Chikungunya fever is a rare form of viral disease characterised by fever, joint pains and spread by mosquitoes. Since late 2005, chikungunya fever has been causing extensive outbreaks in several islands in South-West Indian ocean including Reunion Islands, Seychelles, Mauritius, Mayetta and Madagascar.
In India it was first reported in December 2005 in Andhra Pradesh, where it started as an urban phenomenon and has since then spread to more than 1,400 villages in southern India.
Other regions in grip of this unprecedented epidemic are certain regions of Karnataka, Tamil Nadu, Maharashtra, Orissa and Madhya Pradesh. Unofficial figures point to lakh of cases having been reported in last six months from affected figures.
More than 19 districts of Maharashtra including Pune, Nasik and Ahmdnagar are affected and recently virus has been tested positive in few patients from Khodala village in Thane and few suspected cases (virus report awaited) have been reported from suburbs of Mumbai.
Unlike public perception this disease has nothing to do with poultry, instead it is a viral fever spread by day time biting mosquitoes of genus Aedes i.e. Aedes Aegypti, Aedes Albopicticus (Tiger mosquito). Interestingly both of these types of mosquitoes also spread the dreaded dengue fever. The infected Aedes mosquito can carry both the viruses at same time and infect a person. It is perfectly possible for a person to have chikungunya and dengue fever together at the same time.
With the possibility of dengue raising its head once again in rainy season this combination of a dual epidemic can prove to be catastrophic.
Chikungunya fever is characterised by high fever (101F-104F), headache, vomiting, malaise, severe joint pains including wrist, knees and ankles. The swollen and painful joints are painful to touch and are characteristic of this disease.
They can last from a few days to few months. After 2-3 days of onset of fever a rash may be noticed over trunk and the limbs. The disease is self limiting and rarely fatal and unlike dengue fever the bleeding manifestation are not common in this disease.
The complications although rare are seen mostly in affected children which include menigoencephalitus and pneumonia.
The rather difficult to pronounce "chikungunya" name came from "Swahili" a language spoken in East Africa which literally means "that which bends up" referring to the stooped posture the patient develops because of severe joint pains in this disease; the virus is also known by other names like as "buggy creek" virus and "Chikv".
The disease was first described in 1953, following an outbreak of this fever on border between Tanganyika and Mozambique. In India the first epidemic of this disease was recorded in Kolkata in 1963 and last outbreak of infection occurred in India in 1971. No active surveillance of this disease was done after that and it was assumed that the virus had "disappeared" from the subcontinent.
It was soon a forgotten disease and hence it is not surprising that most present-day health-care providers have not even heard of this disease. The re-emergence of this epidemic in late 2005 in Andhra Pradesh took both the government and doctors off guard and found health administration totally lacking in controlling the situation.
The re-emergence of this long-dormant infection has been a subject of lot of research and discussion in the medical community. A study on virus isolated from Reunion Islands outbreak was studied at Pasteur Institute in Paris and found that the present virus has mutated (changed) itself to a more aggressive from than its predecessor which had cause earlier outbreaks, same authorities however believe that the absence of infection in India for more than 35 years led to no immunity for this virus and could be reason for rapid spread of infection, while others blame it on exponential increase in population of mosquitoes especially of genus, Aedes, in recent times.
There is no preventive treatment for this disease and presently no vaccine is available. Once the patient develops this disease then symptomatic treatment including bed rest, plenty of fluids, vitamins and analgesics for joint pains are needed but should be given in consultation with a doctor as the symptoms of this disease resemble dengue fever. It is necessary to exclude it by blood tests as dengue fever can be associated with complications of bleeding and severely low blood pressure (shock) which can be life threatening.
A double infection with both chikungunya and dengue can occur together which can also be detected with blood tests. There are very few laboratories at present equipped to detect chikungunya virus. Serological test like ELISA detect antibodies against the virus in the blood and are available in select few laboratory only.
IgM capture ELISA test is necessary to distinguish it from dengue. An expensive but more reliable PCR test is available at few bigger laboratories which can detect the virus promptly and in large per cent of cases.
Mumbai because of its very high density of population, large slum dwellings and in this season of heavy rains is very vulnerable to outbreak of this epidemic. In view of very recent reports in of few suspected cases from Goregoan and Vakola in Mumbai, there is an urgent need on part of government to go on a war footing drive against mosquitoes especially to conduct large-scale foggings.
The author is an Associate Professor of Internal Medicine and Unit Head in the Post Graduate Department of Medicine at MGM Medical College and Hospitals, Navi Mumbai. He can be contacted at sahaja firstname.lastname@example.org.