Current and Emerging Diagnostics for Zika Virus

05/03/2023

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)

05/03/2023


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

05/03/2023

Influenza

Enterovirus

Measles

Rubella

Dengue

West Nile Virus

Acute Retroviral Syndrome (HIV)

Chikungunya

Other alphaviruses

Epstein-Barr virus

Parvovirus

Roseola virus


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

05/03/2023


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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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)

05/03/2023

05/03/2023Preparedness 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)


MiSeq (Illumina, Inc.)

05/03/2023

(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 05/03/2023

Can We Identify a Host Biomarker Signature for Zika Infection?


• Profound and sustained changes in transcriptome of acute Lyme disease patients

• Disease-specific immune pathways largely involved at V1 and V2

05/03/2023

(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)

05/03/2023Preparedness for the Zika Virus: A Public Health Emergency

Goal: to identify diagnostic

and prognostic host

biosignatures for Zika

virus infection from blood

Health & Medicine

Current and Emerging Diagnostics for Zika Virus