Ross River Virus (RRV)
With all the floods recently in Australia, I thought it would be a good time to talk a bit about ‘Ross River Fever’. Ross river is a viral infection that is transmitted via mosquitos. The Ross River Virus (RRV) is found in at least 40 species of mosquito, and is reported to be found in Australia and pacific islands with outbreaks occurring most commonly in Spring and after rain or high water levels (flooding!) when mosquitos hatch. Transmission occurs via contamination of blood from the mosquito bite and is most often between 17-31.5 degrees Celsius (peak is 26 degrees). Animals can be hosts of the virus too.
Symptoms can include:
Joint pain (95% of cases)- affecting the wrists, knees, ankles, fingers (MCP & IP), back pain. Pain pattern is often symmetrical with asymmetric severity. Pain can mimic gout.
A rash (50% of cases)- on the palms, soles of feet, face, mouth or limbs/trunk. The lesions can be 1-5mm sparse maculopapular (see pic for example), dense purpuric or small vesicles.
Fever (50% of cases)- a temperature of up to 39 degrees celsius which should resolve within 3 days. Chills and delirium may occur.
Fatigue (90% of cases)
Headache (50% of cases)
Other symptoms can include poor appetite, diarrhoea, muscle aches, stiff neck, photopho
bia, aseptic meningitis and the more commonly known encephalitis.
Symptom presentation often occurs in one of three ways:
Acute febrile illness with
arthritis and rash.
Acute fever, rash or arthritis alone.
Chronic poly-arthritis or poly-arthralgia.
Course: The duration of symptoms varies significantly. The most recent evidence suggests symptoms can resolve within 3-6 months, but some can be more than a year (particularly those with underlying comorbidities, such as depression or rheumatic disease). The incubation period is 3-9 days (or up to 21 days). Severity also depends on genetics.
Prevalence: ages 4-85 years old, slightly more common in women.
Lab testing: there are no specific tests for RRV and the WBC count is typically normal, but with slight elevations in ESR observed.
Treatment: as it is a viral infection the treatment is often just supportive and can include rest, NSAIDS for the pain, or even hydrotherapy.
In Chinese medicine we use the sympto
ms to form an individualised diagnosis. So in general, we could assume RRV to be due to an external invasion (e.g. of wind-damp-heat) that causes disharmony and deficiencies internally (e.g. injure the Spleen Qi and stagnate Qi). Treatment would include acupuncture and herbal medicine to relieve the joint pain, improve energy and to strengthen the body to clear out the infection. RRV can lead to ME (myalgic encephalomyelitis)/CFS (chronic fatigue syndrome) which can also be a focus of treatment with Chinese medicine and acupuncture. Advice would be individualised but with a focus on getting a good balance of rest and movement to help the body function it's best.
Prevent by avoiding mosquito bites by covering up, using a repellent or avoiding areas of flooding water (where possible!).