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Chikungunya fever,
is a viral illness that is spread by the bite of infected mosquitoes. The
disease resembles dengue fever, and is characterized by severe, sometimes
persistent, joint pain (arthritis), as well as fever and rash. It is rarely
life-threatening. Nevertheless widespread occurrence of diseases causes
substantial morbidity and economic loss Epidemiology
and case definition
Epidemics of fever, rash and arthritis, resembling
Chikungunya fever have been recorded as early as 1824 in India and elsewhere. However, the
virus was first isolated between 1952-1953 from both man and mosquitoes
during an epidemic of fever that was considered clinically indistinguishable
from dengue, in the Tanzania.
Chikungunya fever displays interesting epidemiological
profiles: major epidemics appear and disappear cyclically, usually with an
inter-epidemic period of 7-8 years and sometimes as long as 20 years. After a
long period of absence, outbreaks of CHIK fevers have appeared in Indonesia in
1999.
Chikungunya in Asia (1960-1982)
Between 1960 and 1982, outbreaks of Chikungunya fever were
reported from Africa and Asia. In Asia, virus strains have been isolated in
Bangkok in 1960s; various parts of India including Vellore,
Calcutta and Maharastha
in 1964; in Sri Lanka in
1969; Vietnam in 1975; Myanmar in 1975 and Indonesia in 1982.
Recent occurrences
of chikungunya fever
After an interval of more than 20 years, chikungunya fever has been reported from several
countries including India,
Indonesia, Maldives, Thailand
[PDF 81KB] and various Indian Ocean islands including Comoros, Mauritius,
Reunion and Seychelles.
Chikungunya fever
in India
Till 10 October 2006, 151 districts of eight
states/provinces of India
have been affected by chikungunya fever. The
affected states are Andhra Pradesh, Andaman & Nicobar Islands, Tamil
Nadu, Karnataka, Maharashtra, Gujarat, Madhya Pradesh, Kerala and Delhi.
More than 1.25 million cases have been reported from the
country with 752,245 cases from Karnataka and 258,998 from Maharashtra
provinces. In some areas attack rates have reached up to 45%.
Chikungunya and
dengue fevers
The clinical manifestations of chikungunya
fever have to be distinguished from dengue fever. Co-occurrence of both
fevers has been recently observed in Maharashtra state of India thus
highlighting the importance of strong clinical suspicion and efficient
laboratory support. Laboratory Diagnosis
The clinical manifestations of chikungunya
fever resemble those of dengue fever. Laboratory diagnosis is critical to
establish the cause of diagnosis and initiate specific public health
response. Treatment
Chikungunya fever is not a life
threatening infection. Symptomatic treatment for mitigating pain and fever
using anti-inflammatory drugs along with rest usually suffices. While
recovery from chikungunya is the expected outcome,
convalescence can be prolonged (up to a year or more), and persistent joint
pain may require analgesic (pain medication) and long-term anti-inflammatory
therapy. Prevention and
control
No vaccine is available against this virus infection.
Prevention is entirely dependent upon taking steps to avoid mosquito bites
and elimination of mosquito breeding sites.
To avoid mosquito
bites:
 Wear full sleeve clothes and
long dresses to cover the limbs;
Use mosquito coils, repellents
and electric vapour mats during the daytime;
Use mosquito nets – to protect
babies, old people and others, who may rest during the day. The effectiveness
of such nets can be improved by treating them with permethrin
(pyrethroid insecticide). Curtains (cloth or
bamboo) can also be treated with insecticide and hung at windows or doorways,
to repel or kill mosquitoes.
Mosquitoes become infected when
they bite people who are sick with chikungunya.
Mosquito nets and mosquito nets and mosquito coils will effectively prevent
mosquitoes from biting sick people.
To prevent mosquito
breeding
The Aedes mosquitoes that
transmit chikungunya breed in a wide variety of
manmade containers which are common around human dwellings. These containers
collect rainwater, and include discarded tires, flowerpots, old oil drums,
animal water troughs, water storage vessels, and plastic food containers.
These breeding sites can be eliminated by
Draining water from coolers, tanks, barrels, drums and buckets, etc.;
Emptying coolers when not in use;
Removing from the house all objects, e.g. plant saucers, etc. which
have water collected in them
Cooperating with the public health authorities in anti-mosquito
measures.
Role of public
health authorities
National programme for prevention and control of vector borne
diseases should be strengthened and efficiently implemented with multisectoral coordination
Legislations for elimination of domestic/peridomestic
mosquitogenic sites should be effectively enforced
Communities must be made aware of the disease and their active
cooperation in prevention and control measures elicited
Minimizing Transmission of Infection: This can be done in the
following ways:
1. Risk Communication to the household members:
Educate the patient and other
members in the household about the risk of transmission to others and the
ways to minimize the risk by minimizing vector population and minimizing the
contact with vector.
2. Minimizing vector population:
Intensify effort to reduce
larval habitats in and around the houses: remove stagnant water from all junk
items lying around and in the household and in the peri-domestic
areas
Stagnating water in flower pots
or similar containers should be changed daily or at least twice weekly
Introduce larvivorous
fish in aquaria, garden pools, etc
Weeds and tall grasses should be
cut short to minimize shady spaces where the adult insects hide and rest
during hot daylight hours
Drain all water stagnating after
rains
Fogging and street sanitation
with proper waste management(fogging does not appear to be effective, yet it
is routinely implemented in epidemic situation
3. Minimize the vector-patient contact (Aedes
mosquitoes bite during the daytime, mostly in the morning and late afternoon)
At household level:
Have the patient and infants
in the house rest under bed-nets, preferably permethrin-impregnated
nets
Insecticide sprays: bed rooms,
closets and crevices, bathrooms, kitchens, nooks and corners; alternatively,
coils , mats, vapourizers, etc
Have the patient as well as
other members of the household wear full sleeves to cover extremities,
preferably bright coloured clothes
Wire-mesh/nets on doors and
windows
4. Reporting to the nearest public health authority:
Occurrence of the case in the
community needs to be communicated immediately to the nearest public health
official for identification of clusters by person, place and time and for
expansion of the control measures in the community and district levels.
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