When Liberian Patrick Sawyer arrived Nigeria on July 20, 2014, he was already infected with the Ebola virus and he spread the disease to 19 people, of whom 7 died. Sawyer also died after five days at the hospital. But Africa’s most populous nation responded well and before the end of the year, the country was declared free of the haemorrhagic virus. Ebola’s cousin, the Lassa virus is in Nigeria now and has killed three people already. Like it did with Ebola, Nigeria is expected to expedite action in curbing the spread of the deadly Lassa fever which has now affected two states in the country.
Lassa fever, caused by the Lassa virus was first described in 1969 in the town of Lassa, in Borno State, Nigeria.The West African state is one of the countries endemic for the emerging virus which leads to 5,000 deaths per year in Sierra Leone, the Republic of Guinea, Nigeria, and Liberia. The primary animal host of the Lassa virus is the Mastomys natalensis, a multi-breasted mouse found in most of sub-Saharan Africa. The virus is transmitted by contact with the feces or urine of animals. It spreads easily in Africa where most communities have poor sanitary conditions. Poor sanitation helps rats to survive in residential areas. Africans in poor living conditions are, therefore, mostly affected by the virus. However, the fever can be contracted through direct contact with infected human blood excretions and secretions, including through sexual contact.
An outbreak of Lassa fever in northeast Nigerian state and oil-rich Rivers State has led to one and two deaths respectively. Nigeria’s most populous state Lagos State has also warned its residents to be cautious and report to the nearest hospital any symptoms of Lassa fever. But in 80 percent of cases, the disease is asymptomatic. After an incubation period of six to 21 days, an acute illness with multi-organ involvement develops. The World Health Organisation advises that diagnosis and prompt treatment are essential.
While it may be impossible to control rats that transmit the disease, improved hygiene and proper disposal of waste will help keep rodents out of homes and food supplies.
Although the overall mortality rate is estimated to be 1 percent, it could climb to 50 percent during epidemics and more than 80 percent in pregnant women. It is, therefore, important to stop Lassa before it kills more people.