KNOWLEDGE, AWARENESS, AND RISK ASSESSMENT OF LASSA FEVER AMONG RESIDENTS OF ESAN WEST LOCAL GOVERNMENT AREA, EDO STATE, NIGERIA

INTRODUCTION

Lassa fever is an acute viral haemorrhagic fever caused by the Lassa virus, a member of the Arenaviridae family, first described in 1969 in Borno State, Nigeria.¹ The disease accounts for an estimated 300,000 to 500,000 cases and 5,000 to 10,000 deaths annually across West Africa, with an at-risk population of approximately 59 million people spanning Nigeria, Sierra Leone, and Guinea.^2,3 Nigeria bears a disproportionate share of this burden, and Edo State consistently ranks among the most affected states in the country, with Esan West Local Government Area (LGA) recognised as one of its endemic zones.^4,5

Transmission occurs primarily through contact with excretions of the multimammate rat (Mastomys natalensis), the principal reservoir host, and through direct contact of broken skin or mucous membranes with infected blood or body fluids.⁶ Person-to-person transmission, including nosocomial spread, has been well documented, and control of the disease is compounded by the diagnostic non-specificity of its early clinical presentation, the absence of a licensed vaccine, and limitations in health worker capacity at the primary care level.^7,8 In the absence of effective biomedical countermeasures, community-level knowledge of transmission routes, recognition of risk behaviours, and adherence to preventive practices remain the most accessible and actionable targets for public health intervention.

Despite the endemicity of Lassa fever in Esan West LGA and its surrounding communities, population-level data on awareness, knowledge, and behavioural risk have remained limited. Available evidence from comparable West African settings, including Sierra Leone and Liberia, consistently reports low community awareness and persistent high-risk behaviours, suggesting that disease endemicity does not translate into adequate health literacy.^9,10 Within Nigeria, studies among caregivers in Edo State have reported moderate knowledge levels, but below what would be expected given occupational exposure, raising further concern about the adequacy of community-level understanding. ^11,12

Understanding the specific gaps in awareness and knowledge, and identifying the sociodemographic determinants of behavioural risk, is essential for designing targeted and context-appropriate interventions. This study therefore reports the awareness, knowledge, and risk assessment findings among residents of Esan West LGA to provide an empirical basis for community-directed Lassa fever control efforts in this endemic area.

MATERIALS AND METHODS

Study area

Esan West Local Government Area (LGA) is located in Edo State, Nigeria, with a projected population of 147,655 and administrative headquarters at Ekpoma. The LGA is organised into 10 wards spanning both semi-urban and rural communities. Environmental conditions in the area, including mud housing construction, open-air grain drying, and the practice of bush burning, are conducive to commensal rodent activity and facilitate sustained contact between residents and the Mastomys natalensis reservoir host. The Institute of Viral and Emergent Pathogens Control and Research (IVEPCR), located at the Irrua Specialist Teaching Hospital (ISTH) in the adjoining Esan Central LGA, serves as the regional reference centre for Lassa fever diagnosis and surveillance.

Study design and sampling technique

A descriptive cross-sectional study was conducted among residents of Esan West LGA over a 6-month interval. Multi-stage sampling was employed. In the first stage, the 10 wards of the LGA were enumerated, and respondents were allocated proportionally across all wards based on ward population size. In the second stage, where a ward comprised more than one community, a single community was selected by simple random sampling. In the third stage, households within each selected community were identified using the World Health Organisation Expanded Programme on Immunisation (WHO EPI) cluster sampling method, and eligible respondents were recruited from selected households.

Study population and selection criteria

The target population comprised permanent residents of Esan West LGA. Individuals were eligible for inclusion if they were aged five years or older, had resided in the LGA for at least six months preceding the study, and provided written informed consent. Individuals who were critically ill or unable to communicate were excluded.

Sample size determination

The minimum sample size was calculated using the Fisher formula: n = Z²pq/d², where Z = 1.96 (at 95% confidence), p = 0.21 (prior Lassa fever seropositivity rate in the study area),¹³ q = 1 − p = 0.79, and d = 0.05 (margin of error). This yielded a minimum of 255, which was adjusted upward using a design effect correction to 280, and further rounded to 300 to account for potential non-response.

Data collection and measurement

Data were collected using a structured interviewer-administered questionnaire developed by the investigators. The instrument captured sociodemographic characteristics, awareness of Lassa fever, and sources of information. The questionnaire was pretested among 50 residents of Etsako West LGA, a non-study area with comparable characteristics, and necessary revisions were made before deployment.

Data analysis

Data were entered and analysed using IBM SPSS Statistics version 25.0. Frequencies and percentages were computed for categorical variables. Associations between sociodemographic characteristics and the outcome variables of awareness, knowledge grade, and risk level were assessed using the Pearson chi-square test at a significance level of 0.05. Fisher's exact test was applied where any expected cell frequency was less than five.

Ethical considerations

Ethical approval for this study was obtained from the Research Ethics Committee of the Irrua Specialist Teaching Hospital. Written informed consent was obtained from all adult participants before enrolment. For participants below the age of 18 years, written consent was obtained from a parent or legal guardian, with assent obtained from the participant where applicable. Participation was entirely voluntary, and confidentiality of all data was maintained throughout.

