Some states have already taken steps to
bolster influenza surveillance. California, for
example, created a respiratory viral disease
laboratory network shortly before the 2009
pandemic. In its wake, 24 of the 29 local PHLs
in the network have upgraded their molecular testing capabilities for influenza surveillance. And the state PHL’s Viral, Rickettsial
Disease Laboratory has enlarged its stockpile
of influenza PCR reagents.
“We can easily envision a time when we have a novel influenza
outbreak and the usual background outbreaks and we
become overwhelmed.”- Ewa King, PhD, director, Rhode Island State
Health Laboratory
Finally, CDC—through APHL—has set up a
network of CDC-designated laboratories that
any PHL can use for specialized influenza
analytical services. State PHLs in California,
Utah and Wisconsin are performing viral isolation and neuraminidase inhibition analysis, a test for antiviral drug resistance.
a World of eIds
In virtually every regard, from global surveil-
lance to electronic messaging to laboratory
technology, influenza represents the high
point of US EID preparedness. Yet, Jernigan
averred, “Laboratories are better prepared
than they have been in the past, but we are
not where we should be.”
Bartkus said Minnesota is the farthest west
Powassan virus has been reported. “I do
anticipate that as the climate changes we
will continue to see changes in the distribu-
tion of vector-borne diseases,” she said.
All of these investments, said Jernigan, “are
definitely paying off.” The payback is evident
in the speed with which Chinese surveillance systems detected influenza A(H7N9)
and shared findings with international
health authorities. And it is evident in the
speed of the US response.
Part of the problem is the need to prepare
for so many unknowns, as well as unknown
unknowns. While particularly high-profile
pathogens, like influenza, garner attention—
and resources—from policy makers, less
notable microbes often fly under the radar.
Climate change may also be linked to last
year’s deadly WNV outbreak in the Dallas-
Fort Worth area. “Dallas-Fort Worth is in the
northern part of the state, so it’s colder,”
said Kubin. “But the last few winters have
been really mild, so the mosquito population
hasn’t died off.”
“Sometimes the emerging infections are
very local and specific,” said Billie Juni, MS,
microbiology supervisor at the Minnesota
Public Health Laboratory.
Even before CDC scientists had the virus in
hand, they were able to synthesize parts of
it based on the published genetic sequence
and to begin formulating vaccine candidates.
Authorities already knew CDC’s rRT-PCR
Flu Panel could detect the novel virus—as
an unsubtypable influenza A—because the
panel is used in China. Jernigan said, “Based
on those sequences alone, without the virus,
we were able to develop a new PCR assay [for
confirmatory testing].”
In the last three years, for example,
Minnesota has identified two cases of
infection with Naegleria fowleri, a brain-eat-
ing amoeba. The most recent patient,
an elementary school-aged child, died last
summer from a rare form of meningoen-
cephalitis linked to the amoeba. Bartkus
said, “Naegleria fowleri is usually associated
with brackish water in warmer climates. It
gets into people’s noses and then penetrates
into the brain. It had never before been
seen in Minnesota. Is this related to climate
change? I don’t know. But we’re the Land of
10,000 Lakes, so this is a concern.”
Animals for sale in a market in Tibet. Photo credit: Joseph Younis
In addition, CDC used its Influenza Risk
Assessment Tool to gauge the virus’s
capability to emerge and cause severe
disease. Based on ten criteria—the microbe’s
mutation rate, transmissibility in lab
animals, pathogenicity, global distribution
in animals and several others—Jernigan said
H7N9 has a “moderate level of likelihood to
emerge,” which, he said, “is concerning and
the reason why we’re putting so much effort
into preparing PHLs to respond.”
Part of the laboratory’s response, said Juni,
has been to purchase the supplies needed
for molecular testing for the amoeba:
“Maybe you don’t make a change for one
case, but after a second case, we should
probably be ready to deal with it.”
On April 22, the FDA issued an emergency
use authorization, allowing qualified labo-
ratories to implement the CDC Human
Influenza Virus Real-time RT-PCR Diagnostic
Panel-Influenza A/H7 (Eurasian Lineage)
Assay, as the new H7N9 test is known, even
before it goes through the customary FDA
approval process. CDC began distributing the
test April 25.
In 2008, Minnesota had its first confirmed
case of Powassan virus, a central nervous
system infection caused by an organism
carried by Ixodes scapularis, the deer tick that
also transmits Lyme disease. Between 2009
and 2012, five more cases were confirmed,
including one death in 2011.
The Texas Laboratory Services Section
has traditionally grown mosquito-borne
microbes in culture to identify a range of
pathogens, such as the bugs responsible for
St. Louis and LaCrosse encephalitis, as well
as WNV. At the height of last year’s outbreak,
however, the lab had to ramp up its historically low level of PCR testing for WNV—
which delivers results many times faster
than culture—while maintaining its culture
program. “We didn’t want to concentrate
on West Nile and have something sneak
through the back door,” said Kubin.
As of late April, H7N9 is confined to China.
Should it spread, US PHLs are ready.
The sudden presence of the virus in
Minnesota meant another new surveillance
program had to be built up; this one
involving PCR and serologic testing.
As of April, Kubin’s shop is already gearing
up for another big WNV season. “
Municipali-ties,” she said, “are trying to get ahead of the
game this year. Everybody is really aware of
what’s going on.”
Public engagement, spurred by last year’s
prolific media coverage, at least assures the
laboratory of extra state support. Texas’s
health commissioner has agreed to fund up
to 4,000 PCR tests of mosquito pools, and
