West Nile Virus Expert Says We're In Midst Of Largest Mosquito-Borne Virus Outbreak in North American History & Biggest West Nile Virus Outbreak Ever Documented in the World
"This Will Test Whether Organized Mosquito Control & Public Health Can Rally To Protect L.A. & CA Residents"
Backs Local Gov't Efforts But Doubts Sufficient Anti-Mosquito Field Workers Adequate For Giant Area
Introduction & Perspective
(June 14, 2004) -- LBReport.com posts below excerpts of a presentation by Dr. William Reisen, Research Entomologist and Director in Residence, Mosquito & Arbovirus Ecology, Davis Arbovirus Research Unit delivered in Santa Fe Springs at the June 9 meeting of the Greater Los Angeles County Vector Control District's Board of Trustees.
"We're in the middle of the largest mosquito-borne virus outbreak in the history of North America, and the biggest West Nile [Virus] outbreak ever documented in the world," Dr. Reisen said, adding "It's truly a test of organized mosquito control and public health as to whether they can rally to protect the residents of Los Angeles or the residents of California in general."
To our knowledge, LBReport.com was the only L.A. market media outlet in attendance. When Dr. Reisen exited the meeting room, we had an opportunity to ask him some questions related to the LB area...and we post that below.
Government health agencies say most healthy people bitten by mosquitoes carrying West Nile Virus (WNV) won't get sick although some may develop "flu like symptoms." However, an estimated 1 in 150 people bitten by WNV-infected mosquitoes may get seriously ill, which could include encephalitis (inflammation of the brain) requiring hospitalization. And of those 1 in 150, about 1-1.5 in 10 (i.e. roughly 1-1.5 in a 1,000 overall) may die. There is no cure, only supportive care. Those at greatest risk include the elderly, very young and those with weakened immune systems.
People (and birds and horses) get infected with WNV when bitten by infected mosquitoes. Crows and other corvid birds (which can travel considerable distances) are easily infected, and new mosquitoes then bite the infected birds and spread WNV further.
Mosquitoes breed in standing water. For months, government agencies have warned about WNV and urged property owners to prevent standing water from accumulating on private property.
But what happens when government lets standing water collect on property it controls?
One East Long Beach homeowner, who's tried without success to get Long Beach City Hall to fix a broken gutter that's blocking water from draining into a nearby storm drain, recently posted a sign offering a piece of his mind on the subject. (Posted on San Anseline Ave. south of Wardlow Rd.):
Sign text: "Bev O'Neill/Jackie Kell, West Nile Breeding Pond, East Long Beach Wetlands, Brought to you by a Mayor and Council woman who doesn't care, No Fishing, No Swimming."
No, it's not the only such case. Here's what we spotted a few blocks away on Chatwin Ave. north of Wardlow Rd...where a tree is pushing up the gutter, leaving standing water which stretches for the length of several houses:
This is the same standing water, shot from the opposite direction.
East Long Beach also has a large, highly visible population of crows...a bird likely to become infected and spread WNV.
In our view, the net effect of all of this gives ELB and surrounding areas all the ingredients for a "perfect storm." This is no longer just a public works annoyance. It is now a public health matter and should be dealt with accordingly.
In about half of LB (pink on map) mosquito abatement and vector control are performed by the LB Dept. of Health and Human Services (LBDHHS) through its Environmental Services Bureau.
The eastern half of LB, plus parts of NLB, WLB, scattered chunks and Signal Hill (all yellow on map) are within the Greater Los Angeles County Vector Control District (GLACVCD). It's not a County body but a "special district" (a separate layer of government) which is funded by an assessment on ELB property tax bills.
[LB's NW corner (west of the 710 fwy. roughly where it crosses LB Blvd.) is handled by the Compton Mosquito Abatement District.]
(Map is courtesy LBDHHS; mosquito icons on the map indicate mosquito surveillance trap sites; chicken icons indicate "sentinel chicken" sites (chickens routinely tested for WNV); crow icon on Studebaker Rd. near 405 fwy indicates a dead crow, data as of May 28/04).
LBDHHS and GLACVCD treat standing water and other mosquito breeding sources (storm drains are a big problem) with larvaecides and other items...and handle countless flood control channels, storm drains and street gutters as well as the unseen network of underground storm drains stretching for miles.
So how many people does the LB Dept. of Public Health's Environmental Services Bureau have in the field to handle half of LB? We're told about five, five days a week.
