Protecting Students from Mosquitoes and the Zika Virus at Schools Questions and Answers

Protecting Students from Mosquitoes and the Zika Virus at Schools
Questions & Answers
Protecting Students from Mosquitoes and the Zika Virus at Schools, one of a series of school Integrated
Pest Management (IPM) webinars hosted by EPA's Center of Expertise for School IPM, was presented on
September 20, 2016. Included here is information on the presenters and responses to participants'
questions.
On this page:
• Speakers
• Questions and answers
Presenters
• CDR Joseph Laco, US Public Health Service Environmental Heath Scientist, CDC National Center
for Environmental Health
• Michael Merchant, Ph.D., Urban Entomologist, Texas A&M Research and Extension Center
• Dan Lisenko, Grounds and Maintenance Manager, Manatee County (Florida) School District
Questions and Answers
These questions were posed by webinar participants. The questions and responses may have been
refined following the webinar for clarification or to include additional resources.
1. How can I get a copy of the presentation? You can request a PDF of the presentation by sending an
email to school.ipmffiepa.gov using the subject "Zika Webinar Presentation." Once posted, a link to
the recorded webinar will be available on our website.
2. Do you have parent education pamphlets available in English, Spanish, Vietnamese, and
Mandarin?
(CDR Laco) CDC's Zika website provides information, including media for parents, in English and
Spanish.
(Dr. Merchant) Texas A&M AgriLife Extension has two publications in Spanish - What Texans Need to
Know About Zika and Mosquitoes and the Diseases They Transmit.
3. Where can we find the most updated information?
(CDR Laco) CDC's Zika website is updated at least weekly with arbovirus information and resources.
Repellents
4. Considering outdoor gym periods and after school sports, have school districts altered their
policies on mosquito repellent application? And who applies the repellent?
(Mr. Lisenko) In some elementary schools, teachers apply the repellent on the children before they
go outside. Our district does not yet have a protocol for repellents. We have recommended that the
football players use a repellent when they go outside. We are just now trying to get parents and
teachers to understand the importance of protection from mosquitoes and to start bringing in
repellents.

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5. Are Florida school systems allowing students to bring repellents to school or are the schools
supplying repellent?
(Mr. Lisenko) While my district is not supplying repellents, I believe there are some that are
supplying repellents. In my district, students may bring in their own repellent.
6. Are there repellents that can be safely used on children between 6 months and 2 years of age?
(CDR Laco) I would strongly advise you to look at the label on all repellents. The label instructions
have been approved by EPA in accordance with their human health safety standards. I would not
recommend any repellent be used for children under 2 months of age.
7. Are the repellents used on clothing odorless?
(Dr. Merchant) Permethrin should only be applied to clothing and allowed to dry before wearing the
treated clothing. It lasts for multiple washings, and should be odorless once applied and dried.
Other repellents can be applied to clothing, but will not remain active after washing. Picaridin and
IR-3535 are both odorless once applied.
8. Can you recommend a permethrin product for pretreating clothing?
(Dr. Merchant) Any permethrin product labeled for use on clothing should be effective. Brands
include Sawyer®, Ben's® Clothing and Gear, Repel® Permanone, and others.
9. Once you have the virus how long would you be contagious? Are the school systems on here
allowing students to bring repellent to school or after school activities? Are the schools
supplying?
(CDR Laco) That will vary from person to person based on your own status of health, and whether or
not you are immune-compromised. Typically it is going to be 7 to 10 days. Maybe up to two weeks
for some individuals.
10. What recommendations do you have, aside from protective clothing, for pregnant women
wanting to protect themselves against mosquito bites? Are repellents safe for pregnant women?
(Dr. Merchant) All repellents go through extensive safety testing to ensure that risks to humans are
minimal. This applies to pregnant women, unless there is a warning on the label. Risks to humans
from mosquitoes, however, are well known and documented.
11. Is it recommended and safe to pre-treat children's clothing?
(Dr. Merchant) As in the above answer, all EPA registered repellents have been thoroughly tested
and should pose minimal risks to children unless otherwise indicated on the label. The label should
be your guide in determining proper and safe application to children's clothing or skin.
12. Can you apply insect repellents to pets?
EPA cautions people not to use any product on pets or other animals unless the label clearly states it
is for animals.
13. Does wiping your skin with a dryer sheet and putting it in your pants pocket help to decrease
mosquito bites?
(CDR Laco) No. CDC only recommends the use of EPA registered products as repellents. Their
effectiveness is based on scientific data and peer reviewed studies.

