Why Lassa fever continues to claim lives

Lassa fever remains a deadly reality in Nigeria, claiming lives each year despite being preventable. From healthcare workers to vulnerable communities, weak surveillance, delayed diagnosis, inadequate sanitation and systemic lapses continue to fuel outbreaks, exposing urgent gaps in public health preparedness and the need for decisive, sustained action, reports CHINYERE OKOROAFOR

Recently, a young doctor, Salome Oboyi, died after contracting Lassa fever from a pregnant patient she was managing at Bingham University Teaching Hospital (BHUTH) in Jos, Plateau State. According to colleagues, the senior resident in Obstetrics and Gynaecology developed symptoms consistent with the infection — persistent fever and profound weakness — which later deteriorated. Despite medical intervention, complications from the virus proved fatal.

Confirming her passing, the state Commissioner for Health said the government was aware of the case and had procured vaccines that would soon be deployed, alongside intensified public sensitisation campaigns on prevention and control. Yet Dr. Oboyi’s death exposes a deeper and recurring gap in public health preparedness. Jos has experienced Lassa fever outbreaks before, but education, surveillance, and vaccination efforts often remain reactive rather than preventive — a pattern seen not only in Plateau but also in other endemic regions across Nigeria where the disease resurfaces periodically, leaving frontline workers and communities vulnerable until tragedy occurs.

Following her death, the Nigerian Association of Resident Doctors (NARD) raised serious concerns about healthcare worker safety, stressing that her death was not accidental but the result of systemic failures within the health system. The implication is stark: when hospitals lack adequate protective equipment, diagnostic testing is delayed, isolation protocols are weak, and outbreak response is slow, such deaths become predictable rather than unavoidable. Weak funding, insufficient disease surveillance, and delayed government action create conditions where preventable losses occur.

NARD’s position also serves as a warning. If these structural deficiencies persist, healthcare workers will continue to operate under fear, morale will decline, and the ongoing migration of skilled professionals may accelerate. Their message shifts the narrative from mourning one doctor to demanding urgent reforms that will better protect health workers and strengthen national preparedness.

Last week in Kano, another health worker reportedly died during a Lassa fever outbreak. Behind the statistics are grieving families and disrupted futures. Doctors and nurses remain on the frontline, risking exposure daily. Yet they are not alone in danger. Children, pregnant women, farmers, and traders in crowded environments also face significant risk, especially when diagnosis is delayed. For pregnant women in particular, Lassa fever often results in severe complications, including the loss of both mother and child — a devastating reminder that outbreaks are not merely medical events but profound human tragedies.

What is Lassa fever

Lassa fever is a severe viral illness transmitted primarily through exposure to food, water, or household items contaminated by the urine or droppings of infected rodents, particularly the multimammate rat common across West Africa. Human-to-human transmission can also occur through direct contact with the blood, urine, saliva, or other bodily fluids of an infected person, a risk that becomes especially pronounced in healthcare settings where infection-prevention measures are inadequate.

The early symptoms often resemble common tropical illnesses such as malaria or typhoid fever—persistent fever, weakness, headache, sore throat, and body pain—making early diagnosis difficult. In more severe cases, however, the disease can progress to bleeding, respiratory distress, organ failure, and death if treatment is delayed. Prompt diagnosis and supportive medical care significantly improve survival outcomes, underscoring the importance of early presentation to health facilities.

Lassa fever was first identified in 1969 in Lassa, a town in present-day Borno State, following the deaths of two missionary nurses from an unknown illness. Laboratory investigations led to the discovery of a new virus, which was subsequently named after the town. Over the following years, cases emerged in multiple parts of Nigeria, particularly rural communities where human contact with rodents was common.

Researchers later confirmed the multimammate rat (Mastomys natalensis) as the primary reservoir of the virus. By the 1970s, Lassa fever was recognised as an endemic disease in Nigeria, with periodic outbreaks becoming part of the country’s public health landscape. Healthcare workers increasingly became victims due to delayed diagnosis and weak infection-control practices. Over time, institutions such as Irrua Specialist Teaching Hospital evolved into major centres for treatment, training, and research on the disease.

A turning point came in 2018 when Nigeria experienced one of its largest recorded outbreaks, prompting the Nigeria Centre for Disease Control and Prevention (NCDC) to begin publishing routine situation reports. Since then, Lassa fever has demonstrated a predictable seasonal pattern, with most cases occurring during the dry months between December and April. Despite improvements in surveillance and laboratory confirmation, the disease has not receded. Instead, it has become a recurring national health emergency, reflecting persistent systemic weaknesses.

Epidemiological trends and NCDC data

Data from the NCDC reveal a troubling trajectory. In 2021, Nigeria recorded 510 confirmed cases. By 2022, that number had more than doubled to 1,067 cases with 164 deaths. In 2023, confirmed infections rose to 1,170 with 200 deaths—the highest annual toll in recent years. The pattern continued into 2024, with over 1,000 confirmed cases and approximately 190 deaths across multiple states. Healthcare workers remain particularly vulnerable. According to NCDC reports, infections among medical personnel were recorded again in early 2026, highlighting ongoing occupational risks. By the third week of 2026, Nigeria had documented 405 suspected cases and 93 confirmed infections across 28 local government areas in nine states, with 17 deaths and a case fatality rate exceeding 18 per cent.

