Lassa fever – What You Should Know


It’s common knowledge that even though malaria occurs year-round in much of Sub-Saharan Africa, the highest number of cases occur during the rainy season. The rains create standing pools of water that are a perfect breeding ground for the Anopheles mosquitos that carry the malaria parasite.

Did you know that there are infections that occur mostly in the dry season?

There are more outbreaks of Lassa fever and Cerebrospinal Meningitis in the dry season -between October and April than at other times of the year.

The current outbreak of Lassa fever in Nigeria began in December 2016. There are 283 suspected cases through the end of March 2017. There have been 46 deaths reported out of the 93 confirmed and 6 probable cases – a 46.5% case fatality rate. That means that nearly half of the confirmed cases have died!

What is Lassa fever?

Lassa fever is a severe and often fatal viral haemorrhagic illness caused by Lassa virus. It is quite contagious and can spread rapidly. Lassa virus, Ebola, and Marburg, Yellow fever, and Dengue fever viruses, together cause a group of illnesses known as Viral Haemorrhagic Fevers (VHFs) which have several similar features.

Discovered in 1969 in the village of Lassa in Borno State, Nigeria, Lassa fever is now endemic in West Africa.

How do you get Lassa fever?

You become infected through contact with the Multimammate Rat. The rats live in and around our homes – both rural and urban. The infected rats pass the virus in their urine and feces. Direct contact with rat excreta, touching soiled objects, eating contaminated food, and exposure to open cuts or sores, can lead to infection. Other ways you can get it include:

  • Eating an infected rat.
  • Inhaling tiny particles in the air that are contaminated with infected excretions when sweeping and dusting.
  • Direct contact with infected blood/bodily secretions. Caregivers are, particularly at risk.

Incidental contact without exchange of body fluids does not spread Lassa virus. Transmission occurs commonly in hospitals and clinics where proper personal protective equipment (PPE) is not available or not used. Contaminated medical equipment, such as needles can also spread the Lassa virus.


How do you know if you have Lassa fever?

The problem is that in the early stages, Lassa fever is often misdiagnosed as the flu, typhoid or malaria, and so many patients do not receive appropriate medical treatment. The illness starts about 1 to 3 weeks after contact with the virus.

  • Early signs include high fever, headache, feeling unwell, followed by a sore throat, nausea, vomiting, abdominal pain and diarrhea in some cases.
  • After 4 to 7 days, most patients will start to feel better, but some will go on to display symptoms such as swelling, hypertension, bleeding and shock, leading eventually to death.
  • Death from Lassa fever usually occurs 10 to 14 days after the start of symptoms.

A blood test can confirm Lassa fever.

Is there a treatment for Lassa fever?

No vaccine for Lassa fever is currently available. The only available drug, ribavirin, is effective only if administered early in the infection, within the first six days of the disease.

What can you do to prevent Lassa fever?

  • Avoid contact with rats and their excreta.
  • Observe good personal hygiene including hand washing with soap and running water regularly.
  • Dispose of waste properly and clean your environment so that rats are not attracted
  • Store foods in rat-proof containers and cook all foods thoroughly before eating.
  • Discourage rodents from entering the house by blocking all possible entry points.
  • For food manufacturers and handlers, do not store or serve food where rats can have access to it.
  • All fluids from an infected person are extremely dangerous.

Please use rat poison with caution, as it can be poisonous to children and adults as well!!

If you or someone you know has any Lassa fever symptoms or persistent high fever that is not responding to standard treatment for malaria and typhoid fever, report immediately to the nearest health center.

Please tune in to watch The HealthZone every week on Channels TV, starting April 4, 2017.

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