Vector Surveillance Facts & FAQS

The Asian tiger mosquito, Aedes albopictus, has a life cycle that is closely associated with human habitats, and it breeds in any type of container that is holding water, including tires, flowerpot saucers, water barrels, fallen magnolia leaves, etc. 

It is a daytime feeder and can be found in shady areas where it rests in shrubs near the ground. Aedes albopictus feeding peaks in the early morning and late afternoon; it is an opportunistic and aggressive biter with a wide host range including man, and domestic and wild animals.  

The distribution of the Asian tiger mosquito is subtropical, with a temperate distribution in North America. The Asian tiger mosquito was first documented in the United States in Texas during 1985, and in the nearly 30 years since its discovery this species has spread throughout much of the East. The mosquito was most likely transported along highways and other major roadways in shipments of used tires imported from other countries for retreading.  Aedes albopictus populations are currently established in 866 counties in 26 states. Georgia was the first state in the US to report Ae albopictus in every county during the 1990s; it is our number one pest species in non-coastal areas.  

Aedes albopictus is known to be a competent laboratory vector of more than 30 viruses.  Several of these viruses are found in Georgia, including eastern equine encephalitis (EEE) and LaCrosse encephalitis viruses (LAC).  Aedes albopictus has been implicated in the transmission of dengue, but is not a major vector.  It has also been implicated in the transmission of Chikungunya virus, and is the major vector for one variant of the disease.  Fortunately, this is not the variant currently found in Haiti and the Caribbean.  However, Ae albopictus is capable of transmitting the Chikungunya virus found in these areas.  That is why people in the US who have been infected with Chikungunya virus during travel are asked to remain indoors and wear repellent if they go outdoors, to avoid giving the virus to local mosquitoes.   

Aedes albopictus overwinter in the egg stage in temperate climates but are active throughout the year in tropical and subtropical habitats. Eggs are laid singly on the sides of water-holding containers such as tires, animal watering dishes, birdbaths, flowerpots and natural holes in vegetation, and can withstand desiccation up to one year.  Larval emergence occurs after rainfall raises the water level in the containers.  Development is temperature-dependent, but the larvae usually pupate after five to ten days and the pupal stage lasts two days; during a hot Georgia summer Asian tiger mosquitoes can go from egg to adult in a little as one week. 

Source reduction is an effective way for people in the community to manage the populations of container breeding species such as the Asian tiger. Eliminate any standing water on the property, change pet watering dishes, overflow dishes for potted plants, and bird bath water frequently. Do not allow water to accumulate in tires, flowerpots, buckets, rain barrels, gutters etc. Use personal protection to avoid mosquito bites. Lightweight long sleeve shirts and long pants and insect repellent such as DEET will reduce exposure to bites. The Asian tiger mosquito is a day biter with feeding peaks in early morning and late afternoon, so limiting outdoor activities during periods when mosquitoes are most active can also help prevent bites.  Mosquitoes are not strong fliers, so using fans on porches and patios will also help reduce mosquito exposure.   Where breeding habitat is too abundant for effective source reduction, barrier sprays, applied by licensed pest control professionals, can reduce the number of Asian tiger mosquitoes in a local area.  Barrier spray and source reduction used together are most effective.  Contractors licensed in the State of Georgia for mosquito control can be found at https://agr.georgia.gov/search-licenses?id=85.

Repellents, clothing, netting and other personal protection measures can help prevent mosquito bites and the diseases they carry. Insect repellents are effective, but not entirely safe — they must be used with caution. However, to help prevent mosquito-borne diseases like EEE and WNV, they must be used.

• DEET (N, N-diethyl-3-methylbenzamide) is probably the best known insect repellent. It repels both mosquitoes and ticks. It is sold under numerous brand names (Off ®, Cutter ®, etc.) and comes in lotion, spray and many other forms. Concentrations of DEET range from about 5% all the way up to 100%, though after a certain point, higher concentrations do not guarantee greater protection. The federal Centers for Disease Control and Prevention and the American Academy of Pediatrics both recommend using DEET-based repellents to help prevent mosquito and tick bites. The CDC states that DEET-based repellents "are very safe when used according to the directions." The AAP suggests that DEET-based repellents be used to protect against insect- and tick-borne disease and advises parents that products containing up to 30% DEET can be used on children over the age of two months.

As with all repellents, DEET-based products should be applied only according to the directions on the product label.  

