Nigeria’s Lassa fever outbreak contained, but continued vigilance needed

With six weeks of declining numbers and only a handful of confirmed cases reported in recent weeks, the critical phase of Nigeria’s largest-ever Lassa fever outbreak is under control, according to the World Health Organization (WHO). However, Nigeria is endemic for Lassa fever and people could be infected throughout the year, making continued efforts to control any new flare ups crucial.

In the last reporting week, ending on 6 May 2018, three new confirmed cases of Lassa fever were reported. This year a total of 423 confirmed cases including 106 deaths have been recorded. The national case numbers have consistently declined in the past six weeks, and have dropped below levels considered to be a national emergency when compared with data from previous outbreaks.

“Nigeria is to be congratulated for reaching this important milestone in the fight against Lassa fever,” says Dr Ibrahima Socé Fall, Regional Emergencies Director for Africa. “But we cannot let our foot off the pedal. We must use the lessons learnt to better prepare at risk countries in our region to conduct rapid detection and response.”

WHO will continue to support the Nigerian government to maintain an intensified response to the current Lassa fever outbreak in Nigeria. Thirty-seven health workers have been infected with Lassa fever, eight have died. This highlights the need for implementing standard infection prevention and control precautions with all patients – regardless of their diagnosis – in all work practices at all times. WHO continues to help states which have reported new cases by strengthening their capacity to conduct disease surveillance, treat patients, as well as implement infection prevention and control measures, laboratory diagnostics, and engage with communities.

WHO Country Representative Dr Wondimagegnehu Alemu said, “Communities are encouraged to remain vigilant and report any rumors to the nearest health facilities because early diagnosis and treatment can save lives.”  Health care workers are urged to maintain a high index of suspicion for Lassa fever when handling patients, irrespective of their health status. Lassa fever should always be considered in patients with fever, headache, sore throat and general body weakness, especially when malaria has been ruled out with a rapid diagnostic test (RDT), and when patients are not improving. Health workers should adhere to standard precautions, and wear protective equipment like gloves, face masks, face shields and aprons when handling suspected Lassa fever patients.

WHO is monitoring and supporting Nigeria’s neighbouring countries to help improve their level of preparedness to readily respond to any potential outbreaks.  Note to the editors:
Lassa fever is a viral infection, primarily transmitted to humans through contact with food or household items contaminated with rodent urine, faeces, or blood. Person-to-person transmission is through direct or indirect contact with body fluids of an infected person. Prevention of Lassa fever relies on promoting good community hygiene to keep rats out of the house and prevent contamination of food supplies. Effective measures include storing grains and other foodstuff in rodent-proof containers, proper disposal of garbage far from the home, and maintaining clean households.