Fighting Lassa Fever: Lessons from Ebola in Sierra Leone

News Desk

Sierra Leone: In eastern Sierra Leone, ecologist James Koninga and his team are engaged in a critical mission to track and control Lassa fever, a viral haemorrhagic illness transmitted by infected rats.

Koninga, who has personally battled Lassa fever, underscores the importance of their work. Despite its lower fatality rate compared to Ebola, Lassa fever remains a significant threat, causing severe illness in one in five cases and killing around 5,000 people annually in West Africa.

Sierra Leone has not recorded an Ebola case since 2016, largely due to successful vaccine rollouts. However, the scars left by the Ebola epidemic, which claimed over 11,000 lives in the region, continue to influence public health responses.

In Kenema district, once an Ebola epicentre, scientists are leveraging lessons learned to combat Lassa fever.

Lassa fever, with an overall fatality rate of one percent, has been spreading beyond its traditional hotspots. There is no licensed vaccine, and treatment options are limited.

Koninga and his colleagues, like Lansana Kanneh at Kenema Government Hospital (KGH), are focusing on monitoring the rodent population in remote villages.

These areas, characterized by rudimentary mud houses and uncovered food storage, provide ideal conditions for rats, which can transmit the virus through their urine, saliva, or droppings.

The team collects and analyzes samples from trapped rats, ensuring they are the Lassa-carrying Mastomys variety, before releasing them with an injection to prevent viral transmission.

Despite these efforts, the figures for Lassa fever cases likely underestimate the true scale due to surveillance challenges. KGH, Sierra Leone’s only dedicated Lassa treatment center, has seen fluctuating patterns in admissions, with cases now appearing year-round.

The mortality rate among Lassa patients at KGH has alarmingly increased to over 50 percent, often due to late-stage hospital arrivals. Misdiagnosis and delayed treatment are common, as Lassa fever symptoms can resemble those of malaria, cholera, or typhoid.

Additionally, the traumatic memory of Ebola has led to distrust in health workers and reduced hospital admissions.

Efforts to combat this mistrust involve raising awareness in local communities about the importance of seeking rapid medical help and maintaining good domestic hygiene.

Musa Mosoh, a Lassa survivor who lost seven family members to the illness, now advocates for immediate medical attention and uses cats to repel virus-carrying rodents in his village.

Dr Donald Grant, head of the KGH Lassa fever program, is cautiously optimistic about the development of a Lassa vaccine, with phase two trials currently underway in Nigeria and Liberia.

However, he emphasizes the need for proactive measures to prevent another overwhelming health crisis. “We need to act now,” he warns, reflecting on the hard lessons learned from the Ebola epidemic.