Welcome Dept' of Community Medicine Govt' Homoeopathic Medical College, Kozhikode

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WelcomeDept. of Community MedicineGovt.
Homoeopathic Medical College, Kozhikode
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CHIKUNGUNYA FEVER
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What is this tongue twister ?

• It is CHIKUNGUNYA
• To be pronounced as chick-en-GUN-yah
• It is not written as CHICKEN GUINEA
• Derived from the Makonde verb - Kun gunyala
• In Swahili it means to become contorted or
• More specifically as that which bends up
• Refers to the stooped posture of the patient

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Synonyms

• CHIKV Fever
• Buggy Creek virus infection
• Knuckle fever
• Me Tri virus infection
• Semliki Forest virus infection

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Blessed are we !!

• This is not a Dengue epidemic !
• This is not the SARS which stole all the show !!
• This is not Bird-Flu hitting Indian economy !!!
• This is not the Plague epidemic which threatened
  to sweep our country !!!!
• Above all - it is not like HIV or Hepatitis B
  !!!!!
• This is a self limiting, non fatal viral illness
  
• Thanks to the Almighty

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Should we be panicky ?

• A common viral fever
• Self limiting non fatal illness
• Fever, myalgia, arthralgia, lasting 2 - 7 days
• Should give big name for it and be panicky ?
• Should create such media hype and chaos ?
• Above all, should we politicize to this extent?

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CLINICAL EPIDEMIOLOGY
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A disease of Africa and Asia
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Asian Distribution
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Epidemiological Triangle
The Environment
The Vector
Interaction
The Host
The Virus
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History (Its story)

• A viral infection transmitted to humans
• By the bite of an infected mosquito
• It has become endemic in south and central India
• First outbreak in 1952 on the Makonde Plateau
• Border between Tanganyika and Mozambique
• First published report is from Africa in 1955 by
• Marion Robinson and W.H.R. Lumsden
• Recent large epidemic occurred in Malaysis in 1999

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The CHIK Virus
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What is this virus ?

• Causative agent is an RNA VIRUS
• Class Arbor Virus (Arthropod Borne)
• Family Togaviridae
• Genus Alpha Virus
• Species Chikungunya Virus
• Similar to Semliki Forest Viruses (SFV) in Africa
  and Asia.

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Chikungunya Virus - EM
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Transmission

• Reservoir Non-human primates in Africa
• No animal reservoir is found in India
• Maintained in nature by man mosquito man
  cycle
• Vector Aedes aegypti, Ae. albapticus mosquito
• Same vector as for Dengue and Yellow fevers
• Vehicle of transmission None
• No known mode - other than mosquito bite
• Incubation Period 2 days to 12 days

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The Vector
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The Vector

• Aedes aegypti mosquito, flight range lt 100 meters
• Aggressive daytime biter under lights bites
  ankles
• Once infected it has the virus until death (30
  days)
• It is a man made mosquito prefers its owner
• Breeds in man made household containers
• Indoor, peridomestic, fresh water mosquito
• Metallic, plastic, rubber, cement and earthen
  containers - open, left or unused - get filled
  with water
• Air coolers, ACs, Old oil drums, Over head tanks

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Aedes aegypti
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Aedes albaptycus
Tiger Mosquito
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Madam Aedes - at her Lunch
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Water tap A disease trap
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Open Overhead Tanks
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Domestic Water Collections
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Why only Aedes Mosquito ?

• Scanning Electron Micro-graph of the mid gut
  cells of the mosquito
• Location of the Chik Virus binding proteins.
• Not transmitted to the progeny of the mosquito

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The Recent Epidemics
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Notable Outbreaks

• 1963 to 1965 - An epidemic was reported in
  Calcutta
• 4.37 of the people were later found to be
  seropositive
• 1973 An epidemic 37.53 in Barsi - Sholapur
  district
• 2006 Present epidemic after 33 years is the
  largest
• 9,06,360 or more cases in Andhra Pradesh
• 5,43,286 cases from Karnataka 66,109 from Blore
• Maharashtra 2,02,114 cases Gujarat 2,500 cases
• Tamil Nadu 49,567 cases Orissa 4,904 cases,
• Madhya Pradesh 43,784 and Pune 138 cases

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Distribution in India

• The disease is common with periodic epidemics
• Sporadic outbreaks described in Madras and
  Vellore
• Cases were reported in Chennai, Pondicherry,
  Vellore
• Vizag in 1964 Rajahmundri, Kakinada, Nagpur in
  1965
• The last epidemic in India was in 1973
• From Yavat village (Pune) in 2000
• 2.9 in the Andaman Nicobar Islands are
  seropositive
• Infected mosquitoes seen in Pune, Maharastra State