How many people does GLACVCD have in the field to handle the southern part of its sprawling territory stretching through Eastern Long Beach and part of NLB, plus Lakewood, Cerritos, Signal Hill, Hawaiian Gardens, Artesia, Downey, Carson, South Gate, Diamond Bar, Bell, Downey, Los Angeles City, San Marino, Bellflower, Gardena, eastern Los Angeles Co., Bell Gardens, Glendale, Lynwood, Santa Fe Springs, Burbank, Maywood, Huntington Park, Montebello, South El Monte, La Habra Heights, Norwalk, Commerce, Paramount, Whittier, Cudahy, La Mirada and Pico Rivera? We're told about thirty.
GLACVCD staffers (field types we trust, not bureaucrats) say that standing water in gutters or storm drains doesn't automatically mean it's a mosquito breeding ground because GLACVCD may have already treated that water. GLACVCD says its crews systematically treat areas with larvaecides and anti-mosquito substances that last more than a week...and crews return to treat areas repeatedly and as needed. We're told that one abandoned swimming pool on private property can produce far more mosquitoes than a puddle of water in a street gutter.
We're reminded that current measures have kept mosquitoes below nuisance numbers locally, so field workers must be doing something right.
OK, fine...but with all due respect, when Dr. Reisen says we're in the midst of the largest mosquito-borne virus outbreak in the history of North America, and the biggest West Nile [Virus] outbreak ever documented in the world, we think more is called for now.
We have some suggestions that we'll post separately...but first, Dr. Reisen:
Dr. William Reisen, Research Entomologist and Director in Residence, Mosquito and Arbovirus Ecology, Davis Arbovirus Research Unit, Greater Los Angeles County Vector Control District Board of Trustees Meeting, Santa Fe Springs, June 9, 2004
Dr. Reisen: "...This is a really, really exciting time in the world of arbovirology. We're in the middle of the largest mosquito-borne virus outbreak in the history of North America, and the biggest West Nile [Virus] outbreak ever documented in the world...
It's truly a test of organized mosquito control and public health as to whether they can rally to protect the residents of Los Angeles or the residents of California in general. It's going to be, I think, a long, hot summer for all of us...
[shows a slide] ...This is a picture of the Whittier Dam area, at dusk during early last fall. As you can see, there's a heck of a lot of crows there...This area probably has an estimated 50,000 crows which roost there, so if you have a bunch of crows, which are very good hosts [for the West Nile Virus]...a sick and dying crow will have...four orders of magnitude more virus in his blood than is necessary to infect some of these mosquitoes, so if a mosquito bites this sick crow, almost any mosquito will be overwhelmed and become infected, so these very high amounts of virus in these crows are very important, and this Whittier Dam area...the yellow shows where all the dead crows occurred, and they were all associated with this Whittier Narrows Dam area...and this is where the virus was found first in the Los Angeles area this year again which means, not only did it persist and amplify and spread throughout L.A. from this area, it also successfully over winter there was initiated again this year...
The crows leave this area during the spring to reproduce...and some of them have taken up shop in La Mirada and there's been a lot of dead crows reported from there, and we've had quite a few isolates of virus from mosquitoes there this year...
[one of our projects] is one we're just about to initiate, to see if mosquito control, how it affects the surveillance indicators and the occurrence of human cases. We were approached by the CDC to embark upon this project...This is being done in collaboration also with the [CA] Dept. of Health Services...What we wanted to do is to do a statistical, a geographical information system analysis of the surveillance indicator data and the occurrence of human cases and relate this to control operations, but we also want to actually when...the operational staff are out doing [mosquito] control, we want to evaluate the efficacy of this...we are also interested to see if we actually can reduce mosquito abundance and want to quantify this with careful surveillance and see if we actually are able to make a dramatic impact on mosquito populations and how they last, how long the control will last. To really interrupt transmission, you need about a ten day suppression of abundance to very low numbers, and you need to eliminate all the infected mosquitoes during the time when the birds are viremic, so all the birds that are sick will either die or get better and be protected, and this is what you need for a sterilizing control operation...
[Question from GLACVCD Bd of Trustee member]...How do we fight it as an individual or for your family?
Dr. Reisen: Well I think the best way to fight it is the way you're doing right now as a District, through integrated vector management programs that actually try to keep mosquito population levels down low enough that you won't have the amplification of virus and the spread to the human population, which usually requires quite a critical mass before you get this spill-over. I think that's the primary method.
