Molecular diagnostics for lassa fever at Irrua specialist teaching hospital, Nigeria: lessons learnt from two years of laboratory operation

PLoS Negl Trop Dis. 2012;6(9):e1839. doi: 10.1371/journal.pntd.0001839. Epub 2012 Sep 27.

Abstract

Background: Lassa fever is a viral hemorrhagic fever endemic in West Africa. However, none of the hospitals in the endemic areas of Nigeria has the capacity to perform Lassa virus diagnostics. Case identification and management solely relies on non-specific clinical criteria. The Irrua Specialist Teaching Hospital (ISTH) in the central senatorial district of Edo State struggled with this challenge for many years.

Methodology/principal findings: A laboratory for molecular diagnosis of Lassa fever, complying with basic standards of diagnostic PCR facilities, was established at ISTH in 2008. During 2009 through 2010, samples of 1,650 suspected cases were processed, of which 198 (12%) tested positive by Lassa virus RT-PCR. No remarkable demographic differences were observed between PCR-positive and negative patients. The case fatality rate for Lassa fever was 31%. Nearly two thirds of confirmed cases attended the emergency departments of ISTH. The time window for therapeutic intervention was extremely short, as 50% of the fatal cases died within 2 days of hospitalization--often before ribavirin treatment could be commenced. Fatal Lassa fever cases were older (p = 0.005), had lower body temperature (p<0.0001), and had higher creatinine (p<0.0001) and blood urea levels (p<0.0001) than survivors. Lassa fever incidence in the hospital followed a seasonal pattern with a peak between November and March. Lassa virus sequences obtained from the patients originating from Edo State formed--within lineage II--a separate clade that could be further subdivided into three clusters.

Conclusions/significance: Lassa fever case management was improved at a tertiary health institution in Nigeria through establishment of a laboratory for routine diagnostics of Lassa virus. Data collected in two years of operation demonstrate that Lassa fever is a serious public health problem in Edo State and reveal new insights into the disease in hospitalized patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antiviral Agents / therapeutic use
  • Female
  • Hospitals, Teaching
  • Humans
  • Lassa Fever / diagnosis*
  • Lassa Fever / drug therapy
  • Lassa Fever / mortality
  • Lassa virus / genetics
  • Lassa virus / isolation & purification*
  • Male
  • Middle Aged
  • Molecular Diagnostic Techniques / methods*
  • Molecular Sequence Data
  • Nigeria
  • Polymerase Chain Reaction / methods*
  • RNA, Viral / genetics
  • Ribavirin / therapeutic use
  • Sequence Analysis, DNA
  • Survival Analysis
  • Young Adult

Substances

  • Antiviral Agents
  • RNA, Viral
  • Ribavirin

Associated data

  • GENBANK/JN651366
  • GENBANK/JN651367
  • GENBANK/JN651368
  • GENBANK/JN651369
  • GENBANK/JN651370
  • GENBANK/JN651371
  • GENBANK/JN651372
  • GENBANK/JN651373
  • GENBANK/JN651374
  • GENBANK/JN651375
  • GENBANK/JN651376
  • GENBANK/JN651377
  • GENBANK/JN651378
  • GENBANK/JN651379
  • GENBANK/JN651380
  • GENBANK/JN651381
  • GENBANK/JN651382
  • GENBANK/JN651383
  • GENBANK/JN651384
  • GENBANK/JN651385
  • GENBANK/JN651386
  • GENBANK/JN651387
  • GENBANK/JN651388
  • GENBANK/JN651389
  • GENBANK/JN651390
  • GENBANK/JN651391
  • GENBANK/JN651392
  • GENBANK/JN651393
  • GENBANK/JN651394
  • GENBANK/JN651395
  • GENBANK/JN651396
  • GENBANK/JN651397
  • GENBANK/JN651398
  • GENBANK/JN651399
  • GENBANK/JN651400

Grant support

The study was supported by grant I/82 191 from the Volkswagen Foundation, grant GU 883/1-1 from the German Research Foundation (DFG), FP7 grant 228292 (European Virus Archive) from the European Community, and by junior faculty start-up funds at Harvard University. The Irrua Specialist Teaching Hospital is supported by the Federal Government of Nigeria, through the Federal Ministry of Health, Abuja. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.