RESULTS

Sociodemographic Characteristics of Respondents (Table 1, Figure 1)

A total of 300 respondents participated. The mean age was 43.6 ± 21.6 years. The largest age group was 21 to 40 years (111, 37.0%), followed by 41 to 60 years (79, 26.3%), over 60 years (69, 23.0%), 20 years and below (41, 13.7%). The sex distribution was nearly equal: 153 females (51.0%) and 147 males (49.0%). Three-quarters (75.7%) had at least a primary education, while 23.3% had no formal education. Most respondents were Christian (97.7%), Esan (94.0%), in unskilled occupations (66.7%), and married (64.0%). About three-fifths (59.7%) were from Ekpoma communities. The mean (SD) duration of residence was 24.8 (2.6) years; 80.0% had been resident for at least 6 years.

Awareness of Lassa Fever and Sources of Information (Table 2, Figure 2)

One hundred and thirty-two respondents (44.0%) were aware of Lassa fever, while 168 (56.0%) were not. Among those aware, the ISTH Outreach Team was the most common source (21.4%), followed by radio (20.2%), television (19.6%), and other health workers (14.9%). Print media was the least cited source (1.8%). Other sources included schools (5.5%), friends (4.2%), hospitals (3.6%), and churches (1.2%). Awareness was significantly associated with educational level (χ² = 11.14, p = 0.011) and occupation (χ² = 15.05, p = 0.001). No significant association was found with age group (χ² = 0.01, p >0.999), sex (χ² = 2.07, p = 0.150), community type (χ² = 0.00, p >0.999), duration of stay (χ² = 5.85, p = 0.054), or marital status (χ² = 1.44, p = 0.487).

Knowledge of Lassa Fever (Table 3, Figure 3)

Overall, 21 respondents (7.0%) had good knowledge, 178 (59.3%) had fair knowledge, and 101 (33.7%) had poor knowledge. Educational level was the only significantly associated variable (χ² = 19.8, p = 0.011): the proportion with good knowledge rose from 4.2% (no education) to 5.6% (primary), 8.9% (secondary), and 10.0% (tertiary). The relationship of knowledge of Lassa fever with occupation approached significance (χ² = 8.08, p = 0.080), with skilled workers having the highest rate of good knowledge (15.4%). Age group (χ² = 3.37, p = 0.762), sex (χ² = 2.23, p = 0.327), religion (p = 0.893), marital status (p = 0.362), community (χ² = 9.26, p = 0.953), and duration of stay (χ² = 7.94, p = 0.094) were not significantly associated.

Risk Assessment of Lassa Fever (Table 4, Figure 4)

High risk was recorded in 111 respondents (37.0%), moderate risk in 77 (25.7%), and low risk in 112 (37.3%). Sex was significantly associated (χ² = 7.67, p = 0.022): 44.4% of females were high risk compared with 29.3% of males. Occupation was strongly significant (χ² = 8.91, p < 0.001): high-risk classification was present in 46.2% of skilled and 41.5% of unskilled workers versus only 8.3% of the unemployed. Community of residence (χ² = 16.51, p < 0.001) showed marked variation: Ukhun had the highest proportion of high-risk respondents (65.0%) and Ogua the lowest (0.0%). Duration of residence was also significant (χ² = 65.65, p = 0.001): high-risk proportions rose from 25.4% (less than 6 years) to 52.5% (6 to 10 years) and 46.7% (more than 10 years). Age group (χ² = 4.83, p = 0.565), educational level (χ² = 7.77, p = 0.256), religion (p = 0.420), and marital status (p = 0.734) were not significantly associated.

Summary of Significant Associations (Table 5)

Educational level and occupation were predictors of both awareness and knowledge. Sex, occupation, community of residence, and duration of stay were the principal determinants of risk level.

DISCUSSION

This study found low awareness (44.0%) and very low rates of good knowledge (7.0%) of Lassa fever among residents of Esan West LGA, alongside a substantial burden of high-risk behaviour (37.0%). These findings are consistent with reports from Ondo state, Nigeria, by Olowookere et al.¹⁴ and Tobin et al.¹⁵ in Edo state, confirming a persistent gap between disease endemicity and community health literacy in West Africa. Education was the sole significant predictor, consistent with a similar study carried out by Saka et al.¹¹ in Edo state, where the tertiary level of education was significantly associated with increased knowledge of Lassa fever. The non-significant age group effect indicates knowledge does not accumulate meaningfully with age, reinforcing the primacy of formal education over lived experience. Specific deficits in knowledge of person-to-person transmission and safe rat disposal represent particularly dangerous gaps.

The ISTH Outreach Team and electronic media were dominant awareness channels, but do not necessarily reflect their effectiveness in low-literacy rural settings. Print media accounted for only 1.8%, expected given 23.3% had no formal education. The significant associations of awareness with education and occupation confirm that information access is driven by literacy and occupational proximity to formal communication.^16,17 The near-significant trend for duration of stay suggests incremental accumulation of awareness with time in the community, though this did not translate into better knowledge.

The gender disparity in risk reflects domestic roles in rural African communities, bringing women into frequent contact with rodent-contaminated surfaces.¹⁸ The unemployed had the lowest high-risk rate (8.3%), while skilled workers had the highest (46.2%), partly explained by employment in health facilities where nosocomial transmission occurs. Marked spatial variation in risk reflects heterogeneity in housing quality and sanitation. The progressive rise in risk with duration of residence is consistent with cumulative exposure and entrenchment of risk behaviours. Age group was not a significant predictor of risk.

Limitations of this study include the cross-sectional design, researcher-developed scoring tool, potential social desirability bias, and data from 2013. Awareness estimates for collapsed age groups were proportionally derived, as fine age-stratified awareness counts were not provided in the original dataset.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

FUNDING

This study received no external funding.

ACKNOWLEDGEMENTS

The authors thank the ISTH outreach team, medical students of Ambrose Alli University, Ekpoma, and all community participants.