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14. Is there clothing that can prevent mosquitoes from biting through? And should repellent be used
on both exposed skin and clothing?
(CDR Laco) The thinner the clothing, the easier it is for mosquitoes to bite through. I would
recommend using a permethrin product that is labeled for pre-treating clothes to repel mosquitoes.
Or just use a repellent on your skin, clothes and hair.
Larvicides
15. How much larvacide is required for an average storm drain?
(Dr. Merchant) That is going to depend on the label which is slightly different for each product. It is
usually based on the square footage of the water to be treated.
16. Do you have to re-apply Bt to drains after a heavy rain?
(Dr. Merchant) Yes. That is one of the disadvantages of larvicides. They do not last a long time and
certainly any kind of rain event that is going to dilute the Bt and wash it out. Rain is a double-edged
sword. It helps with the West Nile virus, but for the Zika-carrying Aedes mosquitoes, rain will wash
away the larvacide treatments that we put in the drains and allow them to start breeding again
quickly. With the West Nile virus carrying mosquitoes, a good rain that will wash out the breeding
site is just what the doctor ordered. Culex mosquitoes like dirty water (lots of organic material) that
has been sitting awhile and has become stagnant.
17. How long does Altosid (methoprene) last?
(Dr. Merchant) Altosid (methoprene) has about a 30-day life span. It is comparable to the better Bt
formulations that are slow release. Bt does not last as long as Altosid, but if it is in a good slow-
release formulation, it can also extend for 30 days.
18. Our state Health Department will not allow use of larvicides in storm drains or other pools of
water that may flow into streams, ocean, etc., citing the Federal Clean Water Act. Why can other
states do it? Any suggestions for alternate ways of dealing with larvae in these areas of standing
water?
(Dr. Merchant) Your state Health Department may have a policy of not allowing its own employees
to apply larvicides to water, but health departments do not have authority to prevent citizens from
using state and federally registered insecticides for uses that are allowed on the label.
19. Can mosquito eggs take up to 6 months to hatch? If so, how do we treat sites where the larvae
may appear?
(Mr. Lisenko) Mosquito eggs can go dormant up to 10 to 15 years depending on environmental
conditions. Once the larvae, appear I would use an insect growth regulator to control them.
Mosquito Biology
20. If Aedes sp. are low fliers will females still lay eggs in water in roof gutters on the 2nd or 3rd story?
(Dr. Merchant) I wouldn't put past an Aedes mosquito to go up that high. Pay attention to
eliminating potential breeding sites on roof tops and gutters for both Aedes and Culex mosquitoes.
21. Is there a season for mosquitoes?
(Dr. Merchant) Most mosquitoes will be active when temperatures exceed 50-55 degrees F.

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Zika Virus
22. Are there data focused on Zika infection by gender, race or age?
(CDR Laco) I do not know if that has been examined. However, the greatest risk from Zika is for
women who are pregnant or will become pregnant. This disease can have very serious impacts on
developing fetuses and young women. The risk of adverse health effects in children is relatively low.
23. Can microcephaly affect the fully developed fetus infected with Zika through the placenta?
(CDR Laco) Zika virus can have an effect on fetal brain development at any point during the
pregnancy.
24. How does the original person get infected with the Zika virus?
(Dr. Merchant) In areas of active local transmission like we saw in the summer of 2016 in south
Florida, epidemics get started when an infected traveler from an active Zika area arrives. If that
person is bitten by an Aedes mosquito within 5-7 days of first infection, that mosquito can become
infected and pass the virus to the next person it bites.
Mosquitos and Schools Questions
25. Are city officials responsible for monitoring mosquito breeding grounds in areas surrounding
schools?
(Mr. Lisenko) If there is a mosquito problem adjacent but off our school property, we contact the
county's mosquito control program.
26. Who should inspect for mosquitoes on and around school property?
(Mr. Lisenko) I train my pest control department and they do most of the inspections. The
custodians are currently being trained so they can help with inspections. Because we have about 60
facilities, it is hard to do a complete inspection within a reasonable amount of time. When trained,
the custodians and school plant managers will be able to assist.

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