Lassa fever and the rats that carry it

Why this one is different

Most of what this site says about rodents is about damage and nuisance. Lassa fever is the reason rodent control in Nigeria is more than that.

Lassa fever is endemic in Nigeria. The Nigeria Centre for Disease Control and Prevention reports cases every year, with a season that runs roughly from December through March and outbreaks concentrated in particular states.

It is carried by the multimammate rat, a rodent that lives alongside people rather than away from them. It gets into stores, roofs and kitchens, and it sheds the virus in its urine and droppings.

That is the whole reason this article exists. Keeping this animal out of a house is a health measure.

How people actually catch it

Not usually from a bite. The common routes are food and dust.

Food and water left uncovered, or stored where rodents can reach it, becomes contaminated with urine and droppings. Eating it is the main way people are infected.

Sweeping or brushing dried droppings raises contaminated dust that can be breathed in. This is why the advice for cleaning a rodent-soiled area is to damp it down first rather than sweep it dry.

Catching, preparing or eating rats is another route, and one worth stating plainly because it still happens in some places.

It can also pass between people, through direct contact with the body fluids of someone infected, which is why this becomes a hospital and family question once somebody is ill.

What reduces the risk in a household

The measures are the same rodent-proofing measures as ever. What changes is how seriously they are worth taking.

Store food in rigid, sealed containers rather than sacks or open bowls, and keep them off the floor. Cover water. Cover leftovers.

Close the ways in. A young rat passes through a gap of roughly two centimetres. Fill holes around pipework with steel wool and mortar, fit a brush strip under external doors, and mesh open vents with metal rather than plastic.

Clear rubbish away from the outside of the building, and keep the strip along the walls free of clutter. Rodents move along edges.

Dispose of household refuse well away from the house, and do not let it accumulate against a wall.

Do not sweep droppings dry. Damp the area first with disinfectant, wear gloves, and wash your hands afterwards.

If somebody becomes ill

Lassa fever starts like many other things: fever, weakness, headache, sore throat, muscle pain. There is nothing about the first few days that tells you what it is.

That is precisely why it should be tested for rather than guessed at, particularly during the season, particularly in an affected state, and particularly if there are rodents in the house.

Early treatment matters. Go to a health facility, say that Lassa fever is a possibility, and mention the rodents. Health workers need to know so they can protect themselves.

The NCDC publishes current guidance and a case definition, and it is the authority to follow rather than anything on this page.

What this page is not

This is general information about rodents and a disease associated with them. It is not medical advice, it is not a diagnosis, and it is not a substitute for the NCDC's own guidance.

No product sold by C-Success prevents, treats or cures Lassa fever or any other illness. TOPRANK glue traps catch rodents. That is what they do and that is all we claim for them.

Reducing the number of rodents in a building reduces contact with rodents. Whether that changes the outcome for any individual person is a medical question and not one an insecticide company should answer.