The Hindu Business Line : Fighting Chikungunya

The name ‘Chikungunya’ comes from the Swahili language and means that “which bends up”, referring to the patient stooping forward after the virus attacks the joints. This is a viral haemorrhagic fever, caused by the Arbo virus of the Togaviridiae family. The first case report was from Tanzania and Uganda in 1952. There was a massive outbreak of Chikengunya in the French Island of La Reunion in the Indian Ocean in 2005 and 2006, as well as in the neighbouring islands, including Mauritius.

In India we saw Chikungunya in 1963 in Kolkata, in 1965 in Puducherry, Chennai, the Andhra Pradesh districts of Rajahmundry, Vishakapatnam and Kakinada, Sagar in Madhya Pradesh, and Nagpur in Maharashtra. But it was in 1973 that a major outbreak of the disease was reported in Barsi, Maharashtra.

Virus transmission

The virus is transmitted through the bite of the infected Aedes Aegypti mosquitoes. These mosquitoes breed in collections of fresh water, flowerpots, animal water troughs, water storage vessels, and plastic food containers.

Clinical manifestations

There is an incubation period of 2-4 days. The clinical presentation can vary from asymptomatic infection to a severe crippling disease. Sudden onset of fever of varying severity with joint pain is reported. The fever is typically biphasic (it comes on and off) with a period of remission after 1-6 days. Between the second and fifth day of the illness, the patient develops a rash, mostly on the trunk and limbs. Migrating poly arthritis (multiple joint pain, which keeps shifting from one joint to another) is noted in patients with affected joints. Usually the infection subsides spontaneously without any complications. According to the National Vector Borne Disease Control Programme - India, there were 214 districts affected in India with 1,885 confirmed cases. No deaths have been reported.

Eye manifestation

In the early stages, the patient gets eye pain or pain that worsens with eye movement. Conjunctivitis is usually seen. As the severity increases, haemorrhagic manifestations of the viral infection might lead to spontaneous bleeding, causing subconjunctival haemorrhage and, though rarely, retinal haemorrhage. Bilateral macular choroiditis (retinal inflammation) has also been reported after the Chikungunya viral infection.

This infection is confirmed through virus isolation and serology. The clinical manifestations of Chikungunya fever resemble those of dengue fever.

Laboratory diagnosis is critical to establish the cause of infection and initiate specific public health response. Complete eye examination is recommended, including fundus evaluation. In case of eye involvement, prompt treatment is recommended to prevent loss of vision.

Usually the General Practitioner will attend to the affected eye also during the course of treatment. But if there are complications, it is better to see eye specialists. For instance, when Chikungunya had peaked last year, our centre was seeing about two cases a week referred to us by GPs.

Prevention

This includes protection from mosquito bites and elimination of mosquito breeding places. Proper clothing and use of mosquito coils, repellents and electric vapour mats during daytime and at night can help prevent mosquito bites. Elimination of breeding sites requires combined effort from the public and government authorities. This includes preventing unnecessary collection of water, and spraying insecticides. National programmes for prevention and control of vector borne diseases should be strengthened and efficiently implemented with multi-sectoral coordination.

(The author is Managing Director of Dr Agarwal’s Eye Hospital, Chennai)