Follow Us on Google
By Olakunle Olafioye
Grim statistics and rising numbers of deaths from Lassa fever infection have once again put Nigeria in the spotlight for a wrong reason. No fewer than 20 local government areas in eight states across the six geopolitical zones in the country have reported cases of Lassa fever outbreak in 2026 with the attendant fatalities, according to the National Centre for Disease Control and Prevention (NCDC). The affected states include Ondo, Taraba, Edo, Ebonyi and Benue with Bauchi recording the highest cases of 43 cases and eight deaths, while Plateaus has emerged as the new hotspot for the deadly disease.
As of the third epidemiological week, a total of 18 fatalities, including the death of a frontline health worker from a total of 91 cases have been recorded. Health experts across the country have expressed the fear that the figure might soar in the coming weeks amid calls on Nigerians to embrace precautionary measures and protect themselves against contracting the disease.
Last year, no fewer than 184 deaths from confirmed 1,119 cases were recorded across the country. The outbreak primarily affected Ondo, Bauchi, Edo and Taraba states. The four states jointly accounted for 88 per cent of the total cases reported across 21 states in the year.
A public health expert, Dr. Julius Nwaeri, said Lassa fever is endemic in Nigeria with cases of infection and transmission recorded all year round. He, however, noted that there is usually an increase in cases of the infection between November and May during the dry season. According to him, the Lassa fever virus is transmitted by rodents, which can be found in our environment. This, he said, contributed largely, to the risk of spread that occurs in Nigeria and other countries with similar ecological factors.
Explaining the link between the surge in rate of infection of lassa fever and dry season, Nwaeri said rodents including Lassa fever vector, the multimammate rat, are often attracted indoors during dry season. “During dry season some animals and especially rodents in search of food, shelter from extreme environmental conditions and those escaping from predatory animals like snakes are driven indoors and thereby raise the risk of transmission of the virus to humans who may come in contact with their faeces and urine,” he explained.
Health experts identified the primary hosts for the Lassa virus as the multimammate rat (Mastomys natalensis), which is one of the most prevalent rodent species found in Sub-Saharan Africa. Although the multimammate rat is said to have the capacity of reproducing throughout the year, it is known to produce fewer offspring in the rainy season, ostensibly due to flooding, which probably washes its pups away. Even though the multimammate rat serves as the animal reservoir for the Lassa virus, experts maintain that the animal does not become sick as a result of the virus. Multimammate rats, they claim, are more rampant in rural regions, and in lesser numbers in forested and urban areas. Their presence in any area, experts say, is a good predictor of the likelihood of humans being infected with the Lassa virus.
The World Health Organisation describes the disease as a viral haemorrhagic fever with symptoms including weakness, headaches, vomiting and muscle pains. Although the world body puts the fatality rate at about one per cent, Nwaeri said the figure may be higher in Nigeria owing to the large number of factors. He listed these factors to include unreported cases, delayed cases reporting especially from rural areas, limited diagnostic capacity in some areas and continued exposure of healthcare workers.
Another medical expert, Dr. Abiodun Folarin, said getting accurate statistics in a country like Nigeria where the people are very secretive and cagey especially with the issue of health could be a herculean task. “Again when we look at it critically from the figure released by NCDC so far, one can conveniently argue that the fatality rate could be more.” he stated.
Other News
More worrisome dimension to the outbreak of Lassa fever, in the opinion of experts, is that there is currently no vaccine against the virus. “Currently, there is no known vaccine to protect against Lassa fever. Therefore, we only rely on strengthening measures such as ensuring proper sanitation, good personal hygiene and standard care precautions by health workers to prevent the spread of Lassa fever. These measures also depend on personal responsibility as we all have a role to play in preventing the spread of Lassa fever,” he stated.
Community hygiene has been identified as one of the most potent ways to curtail the rising cases of Lassa fever infection in endemic areas. According to the health experts, people can prevent Lassa virus infection by avoiding all forms of contact with the rodents, particularly in the regions where Lassa virus is endemic. In particular, Nwaeri recommended that food should be stored in rodent-proof containers, while also ensuring that the environments are kept clean to prevent rats from breeding in houses.
“Furthermore, people should be discouraged from eating bush meat because they could be infected in the process of trapping, catching, or cleaning an infected animal in the bush. While setting traps to catch multimammate rats might play a role in reducing the number of animals available to act as reservoirs for the Lassa virus, it is not practical to do so because the multimammate rats are widely dispersed.”
He also advocated proper care for people infected with the Lassa virus and adequate protection for medical personnel attending to the victims. “It is expedient to take preventive measures to limit the spread of the infection. Some of the measures that can be taken include setting up biological containment conditions, wearing protective clothes (such as masks, gloves, gowns, and goggles), proper sterilization of equipment, as well as the isolation of infected individuals to prevent the spread of the virus to unprotected persons.
“There are also instances where individuals who travel to areas where Lassa fever is endemic export the virus to their place and areas of residence. Individuals returning with fever symptoms, especially if they have been travelling to endemic regions, should be tested for Lassa fever as soon as possible.
“Finally, people who are resident in endemic regions, particularly those in the rural areas, should be educated on effective means of reducing the rodent population, so as to limit and pre-empt the spread of Lassa fever,” he admonished.
According to NCDC, Lassa fever was first reported in a community known as Lassa in Borno State, Nigeria, in 1969 when two missionary nurses died from an unusual febrile illness. Since then, cases and outbreaks continue to be reported in Nigeria and the diseases is increasingly recognised to be endemic in many parts of West Africa, including Nigeria, Benin, Ghana, Mali and the Mano River region (Sierra Leone, Liberia and Guinea), with the disease probably existing in other West African countries as well.
An estimated 300,000-500,000 cases and 5,000 related deaths occur annually in West Africa. In 2018, NCDC reported the largest ever number of cases in Nigeria, with over 600 confirmed cases and over 170 deaths. The increase is not thought to be due to any new virus strains, and may at least be partially explained by increasing surveillance capacity.
Lassa fever is an epidemic prone disease for immediate notification on the IDSR platform in Nigeria. According to NCDC, The actual incidence rate in Nigeria is unknown, but case fatality rates range from 3 per cent to 42 per cent (and over the last two years has remained between 20 per cent and 25 per cent). Historically, outbreaks occur during the dry season (November to April), however, in recent years, cases have also occurred during the rainy season. Lassa fever importation into non-endemic countries has occurred in the UK, USA, and Germany, amongst others.
