current and emerging diagnostics for zika virus
TRANSCRIPT
05/01/2023
Current and Emerging Diagnostics for Zika Virus Charles Chiu, MD/PhD
Preparedness for the Zika Virus: A Public Health Emergency
Tick-borne encephalitis virus
West Nile VirusMurray Valley Encephalitis VirusJapanese Encephalitis Virus
St. Louis Encephalitis Virus
DENV-1DENV-3
DENV-2DENV-4
Yellow Fever VirusZika Virus
• Family Flaviviridae, genus Flavivirus
• Enveloped single-stranded RNA virus
Zika Virus
(Goldsmith, CDC)
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Preparedness for the Zika Virus: A Public Health Emergency
Clinical Presentation of Acute Zika Infection
• ~80% asymptomatic
• Fever, headache, retro-orbital pain, rash, conjunctivitis, myalgias (muscle pain), arthralgias (joint pain)
• Laboratory Findings: usually normal; can see leukopenia, thrombocytopenia, mild elevation in liver transaminases
Clinically indistinguishable from other mosquito-borne infections
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Influenza
Enterovirus
Measles
Rubella
Dengue
West Nile Virus
Acute Retroviral Syndrome (HIV)
Chikungunya
Other alphaviruses
Epstein-Barr virus
Parvovirus
Roseola virus
Preparedness for the Zika Virus: A Public Health Emergency
Malaria
Post-infectious arthritis
Rheumatologic diseases
Differential Diagnosis of Zika Virus Infection
• Scarlet fever (Group A Strep)
• Meningococcemia
• Typhoid fever
• Other bacterial septicemia
• Leptospirosis
• Rickettsial diseases
BACTERIAL VIRAL OTHER
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Preparedness for the Zika Virus: A Public Health Emergency
Zika Virus Diagnostic TestingCulture for virus (generally not used clinically)
Acute phase (≤7 days after onset) Zika specific polymerase chain reaction for viral RNA (PCR) in serum, saliva (may be more sensitive), or urine (may be positive longer)
CDC ZIKV assay consists of two PCR reactions; both reactions must be positive (analytical sensitivity 100 and 25 copies)
Subacute/Chronic phase (2-12 weeks) IgM anti-ZikaV (ELISA) , 20-40% cross-reactivity with YFV, WNV, DENV; confirmatory plaque reduction neutralization test (PRNT) more specific
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Preparedness for the Zika Virus: A Public Health Emergency
Commercial Diagnostic Tests for Zika
Altona Diagnostics RT-PCR kit (RUO in US; CE Mark approval in Europe)CDC IgM ELISA (FDA EUA approval)
Siemens Versant kPCR Molecular
System (RUO)
• GenArraytion (RUO, multiplex testing)• Vela Diagnostics (RUO, multiplex testing)• Fast Track Diagnostics (RUO)
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05/01/2023Preparedness for the Zika Virus: A Public Health Emergency
What’s Next?Metagenomic Sequencing – Casting a Wide Net
MetagenomicSequencing
Conventional Testing
Metagenomic Sequencing has Comparable Sensitivity to PCR
*co-infection with chikungunya virus; ND = not detected
Sample # # Raw reads
# Zika reads
Metagenomic Seq PCR
1 1,486,130 63 + +2 1,449,221 87 + +3 11,546 2 + +4 1,321,572 9 + +5 1,114,194 24 + +6 1,179,486 11 + ND7 6,903,397 419,115 + +*8 1,094,355 83 + +9 743,266 1,072 + +
10 1,031,160 16 + ND11 933,134 125 + +12 1,727,181 33 + +13 1,180,561 2 + ND14 1,744,295 0 ND +15 1,353,875 11 + ND
(Sardi, Somasekar, et al., 2016, in preparation)
Preparedness for the Zika Virus: A Public Health Emergency
MiSeq (Illumina, Inc.)
05/01/2023
(Greninger, et al., 2015, Genome Medicine 7:99)MinION (Oxford Nanopore Technologies)
Nanopore Sequencing for Real-Time Diagnosis of Febrile Illness
Preparedness for the Zika Virus: A Public Health Emergency 05/01/2023
Can We Identify a Host Biomarker Signature for Zika Infection?
Preparedness for the Zika Virus: A Public Health Emergency
• Profound and sustained changes in transcriptome of acute Lyme disease patients
• Disease-specific immune pathways largely involved at V1 and V2
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(Bouquet, et al., 2016, mBio 7(1):e00100-16)
Differential Diagnosis of Acute Hemorrhagic Fever byGene Expression Profiling
(Bouquet, et al., 2016, manuscript in preparation)
05/01/2023Preparedness for the Zika Virus: A Public Health Emergency
Goal: to identify diagnostic
and prognostic host
biosignatures for Zika
virus infection from blood