CHIKUNGUNYACHIKUNGUNYA

Dr.T.V.Rao MDDr.T.V.Rao MD

What is ChikungunyaWhat is Chikungunya

Manifest with Crippling Arthritic Manifest with Crippling Arthritic disease of sudden onset.disease of sudden onset.

Name is derived from Swahili – Name is derived from Swahili – Chikungunya meaning that which Chikungunya meaning that which bends upbends up

Virus isolated in 1953 from serum Virus isolated in 1953 from serum and Aedes mosquitoes and Culex sppand Aedes mosquitoes and Culex spp

ChikungunyaChikungunya Virus Virus

Family – TogaviridaeFamily – Togaviridae Genus - Alpha virusGenus - Alpha virus Chikungunya viral infection manifests Chikungunya viral infection manifests

with febrile illnesswith febrile illness

Epidemics of Epidemics of ChikungunyaChikungunya

Large epidemics were Large epidemics were recognized in Transvaal of recognized in Transvaal of South Africa, Zambia, India South Africa, Zambia, India

and South east Asia, and South east Asia, PhilippinesPhilippines..

Update - ChikungunyaUpdate - Chikungunya

Out Breaks of Out Breaks of ChikungunyaChikungunya

Out breaks occur during rainy season Out breaks occur during rainy season with increasing densities of Aedes with increasing densities of Aedes aegypti mosquitoaegypti mosquito

Mosquitos bites infect the HumansMosquitos bites infect the Humans Laboratory acquired infection can Laboratory acquired infection can

also occuralso occur

Chikungunya a Mosquito Chikungunya a Mosquito transmitted viral infectiontransmitted viral infection

Cycle of InfectionCycle of Infection

HistoryHistory

Isolated in Aedes aegypti mosquitoes Isolated in Aedes aegypti mosquitoes and man in 1952 in Tanzaniaand man in 1952 in Tanzania

Appeared in India in 1963Appeared in India in 1963 Major epidemic outbreaks in Major epidemic outbreaks in

Calcutta, madras and other areasCalcutta, madras and other areas Manifested with Major epidemics till Manifested with Major epidemics till

19731973

Clinical featuresClinical features

Incubation 3 – 12 daysIncubation 3 – 12 days Fever may rise to 103Fever may rise to 10300c to 104c to 10400c with c with

rigorsrigors Viremia lead to fever.Viremia lead to fever.

Fever leads to release of large Fever leads to release of large amount of Interferonsamount of Interferons

Clinical manifestationsClinical manifestations

Fever,Fever, Crippling Joint painsCrippling Joint pains LymphadenopathyLymphadenopathy ConjunctivitisConjunctivitis A Maculopapular rashA Maculopapular rash May lead to hemorrhagic manifestations,May lead to hemorrhagic manifestations, Fever is biphasic with remission after 1 - 6 Fever is biphasic with remission after 1 - 6

days of fever.days of fever.

How some Indian patients How some Indian patients presentedpresented

In India but not in Africa, patients In India but not in Africa, patients presented with Inguinal presented with Inguinal lymphadenopathy and red swollen lymphadenopathy and red swollen ears, and are observed as part of ears, and are observed as part of clinical picture.clinical picture.

Morbidity and MortalityMorbidity and Mortality

Fatalities are rare and when they Fatalities are rare and when they occur are associated with either with occur are associated with either with young age or with Thrombocytopeniayoung age or with Thrombocytopenia

Hemorrhagic version of illness, that Hemorrhagic version of illness, that can lead to shockcan lead to shock

DiagnosisDiagnosis

The primary differential diagnosis of The primary differential diagnosis of Chikungunya, should be made from Chikungunya, should be made from Dengue, and O’Nyong nyong feversDengue, and O’Nyong nyong fevers

Chikungunya manifest with Myalgia Chikungunya manifest with Myalgia rather than Arthritis.rather than Arthritis.

Microbiological Microbiological DiagnosisDiagnosis

Isolation of Virus Isolation of Virus Amplification of Nucleic acidAmplification of Nucleic acid Routine Diagnosis with serologyRoutine Diagnosis with serology

Detection of IgM antibody Detection of IgM antibody provides a specific and reliable provides a specific and reliable

means for early diagnosismeans for early diagnosis

ELISA and Dot blotting methods are ELISA and Dot blotting methods are usedused

TreatmentTreatment

Chikungunya fever is not a life threatening Chikungunya fever is not a life threatening infection. Symptomatic treatment for infection. Symptomatic treatment for mitigating pain and fever using anti-mitigating pain and fever using anti-inflammatory drugs along with rest usually inflammatory drugs along with rest usually suffices. While recovery from Chikungunya suffices. While recovery from Chikungunya is the expected outcome, convalescence can is the expected outcome, convalescence can be prolonged (up to a year or more), and be prolonged (up to a year or more), and persistent joint pain may require analgesic persistent joint pain may require analgesic (pain medication) and long-term anti-(pain medication) and long-term anti-inflammatory therapyinflammatory therapy

