Vector Control Att B

A d v A n c E m E n t o f t H E PraCtICE

 D I r E C t F r o M C D C e n v I r o n m e n t A L h e A Lt h S e r v I c e S B r A n c h

Where Have All the Vector

Control Programs Gone?

Part one
michael e. herring,
mPh, rehS (cAPt, uSPhS)

e d i t o r ' s N o t e : NEHA strives to provide up-to-date and relevant in­
formation on environmental health and to build partnerships in the profes­
sion. In pursuit of these goals, we feature a column from the Environmental
Health Services Branch (EHSB) of the Centers for Disease Control and Pre­
vention (CDC) in every issue of the Journal.
In this column, EHSB and guest authors from across CDC will highlight a
variety of concerns, opportunities, challenges, and successes that we all share
in environmental public health. EHSB’s objective is to strengthen the role of
state, local, and national environmental health programs and professionals
to anticipate, identify, and respond to adverse environmental exposures and
the consequences of these exposures for human health. The services being
developed through EHSB include access to topical, relevant, and scientific in­
formation; consultation; and assistance to environmental health specialists,
sanitarians, and environmental health professionals and practitioners.
The conclusions in this article are those of the author(s) and do not neces­
sarily represent the views of the Centers for Disease Control and Prevention.
CAPT Mike Herring is a senior environmental health scientist in the Envi­
ronmental Health Services Branch. He is the branch lead for vector control
issues and has done extensive work internationally and within the U.S. pro­
moting the principles of integrated pest management.

T

he 1999 emergence of West Nile virus
(WNV) in the United States was a vec­
tor wake-up call for public health in
this country. By the end of 1999, WNV—an
illness previously confined primarily to Afri­
ca, the Middle East, and parts of Europe and
Asia—had sickened 62 persons in New York,
seven of whom died. WNV is now endemic
throughout the continental United States.
Although most infections are asymptomatic,
approximately 341,000 cases of West Nile fe­
ver (WNF) have occurred, 12,188 infections

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volume 73 • number 4

have resulted in West Nile neuroinvasive
disease, and 1,164 infections have resulted
in death. Based on a ratio of 140 infections
for every case of West Nile neuroinvasive
disease, CDC projects that 1.7 million WNV
infections have occurred in the United States
since 1999.
Vector control programs and activities,
once a primary component of local environ­
mental health (EH) programs, were experi­
encing a lengthy period of decline prior to
the arrival of WNV. By the time WNV disease

cases peaked in 2003, many health depart­
ments saw increases in vector control bud­
gets to combat the disease. Unfortunately,
the trend did not last. After WNV became
old news, vector control capacity continued
to decline.
Although no studies exist to indicate how
many programs or activities have been elimi­
nated or reduced, informal reports from the
EH workforce indicate that the loss of vector
control capacity is severe. The resulting po­
tential health impacts are alarming: approxi­
mately 75% of recently emerging infectious
diseases affecting humans are zoonotic (of
animal origin and transmittable to humans,
often by a vector), and approximately 60%
of all known human pathogens are zoonotic.
Continued elimination of programs to con­
trol the majority of emerging diseases afflict­
ing the world today is troubling, especially
when the next zoonotic epidemic may be just
a plane ride away.
The continued shift of funding for EH
programs from local government support to
fee-for-service programs may be contributing
to the loss of vector control capacity. Several
core EH activities (e.g., food safety, onsite
wastewater programs) can generate sustain­
ing revenues through permit and inspection
fees, but vector control programs are usually
seen as revenue negative. Control programs
for rodents, mosquitoes, and other vectors
and pests can be costly and time intensive.
Declining public revenues have led to elimi­
nation or substantial reduction of vector con­
trol activities to help local governments meet
other pressing budget demands.
The overall health impact of reduction in
local vector control capacity is difficult to

measure. EH experts note that when resi­
dents of inner-city urban areas are asked
about the most serious EH issues facing their
communities, rodent infestations are almost
universally the top issue. Rodent control pro­
grams across the country have been severely
impacted in recent years, however.
The decline of local vector control capac­
ity is a possible contributor to the nationwide
resurgence of bed bug populations that has
overwhelmed the capability of many local
health departments to respond to infesta­
tion complaints. This challenge is exacer­
bated by limited technical knowledge of bed
bug control in local EH programs since bed
bugs nearly disappeared as a common public
health pest approximately 50 years ago. Al­
though bed bugs are not believed to be a dis­
ease vector, they are a pest of significant pub­
lic health importance because of the physical
and mental health consequences associated
with bed bug bites and infestations (Centers
for Disease Control and Prevention & U.S.
Environmental Protection Agency, 2010).
Although local health departments are
often the front lines of defense against vec­
torborne diseases, state health agencies con­
duct vector surveillance and serve important
technical and laboratory assistance roles. In
2007, a survey of the State Public Health
Vector Control Conference by the Associa­
tion of State and Territorial Health Officials
(ASTHO, 2007) found that

• 74% did not have sufficient numbers of
public health workers to effectively staff
their vector control units;
• 38% said inadequate funding was the most
challenging aspect for state vector control
activities;
• 80% stated that their agencies had not taken
any action to prepare for the effect of cli­
mate change on vectorborne disease; and
• several states reported that they had no
ability to conduct vector surveillance of
any kind.
Although comparable studies are not avail­
able for local vector control programs, prob­
lems confronting the local level would be
similar, if not more severe, because local vec­
tor programs often rely on state funding along
with surveillance and laboratory support.
The growing challenge of meeting the
threats of vectorborne illness by local health
departments is intensified by the unprecedent­
ed loss of professionals in the environmental
public health workforce over the past two
years (National Association of County and
City Health Officials, 2009). Research into the
loss of vector control capacity and the poten­
tial public health impact is greatly needed.
Ongoing efforts at the Centers for Disease
Control and Prevention to confront the chal­
lenges created by the loss of vector control
programs and capacity at state, tribal, and lo­
cal health departments will be discussed in
next month’s “Direct from CDC” column.

Corresponding Author: CAPT Michael E.
Herring, Senior Environmental Health Scien­
tist, Environmental Health Services Branch,
Division of Emergency and Environmental
Health Services, National Center for Environ­
mental Health, CDC, 4770 Buford Highway,
N.E., M.S. F-60, Atlanta, GA 30341. E-mail:
[email protected].

References
Association of State and Territorial Health
Officials. (2007). State public health vec­
tor control conference: Workforce and dis­
ease priorities needs assessment summary.
Arlington, VA: Author. Retrieved June 1,
2010, from http://www.astho.org/Display/
AssetDisplay.aspx?id=2335
Centers for Disease Control and Prevention
& U.S. Environmental Protection Agency.
(2010). Joint statement on bed bug control in
the United States from the U.S. Centers for
Disease Control and Prevention (CDC) and
the U.S. Environmental Protection Agency
(U.S. EPA). Atlanta: U.S. Department of
Health and Human Services.
National Association of County and City
Health Officials. (2009). 2008 national
profile of local health departments.
Washington, DC: Author. Retrieved June 1,
2010, from http://www.naccho.org/topics/
infrastructure/profile/resources/2008report/
index.cfm

November 2010 • Journal of Environmental Health

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