United States: Lassa Fever, the virus which is considered to be endemic in West Africa, has damaged around 2.7 million people a year, according to the latest information from health agencies. Reportedly, this is approximately ten times more than the health authorities’ assumption.
The World Health Organization, which is known as WHO, has designated this infection as a disease that has no licensed vaccines or specific treatments. The WHO gave this designation in 2016, and currently, the health agency has claimed it is a top pandemic threat, according to Medical News.
Following this warning, the experts have been conducting research for four candidate vaccines, which are now being tested on people. Out of all, one reached advanced trials last week. The current research has been conducted by a team of 16 scientists in Nigeria, and experts at the University of Oxford in England have calculated how the true burden of the disease will feel and how vaccines could be used to reduce the same.
A study has revealed that if the high-risk population is vaccinated, then it could avert up to 4,400 deaths in West Africa and also result in the reduction of societal costs, such as labor losses and healthcare. The cost may decrease by almost USD 129 million per year.
Lassa Fever: A Widening Threat Across West Africa
The virus that has become a significant health threat now pervades all 15 countries within the bounds of continental West Africa. Notably, its presence is most concentrated in Nigeria, Guinea, Liberia, and Sierra Leone. Furthermore, the World Health Organization has now classified Benin, Ghana, Mali, and Togo as endemic regions for the disease.
Initially, it was presumed that the Lassa fever virus resided exclusively within the multimammate rat population, a species that dominates the Sub-Saharan landscape. Nearly all human cases of Lassa fever stem from zoonotic transmission, with inter-human contagion being an anomaly, usually involving healthcare professionals. However, recent findings have uncovered the virus in additional rodent species, expanding its ecological range.
It appears that the territories at heightened risk are broadening, particularly as climate change reshapes the environment, according to Medical News.
Growing Concern Amid Climate Shifts
Robert Garry, a preeminent Lassa fever specialist from Tulane University, USA (not affiliated with the study), underscores how shifts in land use patterns exacerbate human exposure to contaminated rodent excreta. Lassa fever has surpassed even Ebola in its likelihood to cross over into human populations.
Yet, quantifying the virus’s full impact has proven elusive. Disease monitoring across West Africa remains sparse, and historically, diagnostic testing has been both costly and inaccessible. Nonetheless, a more affordable and straightforward test has recently been deployed in Sierra Leone, according to Garry.
The oft-cited statistic of 300,000 annual cases and 5,000 deaths stems from a single study conducted nearly four decades ago, further complicating assessments.
Challenges in Diagnosis and Symptoms
A significant challenge has been the clinical similarity between Lassa fever and other local febrile illnesses, which frequently results in misdiagnosis. For instance, the early stages of the 2014 Ebola outbreak were initially mistaken for Lassa fever, delaying critical response efforts.
Moreover, the majority of Lassa infections are asymptomatic or produce only mild symptoms. According to David Smith of Oxford University, a principal investigator in the new study, only 0.9% of cases progress to severe illness. However, for those requiring hospitalization, the mortality rate climbs to 16%, and a substantial number of survivors experience permanent hearing loss.
The research team conducted this investigation in anticipation of future vaccine developments. They assert that a deeper comprehension of infection dynamics is vital to ensure the effective deployment of vaccines, should they become available.