Management decisions on when and how to evaluate
risks from WNV and associated management strategies will be determined
on a site-by-site basis, in accordance with NPS Management Policies 2001.
This evaluation shall be based on parameters specific to the site which
include, but are not limited to: site use, confirmed presence of WNV in
birds and/or mosquito populations (scientific testing), presence of competent
vectors, mosquito predators, associated monitoring/surveillance data,
site ecology, presence of rare or endangered species, weather patterns
and temperature. In addition, mosquito management efforts will be initiated
only when a clear and defined threat to park resources and/or human health
has been determined through a consultation process with experts, and where
human health is concerned, when advised to do so by the U.S. Public Health
Service (NPS Public Health Program and Centers for Disease Control). Nuisance
mosquitoes will not be managed unless specific and exceptional situations
It is difficult to determine the risk WNV has on wildlife populations
unless baseline data is available. Threatened and endangered species or
species of concern, such as genetically significant wildlife/stock, should
be surveyed early on to achieve a baseline (general health status) and
then periodically monitored for presence of WNV. Parks may find useful
baseline data through previous wildlife surveys from outside organizations.
An example for birds would be the annual Christmas Bird Counts, or others.
Risks to humans can be reduced through education of the public and employees
in self- protection and avoidance. Efforts towards risk reduction shall
be based on identifying and locating high-risk areas/situations, and on
surveillance and quantitative monitoring programs.
Risk Reduction Through Management Action
Management decisions on how to reduce risk from WNV and associated
management strategies to humans, the resource and the environment are
site specific. Reducing the risk involves decreasing the chance of a human/animal
from contracting the disease and/or reducing the risk of pesticide exposure.
Risk reduction should include a variety of short and long term management
actions such as: education of staff and visitors, monitoring /surveillance
programs, sanitation programs, reduction of non-natural (man-made) habitat,
site restoration initiating periodic park or specific site closures, insecticide
application, request funding for future surveys; or no action. Note that
requests for insecticide applications (adulticide or larvicide) use will
be considered after all other pest management tools have been reviewed
and it has been determined through the NPS
IPM Program and technical advisors that the pesticide is a necessary
component in order to reduce risk of WNV on the site.
The following excerpts from Management
Policies 2001 will be helpful when addressing risk in parks. Please
read the entire Chapter 4 (Natural Resources Management) section 4 (Biological
Resource Management) sub-section 5 (Pest Management) for clarification:
· Section 4.4.5 Pest Management
· Section 18.104.22.168 Pests “Pests are living organisms that interfere
with the purposes or management objective of a specific site within a
park, or that jeopardize human health or safety.…Native pests shall be
allowed to function unimpeded, except as noted below…(such as) ..Manage
a public health hazard when advised to do so by the U.S. Public Health
Service (which includes NPS Public Health Service and Centers for Disease
Control), or to otherwise protect against a threat to human safety."
· Section 4. 4. 5. 2 Integrated Pest Management Program “The Service
conducts an Integrated Pest management Program (IPM) to reduce risks to
the public, park resources and the environment”.
· Section 4. 4. 5. 3: Pesticide Use "The decision to incorporate
a chemical, biological, or bio-engineered pesticide into a management
strategy is based on a determination by a designated IPM Specialist that
it is necessary and that all other available options are either not acceptable
or not feasible".
a. Understand the disease ecology and evaluate your risk of contracting
West Nile Virus Information)
b. Reduce artificial mosquito breeding habitat around developed areas.
c. Understand the biology of natural areas, food chain, affects of natural
Mosquito Control Association)
d. Use of personal repellants (insecticides)
(NPS ZED WNV Personal Protection Factsheet,
WNV Insect Repellent)