• Picaridin has effectiveness comparable that of DEET. Products with picaridin can be expected to provide better and longer-lasting protection than plant-based repellents. Cutter Advanced® contains picaridin as an active ingredient.
• Oil of lemon eucalyptus, or PMD, has been tested against mosquitoes found in the US, and provides protection similar to repellents with low concentrations of DEET. Be sure to check with your health care provider for best use practices if you are pregnant, nursing, or are applying repellent to children under the age of 2 years.

Other Repellents

Repellents derived from plants such as citronella, geranium, basil, garlic and peppermint generally provide only temporary protection from mosquitoes, if any at all.

• Bite Blocker ®, a plant-based repellent released in 1997 containing soybean oil, geranium oil and coconut oil, has shown to be a good repellent for up to 3 1/2 hours against Aedes aegypti (the mosquito that transmits yellow fever).
• Avon’s Skin-So-Soft ® bath oil has gained popularity as a mosquito repellent, but its effects are only slight and not long-lasting. Skin-So-Soft ® is not nearly as effective as DEET.
• Citronella candles can be mildly effective mosquito repellents. However, there effectiveness is not much greater than that of ordinary candles.

Permethrin is a pesticide rather than a repellent. It is not for use on the skin, but is intended for clothing. Permethrin products are sold in lawn, garden or sporting goods stores under names such as Permanone Repel ®. Permethrin can retain its potency for at least two weeks — even through several launderings. The combination of Permethrin-treated clothing and DEET-treated skin creates almost complete protection against mosquito bites. In field trials conducted in Alaska, Permethrin-treated clothing and 35% DEET on exposed skin provided greater than 99.9% protection.

Safe Repellent Use

DO:

• Use aerosol or pump sprays for treating skin and clothing. These products provide an even application.
• Use liquids, creams, lotions or sticks to more precisely apply the product to exposed skin. Wash DEET-covered skin with soap and water after outdoor activity.
• Keep insect repellents out of the reach of children at all times.

DON'T:

• Apply to eyes, lips or mouth, or over cuts, wounds or irritated skin.
• Over-apply to the skin, or saturate clothing.
• Apply to skin beneath clothing, or to skin that is not exposed.
• Apply more or more often than recommended on the product label

New repellents occasional come on to the market. To check the usefulness and safety of new repellents, go to https://www.cdc.gov/west-nile-virus/prevention/, https://www.epa.gov/insect-repellents, and http://cfpub.epa.gov/oppref/insect/.



 

The MOSQUITO MAGNET and the use of OCTENOL or LUREX 

If you live in Georgia, in an urban or suburban area, and are being bitten during the day by a black & silver-colored mosquito, it is likely that you are being bitten by Aedes albopictus, the Asian tiger mosquito. Although there are other species that are similar-looking and will bite during the day, including some of the saltmarsh species, the Asian tiger mosquito is usually the number one pest species in urban and suburban areas of Georgia. 

The best place to set your mosquito trap is away from your home or pool. These traps do attract mosquitoes, and will catch some of the mosquitoes in your yard. However, if there are a lot of mosquitoes in the area, you will probably not see a reduction in the number of mosquitoes biting you. Also, these traps do not catch some of the Culex spp very well. These are the mosquitoes that are known to carry West Nile virus. So, it is still important to wear repellent when you are outside and to be sure to eliminate mosquito-breeding sites around your home. 

For additional information, check out the American Mosquito Control Association site at http:// www.mosquito.org/page/traps. 

For additional information on which attractant to use, visit http://www.mosquitomagnet.com/ advice/keys-to-success/attractants-101. 

Since the Mosquito Magnet was developed, new trap types have come on to the consumer use market. For more information, check out https://www.consumerreports.org/health/insect-repellent/mosquito-traps-lures-bug-zappers-a6094812568/.

Why doesn't my county spray? 

