Environmental changes, including deforestation, biodiversity loss and changing rainfall patterns, are accelerating the spread of Lassa fever in Nigeria, a public health expert has said.
Dr. Ekpereonne Esu, Associate Director of Cochrane Nigeria, made this known on Thursday during a two-day evidence-based healthcare workshop and media roundtable in Calabar.
Lassa fever is a viral haemorrhagic disease caused by the Lassa virus and transmitted mainly through contact with urine, saliva or droppings of infected multimammate rats.
Esu said seasonal rainfall influences the movement of multimammate rats — the primary reservoir of the Lassa virus — into homes, thereby increasing human exposure and infection risks during the rainy season.
According to him, biodiversity loss caused by human activities has reduced populations of natural predators that ordinarily help control rodents, allowing infected rat populations to thrive.
“Biodiversity loss, caused by human activities, reduces natural predators that ordinarily control rat populations, allowing the rodents to multiply and spread infections more easily.
“Expanding farmland through forest destruction creates favourable habitats for rodents, making balanced land-use planning essential for reducing Lassa fever risks,” he said.
The expert advocated a One Health approach that integrates environmental, agricultural and health policies to address the environmental and socioeconomic factors driving the disease.
He also identified poor housing conditions, weak sanitation systems and inadequate waste disposal as major contributors to rodent infestation around homes and communities.
Esu called for increased investment in cleaner environments, improved living conditions and additional reference laboratories nationwide to enhance early diagnosis and response efforts.
He said handling the Lassa virus requires specialised facilities because of its highly infectious nature, emphasising the need to strengthen laboratory capacity across the country.
While expressing optimism about ongoing vaccine research, Esu urged Nigerians to sustain preventive measures such as proper food storage, environmental hygiene and regular handwashing.
Also speaking, the Director of Cochrane Nigeria, Prof. Angela Oyo-Ita, said the organisation was equipping journalists with skills to improve public understanding of evidence-based healthcare.
She explained that evidence-based healthcare combines the best available research with clinical expertise to support treatment decisions, policymaking and informed health choices.
According to Oyo-Ita, systematic reviews help assess and combine quality research while identifying possible biases, enabling users to determine the reliability of scientific evidence.
“The increasing volume of scientific publications makes evidence synthesis necessary for clinicians, policymakers, patients and researchers seeking dependable health information,” she said.
She urged journalists to accurately interpret and communicate research findings, noting that scientific studies have greater impact when translated into information that informs public health decisions.

