Nigerian authorities have announced increased emergency measures to contain the latest outbreak of Lassa fever in the West African country, following the death of 29 people this month from the viral disease."As at 24th of January 2020, 195 confirmed cases and 29 deaths had been reported in 11 states," the Nigeria Centre for Disease Control (NCDC) said in a statement on Saturday.A national emergency operations centre had been activated to coordinate the response "to the increasing number of Lassa fever cases" across the country. Symptoms and treatmentLassa fever is asymptomatic in 80% of cases but for others it can cause fever, physical fatigue, nausea, vomiting, diarrhoea, headaches, abdominal pains or sore throat. Neck or facial swelling can sometimes be observed.According to the World Health Organisation (WHO), the antiviral drug ribavirin appears to be an effective treatment for Lassa fever "if given early on in the course of the clinical illness".2019 ARCHIVE | Nigeria's new outbreak of Lassa fever kills 16Nigeria, Africa's most populous nation with a population of some 200 million, has five laboratories with the capability to diagnose Lassa fever.Previous outbreaksThe number of Lassa fever infections across 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 (CDC).Last year, the disease claimed more than 160 lives in Nigeria. ALSO READ | China virus toll spikes to 80, more than 2,700 cases confirmedIn some areas of Sierra Leone and Liberia, 10 to 16% of the people admitted to hospitals annually have Lassa fever, according to CDC, demonstrating the serious impact the disease has on the region.The number of cases usually climbs in January due to weather conditions during the dry season.