Prevalence of Lassa Virus Disease (LVD) in Nigerian children with fever or fever and convulsions in an endemic area

PLoS Negl Trop Dis. 2017 Jul 3;11(7):e0005711. doi: 10.1371/journal.pntd.0005711. eCollection 2017 Jul.

Abstract

Background: Convulsions with fever in children are a common neurologic emergency in the tropics, and determining the contribution of endemic viral infections can be challenging. In particular, there is a dearth of data on the prevalence and clinical differentiation of Lassa virus disease (LVD) in febrile children in endemic areas of Nigeria, which has multiple lineages of the virus. The aim of this study was to determine the prevalence and presentation of LVD in febrile children with and without convulsions.

Methodology/principal findings: This was a prospective study of consecutive febrile children aged ≥1 month- 15 years admitted to the Children's Emergency Room of Irrua Specialist Teaching Hospital over a period of 1 year. Febrile children with convulsions (Cases) were compared with those without convulsions (Controls). LVD was defined by the presence of a positive Lassa virus RT-PCR test. Rates were compared between groups using χ2 or Fisher's exact tests and p <0.05 taken as significant. 373 (40.9%) of 913 admissions had fever. Of these, 108/373 (29%) presented with convulsions. The overall prevalence of LVD was 13/373 (3.5%; 95% CI = 1.9%, 5.7%) in febrile admissions, 3/108 (2.8%) in Cases and 10/265 (3.8%) in Controls [(Odds Ratio (95% Confidence Interval) (OR (95% CI)) of LVD in Cases versus Controls = 0.73 (0.2, 2.7)]. Only vomiting (OR (95% CI) = 0.09 (0.01, 0.70)) and bleeding (OR (95% CI) = 39.56 (8.52, 183.7)) were significantly associated with an increased prevalence of LVD.

Conclusions/significance: LVD is an important cause of fever, including undifferentiated fever in children in endemic areas, but it is not significantly associated with convulsions associated with fever. Its prevalence, and lack of clinical differentiation on presentation, underscores the importance of a high index of suspicion in diagnosis. Screening of febrile children with undifferentiated fever in endemic areas for LVD could be an important medical and public health control measure.

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Endemic Diseases*
  • Female
  • Hospitals, Teaching
  • Humans
  • Infant
  • Lassa Fever / complications*
  • Lassa Fever / epidemiology*
  • Lassa Fever / pathology
  • Lassa virus / genetics
  • Lassa virus / isolation & purification*
  • Male
  • Nigeria / epidemiology
  • Prevalence
  • Prospective Studies
  • Reverse Transcriptase Polymerase Chain Reaction
  • Seizures / epidemiology*
  • Seizures / etiology*

Grants and funding

This work was supported by grant GU 883/4-1 from the German Research Foundation (DFG) and the German Partnership Program for Excellence in Biological and Health Security. Irrua Specialist Teaching Hospital is supported by the Federal Government of Nigeria through the Federal Ministry of Health. PS and CTH are supported by the NIH, USA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.