Monday, June 30, 2008

Chikungunya, Dengue, Leptospirosis and Malaria: A Simple Algorithm to Differentiate

Chikungunya epidemic has now spread to most parts of Dakshina Kannada District and a few deaths have also been reported. Added to this, there are reports of Dengue, Leptospirosis and malaria from the affected areas. This has resulted in lot of anxiety and fear among the public and confusion among the medical fraternity. There is a felt need for a simple algorithm to help in the diagnosis and treatment of these infections and therefore we suggest the following, based on the review of the relevant literature:

There are many similarities in the clinical manifestations of chikungunya, dengue and leptospirosis and it may not be easy differentiating them. Fever, joint pains and rash are common to chikungunya, dengue and leptospirosis. The fever in chikungunya and dengue starts abruptly, and remits after 1-2 days and can recur after 1-2 days for another day or two. Usually, therefore, the fever lasts 5-6 days and subsides on its own. Dengue fever is characterized by severe headache, pain in the muscles of upper and lower limbs, joint pains and pain on moving the eye balls. In chikungunya, pain and swelling of the joints is a characteristic feature. In chikungunya, a reddish rash appears on the second or third day over the face and the chest. The rash in dengue appears on the third or fourth day, predominantly over the legs and trunk and in some, these rashes may be haemorrhagic (purpuric). Abrupt, high grade fever with severe aches in the muscles of the limbs and the back is seen in leptospirosis too. Over the next 4-7 days, the fever continues and suffusion of eyes, headache, cough etc., may appear. After remitting for 1-2 days, the fever recurs, along with complications like jaundice, kidney failure and bleeding disorders, resulting in haemorrhagic rashes over the legs. In malaria, joint pains, muscle pains and rash are not seen and the fever occurs daily or intermittently on alternate days; some patients may have jaundice.

The diagnosis is helped by simple tests in the blood and urine. The total leukocyte count is lower in chikungunya and dengue while it is elevated in leptospirosis. As the kidneys are invariably affected in leptospirosis, urine examination in these cases would show abnormalities. Malaria can be confirmed by a peripheral blood smear.

Chikungunya and dengue are self limiting infections and do not need any specific treatment. If the fever and/or joint pains are very severe, simple analgesic like paracetamol can be used. Potent pain killers can cause more harm than good. Steroids have absolutely no role to play in the treatment of acute chikungunya and dengue. If the joint pain and swelling in chikungunya persist even after 10-15 days, chloroquine can be tried. Leptospirosis is treated with penicillin or doxycyline.

Fatal complications are extremely rare in chikungunya. Dengue, leptospirosis and falciparum malaria can lead to complications that may be fatal, if not properly treated. Any patient with the following signs should be immediately shifted to a tertiary care hospital: Hypotension (drop in blood pressure), bleeding, breathlessness, altered sensorium, decreased urine output, jaundice or convulsions.

Simple Algorithm to Differentiate Chikungunya, Dengue, Leptospirosis and Malaria

For details:

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