Context:

Recent Lassa fever outbreak in Nigeria has resulted in 138 deaths, with 717 confirmed cases reported across 18 states. The case fatality rate stands at 19.2%, slightly higher than the 18% recorded during the same period in 2024.

About Lassa Fever:

Lassa fever is an acute viral hemorrhagic illness caused by the Lassa virus, first discovered in 1969 in the town of Lassa in northeastern Nigeria. It is endemic in several West African countries, including Nigeria, Sierra Leone, Guinea, and Liberia.

Key Facts about the Disease:

·         Reservoir: The primary carrier is the multimammate rat (Mastomys natalensis), which is widespread in the region.

·         Mortality: While the overall death rate is approximately 1%, it is significantly higher among hospitalized patients and pregnant women, especially during the third trimester.

·         Symptoms: About 80% of infected individuals show no symptoms. Symptomatic cases can present with fever, sore throat, vomiting, chest pain, and in severe cases, internal bleeding and organ failure.

Demographics and Transmission:

·         Age Group: Predominantly affects young adults aged 21–30 years, with the median age of infection being 30 years.

·         Gender Ratio: Slightly more males are affected than females, with a male-to-female ratio of 1:0.8.

Modes of Transmission

·         Primary Vector: Lassa virus is spread to humans through ingestion or inhalation of food particles or household items contaminated by the urine or feces of infected multimammate rats.

·         Human-to-Human Transmission: Rare, but can occur through direct contact with the bodily fluids of an infected person or contaminated medical equipment. This makes infection control in healthcare settings critically important.

Challenges and public health concerns: 

The persistent recurrence of Lassa fever outbreaks in Nigeria raises broader public health concerns. Challenges include:

·         Poor sanitation and rodent control in many rural and peri-urban areas

·         Inadequate healthcare infrastructure in affected regions

·         Lack of public awareness in high-risk communities

·         Limited access to rapid diagnostics and treatment, especially in remote areas

Conclusion:

Lassa fever remains a serious public health threat in Nigeria and West Africa, prompt and sustained action is crucial. This includes enhanced surveillance, community engagement, and strengthening the capacity of health systems to manage and prevent future outbreaks. Effective rodent control, public education, and early treatment are pivotal in curbing the spread of this endemic disease.