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9C - Update on West Nile Virus/Mosquito Monitoring & Control PlanDO NOT REMOVE - PRAB F~le Matertal CITYOFBOULDER PARKS AND RECREATION ADVISORY BOARD AGENDAITEM MEETING DATE: March 31, 2003 (Agenda Item Preparation Datc: March 20, 2003) AGENDA TITLE: Update on West Nile Virus/Mosquito Monitonng & Control Plan REQLTESTING DEPARTMENT: Jan Geden, CPRP, Director of Pazks and Recreaaon Doug Hawthorne, CPRP, Parks Supenntendent Cate nradley, Planner Alice Guthrie, City IPM Coordinator FISCAL IMPACT: To be determmed. Prehmmary estimates are $13,000 for plan development. Momtoring and treatment costs aze eshmated to be $24,000 for city-owned lands within the city limits The purpose is to update the Pazks and Recreauon Advisory Boazd on the status of West Nile Vuvs (WNVI and mosquito control planning arid get input from the PRAB on the direcuon of the plan. BACKGROUND: West Nile Virus (WN~ West Nile Virus (WNV) is a mosqwto-bome virus that can cause encephalit~s (inflauunadon of the brain) or menuigitis (inflammauon of the lining of the bratn and spmal cord). People become infected when bitten by a mosquito infected with WNV. Most people who are infected do not develop symptoms (-80%) and about 20% develop flu-like symptoms of West Nile Fever. Less than 1% of infectrons result m senous illness and 3-15% of the senous cases result m death. Those most at risk aze the elderly and young ctuldren. WNV is maintamed in the bud populat~on. Buds such as magpies, cmws and jays appeaz most susceptible to the virus. Mosquitces become infected when they bite an infected bird and can transmit the virus to another host when they bite. Horses and humans are "dead-end" hosts for the """"' vuus, in that the virus is not transmitted from human or horse to mosquito. i..- AGENDA 1TEM # IX-C : PAGE 1 The vuus first appeazed in Colorado in August 2002. As of Febmazy 28, 2003, there were 13 human ,.~ cases (but no fatalit~es) and WNV was confumed m birds and horses m Boulder County (see ,,,~ Attachment A: Colorado West Nile Virus Surveillance Map) Most of the cases were in Weld County. The Boulder County Deputment of Health (BCHD} anucipates that there will be many more instances of WNV m 2003 and even more m 2004, based on the patterns the vuus has exlubited ia the eastem United States. They have requested that all Boulder Counry municipaliUes prepare and implement a mosquito control plan for 2003. Based on a recent news article in the Rocky Mountain News, (attachment B), it appears that the WNV may cause a higher rate of serious nervous system problems than researchers had thought. There aze over 30 species of mosquitces that cany WNV, but only two aze m Colorado, Culex tarsalus and C. p:p:ens, but C. tarsalus is the most common. There are many other species of mosquitces m Colorado, most of wluch aze nuisance mosquitces. Theu breeding habitats vary and can range from moist soil to standmg water. Control Methods Mosqwto control can be accomphshed in either the larval or adult stage. Larval control is the most effect~ve and has fewer human and environmental impacts. ' The main larval control ts a natwally occumng bactenum, Bacillus thunngiens~s (Bta). It is not specific to mosquito larvae, but also kills nudge and fly larvae. The larva must mgest the Bti for it to be fatal. It is apphed by granules or bncks, depending on the water body. Another larval control is methoprene, an msect growth regulator, wluch disrupts normal larval development. It is applied as i~w, briquettes, pellets, granules, or liquid. Both these control methods aze considered biological control ~+ from an integrated pest management perspective. Oils and monomoleculaz films can also be used to control mosquito larvae. They may be toxic to non-tazget orgazusms, smce they form a coatrng on top of standuig water and drown larvae, pupae and emerguig adults One organophosphate chemical, Temephos, is registered as a mosquito larvicide. P_~?