DR Kevin Harvey, the chief medical officer, last Thursday confirmed that Jamaica now has its first imported case of the chikungunya virus.

A report from the Caribbean Public Health Agency (CARPHA) had confirmed that a sample sent last Tuesday was positive for the virus.

The case is of an individual who travelled from an affected country and fell ill.

What is chikungunya?

Chikungunya is a mosquito-borne disease that is transmitted to people predominantly by the Aedes aegypti mosquito.

Symptoms

The most common symptoms of chikungunya virus are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, or rash.

Fever typically lasts from several days up to a week while joint symptoms are usually symmetric and occur most commonly in hands and feet. The rash usually occurs two to five days after onset of fever in approximately half of all patients. It is typically maculopapular, involving the trunk and extremities, but can also include palms, soles, and face.

How long before one starts experiencing the symptoms?

In humans bitten by an infected mosquito, disease symptoms typically occur after an average intrinsic incubation period of three to seven days, which can go up to 12 days.

Who is at risk?

All individuals not previously infected with chikungunya are at risk of acquiring infection and developing disease. Infants and the elderly are at greater risk for more severe disease. There are some diseases that may increase the risk for severe disease such as diabetes mellitus and cardiovascular disease.

Can one be reinfected?

It is believed that once exposed to chikungunya, individuals will develop long-lasting immunity that will protect them against reinfection.

Is it the same as dengue fever?

Dengue fever has the potential for much worse outcomes, including death. In chikungunya, shock or severe haemorrhage is very rarely observed; the onset is more acute and the duration of fever is much shorter. In chikungunya, maculopapular rash also is more frequent than in dengue fever. Although people may complain of diffuse body pain, the pain is much more pronounced and localised to the joints and tendons in chikungunya.

How is it treated?

There is no specific antiviral drug treatment for chikungunya but symptomatic treatment is

recommended after excluding more serious conditions like malaria, dengue and bacterial infections.

Treatment is symptomatic, comprised of rest and the use of acetaminophen or paracetamol to relieve fever, and ibuprofen, naproxen, or another non-steroidal anti-inflammatory agent (NSAID). In patients with severe joint pains that are not relieved by NSAID, narcotics or short-term corticosteroids can be used after evaluating the risk-benefit of these treatments.

Patients should drink plenty fluids to replenish fluid lost from sweating, vomiting and other insensible losses.

While recovery is the expected outcome, convalescence can be prolonged, sometimes up to a year or even more, and persistent joint pain may require pain management, including long-term anti-inflammatory therapy.

Can it be prevented?

The best way to prevent chikungunya infection is to avoid mosquito bites. You can protect yourself by using insect repellants containing DEET, Picaridin, oil of lemon eucalyptus, or IR3535 on exposed skin, wearing long-sleeved shirts and long pants; using air conditioning or having windows and doors securely closed or screened when indoors; and sleeping under mosquito nets.

SOURCES: CARPHA and Pan American Health Organisation