Lassa Fever Healthcare Worker Advisory

Thursday, January 28, 2021


Lassa fever 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 have also been identified as carriers of the virus.

Lassa fever remains a major public health challenge in West Africa with Nigeria bearing the highest burden. Lassa fever occurs throughout the year but more cases are recorded during the dry season i.e. November through May.

Lassa fever is spread through:

1. Direct contact with urine, faeces, saliva or blood of infected rats.

2. Contact with objects, household items and surfaces or eating food, contaminated with urine, faeces, saliva or blood of infected rats.

3. Person-to-person transmission of Lassa fever can also occur through contact with blood, urine, faeces, vomitus and other body fluids of an infected person, particularly within a hospital environment where there is poor infection prevention and control measures.

Signs and symptoms of Lassa fever:

Lassa fever presents initially like any other febrile illness such as malaria. Its symptoms 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 and other body openings.

The time between an infection and appearance of symptoms of the disease is 3 to 21 days. Early diagnosis and treatment increases the chances of survival.

Healthcare workers are most at risk of person-to-person transmission of Lassa fever especially:

 Doctors, nurses and other health workers providing direct patient care in the absence of standard precautions.

 Hospital staff who clean and disinfect contaminated surfaces, materials and supplies without adequate protective gear

 Laboratory staff who handle blood samples of suspected Lassa fever patients without appropriate precautions

 Medical or support staff who prepare and or handle dead bodies of Lassa fever patients without appropriate precautions

To reduce the risk of Lassa fever, the Nigeria Centre for Disease Control (NCDC) offers the following advice to all healthcare workers:

 Practice standard precautions at all times while handling patients and body fluids i.e. always wear Personal Protective Equipment (PPE) irrespective of patient’s provisional diagnosis

 Maintain a high index of suspicion for Lassa fever i.e. be vigilant and lookout for Lassa fever, not all fevers are malaria. Lassa fever presents initially like any other febrile illness such as malaria

 Test all suspected cases of malaria using Rapid Diagnostic Test (RDT). When the RDT is negative, other causes of febrile illness including Lassa fever should be considered

Any febrile illness that has not responded to use of anti-malaria or antibiotics after 48 hours 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 (

Please report all suspected cases of Lassa fever to your Local Government Area disease surveillance and notification officer who are the initial linkage to response and care for Lassa fever cases in Nigeria.

About the NCDC

The Nigeria Centre for Disease Control is the country’s national public health institute, with the mandate to lead the preparedness, detection and response to infectious disease outbreaks and public health emergencies. The Bill for an Act to establish NCDC was signed into law in November 2018, by President Muhammadu Buhari. The mission for the NCDC (2017-2021) is ‘To protect the health of Nigerians through evidence-based prevention, integrated disease surveillance and response activities, using a One Health approach, guided by research and led by a skilled workforce’.


NCDC Toll-free Number: 0800-970000-10 | SMS: 08099555577 | WhatsApp: 07087110839 Twitter: @NCDCGov | Facebook: @NCDCgov | Instagram: @NCDCgov | NCDC Media Releases

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