~~2t coc~~: :s 3o~e bJ ch~nucal sp ~}u.g, :rd is repo:ted to be 25% - 30% effecuve The most common products are organophosphates (Malattuon, Naled) and synthetic pyrethmids (permethnn, resmethrin, sumithnn) applied as ultra-low volume sprays They are lughly toxic to some insects. Malattuan was scheduled for assessment for re-registrahon m 2002. Malathion and Naled can damage the human nervous system at lugh doses and cause conwlsions, respuatory paralysis and death. ANALYSIS: Education Education of Boulder cihzens is key to help prevent WNV uifecGon. There are many tkungs that citizens can do to protect themselves and reduce mosquito breeding azeas around their homes. Key actions include the following• - Wear long-sleeve shuts, long pants and socks if outside at dawn and dusk. - Apply insect repellent to skui or clotlung. - Elimmate areas of standing water, mcluding ones as small as cans and plastic pots. '"`"' - Change or clean water regularly in pools, saunas and budbaths. AGENDA TI'EM # IX-C ; PAGE 2 ~ - Ensure that wmdow and door screens are tighdy fitted StafF also is cooperating with BCHD on outreach matenals for the public, focusmg on protect~ve clothiag and act~ons individuals can take around their homes. One of the utiliry bill inserts for May will be devoted to WNV/mosquito control options. Information will also be available on the city website. Staff is reviewing other outreach ophons avazlable. City Efforts Staff from several ciry departments (Pazks and Recreatron, Open Space/Mountain Pazks, Pubhc Affazrs, Water Quality, City Attomey's Office) are coordinating to develop a West Nile Virus/mosquito monitoring and control plan for city lands. The Boulder County Health Department is pmviding some guidance. Staff has idenafied a consultant with expertise in mosquito momtormg and plan development and has met wrth them to develop a draft scope of work. The plan will contain the followmg information: • mapping and monitoring of mosquito habitat • thresholds for treatment • npri~IIc for control, fncus~ng on larval control when warranted • envuonmental impacts of the various conuol methods • data collection and mformation for 2004 At ttus point, staff anticipates utilizmg the consultant for surveillance and monitoring acuviues and hinng a contractor for any treatment that is deemed necessary. ~ As the plan is developed, staff will review areas of known mosquito populations and nuisance complaznts from prior years. A key component of the monitonng progam will be to deternune where populations of C. tarsalus aze breeding and review what abatement or treatment actions could be taken. The plan will focus on momtonng for C. tarsalus not nuisance mosquito species. Staff is working with the Planning Depaztment to determine the extent of mapped wedands on Pazk lands and wIll have more u~formation at the PRAB meeting. Alice Guthne met with the Wedands Review Group to discuss whether or not a wetlands permit is required if larval treatment is warranted m a regulated wetland. It was the consensus of the group that a permit is needed, but how to determine impacts to the wedand and the scope of the mitigation requirements are unclear. The Wetlands Review Group suggested that they be mvolved as the plan is developed, so it can address permitt~ng and mitigation reqwrements. Staff will keep PRAB advised as we move forwazd. Prevention is a basic principle of mtegrated pest management and staff is investigat~ng what options are available. Ehmina6ng standu-g water may not be feasible if the water body is a mapped wedand, but might be possible in some cases. Staff is working to deternune how to work with ungauon ditch compazues to mmimize standing water from irrigauon ditches that flow through pazklands. Aeraaon is another way to eliminate mosquito-breeding habitat m ponds, but purchasing and installing aerators is expensive. The Colorado Department of Public Health and Environment is offering workshops on mosquito surveillance techniques and how to collect and properly document dead birds. Staff is continwng to ,..~, work with the Boulder County Health Department (BCHD) to clanfy legal authority and protocols ~ for action if a public health emergency is ident~fied. AGENDA IT'EM # IIL-C : PAGE 3 Budget Impacts „~ As listed above, the cost to develop the plan is esumated at $13,000. Ttus cost is for a simplified ...~ scope of work that focuses on surveillance and mapputg prior to any treatment. The Office of Envuonmentai P.ffaus will pay for tlus part of the pro~ect. The esumated cost for surveIllance and treatment of areas within the city limits ($24,000) is a"most treatmenY' option and includes all city- owned lakes and ponds, not specifically Pazks and Recreation Depaztment managed lands. Open Space/Mountain Pazk properhes located outside the City limiu are not included m the $24,000 budget amount. This budget also assumes the highest level of momtoring, but only larval stage treatmeat. Staff is still working with the consultant to develop the spec~cs of the plan. We can provide more detail on actual costs per land management department once the spec~cs and scope of work is developed. Based on mformauon from ciues m the eastem Umted States, the seventy of the problem seems to peak in the third yeaz, whtch would be in 2004 in Colorado. However, the