• Many counties that do have spraying programs in place have been spraying for years. This spraying is done to protect against nuisance mosquitoes.
• A list of Georgia counties with mosquito control programs can be found at http:// www.gamosquito.org/resources/GA_Mosquito_Control_Programs2017.pdf.
• Adulticiding is just one of the tools used for mosquito-borne disease prevention. Public education on personal protection, along with source reduction and larviciding, should also be part of the program for the prevention of mosquito-borne diseases. See Mosquito Control BMPs (http://www.gamosquito.org/resources/papers/AMCA_BMP.pdf) for additional information.
• Most counties in Georgia do not have the resources to provide effective mosquito control. Mosquito control programs require sustainable funding.
• There is evidence that well-integrated mosquito control programs, including surveillance, source reduction (eliminating mosquito breeding areas), larviciding (placing specific chemicals in places where there are mosquito larvae) and adulticiding, can reduce mosquito numbers and prevent pesticide resistance, which will help with disease control.
• While mosquito control decisions, including whether or not to spray, are made at the local level, state public health officials in Georgia support an integrated approach for mosquito control. Local officials can contact the Department of Public Health for more information about how to conduct an integrated program in their counties. 

What can I do to protect myself? 

• Most mosquitoes that carry WNV don't travel more than ½ mile from their breeding place. Mosquitoes that can carry ZIKV fly only about 200 yards. The best way to protect your family against mosquito-borne diseases is to remove standing water from around your home, and the best time to start is now.
• Persons can protect themselves from mosquito bites by wearing light-weight long-sleeved shirts and long pants, weather permitting, when mosquitoes are biting, and by using mosquito repellent containing N,N-DIETHYL-META- TOLUAMIDE (DEET) or other repellents recommended by the CDC (https://www.cdc.gov/west-nile-virus/prevention/).
• The AAP suggests that DEET-based repellents be used to protect against insect- and tick-borne disease and advises parents that products containing up to 30% DEET can be used on children over the age of two months. However, pregnant women, nursing mothers, and parents of children under the age of 2 years should contact their health care provider before using these products.
• Be sure to read and follow the manufacturer’s DIRECTIONS FOR USE, as printed on the product.
• Permanone can be used ON CLOTHING to repel mosquitoes. These products should never be applied to the skin. Be sure to read and follow the manufacturer’s DIRECTIONS FOR USE, as printed on the product.

Why do mosquito surveillance? 

• Mosquito surveillance helps public health officials know if human risk of disease isrising and when and where to apply mosquito control measures. Without surveillance, chemicals may be sprayed where mosquitoes are not a problem and places where mosquitoes are a problem can be missed.
• Surveillance enables the public (through local source reduction) and public health officials (through integrated mosquito control) to reduce mosquito breeding before mosquitoes become a public health problem. 

Where can I go to learn more about this? 

Check out the Georgia Mosquito Control association website at http://www.GAmosquito.org. 

Also, check the CDC’s WNV page at http://www.cdc.gov/ncidod/dvbid/westnile/index.htm and the CDC ZIKV page at https://www.cdc.gov/zika/.

Why are animals important in West Nile virus transmission? 

West Nile virus is a disease of birds. Hundreds of different species of birds have been found to be infected with West Nile virus, but not all of them die. Crows and blue jays are most likely to die from infection with West Nile virus, while other birds like chickens seem to develop no symptoms at all. West Nile virus is spread to humans when a mosquito bites a bird that is carrying the virus and then bites a human. In this same way, other animals can be infected with the virus. Horses can be infected and become ill when they are bitten by a mosquito carrying the virus. Other animals such as dogs and cats can also be infected in this manner, but they are unlikely to show any symptoms of illness. 

What are the symptoms of West Nile virus in horses? 

Horses that are infected with West Nile virus may or may not show symptoms of illness. If they become sick, they may have depression, apprehension, weakness of limbs, partial paralysis, inability to stand, muscle twitching, or incoordination. 

Will all horses that are affected by the virus die? 

No. About 30% of horses that get sick with West Nile virus will die or need to be euthanized. 

Will horses affected by the virus be quarantined? 

No. Since infected horses are not carriers for the disease and do not infect mosquitoes, it is unlikely that quarantine would be necessary. 

Is there a vaccine for horses to protect against West Nile virus? 

Yes, there is a vaccine for use in horses. For the vaccine to be the most effective, it must be given in two doses, 3 to 6 weeks apart, with the last dose given 4 weeks before the beginning of the mosquito season. An annual booster is needed every year. Please contact your veterinarian for information about obtaining the vaccine for your horse. 

There is currently no vaccine for animals other than horses. 

Is there anything I can do to protect my horse from West Nile virus? 

