Emergent and Travel Related Mosquito Viruses

Zika Virus

During 2016, Zika virus cases have been reported from both returning travelers to the US and locally acquired in the states of Florida and Texas primarily from the bite of infected Ae. aegypti mosquitoes.

As the status of Zika virus in Massachusetts and the United States changes, information can be found at the following state and federal websites:

Chikungunya Virus (CHIKV)

Chikungunya virus is transmitted to people by mosquitoes. The most common symptoms of chikungunya virus infection are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash. There is no vaccine to prevent or medicine to treat chikungunya virus infection. Travelers can protect themselves by preventing mosquito bites. When traveling to countries with chikungunya virus, use insect repellent, wear long sleeves and pants, and stay in places with air conditioning or that use window and door screens.

For more information on Chikungunya Virus please visit:

Dengue Virus (DENV)

A continuing arboviral concern in the continental United States is Dengue virus (DENV), also known as “Break bone fever”. Very few cases of locally-acquired Dengue are confirmed in the US every year. Symptoms of Dengue include high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding. A more dangerous manifestation, frequently when there have been multiple dengue episodes in an individual, is Dengue hemorrhagic fever. After the fever declines, there is persistent vomiting, severe abdominal pain, and difficulty in breathing. This can be followed by excessive bleeding into the body cavities leading to circulatory failure and shock, followed by death. There is no medication for the prevention or treatment of Dengue.

For more information on Dengue Virus please visit:

Jamestown Canyon Virus (JCV)

Jamestown Canyon virus (JCV) was first isolated in 1961 from a mosquito in Colorado and was first recognized to cause human disease in 1980. Jamestown Canyon virus disease is relatively rare; in the United States, the CDC found only 31 disease cases from 2000-2013, but it is likely under-recognized and probably endemic throughout most of the United States. JCV persists among white-tailed deer and 22 different species of mosquitoes including Aedes and Anopheles. The infection occurs in June through September with a peak in mid-June to mid-July. Clinical features include mild febrile illness with acute central nervous system infection including meningitis and encephalitis and frequently respiratory system involvement in patients more than 18 years old.

In 2013, of 10 states reporting cases, eight states (Georgia, Idaho, Massachusetts, Minnesota, New Hampshire, Oregon, Pennsylvania, and Rhode Island) reported their first JCV cases. In Connecticut, human cases have been rare, but mosquitoes in eight towns, including Stamford and Norwalk, have tested positive for the virus in 2014. In August 2015 the Iowa Department of Public Health announced that one case of JCV has been confirmed.

In 2017, a Maine resident was diagnosed with JVC. See article here

For more information on JVC Virus please click here.

Saint Louis Encephalitis Virus (SLEV)

Saint Louis encephalitis virus (SLEV) is transmitted to humans by the bite of an infected mosquito. Most cases of SLEV disease have occurred in eastern and central states. Culex pipiens are one of the primary mosquito vectors for this bird disease. Most persons infected with SLEV have no apparent illness. Initial symptoms of those who become ill include fever, headache, nausea, vomiting, and tiredness. Severe neuroinvasive disease (often involving encephalitis, an inflammation of the brain) occurs more commonly in older adults. In rare cases, long-term disability or death can result. There is no specific treatment for SLEV infection; care is based on symptoms. The majority of cases have occurred in eastern and central states, where episodic urban-centered outbreaks have recurred since the 1930s. New Hampshire reported one human case in 2006.

For more information on SLE Virus please click here.