Lassa fever is a major public health challenge in West Africa, with Nigeria bearing the highest burden. It is an acute viral haemorrhagic fever (VHF) caused by the Lassa virus. The natural reservoir for the virus is the Mastomys natalensis rodent (commonly known as the multimammate rat). Other rodents that carry the virus have also been identified.
Epidemiological data show that Lassa fever occurs throughout the year, but more cases are recorded during the dry season i.e. November through May.
How Does Lassa Fever Spread?
Lassa fever is spread through:
1. Direct contact with urine, faeces, saliva or blood of infected rodents.
2. Ingesting food and drinks contaminated with urine, faeces, saliva or blood of infected rats.
3. Contact with objects, household items or surfaces contaminated with urine, faeces, saliva or blood of infected rats.
4. Person-to-person transmission can also occur through contact with blood, urine, faeces, vomitus and other body fluids of an infected person, particularly in hospital environment where infection prevention and control practices are not optimal.
Signs and Symptoms
Early diagnosis and treatment increase the chances of survival.
The early stages of Lassa fever present initially like other febrile illness such as malaria. Symptoms of the disease generally include fever, headache, sore throat, general body weakness, cough, nausea, vomiting, diarrhoea, muscle pains, chest pain, and in severe cases; unexplainable bleeding from ears, eyes, nose, mouth, vagina, anus and other body orifices. It could also present as persistent bleeding from sites of intravenous cannulation.
Any illness that has not responded to 48 hours use of anti-malaria or antibiotics should raise suspicion for Lassa fever!
The incubation period (time between an infection and appearance of symptoms of the disease) is 3 to 21 days. Early diagnosis and treatment increase the chances of survival.
Any febrile illness that has not responded to 48 hours use of anti-malaria or antibiotics should raise an index of suspicion for Lassa fever!
The national guidelines for Lassa fever case management and Infection prevention and control are available on the NCDC website for download (http://ncdc.gov.ng/diseases/guidelines).
Please report all suspected cases of Lassa fever to your Local Government Area Disease Surveillance and Notification Officer (DSNO). They are the first link to response and care for Lassa fever cases in Nigeria.
NCDC Toll-Free Number: 0800-970000-10