Yes. You should have your horse vaccinated for West Nile virus through your veterinarian. Additionally, you should limit your horse’s exposure to mosquitoes. The best way to do this is by removing any potential sources of water in which mosquitoes can breed. Dispose of any water-holding containers on your property. Drill holes in the bottom of containers that are left outdoors. Clean clogged roof gutters. Keep swimming pools and ornamental ponds properly cleaned and maintained. Routinely empty, clean, and refill livestock watering troughs. Fill in any low areas in the yard or pasture where water tends to collect. The larvicides Bti and altosid can also be used in water to prevent mosquito breeding. These pesticides are safe to use in animal drinking water if applied according to label.

It may be advisable to keep horses inside a barn with the doors closed at night to reduce the probability of them being bitten by a mosquito. Window screens and fans may also reduce the number of mosquitoes biting in the barn. 

Do not use repellents designed for humans on horses or other animals. If a repellent is required, have your veterinarian recommend a suitable product. 

When I vaccinate my horse against Eastern Equine Encephalitis (EEE), Western Equine Encephalitis (WEE), or Venezuelan Equine Encephalitis (VEE), will that protect against infection with West Nile virus? 

No. The equine encephalitis viruses and West Nile virus belong to different families, so the vaccines do not provide cross-protection. Ask your veterinarian about a combination vaccine to protect against WNV and EEE. In Georgia, it is important to have your horse vaccinated for both West Nile virus and Eastern Equine Encephalitis virus prior to the beginning of the mosquito season. 

What animals other than birds can get West Nile virus? Do I have to worry that my pets or livestock will get West Nile virus? 

Many species of wild and domestic animals (i.e. dogs, cats, squirrels, sheep, chickens, pigs, cows, bats, etc.) can become infected with West Nile virus by the bites of infected mosquitoes. However, most animals other than birds will not become ill or die when they are infected with the virus. Horses and farmed alligators are susceptible to WNV, and may become sick and/or die from infection. You should keep your pet birds inside to keep them from becoming infected by biting mosquitoes. Cats may also become infected with West Nile virus by eating an infected mouse, but are unlikely to become ill. Dogs and cats that become sick when infected with WNV are usually otherwise immunocompromised. 

My pet is sick. Can I have him/her tested for West Nile virus infection? 

Please contact a veterinarian to evaluate and treat any pets or domestic animals that become ill. The Georgia Public Health Laboratory is not testing small mammals or pets (dogs, cats, squirrels, chipmunks, etc.) for West Nile virus as part of Georgia’s surveillance for the virus. 

Laboratory testing of ill animals other than horses or birds might be available at commercial laboratories and arrangements should be made through local veterinarians. 

If your pet becomes ill from West Nile virus infection, this is a sign that there are mosquitoes in your area that are actively transmitting the virus. Take extra precautions to protect yourself from mosquito-borne diseases by using insect repellent containing DEET and wearing protective clothing.

What is the treatment for an animal that is infected with West Nile virus? Should an infected animal be destroyed?

There is no specific treatment, medication, or cure for illnesses caused by West Nile virus in dogs, cats, horses, or other animals. However, the symptoms and complications of the disease can be treated with supportive therapy that is consistent with standard veterinary practices for animals infected with a viral agent. Full recovery from the infection is likely and there is no reason to destroy an animal that is infected. Ask your veterinarian about new experimental drugs that have been given conditional license by the USDA for use in horses that are sick with West Nile infection.

Can infected dogs or cats (or other animals) be carriers (i.e. reservoirs) for West Nile virus and transmit the virus to humans or other animals?

West Nile virus is transmitted by infected mosquitoes. You cannot get WNV through contact with an infected animal or human, including from the bite of an infected dog. In addition, animals other than birds are considered dead end hosts. This means they do not produce enough virus to infect mosquitoes that feed on them. Veterinarians should take normal infection control precautions when caring for an animal suspected to have this or any viral infection.

Do I have to worry that my poultry (chickens, turkeys) will get West Nile virus? Should I continue to eat their eggs?

Most chickens and turkeys that are infected with West Nile virus will make antibodies to the virus but will not become ill or die. There is no reason to believe that eating properly cooked chicken or turkey will transmit the virus. You may continue to eat your chickens' eggs. There is no evidence that West Nile virus or other mosquito-transmitted viruses appear in chickens' eggs. You should always cook your eggs thoroughly to prevent food-borne illnesses.

Are wild game hunters at risk for West Nile virus infection?

Because of their outdoor exposure, hunters may be at risk if they are bitten by mosquitoes in areas where there is West Nile virus activity. Hunters should take precautions to avoid mosquito bites, such as applying mosquito repellent to clothing and skin according to label instructions. Hunters should also follow the usual precautions when handling wild animals.