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Although comprehensive national data specifically tracking pregnancy-related deaths are limited, public health evidence consistently identifies pregnant women, children, and immunocompromised individuals as high-risk groups. Mortality rates are often higher among these populations, particularly when diagnosis is delayed. Geographically, the burden of disease remains concentrated. Ondo State and Edo State frequently account for more than half of confirmed cases during peak outbreak periods, with additional clusters reported in Bauchi, Ebonyi, Taraba, Benue, and Nasarawa states. In Epidemiological Week 6 of 2026 alone, 74 new confirmed infections were reported, contributing to 240 confirmed cases and 51 deaths recorded between Weeks 1 and 6—figures already higher than the same period in the previous year.

Public health authorities caution that confirmed cases represent only a fraction of the true burden. In many rural communities, limited access to diagnostic facilities means infections may go undetected, while some deaths occur before patients ever reach a hospital. Seasonal surges during the dry months have therefore become predictable national crises rather than unexpected outbreaks.

The NCDC acknowledges operational constraints that hinder rapid containment. Its Director-General, Jide Idris, has cited high transportation costs, weak reporting systems, and data gaps as major barriers to early detection. Transporting diagnostic samples from remote areas to reference laboratories remains expensive and slow, delaying confirmation and response. Reporting lapses—such as tertiary hospitals confirming cases without notifying state authorities—further disrupt surveillance accuracy. Poor internet connectivity and inadequate funding for data transmission also compromise timely reporting.

While national coordination structures exist, outbreak control ultimately depends on effective action at state and local levels. The recurring pattern of infections suggests that Nigeria’s challenge is no longer about identifying the disease but about addressing systemic weaknesses that allow it to persist. More than five decades after its discovery, Lassa fever’s annual resurgence raises a fundamental question: whether the country can transition from reactive crisis management to sustained prevention and preparedness.

How governance gaps keep Lassa fever alive

According to the President of the African Pest Control Association (APCA), Mr. Innocent Onjeh, Lassa fever is neither mysterious nor inevitable. The virus is carried by multimammate rats—common household pests that flourish in environments marked by poor waste disposal, unsafe food storage, overcrowded housing, and weak sanitation systems. In practical terms, the persistence of Lassa fever reflects governance and infrastructure deficits rather than biological uncertainty. “Open refuse dumps, food dried on bare ground, grains stored in easily accessible containers, bush burning, and overcrowded housing all push rats into homes,” Onjeh explained. “These are not acts of fate; they are infrastructure and policy failures. Yet every year, Nigeria responds as if each outbreak is a sudden emergency.”

He emphasised that rodent control remains the most critical pillar of prevention. Rats inhabit homes, markets, and food storage facilities, shedding the virus through urine and droppings while reproducing rapidly. From this perspective, Lassa fever is as much an environmental and sanitation problem as it is a medical one. Unfortunately, Nigeria’s rodent-control strategy is largely reactive—intensifying during outbreaks instead of being sustained year-round. Preventive measures at the community level remain weak, while long-term environmental improvements receive insufficient policy attention.

Onjeh identified several structural gaps undermining effective control, including the absence of a coordinated national rodent-control policy, weak enforcement of sanitation regulations, inadequate funding for integrated pest management programmes, and limited public education on prevention. These systemic weaknesses allow the ecological conditions that sustain the virus to persist across communities.

Yet there are clear examples demonstrating that Lassa fever deaths can be significantly reduced when systems function properly. Onjeh pointed to specialist treatment centres in Edo and Ondo states—particularly facilities associated with Irrua Specialist Teaching Hospital—where early diagnosis, dedicated isolation wards, prompt administration of ribavirin, and strict infection-prevention protocols have improved survival outcomes. “These successes prove Lassa fever can be controlled,” he said. “But what works in a few centres must reach the entire country.”

Nigeria has made measurable progress in recent years, including expanded laboratory capacity and stronger surveillance coordination through the Nigeria Centre for Disease Control and Prevention (NCDC). However, major gaps remain. Sanitation enforcement is inconsistent, rodent-control programmes are limited in scope, and rural communities still experience delays in testing and treatment due to logistical barriers. Without sustained financing and systemic reforms, outbreaks will continue to recur.

Onjeh also noted that although vaccines and new treatments are under research globally, none is yet widely available for routine public use. This reality makes environmental hygiene, early detection, and infection control the most effective tools currently available. Prevention, he stressed, must take priority over emergency response. He advised households to adopt practical protective measures such as storing food in sealed containers, covering waste bins, blocking entry points in homes, avoiding contact with rodents, maintaining hand hygiene, and seeking prompt medical attention for persistent fever. However, he cautioned that individual vigilance cannot substitute for institutional responsibility. “Citizens can be careful, but only strong systems, consistent funding, and proper infrastructure can stop Lassa fever from returning every year,” he said.

Ultimately, he argued, the responsibility lies with government authorities to determine whether Lassa fever remains an annual tragedy or becomes a preventable disease. The first step, he suggested, is straightforward: environmental sanitation and rodent control must occur continuously—not only during outbreaks. “Government must enforce sanitation laws, invest in proper waste management, and launch a national rodent-control programme across all local governments,” Onjeh said. “As long as rats continue to thrive in homes and markets, Lassa fever will not disappear.”

He also underscored the importance of strengthening early detection systems. Diagnostic laboratories must expand beyond major cities, surveillance networks must improve, and test results must be delivered more rapidly to enable timely treatment. Healthcare workers, he added, require reliable supplies of protective equipment, regular training, and strict infection-control protocols. “If we fail to protect healthcare workers, we weaken the entire health system,” he warned. Without decisive and sustained action, Onjeh concluded, Lassa fever will continue to claim Nigerian lives each year. The challenge is no longer about understanding the disease but about fixing the governance gaps that allow it to endure.