorities officially declared the country was free of the Ebola virus transmission in October 2014, after a small outbreak of 20 cases occurred. The country reported eight deaths related to the virus.

The outbreak - characterised by blurred vision, headache and loss of consciousness - started in the Ode-Irele town, Ondo state, and spread rapidly.

Laboratory tests have so far ruled out Ebola or any other virus, Ondo government spokesman Kayode Akinmade was quoted as saying by the AFP news agency. He described the illness as "mysterious".

The unidentified disease, which killed the victims within 24 hours of falling ill, appears to be attacking the central nervous system, state health commissioner Dayo Adeyanju told Nigeria's Premium Times.

Situation is under control

On 20 April, the Minister of State for Health, Fidelis Nwankwo provided insights on the causes of illness and sudden deaths in two communities of Irele.

In his speech at a press briefing held at the conference hall of the Federal Ministry of Health (FMOH) in Abuja, he also disclosed that "no new cases have been reported in the past 100 hours and no related mortality in the last 72 hours. We therefore believe that the situation is under control".

Nwankwo also stated that preliminary epidemiological and laboratory investigations indicate the disease is not attributed to any infectious disease.

Available records showed the reported cases were among males, between the ages of 20 and 75 years old. Equally, 71% had history of having consumed locally brewed gin and were farmers.

According to the minister: "Epidemiological findings indicate a strong linkage of the outbreak with the consumption of local gin that might have been contaminated with methanol".

However, he added that the laboratory investigation is ongoing.