Lassa fever outbreak in Nigeria kills 40

The Health Minister of Nigeria, Isaac Adewole, has confirmed that 40 people have died in Nigeria in a suspected outbreak of Lassa fever in 10 states across the country.

Adewole told a news conference in the capital Abuja that, "The total number (of suspected cases) reported is 86 and 40 deaths, with a mortality rate of 43.2 percent."

The minister said that so far, laboratory tests have confirmed that 22 of the 86 suspected cases were Lassa fever and results were expected on the remainder. Seven of the affected states are in the north -- Bauchi, Nasarawa, Niger, Taraba, Kano, Plateau and Gombe -- while the remaining three are in the south -- Rivers, Edo and Oyo.

Adewole said recorded cases of Lassa fever in Nigeria peaked in 2012 at 1,723 with 112 fatalities but rates have declined since then. In the latest outbreak, the minister said "most of the cases that we recorded are not through person-to-person contact but the number of deaths was unusual."

He also expressed fears about the disease notification, especially in Niger state, where "unusual" deaths in August were not reported for up to four months. The government of Lagos state, Nigeria's most populous city of more than 20 million people, on Thursday alerted residents on the need to observe proper hygiene to curb the spread of the disease. Lagos state is about 80 kilometres from Oyo state, where suspected cases have been reported.

According to the WHO, Lassa fever is an acute haemorrhagic illness which belongs to the arenavirus family of viruses, which also includes the Ebola-like Marburg virus.  People with Lassa fever do not display symptoms in 80 percent of cases but it can cause serious symptoms and death in the remainder.

The virus, which is endemic in rodents in West Africa, is transmitted to humans by contact with food or household items contaminated with the animals' faeces and urine. Person-to-person contact is also possible through bodily fluids, particularly in hospitals when adequate infection control measures are not taken.

It is estimated that the number of Lassa fever infections in west Africa every year is between 100,000 to 300,000, with about 5,000 deaths, according to the US Centers for Disease Control and Prevention.