Lyme disease: Caused by a bacterium. Early symptoms appear three to 30 days after a bite by an infected tick (usually the deer tick) and can include fatigue, fever, headache and joint and muscle pain. A red “bull’s-eye” rash is reported in about half of the cases in Maine. Later symptoms can include arthritis and neurological problems. Accurate diagnosis can be difficult. Lyme is treated with antibiotics, but doctors disagree about how long antibiotics should be given.  
 

Babesiosis: Caused by a parasite that infects red blood cells. Symptoms typically appear one to nine weeks after a bite by an infected tick (usually the deer tick), though they can take longer to appear. Symptoms include fatigue, fever, aches, chills, sweating, dark urine and possibly anemia. Babesiosis is treated with antibiotics.
 

Anaplasmosis: Caused by a bacterium that infects white blood cells. Symptoms appear five to 21 days after a bite by an infected tick (the deer tick). Symptoms range from very mild to very severe, and include fatigue, fever, headache, muscle pain, chills, nausea, stomach pain, cough and confusion. More severe symptoms can include difficulty breathing, hemorrhage, kidney failure and neurological problems. Anaplasmosis is treated with antibiotics.

Powassan virus: Caused by a virus transmitted by infected ticks.There are two types of the virus: One associated with the woodchuck tick or squirrel tick, and one associated with the deer tick. Human cases are rare, but Maine has seen a few in the past decade. Most people do not get ill. Those who do typically see symptoms develop one week to one month after the bite of an infected tick. Symptoms can include fever, headache, vomiting, weakness, confusion, loss of coordination, speech problems and seizures. Powassan can also infect the central nervous system and cause inflammation in and around the brain. About half of survivors have permanent neurological problems.There is no specific treatment for the Powassan virus.

  

Diseases carried by mosquitoes already in Maine:
 

EEE: Eastern equine encephalitis is caused by a virus that can cause inflammation of the brain. Although EEE is rare, it has a high mortality rate. Many people will have no obvious symptoms. For those who do get sick, symptoms typically appear four to 10 days after a bite from an infected mosquito and can include fever, chills, body and muscle pain and weakness. Severe cases begin with sudden, high fever (103 to 106 degrees), headache, stiff neck, chills and vomiting, before quickly progressing to an altered mental state, seizures and brain inflammation. About one-third of EEE patients die and many survivors have brain damage. There is no specific treatment for EEE. 

West Nile virus: Caused by a virus that leads to fever and inflammation in and around the brain. Most people infected by West Nile (70 to 80 percent) don’t get sick. For those who do, symptoms appear two to 14 days after a bite by an infected mosquito and can include fever, headache and body aches, often with a skin rash and swollen lymph glands. In less than 1 percent of cases, patients will develop a neurological illness, such as encephalitis or meningitis. There is no specific treatment for the West Nile virus.

Some diseases carried by mosquitoes that could come to Maine in the future:

 

Zika virus: Spread by the bite of an infected Aedes species of mosquito, a bug that has not been found in Maine but is moving north and could expand into the state in the coming years, experts say. Experts don’t know how long it takes for symptoms to appear, but they believe it’s likely a few days to a week after infection. Common symptoms include fever, rash, joint pain and conjunctivitis. Many people never realize they’re sick and patients very rarely die. However, Zika has been linked to severe birth defects in babies whose mothers had the virus while pregnant. There is no specific treatment for the Zika virus.

Dengue fever: Also spread by the bite of an infected Aedes species of mosquito. Symptoms can begin within three to 10 days of infection and include high fever, severe headache, pain behind the eyes, joint pain, muscle and bone pain, easy bruising and mild bleeding from the nose or gums. It can also lead to dengue hemorrhagic fever, a severe illness that can cause circulatory system failure, shock and death. There is no specific treatment for dengue fever.

Chikungunya virus: Also spread by the bite of an infected Aedes species of mosquito. Symptoms usually begin three to seven days after the bite of an infected mosquito and typically include fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling and rash. Chikungunya virus does not usually cause death, but the symptoms can be severe. There is no specific treatment for the chikungunya virus.