EXPLAINER: What is Lassa fever and should South Africans be concerned?

Lassa fever is not endemic to South Africa. South African travellers to endemic countries may be at risk if they are exposed to environments where infected rats are found. File picture: Pexels

Lassa fever is not endemic to South Africa. South African travellers to endemic countries may be at risk if they are exposed to environments where infected rats are found. File picture: Pexels

Published Oct 30, 2024

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Since the beginning of the Covid-19 pandemic, the scientific community and citizens have been on edge after experiencing how a virus call sweep through the globe so quickly, wreaking havoc and killing indiscriminately.

Recently, a man in Iowa, in the US, died from Lassa fever after contracting the illness in West Africa.

But what is Lassa fever and should South Africans be concerned?

The National Institute for Communicable Diseases (NICD) describes Lassa fever as an illness caused by a virus that spreads from animals to humans. The ‘multimammate rat’ (Mastomys natalensis) is the animal that spreads the virus.

Lassa fever occurs naturally in the West African countries of Sierra Leone, Liberia, Guinea and Nigeria,” explained the organisation.

Individuals living in countries where it is endemic are more likely to contract Lassa fever.

How is Lassa fever transmitted?

“The most prevalent mode of transmission is inhalation and ingestion. Once infected, rats continue to emit the virus in their urine and droppings for lengthy periods of time.

“Contact with infected matters, such as soiled objects, food, or injured skin, can cause illness. Airborne infection can arise when infected particles (dust) are inhaled.”

Direct contact with contaminated blood and body fluids poses a risk for hospital workers and individuals in close touch with Lassa fever patients. The virus might be aerosolised (having the form of a fine spray or colloidal suspension in the air) in the hospital when certain medical treatments are performed.

Travellers to endemic regions who come into touch with polluted environments (see section on transmission) are also at risk.

“Lassa fever is not endemic to South Africa. South African travellers to endemic countries may be at risk if they are exposed to environments where infected rats are found.”

However, in 2022, a case was identified in KwaZulu-Natal. The NICD indicated that the male patient had travelled extensively in Nigeria prior to returning to South Africa.

“He fell ill after entering South Africa and was hospitalised in a Pietermaritzburg hospital,” said the NICD. “The diagnosis of Lassa fever was confirmed through laboratory testing conducted at the NICD. Sadly, the man succumbed to the infection.”

Symptoms of Lassa fever

The signs often occur one to three weeks after being exposed to the virus.

  • Low grade fever
  • Headache
  • Malaise (a general feeling of discomfort, illness, or unease whose exact cause is difficult to identify).

How it can prevented

The prevention of Lassa fever is based on decreasing or avoiding exposure to rats. To maintain a rat-free environment, it’s vital to keep houses and public places clean, provide enough sanitation and garbage clearance, store food in containers, capture rats, and employ suitable poisoning methods.

IOL