from the bench
Figure 1: Weekly Zika Testing Volume for 2016
Testing the Test
for Zika
During the surge, BPHL participated in
applied research for Zika virus detection,
evaluating specimen types other than serum
such as urine and saliva. Results indicated
that the Zika virus was detected in urine
for a longer period than in serum. These
findings, published in the MMWR article
Interim Guidance for Zika Virus Testing of
Urine – United States, 2016, resulted in the
addition of urine as an acceptable specimen
type to the CDC Trioplex PCR assay.
the surge, finding trained and licensed
personnel was a daunting task and, due
to the complexity of the Zika algorithm,
it was difficult to ensure that the right
tests were performed on the right
specimens. Certain BPHL laboratory staff
were temporarily reassigned to assist
the virology laboratory with testing. The
laboratory also received assistance from
the Bureau of Epidemiology in performing
triage and outreach with submitters as
It’s no surprise: early
preparation makes for an effective
public health response.”
well as assistance from the US Centers
for Disease Control and Prevention (CDC).
Meanwhile BPHL-Miami began testing
samples by Trioplex PCR to screen for
Zika. They performed the Trioplex assay
in Miami on urine specimens as part
of a survey of asymptomatic residents
near the local transmission areas in
Miami-Dade County. Later on in the
outbreak, BPHL-Miami implemented
Trioplex PCR for diagnosis, which helped
alleviate some of the testing load at the
Jacksonville and Tampa laboratories.
In August, during the height of local
transmission in south Florida, the
DOH offered free Zika testing to all
pregnant women residing in Florida. To
prevent a testing backlog at BPHL and
PublicHealthLabs
@APHL
to accommodate the increased demand
for testing, the DOH contracted with
commercial laboratories who, by this
time, had implemented Zika testing. In
addition, BPHL began sending samples
to CDC which had increased its testing
capacity to support the states. Procedures
for samples sent to commercial
laboratories and CDC included collating
data for shipped samples, packaging
and shipping the samples, and handling
results and reporting. Over a six-week
period, approximately 1500 samples were
tested by CDC for BPHL. This complex
coordination took the effort of many. By
December 2016, the BPHL had performed
more than 12,000 Zika PCR tests and
10,000 IgM MAC-ELISA tests (see Figure 1).
The “New Normal”
Despite the diversion of significant
resources to Zika testing, BPHL’s overall
2016 testing volume did not decrease
from 2015. Fortunately, with support
from CDC and commercial laboratories
as well as strong collaboration within the
Florida DOH, BPHL was able to respond
to the demands of the Zika outbreak
while sustaining public health testing
services for the state. Nevertheless, BPHL
and DOH knew there were opportunities
for improvement. At an “after action”
meeting for DOH, participants reviewed
the 2016 response and developed a list
of action items for 2017 and beyond. For
the laboratory this included incorporating
APHL.org
BPHL also collaborated with Florida
universities and the US Army Medical
Research Institute of Infectious Diseases
(USAMRIID) on whole genome sequencing
projects to look at the diversity and spread
of the Zika virus in the Americas, and the
epidemiological evidence for multiple
introductions of the virus into the US. These
collaborations led to two publications in
Nature, “Genomic epidemiology reveals
multiple introductions of Zika virus
into the United States” and “Zika virus
evolution and spread in the Americas.”
protocols to streamline the Zika testing
process (notably, BPHL implemented the
Trioplex molecular assay at all three BPHL
locations eliminating the need to perform
three separate protocols for dengue,
chikungunya and Zika); adding trained
personnel; investing in more efficient,
high throughput instrumentation;
and continuing to educate healthcare
providers about specimen submission
and result interpretation.
And the bottom line? It’s no surprise:
early preparation makes for an effective
public health response. BPHL’s response to
the Zika outbreak was facilitated by three
factors—surge testing plans, a funding
mechanism to purchase emergency
supplies and equipment, and anticipation
of the next epidemic and implementing
the appropriate testing capability—all
of which were in place prior to the
emergency. Should local transmission of
Zika virus be detected again in Florida
in 2017, BPHL stands ready to respond to
the testing needs with more resources,
improved protocols and communications
networks built over a year of challenges. n
Summer 2017 LAB MATTERS
27