Chikungunya



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Chikungunya

  • DR.I.SELVARAJ IRMS
  • B.Sc., M.B.B.S.,(M.D Community Medicine)., D.P.H., D.I.H., PGCH&FW(NIHFW,New Delhi)
  • Sr.D.M.O (SELECTION GRADE)
  • INDIAN RAILWAYS

Chikungunya is a relatively rare form of viral fever ("debilitating non-fatal viral illness." ) caused by an alphavirus that is spread by mosquito bites from the Aedes aegypti mosquito.

EPIDEMIOLOGY

Chikungunya was first described in Tanzania, Africa in 1952.

  • Chikungunya was first described in Tanzania, Africa in 1952.
  • An outbreak of chikungunya was discovered in Port Klang in Malaysia in 1999 affecting 27 people.
  • In February 2005, an outbreak was recorded on the French island of Réunion in the Indian Ocean. As of May 18, 2006, 258,000 residents have been hit by the virus in the past year (out of a population of about 777,000). 219 official deaths have been associated with chikungunya.
  • In neighboring Mauritius, 3,500 islanders have been hit in 2005.
  • There have also been cases in Madagascar, Mayotte and the Seychelles.

The name is derived from the Makonde word meaning "that which bends up" in reference to the stooped posture developed as a result of the arthritic symptoms of the disease.

  • The name is derived from the Makonde word meaning "that which bends up" in reference to the stooped posture developed as a result of the arthritic symptoms of the disease.
  • The disease was first described by Marion Robinson and W.H.R. Lumsden in 1955, following an outbreak on the Makonde Plateau, along the border between Tanganyika and Mozambique, in 1952.
  • Chikungunya is closely related to O'nyong'nyong virus.
  • Chikungunya is not considered to be fatal. However, in 2005-2006, 200 deaths have been associated with chikungunya on Réunion island.

— first reported in India in 1963 — had returned after a three-decade dormancy and 121 districts across seven States were affected by it with a total of 9,74,541 suspected cases. Of the 10,611 samples sent to laboratories, 992 tested positive.

  • — first reported in India in 1963 — had returned after a three-decade dormancy and 121 districts across seven States were affected by it with a total of 9,74,541 suspected cases. Of the 10,611 samples sent to laboratories, 992 tested positive.
  • In 2006, there was a big outbreak in the Andhra Pradesh state in India. Nearly 200,000 people were affected by this disease in the districts of Praksham and Nellore in this state.
  • In Bangalore, the state capital of Karnataka (India), there seems to be an outbreak of CHIK now (May 2006) with arthralgia/arthritis, rashes.
  • In the 3rd week of May 2006 the outbreak of Chikungunya in North Karnataka is severe. All the North Karnataka districts specially Gulberga, Koppal, Bellari, Gadag, Dharwad are affected.
  • A separate outbreak of chikungunya fever was reported from Malegaon town in Nasik district, Maharashtra state, in the first two weeks of March 2006, resulting in over 2000 cases. In Orissa state, amost 5000 cases of fever with muscle achesand headache were reported between February 27 and March 5, 2006.

Virus classification

  • Virus classification
  • Group: Group IV ((+) ssRNA)
  • Family: Togaviridae
  • Genus: Alphavirus

EPIDEMIOLOGICAL TRIAD

  • AGENT
  • HOST
  • ENVIRONMENT
  • VECTOR

VECTOR

  • It is transmitted by AEDES,CULEX and MANSONIA species
  • Mosquitoes - Aedes aegypti,
  • Aedes albopictus
  • Aedes aegypti mosquito

AEDES MOSQUITOES

  • Household container breeders
  • Breeds in
    • clean water
    • In all stored water for drinking, washing and bathing
    • Rainwater collected in unused materials like coconut shells, mud pots, plastic cups, tyres etc

BREEDING SOURCES

HOST

  • HOST
  • MAN
  • The main virus reservoirs are monkeys, but other primates, mammals and birds can also be affected

AEDES MOSQUITOES

  • Aggressive day time Bite
  • Major period of activity – sunrise and sunset

ENVIRONMENT

  • Population explosion
  • Deforestation
  • Global warming
  • Floods
  • Competition for food
  • fast movement of population

ENVIRONMENT

  • Emergence of world as single village
  • Unplanned urbanization
  • Inadequacy of sanitation,
  • Improper disposal of garbage and pollution of aquatic systems
  • Development of resistance in vectors to insecticides

TRANSMISSION

  • This virus is transmitted only by mosquitoes
  • The mosquito picks up the virus from an infected person during the viraemic period – within five days from the day of starting of symptoms
  • An infected mosquito will remain infected all its life span and can transmit the virus each time it bites
  • An infected person cannot spread the infection
  • directly to other persons

SYMPTOMS

  • Fever Which Can Reach 39°C, (102.2 °F)
  • Petechial or Maculopapular Rash Usually Involving the Limbs and Trunk
  • Arthralgia or Arthritis Affecting Multiple Joints Which Can Be Debilitating.
  • Headache, Conjunctival Injection and Slight Photophobia.

