Aedes in the context of Aedes albopictus

Dengue fever is a mosquito-borne disease caused by dengue virus, prevalent in tropical and subtropical areas. Most cases of dengue fever are either asymptomatic or manifest mild symptoms. Symptoms typically begin 3 to 14 days after infection. They may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic skin itching and skin rash. Recovery generally takes two to seven days. In a small proportion of cases, the disease develops into severe dengue (previously known as dengue hemorrhagic fever or dengue shock syndrome) with bleeding, low levels of blood platelets, blood plasma leakage, and dangerously low blood pressure.

Dengue is spread by several species of female mosquitoes of the Aedes genus, principally Aedes aegypti. The virus has four confirmed serotypes; infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of severe complications, so-called antibody-dependent enhancement. The symptoms may resemble those of malaria, influenza, or Zika. Blood tests to confirm the diagnosis including detecting viral RNA, or specific antibodies.

Zika fever, also known as Zika virus disease or simply Zika, is an infectious disease caused by the Zika virus. Most cases have no symptoms, but when present they are usually mild and can resemble dengue fever. Symptoms may include fever, red eyes, joint pain, headache, and a maculopapular rash. Symptoms generally last less than seven days. It has not caused any reported deaths during the initial infection. Mother-to-child transmission during pregnancy can cause microcephaly and other brain malformations in some babies. Infections in adults have been linked to Guillain–Barré syndrome (GBS).

Zika fever is mainly spread via the bite of mosquitoes of the Aedes type. It can also be sexually transmitted and potentially spread by blood transfusions. Infections in pregnant women can spread to the baby. Diagnosis is by testing the blood, urine, or saliva for the presence of the virus's RNA when the person is sick, or the blood for antibodies after symptoms are present more than a week.

Chikungunya is an infection caused by the chikungunya virus. The most common symptoms are fever and joint pain, typically occurring four to eight days after the bite of an infected mosquito; however some people may be infected without showing any symptoms. Other symptoms may include headache, muscle pain, joint swelling, and a rash. Symptoms usually improve within a week; however, occasionally the joint pain may last for months or years. The very young, old, and those with other health problems are at risk of more severe disease.

The virus is spread between people by two species of mosquito in the genus Aedes: Aedes albopictus and Aedes aegypti, which mainly bite during the day, particularly around dawn and in the late afternoon. The virus may circulate within a number of animals, including birds and rodents. Diagnosis is done by testing the blood for either viral RNA or antibodies to the virus. The symptoms can be mistaken for those of dengue fever and Zika fever, which are spread by the same mosquitoes. It is believed most people become immune after a single infection.

La Crosse encephalitis is an encephalitis caused by the La Crosse virus which has a mosquito vector (Ochlerotatus triseriatus synonym Aedes triseriatus).

La Crosse encephalitis virus (LACV) is one of a group of mosquito-transmitted viruses that can cause encephalitis, or inflammation of the brain. LAC encephalitis is rare; in the United States, about 80–100 LACV disease cases are reported each year, although it is believed to be under-reported due to minimal symptoms experienced by many of those affected.

Keystone virus (Orthobunyavirus keystoneense) is a mosquito-borne virus which can infect mammals. It was first discovered in animals in the Florida area, where it is spread in part by local species of Aedes mosquitoes. In 1964, a case of human infection, producing minor symptoms of a rash and fever, was circumstantially diagnosed. Conclusive laboratory demonstration of the virus in humans was first obtained and reported in 2018.