Summary about Disease
Ross River fever (RRF) is a mosquito-borne viral disease caused by the Ross River virus (RRV). It's primarily characterized by joint pain (arthritis), often accompanied by fever and rash. While not typically life-threatening, the symptoms can be debilitating and persist for months. It is endemic to Australia, Papua New Guinea, and other parts of the South Pacific.
Symptoms
Joint pain (Arthritis): This is the most common symptom, affecting multiple joints, particularly in the fingers, wrists, ankles, and knees.
Fever: Mild to moderate.
Rash: A maculopapular rash (flat, red spots with small bumps) often appears on the trunk and limbs.
Fatigue: Can be significant and prolonged.
Muscle aches (Myalgia):
Headache:
Swollen lymph nodes (Lymphadenopathy):
Causes
Ross River fever is caused by infection with the Ross River virus (RRV). The virus is transmitted to humans through the bite of infected mosquitoes. Many different species of mosquitoes can transmit the virus. The virus circulates in native animals, such as kangaroos and wallabies, which serve as reservoirs.
Medicine Used
There is no specific antiviral medication for Ross River fever. Treatment focuses on relieving symptoms:
Pain relievers: Over-the-counter pain relievers like paracetamol (acetaminophen) or ibuprofen are commonly used to manage pain and fever.
Anti-inflammatory drugs: In some cases, nonsteroidal anti-inflammatory drugs (NSAIDs) may be prescribed for joint pain and inflammation.
Rest: Adequate rest is crucial for recovery.
Physical therapy: May be recommended for persistent joint stiffness.
Is Communicable
Ross River fever is not directly communicable from person to person. It can only be spread through the bite of an infected mosquito.
Precautions
Mosquito bite prevention:
Use insect repellent containing DEET, picaridin, or oil of lemon eucalyptus.
Wear long-sleeved shirts and long pants, especially during dawn and dusk when mosquitoes are most active.
Use mosquito nets over beds, especially when sleeping outdoors or in unscreened areas.
Install screens on windows and doors.
Reduce mosquito breeding grounds:
Empty standing water from containers such as tires, buckets, and flower pots.
Maintain swimming pools properly.
Clear gutters of debris.
How long does an outbreak last?
The duration of a Ross River fever outbreak depends on factors like mosquito populations, rainfall, and temperature. Outbreaks often coincide with periods of increased mosquito activity, such as after heavy rainfall or during warmer months. Outbreaks can last for several weeks to months.
How is it diagnosed?
Ross River fever is diagnosed through blood tests:
Antibody tests: These tests detect the presence of antibodies to the Ross River virus in the blood. Two types of antibodies are typically measured: IgM (indicating recent infection) and IgG (indicating past infection or immunity).
PCR testing: A polymerase chain reaction (PCR) test can detect the virus's genetic material in the blood, but is typically only useful in the very early stages of infection.
Timeline of Symptoms
Incubation period: The incubation period (time between mosquito bite and symptom onset) is typically 3 to 11 days.
Acute phase: Symptoms usually develop suddenly. The acute phase lasts for several weeks.
Recovery phase: Most people recover within a few months, but some experience persistent joint pain and fatigue for longer periods (chronic Ross River fever). This can last for months or even years.
Important Considerations
Chronic symptoms: A significant proportion of people with Ross River fever experience chronic symptoms, including persistent joint pain, fatigue, and depression.
No vaccine: There is currently no vaccine available for Ross River fever.
Differential diagnosis: Ross River fever symptoms can resemble other viral illnesses, such as chikungunya, Barmah Forest virus infection, and rheumatoid arthritis, so proper diagnosis is important.
Geographic location: Ross River fever is most common in Australia, Papua New Guinea, and other parts of the South Pacific. Travel to these areas increases the risk of infection.