Dozens of people have died in Nigeria following a Lassa fever outbreak amid fears the death toll might increase. At least 44 people were declared dead across more than 10 states after being infected with the hemorrhagic fever.

Authorities said the outbreak is under control and urged citizens to remain calm. The federal government announced it intends to appoint a National Lassa Fever Action Committee to discuss on how to halt the outbreak on 19 January.

The minister of health, Isaac Adewole, was quoted by local media as saying that isolation centres had been activated in several hospitals to curb the spread of the virus.

What is Lassa fever?

First identified in 1969, this is a hemorrhagic fever caused by the Lassa virus. It can be transmitted via contact with urine, faeces and blood of a rodent, commonly know as the "multimammate rat."

Human-to human transmission is also possible.

The virus is widespread in West Africa, particularly in Benin, Guinea, Liberia, Sierra Leone and Nigeria.

Lassa fever can be deadly if not cured during its early stage. Typical symptoms of this disease include high fever, general weakness, sore throat, cough, nausea, vomiting, diarrhoea. Later symptoms include bleeding, rashes and swelling of the eyes and genitals.

The incubation period lasts from 6 till 21 days, according to the World Health organisation (WHO).

Contamination can be prevented by, among other things, storing food in containers not accessible to rodents, disposing of garbage far from home and avoiding contact with bodily fluids of sick people.

See WHO's full recommendation list here.

Chikwe Ihekweazu, an infectious disease epidemiologist, expressed concern over the wide geographical area in which Lassa fever cases were reported. He told AFP: "It is possible we are only seeing the tip of the iceberg. My biggest worry at the moment is that given that the cases that have been reported are from a very wide geographical area, transmission chains will be difficult to identify, making control very difficult."

The first case of Lassa fever in the latest outbreak in Nigeria was reported in August 2015. However, the outbreak was officially declared in January 2016, when a student from the Ahmadu Bello University in the northern state of Kaduna was reported ill when he arrived in Lagos on 9 January.

After being monitored for several days, he was diagnosed with Lassa as his symptoms, including high fever and sore throat, were consistent with the virus.

At least 25 people were diagnosed with Lassa fever in Nigeria's Edo state between 2005 and 2008. More recently, the West African nation has been hit by Ebola, another deadly hemorrhagic fever.

The Ebola outbreak was sparked in West Africa in January 2014. Sierra Leone, Liberia and Guinea were ravaged by the virus, which caused more than 28,000 deaths in West Africa, with three deaths also reported in Europe and four in the US.

Nigeria was also affected by the outbreak, with at least eight deaths reported. The country was deemed a success case in the fight against Ebola.

Nigeria up close: Check out our Flipboard magazine