Ross River and Barmah Forest viruses
Most cases are asymptomatic. Severity is variable. Typical symptoms include a rash, particularly on palms; polyarthritis/arthralgia; myalgia; lethargy and low-grade fever. Symptoms such as arthralgia, myalgia and lethargy may occasionally persist for months.

Chikungunya virus
Similar to Ross River and Barmah Forest. Flu-like, with high fevers, chills and muscle aches. Other symptoms include severe headaches; a rash on the arms, legs and trunk; and nausea and vomiting. In 80 percent of cases, there is pain or inflammation in the small joints of the hands and feet; this can persist for weeks or months.

Dengue fever
Classical dengue fever is more commonly seen in older children and adults. Symptoms include sudden onset of fever; headache, particularly retro orbital; myalgia and arthralgia; and a fine rash, which may be itchy and usually begins on the extremities but spares the palms and soles. Other symptoms include weakness, depression, anorexia, abnormal taste, sore throat, coughing, vomiting and abdominal pain.

Dengue haemorrhagic fever
This can occur when a person who has previously had one type of dengue fever becomes infected by another type. It is most commonly seen in children under 15 years of age but can also occur in adults. Onset same as classical dengue followed after 2–5 days by haemorrhagic manifestations and hypovolaemic shock (dengue haemorrhagic fever/dengue shock syndrome).

Murray Valley encephalitis, Japanese encephalitis and Kunjin
More than 99 percent of infections are asymptomatic. Symptoms are variable but typically include sudden onset of fever, anorexia and headache. Vomiting, nausea and diarrhoea, muscle aches and dizziness may also occur.
Encephalitis: photophobia, lethargy, irritability, drowsiness, neck stiffness, confusion ataxia, aphasia, intention tremor, convulsions, coma and death. Twenty five percent of symptomatic cases of Murray Valley and Japanese encephalitis are fatal, and a further 25 percent result in permanent disability. It is rare for encephalitis to follow Kunjin infection.

Sindbis
Fever, arthritis, rash.

Tick-borne encephalitis
Most infections are asymptomatic. Symptoms can include fever, malaise, headache, nausea, vomiting, myalgia and muscle fasciculation. Within one week, these symptoms resolve spontaneously, but in less than 0.5 percent of infections, there is a relapse after 2–8 days with high fever, headache, vomiting, meningitis, encephalitis or myelitis.

West Nile encephalitis
Most infections are symptomatic. Features can include fever, malaise, headache, arthralgia, myalgia, anorexia, nausea, vomiting, diarrhoea, coughing, sore throat, flushed face, conjunctival injection, generalised lymphadenopathy, maculopapular rash and hepatosplenomegaly. Encephalitis or myelitis occurs in less than 1 percent of cases.

Yellow Fever
Ranges from an asymptomatic or mild, undifferentiated febrile illness to a haemorrhagic fever with 50 percent mortality. Fever, headache, myalgia, conjunctival infection, facial flushing and relative bradycardia are common. In severe cases, these symptoms remit for a few hours to days then recur with high fever, headache, lumbosacral pain, nausea, vomiting, abdominal pain, impaired level of consciousness, severe hepatitis, shock and multisite haemorrhage.