They should wear gloves when handling and cleaning animals to prevent blood exposure to bare hands and meat should be cooked thoroughly.

For additional information, go to https://www.agr.georgia.gov/sites/default/files/documents/animal-health/west-nile-virus.pdf

 

 

What is tick paralysis?

Tick paralysis refers to acute onset of paralysis caused by a tick bite. The condition is primarily found in the Rocky Mountain and northwestern regions of the United States and is rare in Georgia. The number of cases per year is unknown because physicians are not required to report cases of tick paralysis to Public Health.

How is tick paralysis spread?

Tick paralysis results from a neurotoxin that is secreted in the saliva of certain ticks when they feed. The tick must be attached for several days. Person-to-person transmission of tick paralysis has not been documented.

Who gets tick paralysis?

Anyone who is bitten by a tick can get tick paralysis, but it most commonly affects children less than 10 years of age.

What are the symptoms of tick paralysis?

The symptoms of tick paralysis include weakness in the legs and arms, followed by paralysis beginning in the legs and moving upward. If unrecognized, tick paralysis may progress to respiratory failure and may be fatal in 10% of cases.

What is the treatment for tick paralysis?

Treatment for tick paralysis is simply removal of the tick. Once the tick is found and removed, the patient recovers fully, often within a matter of hours. It is often difficult to find the tick, which can be attached to the scalp and hidden in the hair.

What can be done to prevent the spread of tick paralysis?

There are no vaccines to prevent tick-borne disease, so limiting exposure to ticks is very important. When spending time outdoors in places where contact with ticks may occur, take the following precautions:

• Wear light-colored clothing so that crawling ticks can be easily seen.
• Wear pants and long sleeves to reduce skin exposure to ticks.
• Tuck pants into socks and shirts into pants to prevent ticks from crawling up pants legs.
• Apply insect repellent containing DEET to exposed skin, and permethrin to clothing.
• After spending time outdoors, thoroughly inspect your body for crawling or attached ticks.

How should a tick be removed?

To remove an attached tick, grasp with fine-tipped tweezers as close to the skin surface as possible, and pull upward and out with a firm, steady pressure. If tweezers are not available, use fingers shielded with tissue paper or rubber gloves. Do not handle with bare hands. Do not use petroleum jelly, fire, or other home remedies; these methods may actually increase the risk of infection. Be careful not to squeeze, crush, or puncture the tick’s body, which may contain infectious fluids. After removing the tick, thoroughly disinfect the bite area and wash hands.

Consult with a physician if there is concern about incomplete tick removal.

Where can I get additional information about tick paralysis?

Adapted from: CDC. Tick Paralysis—Washington, 1995. MMWR 1996; 45(16):325-6.

 

 

• Ticks feed by inserting their mouthparts into the skin of their host and slowly sucking in blood. Sometimes humans act as hosts for ticks, causing tick-borne diseases to be an important public health problem.
• Ticks are commonly found in shady areas, moist ground litter, tall grass, brush, and low tree branches, and along trails in the woods. They can also be found in backyards that back up to woody areas.
• To remove a tick, grasp the tick as close to the skin surface as possible with fine-tipped tweezers. Pull the tick straight out slowly.
• Wash and treat the bite area with a disinfectant. Not all ticks carry diseases, but see your doctor if you develop early symptoms of tick-borne disease within the next 1 to 4 weeks.

Lone Star Tick (Amblyomma americanum)

• Most common tick in Georgia
• Transmits the bacteria that cause human monocytic ehrlichiosis (HME) and southern tick-associated rash illness (STARI)
• https://www.cdc.gov/ticks/data-research/facts-stats/lone-star-tick-surveillance.html

American Dog Tick (Dermacentor variabilis)

• Second most common tick in Georgia
• Transmits the bacterium that causes Rocky Mountain spotted fever
• Requires attachment for at least 4 hours to cause illness
• https://www.cdc.gov/ticks/data-research/facts-stats/american-dog-tick-surveillance.html

Black-legged Tick or “Deer Tick” (Ixodes scapularis)

• Transmits the bacteria that cause Lyme disease and human granulocytic anaplasmosis (HGA)
• Requires attachment for at least 24 hours to cause illness
• https://www.cdc.gov/ticks/data-research/facts-stats/blacklegged-tick-surveillance.html