Category: Uncategorized

As we officially welcome the summer season this Friday, the Virginia Department of Health reminds everyone the importance of eliminating mosquito breeding sites and taking the proper steps to prevent mosquito bites. Mosquitoes are not only a nuisance, but can also pose a serious risk for the spread of disease.

Every summer the Northern House mosquito transmits West Nile virus (WNV) in Virginia, and 2018 was a record year for WNV, causing severe disease and multiple fatalities throughout the Commonwealth. This particular mosquito species breeds in stagnant water that contains high levels of organic materials (such as dead leaves, algae, grass clippings, or livestock manure).  It is an active biter in the evening, nighttime, or early morning hours.  This mosquito will also enter homes through any unscreened doors or windows and bite residents after the lights are out at night.

Consider landscaping or filling with sand and gravel to reduce puddles of standing water, draining and covering any unmaintained swimming pools, or any ornamental ponds that do not contain fish, or larviciding un-dumpable aquatic mosquito habitats with dunks or granules to reduce the risk of breeding mosquitoes in the standing water that serves as ideal breeding habitats for WNV-transmitting mosquitoes. Wherever possible; tip, toss, and cover water-holding containers such as buckets, wheel barrows or plastic tubs to prevent mosquitoes from breeding in your yard. The State Public Health Entomologist, Dr. David Gaines, recommends sitting in a well-lit area if outside at night and wearing long pants, and a long-sleeved shirt with EPA-registered insect repellent applied during any outdoor activity.

The majority of people infected with WNV never feel sick. However, about 1 in 150 of infected people will develop a serious, and sometimes fatal, illness. There are several other mosquito-borne viruses such as the La Crosse encephalitis virus, St. Louis encephalitis virus, or the Eastern equine encephalitis virus that may be carried by other backyard breeding mosquitoes and may similarly cause illnesses in Virginia citizens.

Stay up-to-date with WNV case data and learn more about mosquito surveillance in Virginia by checking out the “Virginia Mosquito Activity Reports” on the “Bugs & Human Health” statistics page. Tune in to hear about WNV prevention from Fairfax County’s MC Bugg-Z in his newest rap “West Nile Story”.

We hope you and your family have a safe and healthy summer!

In November of 2017, a tick species previously unknown to the US called Haemaphysalis longicornis, or the Asian longhorned tick, was discovered both on a sheep and in a pasture in New Jersey.  Since then, this new tick species has been found in eight additional states, including 17 counties and one city in Virginia.

The Asian longhorned tick is native to East Asia and has also been well described in New Zealand and Australia. In the tick’s native range, it has been known to cause Theileriosis disease in cattle, as well as a frequently fatal viral disease called “Severe Fever with Thrombocytopenia Syndrome” (or SFTS) in humans;  the SFTS virus resembles Heartland virus, a pathogen that may be found in Virginia’s environment. There is also some research from this tick’s native territory in Asia showing that the Asian longhorned tick might be capable of transmitting Lyme disease (from an Asian Borrelia species), as well as Human Anaplamsosis and Ehrlichiosis pathogens, and a Spotted fever Rickettsiosis.  However, more time will be needed to assess the tick’s ability to acquire and transmit these various pathogenic agents found in the United States.

An interesting feature of this tick and a major factor enabling its rapid spread, is the ability to reproduce asexually, a process known as parthenogenic reproduction. To date, no males of this species have been confirmed among the many thousands of females that have been discovered. This tick also boasts a broad host range and has been found on birds, rodents, terrestrial mammals, livestock, domestic pets, and even humans. Also, this species of tick has been found in both field and forested environments in Virginia and may be common in pasturelands where livestock might be found grazing. This is atypical of Virginia’s most common human-biting tick species, as they are more likely to be found in a forested environment.

For safety purposes, it is important to take precautionary measures to help reduce your risk of tick bites year round. Here are some steps you can take to avoid being bitten:

• Use EPA registered repellents, such as permethrin, to treat your shoes, socks, pants, and shirts, and ALWAYS follow the product label for use.
• Ticks typically start to climb onto people from the ground, or from low vegetation, so the use of repellents and protective clothing should also be from the ground, up. Tuck your pant legs into your socks and shirt into your pants when in forest or pasture environments.
• Avoid any unnecessary walks in brushy or wooded environments, or grassy fields, especially when not using repellents.

For more information regarding ticks and tick-borne illnesses, visit our ‘Bugs’ and Human Health page on the Virginia Department of Health website under Environmental Epidemiology at https://www.vdh.virginia.gov/environmental-epidemiology/bugs-human-health