Vaccines for Vaccines for ChikungunyaChikungunya

An experimental – live attenuated An experimental – live attenuated vaccine ( TSI – GSD – 218 ) vaccine ( TSI – GSD – 218 ) enveloped by passage of an isolate enveloped by passage of an isolate from Thailand in MRC – 5 cell.from Thailand in MRC – 5 cell. At present used in some laboratory At present used in some laboratory

workers who can be protected, workers who can be protected, Vaccine produces neutralizing Vaccine produces neutralizing

antibodiesantibodies

How Chikungunya can be How Chikungunya can be PreventedPrevented

There is neither Chikungunya virus vaccine nor There is neither Chikungunya virus vaccine nor drugs are available to cure the infection.  drugs are available to cure the infection.  Prevention, therefore, centers on avoiding mosquito Prevention, therefore, centers on avoiding mosquito bites.  Eliminating mosquito breeding sites is bites.  Eliminating mosquito breeding sites is another key prevention measure.   To prevent another key prevention measure.   To prevent mosquito bites, do the following: mosquito bites, do the following:

Use mosquito repellents on skin and clothing Use mosquito repellents on skin and clothing When indoors, stay in well-screened areas.   Use bed When indoors, stay in well-screened areas.   Use bed

nets if sleeping in areas that are not screened or air-nets if sleeping in areas that are not screened or air-conditioned. conditioned.

When working outdoors during day times, wear long-When working outdoors during day times, wear long-sleeved shirts and long pants to avoid mosquito bite. sleeved shirts and long pants to avoid mosquito bite.

  

Control of breeding of Control of breeding of Aedes MosquitosAedes Mosquitos

              Source reduction MethodSource reduction Method (i)                 By elimination of all potential vector (i)                 By elimination of all potential vector

breeding places near the domestic or peri-domestic breeding places near the domestic or peri-domestic areas. areas.

(ii)               Not allowing the storage of water for more (ii)               Not allowing the storage of water for more than a week.  This could be achieved by emptying than a week.  This could be achieved by emptying and drying the water containers once in a week. and drying the water containers once in a week.

(iii)             Straining of the stored water by using a (iii)             Straining of the stored water by using a clean cloth once a week to remove the mosquito clean cloth once a week to remove the mosquito larvae from the water and the water can be reused.  larvae from the water and the water can be reused.  The sieved cloth should be dried in the sun to kill The sieved cloth should be dried in the sun to kill immature stages of mosquitoes.immature stages of mosquitoes.

Use of larvicidesUse of larvicides

(i)                 Where the water cannot be (i)                 Where the water cannot be removed but used for cattle or other removed but used for cattle or other purposes, Temephos can be used once a purposes, Temephos can be used once a week at a dose of 1 ppm (parts per week at a dose of 1 ppm (parts per million). million).

(ii)               Pyrethrum extract (0.1% ready-(ii)               Pyrethrum extract (0.1% ready-to-use emulsion) can be sprayed in rooms to-use emulsion) can be sprayed in rooms (not outside) to kill the adult mosquitoes (not outside) to kill the adult mosquitoes hiding in the house.hiding in the house.

Indian EpidemicIndian Epidemic

The states affected by chikungunya The states affected by chikungunya

are Andhra Pradesh, Karnataka, are Andhra Pradesh, Karnataka, Maharasthra, Madhya Pradesh, Tamil Maharasthra, Madhya Pradesh, Tamil Nadu, Gujarat & Kerala. In the year Nadu, Gujarat & Kerala. In the year 2006, total number of 1390322 2006, total number of 1390322 suspected Chikungunya fever cases suspected Chikungunya fever cases were reported from the country. were reported from the country.

Severity of Indian Severity of Indian EpidemicEpidemic

Till 10 October 2006, 151 districts of eight Till 10 October 2006, 151 districts of eight states/provinces of India have been affected states/provinces of India have been affected by Chikungunya fever. The affected states by Chikungunya fever. The affected states are Andhra Pradesh, Andaman & Nicobar are Andhra Pradesh, Andaman & Nicobar Islands, Tamil Nadu, Karnataka, Islands, Tamil Nadu, Karnataka, Maharashtra, Gujarat, Madhya Pradesh, Maharashtra, Gujarat, Madhya Pradesh, Kerala and Delhi. Kerala and Delhi.

More than 1.25 million cases have been More than 1.25 million cases have been reported from the country with 752,245 reported from the country with 752,245 cases from Karnataka and 258,998 from cases from Karnataka and 258,998 from Maharashtra provinces. In some areas Maharashtra provinces. In some areas attack rates have reached up to 45%. attack rates have reached up to 45%.

Current Research on Current Research on ChikungunyaChikungunya

Researchers at the Institut Pasteur have Researchers at the Institut Pasteur have managed to retrace the origin and evolution managed to retrace the origin and evolution of the Chikungunya virus in the Indian Ocean of the Chikungunya virus in the Indian Ocean through complete sequencing of the genome through complete sequencing of the genome of six viral strains isolated from patients from of six viral strains isolated from patients from Reunion Island and the Seychelles, as well as Reunion Island and the Seychelles, as well as through partial sequencing of the viral protein through partial sequencing of the viral protein E1 from 127 patients from the Indian Ocean E1 from 127 patients from the Indian Ocean islands (Reunion,Madagascar, Seychelles, islands (Reunion,Madagascar, Seychelles, Mauritius, Mayotte). Their study, published in Mauritius, Mayotte). Their study, published in PLoS Medicine, opens up new research paths PLoS Medicine, opens up new research paths that should help to explain the magnitude of that should help to explain the magnitude of the epidemic and the occurrence of severe the epidemic and the occurrence of severe forms of the disease.forms of the disease.

Created for Health Created for Health Awareness on Awareness on ChikungunyaChikungunya

Dr.T.V.Rao MD.Dr.T.V.Rao MD.

EmailEmail

doctortvrao@gmail.comdoctortvrao@gmail.com