When you get into emergency control...where you're trying to get rid of the virus, and if you're at that point you're also coupling that with public education, and you've got a wonderful public education system here in personnel to do that, with media releases, and at that point, personal protection, avoidance through maybe you might have to consider closing down nighttime activities, they've had outbreaks, for example, of St. Louis encephalitis in Florida resulted in Disney World closing down at night because they just didn't want to be faced with the risk, so there are those alternatives...
...Probably the best thing to the health of Californians with encephalitis virus is cold beer, air conditioning and Dan Rather because everybody comes home from work, sits down, watches the evening news, they're indoors with the air conditioning instead of sitting on the porch or out in the street or out in the curb where they used to years ago, and this brings them in, away and protected from mosquitoes when they're biting during early evening which is their primary feeding time is right after sunset...
[Question re what should be done if someone finds a dead crow]...Actually, the state has a system for this. These crows when they die are just full of virus, and it's not really recommended as much as possible to have people picking them up...There's a hotline number, 1-877-WNVBIRD and you call that and they'll ask you how old the bird is, in other words, if it's dead and flattened by twenty semis, we probably can't test it anymore. But if it's a freshly killed bird, or a bird that died fresh, then they will assign a number and will go into a database. If you were to call, they would call the District, and then the District would organize picking it up...
[Following presentation, outside meeting room]:
LBReport.com: The [GLACVCD] District apparently has about 30 staff people that cover the whole area from Burbank down to Orange County [our summary description; Dr. Reisen likely knows the District excludes part of the San Gabriel Valley, half of LB and the west side of LA County]. Do you think that that's sufficient to handle that large an area?
Dr. Reisen [long, thoughtful pause lasting several seconds]: No, I actually don't think so. And especially if you want to give them the mandate of cleaning up everybody's backyard and all of the sewer system...The District really does the best they can with the resources available, and the people of L.A. have provided quite a lot of resources for them, but it's just very hard to do inspections of 10 million properties, or however many there are in the District...
LBReport.com:...I watched last Sunday [as] a fellow saw this puddle, a pool in front of his house, he took out a push broom and pushed it into the storm drain. Is there anything wrong with self-help like that? Would that be helpful?
Dr. Reisen: Well, it all depends. If you had a good rain later on that washed out the storm drain it'd be fine, but what we found is there was a lot of [mosquito] breeding when people did things like that, because this will dam up in the undergrounds and cause these guys problems, because this plant material will rot and that's what the mosquitoes love to be in.
LBReport.com: So that might be counterproductive.
Dr. Reisen: And when they go ahead and throw it over the backyard fence and block the V-gutters that drain the freeways, that's another good source of breeding, and it's hard for these guys to...there's thousands and thousands of these new, little wetlands that handle water coming off the freeways, and all these have to be attended to and inspected.
LBReport.com: ...Would you say it's counterproductive?
Dr. Reisen: When you have a wet season and it flushes out these undergrounds...it's good for the mosquito control people 'cause it does part of their job. But if these things just get trickles of curb runoff and then you have this stuff, debris damming in the undergrounds, this is really a great place for mosquito breeding.
LBReport.com: So that might be counterproductive.
Dr. Reisen: Yes.
LBReport.com: What would you suggest? What should folks do?
Dr. Reisen: Well, the best thing to do is to pick it up and put it in a garbage can or something and have it thrown out properly...
LBReport.com: What should I tell the readers?...
Dr. Reisen: ...I'm certainly not a refuse expert...I think the best thing to do is pick it up and put it in a proper receptacle and have it taken off to a proper disposal mechanism.
LBReport: One last thing. The East Long Beach area is loaded with crows...[You indicated in your presentation] that if the crows get infected [in large numbers], the virus can take hold [in an area]. Is that accurate?
Dr. Reisen: Yes...Everywhere they've had big outbreaks of West Nile so far has been pretty associated with either Blue Jays or Crows.
LBReport.com: The figures I've seen [on people getting sick if bitten by an infected mosquito] are either 1 in a 1,000 or 1 in 150 get sick. What's accurate?
Dr. Reisen: After the epidemic in New York initially, and here in Los Angeles after the St. Louis [encephalitis] epidemic [in the 1980s], they estimated that about one and a half to two percent of the population had been infected. That means they were bitten by a mosquito that had the virus. Of those with West Nile, and right now between West Nile fever and West Nile encephalitis, they're estimating that probably one in ten people, or one in five actually, have some kind of an ailment. And about 1 in a 150 develop neurological problems, and out of that 1 in a 150, about ten or fifteen percent die if they're older people.
Return To Front Page
Contact us: mail@LBReport.com