species of mosquito that is the primary carrier of West Nile virus m Colorado is a different one from the mazn species on the East Coast, so there are some unknowns. If we assume that the situations are compazable, we can anticipate havmg to momtor and treat at similaz levels in 2004. In theory, the monitoring would be more efficient, since personnel will be fanuhar with the areas and hot spots may be identified m 2003. Questions for PRAB Your feedback on the followmg quest~ons will help staff as we move forward with discussions with other city boards and Crty Council: ~ 1. Dces PRAB agree with the general dtrecuon of the city efforts and groposed plan? ~" 2. What concerns dces PRAB have about the poten6al impacts of the pmposed approach on Pazk lands and departmental resources? 3. Would PRAB like to review the draft plan? PUBLIC CGAru'v~NT AND PROCESS: This item is bemg heazd at tlus pubhc meeting as advertrsed in the Dai[y Camera STAFF RECONII~NDATION: Not apphcable. ATTACHNIENTS: A. Colorado West Nile Vuvs Surveillance Map B Rocky Mountau- News azvcle - 2-10-03 ~ AGENDA ITEM # IX-C : PAGE 4 ~ ~ ~ I' " D m I ~) Calorado West Nile Virus Surveillance Final Map - December 2~~2 • 5entlnnelNocks Wt+lV PpSiAvQs 1~ Birds ~ Horses Su6mitting Counties [~ Yes Y ~ 0 ~ 5 a Rocky Mountain News: State Rocky Mountain News ~ To print this page, select File then Print from your browser URL http //www rockymountainnews com/drmn/state/article/0,1299,DRMN_21_3734309,00 html ~ West Nile virus study raises fears Nervous system damage may be more frequent than was first thought By Jim Ericksan, Roeky Mountain News February 10, 2003 Attachment B NEW ORLEANS - West Nile virus appears to cause a higher rate of serious nervous system problems than researchers had thought, including Parkinson's-like movement disorders and temporery limb paralysis, a government neurologist reported Sunday Researchers had previously assumed that fewer than 1 percent of people bitten by ~nfected mosquitoes develop severe central nervous system illnesses - a tiny tip of the West Nile iceberg, according to Dr. James Se7var of the Centers for Disease Control and Prevention But a small West Nile study that started ~n August in St. Tammany Parish, north of New Orleans, suggests "the tip of that iceberg may be bigger than we thought," Se)var said at the Fourth National Conference on West Nde Virus in the Umted States. About 360 people, mostly federal, state and county public health workers, are attending the three-day meet~ng. West Nile swept across the United States last summer, sickening about 4,000 people and kdling 263. The virus was detected in Colorado in mid-August, and the state finished the year with 13 non-fatal human cases. The Colorado case count is expected to nse in 2003. W...- In the St. Tammany Parish study, CDC researchers worked with tocal physicians ta find 42 people with fever of unknown ongin or symptoms of encephalitis or meningitis, the two diseases most often associated with severe West Nile dlness Sixteen of the 42 tested positive for West Nde and are being trecked in a study that will last at least a year, Se~var said. FiReen of the 16 displayed tremors - sometimes severe enough to intertere with eating and groommg - dunng their illness. Ten patients experienced an involuntary ~erking or twitching of the muscles In many cases, the tremors and twitch~ng persisted more than five days, Se~var said.Eleven of the 16 showed Parkinson's-like symptoms, including "cogwheel rigidity," which combines ngid muscles with tremors, balance problems, and slowed body movements Three of the 16 displayed temporary paralysis in a limb or on one side of the body "What appears to be going on is that the virus is affecting regions of the brain that direct and control motion," Se7var said The Louisiana study marks the first time many of these movement d~sorders have been tied to West Ntle illness, he said. Lyle Petersen, deputy director of the CDC lab in Fort Collins, called the findings "very important." "They tell us something about the pathology of the disease and they give us some clue about what the long-term consequences of having West Nile virus infection might be."None of the 16 patients died. But in telephone interviews five to six months after their dlness, most reported they were still experiencing persistent headaches, memory "" problems, fatigue and an mabdity to concentrate. ~ A much larger follow-up study is needed to flesh out the details of the findings uncovered m the St. Tammany pilot pro7ect, Se~varsaid: ~~~ (~-~~P~1~ http://www rockymountainnews.com/cr/cda/azucle_pnnU1,1250,DRMN_21_1734309,OO.htm1 2l10/2003