DIAGNOSIS

  • The diagnostic tests include detection of antigens or antibodies in the blood, using
  • ELISA (or EIA - enzyme immunoassay)
  • polymerase chain reaction (PCR).

DIFFERENTIAL DIAGNOSIS

  • DENGUE
  • WEST NILE FEVER
  • ONYONG NYANG FEVER

COMPLICATIONS

  • However, neurological complications such as meningoencephalitis have been reported in a small proportion of patients
  • Mother to child transmission of chikungunya virus was a new observation recorded during the recent French Reunion islands outbrea

COMPLICATIONS

  • Symptoms are generally self-limiting and last
  • 1–10 days.
  • Arthralgia may persist for months or years.
  • In some patients, minor hemorrhagic signs such as epistaxis or gingivorrhagia have also been described

IS THERE ANY EFFECTIVE TREATMENT ?

  • There is no active treatment against chikv
  • Presently treatment is purely symptomatic - supportive care and rest and nutrition
  • Analgesics, antipyretics and fluid supplementation are important aspects in managing this infection.

TREATMENT

  • Self-limiting and Will Resolve With Time.
  • No Specific Treatment for Chikungunya.
  • Supportive or Palliative Medical Care With Anti-inflammatories
  • Vaccine Trials Were Carried Out in 2000, the Project Was Discontinued and There Is No Vaccine Currently Available.
  • Supportive care with rest is indicated during the acute joint symptoms.
  • Movement and mild exercise tend to improve stiffness and morning arthralgia, but heavy exercise may exacerbate rheumatic symptoms.
  • aspirin and nonsteroidal antiinflammatory drugs, chloroquine phosphate (250 mg/day) has given promising results."

Is there any vaccine?

  • Currently there is no marketable vaccine available for man
  • Chikungunya confers a life-long immunity on the infected person.

Analysis of the recent outbreak has suggested that the increased severity of the disease may be due to a change in the genetic sequence, altering the virus' coat protein, which potentially allows it to multiply more easily in mosquito cells.

  • Analysis of the recent outbreak has suggested that the increased severity of the disease may be due to a change in the genetic sequence, altering the virus' coat protein, which potentially allows it to multiply more easily in mosquito cells.

PREVENTION

  • Elimination of stagnant water at home, schools and work place to avoid breeding of mosquitoes.
  • Using insect repellents over the exposed parts of the body.
  •  
  • Using mosquito screens or nets in non – Air-conditioned rooms. 
  • Wearing the long sleeved clothes like long trousers of a light shade for protection against mosquitoes.

Properly covering all water tanks so that mosquitoes cannot get in

  • Properly covering all water tanks so that mosquitoes cannot get in
  • Getting rid of any container capable of retaining water in the outdoor surroundings (used tyres, food cans, garbage, saucers under flower pots, etc)
  • Renew water in flower vases at least once a week

CONTROL

  • Aedes species is the main target of control
  • Source reduction of breeding sites of mosquitoes
  • Requires community involvement to keep the water storage containers free of mosquitoes
  • Eliminate other breeding places in and around houses

BIOLOGICAL CONTROL

  • Introduction of larvivorous fish, namely Gambusia and Guppy in water tanks and other water sources.

ANTI – MOSQUITOE MEASURES

  • The organophosphorous insecticide ABATE is being used in a large scale
  • ABATE can prevent breeding upto 3 months when applied to sand granules
  • It does not affect man or the taste of water

THERMO FOGGING

  • THERMO FOGGING
  • ULV treatments 10 days apart has shown to reduce mosquito densities more tham 98%
  • Aerosol spray of ultra low volume [ULV] of MALATHION or SUMITHION 250 ml/hectare is effective in interrupting transmission and stopping epidemics

YOUR ROLE?

  • Educate community about the disease, mode of its transmission, availability of treatment and adoption of control measures.
  • Changes in practice of storage of water and personal protection should be encouraged
  • They should also be reassured that this a preventable disease
  • Community should be advised to cooperate in fogging
  • Take measures for eliminating breeding places
  • Special campaigns may be carried out involving mass media including local vernacular newspapers/magazines, radio and TV as well outdoor publicity like hoardings, miking, drum beating, rallies etc
  • Health education materials should be developed and widely disseminated in the form of posters, pamphlets, handbills.
  • Interpersonal communication through group meetings, traditional/folk media particularly must be optimally utilized.

CAUTION

  • A person with chikungunya fever should limit their exposure to mosquito bites in order to avoid further spreading the infection, and should stay indoors or under a mosquito net.
  • Before using repellents, pregnant women and children under the age of 12 years should consult a physician or pharmacist
  • For newborn children under three months, repellents are not recommended ; instead, insecticide-treated bed nets should be used

ICD-10 A92.0

  • Inter National Classification of Diseases
  • Code for Chikungunya
  • THANK YOU
  • ACKNOWLEDGEMENT:
  • DR.ARUNMURUGAN(M.D S.P.M)


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