West nile virus primary prevention: Difference between revisions
Jump to navigation
Jump to search
Line 95: | Line 95: | ||
*The objective of the adult [[mosquito]] control component is to complement the larval management program by reducing the abundance of adult [[mosquitoes]] in an area, thereby reducing the number of eggs laid in breeding sites. | *The objective of the adult [[mosquito]] control component is to complement the larval management program by reducing the abundance of adult [[mosquitoes]] in an area, thereby reducing the number of eggs laid in breeding sites. | ||
*It is also intended to reduce the abundance of biting, infected adult [[mosquitoes]] in order to prevent them from transmitting WNV to humans and to break the mosquito-bird transmission cycle. | *It is also intended to reduce the abundance of biting, infected adult [[mosquitoes]] in order to prevent them from transmitting WNV to humans and to break the mosquito-bird transmission cycle. | ||
*In situations where vector abundance is increasing above acceptable levels, targeted | *In situations where vector abundance is increasing above acceptable levels, targeted [[pesticides]] against the adult mosquito can assist in maintaining vector abundance below threshold levels. | ||
*Pesticides for adult [[mosquito]] control can be applied from hand-held application devices or from trucks or aircraft. | *[[Pesticides]] for adult [[mosquito]] control can be applied from hand-held application devices or from trucks or aircraft. | ||
*Hand-held or truck-based applications are useful to manage relatively small areas, but are limited in their capacity to treat large areas quickly during an outbreak. In addition, gaps in coverage may occur during truck-based applications due to limitations of the road infrastructure. | *Hand-held or truck-based applications are useful to manage relatively small areas, but are limited in their capacity to treat large areas quickly during an outbreak. In addition, gaps in coverage may occur during truck-based applications due to limitations of the road infrastructure. | ||
*Aerial application of [[mosquito]] control | *Aerial application of adult [[mosquito]] control [[pesticides]] is required when large areas must be treated quickly, and can be particularly valuable because controlling WNV vectors such as Cx. quinquefasciatus or Cx. pipiens often requires multiple, closely spaced treatments. | ||
* Both truck and aerially-applied pesticides for adult [[mosquito]] control are applied using ultra-low-volume (ULV) technology in which a very small volume of pesticide is applied per acre in an aerosol of minute droplets designed to contain sufficient pesticide to kill [[mosquitoes]] that are contacted by the droplets. | * Both truck and aerially-applied [[pesticides]] for adult [[mosquito]] control are applied using ultra-low-volume (ULV) technology in which a very small volume of [[pesticide]] is applied per acre in an aerosol of minute droplets designed to contain sufficient [[pesticide]] to kill [[mosquitoes]] that are contacted by the droplets. | ||
|- | |- | ||
| style="padding: 5px 5px; background: #F5F5F5;" colspan=3|<small><small>Adapted from West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control<ref name="CDC SPC"></ref></small></small> | | style="padding: 5px 5px; background: #F5F5F5;" colspan=3|<small><small>Adapted from West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control<ref name="CDC SPC"></ref></small></small> |
Revision as of 15:06, 11 September 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]
Overview
Vaccines are not available for west nile virus infection. In the absence of a vaccine, prevention of WNV disease depends on community-level mosquito control programs to reduce vector densities, personal protective measures to decrease exposure to infected mosquitoes, and screening of blood and organ donors.
Primary Prevention
Vaccination
There is no vaccine available against west nile virus.
Preventing Mosquito Bites[1]
- Use insect repellents when you go outdoors.
- Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection.
- To optimize safety and effectiveness, repellents should be used according to the label instructions.
- When weather permits, wear long sleeves, long pants, and socks when outdoors.
- Mosquitoes may bite through thin clothing, so spraying clothes with repellent containing permethrin will give extra protection.
- Do not apply repellents containing permethrin directly to skin.
- Do not spray repellent on the skin under your clothing.
- Take extra care to use repellent and protective clothing from dusk to dawn or consider avoiding outdoor activities during these times.
Integrated Vector Management (IVM)
- Mosquito abatement programs successfully employ integrated pest management (IPM) principles to reduce mosquito abundance, providing important community services to protect quality of life and public health[2].
- Prevention and control of WNV and other zoonotic arboviral diseases is accomplished most effectively through a comprehensive, integrated vector management (IVM) program applying the principles of IPM.
- IVM is based on an understanding of the underlying biology of the arbovirus transmission system, and utilizes regular monitoring of vector mosquito populations and WNV activity levels to determine if, when, and where interventions are needed to keep mosquito numbers below levels which produce risk of human disease, and to respond appropriately to reduce risk when it exceeds acceptable levels.
- Operationally, IVM is anchored by a monitoring program providing data that describe:
- Conditions and habitats that produce vector mosquitoes.
- Abundance of those mosquitoes over the course of a season.
- WNV transmission activity levels expressed as WNV infection rate in mosquito vectors.
- Parameters that influence local mosquito populations and WNV transmission.
- These data inform decisions about implementing mosquito control activities appropriate to the situation, such as:
- Source reduction through habitat modification.
- Larval mosquito control using the appropriate methods for the habitat.
- Adult mosquito control using pesticides applied from trucks or aircraft when established thresholds have been exceeded.
- Community education efforts related to WNV risk levels and intervention activities.
- Monitoring also provides quality control for the program, allowing evaluation of:
- Effectiveness of larval control efforts.
- Effectiveness of adult control efforts.
- Causes of control failures (e.g., undetected larval sources, pesticide resistance, equipment failure).
Surveillance Programs
- Effective IVM for WNV prevention relies on a sustained, consistent surveillance program that targets vector species.
- The objectives are to identify and map larval production sites by season, monitor adult mosquito abundance, monitor vector infection rates, document the need for control based on established thresholds, and monitor control efficacy.
- Surveillance can be subdivided into three categories based on the objective of the surveillance effort; these are: larval mosquito surveillance, adult mosquito surveillance and WWNV transmission activity.
- However, the surveillance elements are complementary, and in combination provide the information required for IVM decisions.
Larval Mosquito Surveillance | Adult Mosquito Surveillance | WNV Transmission Activity |
---|---|---|
|
|
|
Adapted from West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control[3] |
Mosquito Control Activities
- Integrated efforts to control mosquitoes are implemented to maintain vector populations below thresholds that would facilitate WNV amplification and increase human risk.
- Efforts to reduce the abundance of WNV-infected biting adult mosquitoes must be quickly implemented to prevent risk levels from increasing to the point of a human disease outbreak.
- Properly implemented, a program monitoring mosquito abundance and WNV activities in the vector mosquito population will provide a warning of when risk levels are increasing.
- Because of delays in onset of disease following infection, and delays related to seeking medical care, diagnosis, and reporting of human disease, WNV surveillance based on human case reports lags behind increases in risk and is not sufficiently sensitive to allow timely implementation of outbreak control measures.
- In outbreak situations, larval control complements adult mosquito control measures by preventing new vector mosquitoes from being produced.
- Source reduction and larvicide treatments may be inadequate to maintain vector populations at levels sufficiently low to limit virus amplification.
Larval Mosquito Control | Adult Mosquito Control | |
---|---|---|
|
| |
Adapted from West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control[3] |
References
- ↑ "CDC West Nile Virus Prevention & Control".
- ↑ Rose RI (2001). "Pesticides and public health: integrated methods of mosquito management". Emerg Infect Dis. 7 (1): 17–23. doi:10.3201/eid0701.700017. PMC 2631680. PMID 11266290.
- ↑ 3.0 3.1 "CDC West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control" (PDF).