Charles Chiu, MD, PhD

1. 3/9/2016
Current and Emerging
Diagnostics for Zika Virus
Charles Chiu, MD/PhD

2. Preparedness for the Zika Virus: A Public Health Emergency
Tick-borne
encephalitis virus
West Nile Virus
Murray Valley Encephalitis Virus
Japanese Encephalitis Virus
St. Louis Encephalitis Virus
DENV-1
DENV-3
DENV-2
DENV-4
Yellow Fever Virus
Zika Virus
• Family Flaviviridae, genus
Flavivirus
• Enveloped single-stranded
RNA virus
Zika Virus
(Goldsmith, CDC)
3/9/2016

3. 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
3/9/2016

4.  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
3/9/2016

5. Preparedness for the Zika Virus: A Public Health Emergency
Zika Virus Diagnostic Testing
Culture 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
3/9/2016

6. 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)
3/9/2016

7. 3/9/2016Preparedness for the Zika Virus: A Public Health Emergency
What’s Next?
Metagenomic Sequencing – Casting a Wide Net
Metagenomic
Sequencing
Conventional
Testing

8. 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 + ND
7 6,903,397 419,115 + +
*8 1,094,355 83 + +
9 743,266 1,072 + +
10 1,031,160 16 + ND
11 933,134 125 + +
12 1,727,181 33 + +
13 1,180,561 2 + ND
14 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.)
3/9/2016

9. (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 3/9/2016

11. 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
3/9/2016
(Bouquet, et al., 2016, mBio 7(1):e00100-16)

12. Differential Diagnosis of Acute Hemorrhagic Fever by
Gene Expression Profiling
(Bouquet, et al., 2016, manuscript in preparation)
3/9/2016Preparedness for the Zika Virus: A Public Health Emergency
Goal: to identify diagnostic
and prognostic host
biosignatures for Zika
virus infection from blood