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Most Recent Epidemics

• Epidemic of CHIKV occurred in Malaysia 1999
• French island of Réunion in the Indian Ocean-
  2005
• Epidemic was recorded in Mauritius 2005
• Madagascar, Mayotte and Seychelles 2005
• Hong Kong and Malaysia early 2006
• Present indian epidemic is the largest -from Dec
  05
• Maximum of cases from Andhra Pradesh so far

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The Indian Epidemic

• Present epidemic has started in Nov 2005
• Andhra Pradesh, Karnataka, Maharashtra, Madhya
  Pradesh, Orissa, Gujarat, Tamilnadu, Rajasthan,
  Kerala are under its onslaught
• This is spreading far and wide at a rapid rate
• Not much spread to the northern states like
  Delhi, Haryana, Punjab as yet.
• Not much cry from U.P. and Bihar

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Attack Rates

• In urban localities it is more why ?
• Usual age group is above 15 years
• Less common in children and infants
• Family clustering of cases usual
• Attack rates vary from 3 to 40 of population
• Average attack rate is 10
• Herd immunity restricts further spread

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Why is this sudden epidemic ?

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

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Why is this quasi-pandemic ?

• Several distinct variants of the virus
• A change at position 226 of the E1 coat protein
• This A226V mutation caused the virus to more
  easily invade and multiply in the mosquitoes
• Three protein changes in non-structural proteins
• nsP1 (T301I), nsP2 (Y642N), and nsP3 (E460
  deletion)
• This mutant virus - from a neonatal
  encephalopathy case

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Clinical Features
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Symptoms

• Sudden onset of fever, chills
• Headache, nausea, vomiting, abdominal pain
• Joint pain with or without swelling,
• Low back pain and rash
• Very similar to those of Dengue but
• Unlike in Dengue, no hemorrhagic or shock syndrome

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Clinical Features

• Incubation period is 2-12 d usually 3-7 days
• Viremia last for 5 days (infective period)
• Silent CHIKV inapparent infections in children
• Flu-like symptoms, Severe headache and chills
• High grade fever (40C or 104F),
• Arthralgia or arthritis lasting several weeks
• Conjunctival suffusion and mild photophobia
• Nausea, vomiting, abd. pain, severe weakness

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The Arthralgia

• The small joints of the lower and upper limbs
• Migratory poly arthralgia not much effusions
• Larger joints may also be affected (knee, ankle)
• Pain worse in the morning less by evening
• Joints may be swollen painful to the touch
• Some patients have incapacitating joint pains
• Arthritis may last for weeks or months.

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Kun gunyala
The Contorted Posture
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Acute CHIKV Fever
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Skin Rash in Dengue
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Skin Rash in CHIKV
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Petechiae on feet
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The Burden of CHIKV
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Rare Clinical Features

• A petechial or maculo papular rash usually
  involving the limbs may occur.
• Hemorrhage is rare
• Nasal blotchy erythema, freckle-like pigmentation
  over centro-facial area,
• Flagellate pigmentation on face and extremities
• Lichenoid eruption and hyper pigmentation in
  exposed areas

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Rare Clinical Features

• Multiple aphthous-like ulcers over
• scrotum, crural areas and axilla
• Unilateral or bilateral lympoedema of the limbs
• Lymphadenopathy not common
• Multiple ecchymotic spots in children
• Vesiculo-bullous lesions in infants and
• Sub-ungual hemorrhages
• Severe menigo-encephalitis rare may be fatal

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Course of Illness

• Fever typically lasts for 2 - 3 days and comes
  down
• Fever may reoccur after 3 days saddle back
  fever
• Some rare cases - fever lasts up to a couple of
  weeks
• Patients do have prolonged fatigue for several
  weeks
• High fever crippling joint pain marked this
  epidemic
• Joint pain, intense headache, insomnia and an
  extreme degree of prostration may last for 5 to 7
  days
• Life long immunity, once one suffers this
  infection

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Who are at greater risk ?

• Pregnant women
• Elderly people
• Newborns
• Women in general
• Diabetics
• Immuno-compromised patients
• Patients with severe chronic illnesses

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CHIKV Morbidity

• Chikungunya is a self-limiting illness
• Causes of prolonged morbidity are
• Severe dehydration
• Electrolyte imbalance and
• Loss of glycemic control
• Recovery is the rule
• In about 3 to 5
• Incidence of prolonged arthritis

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Mortality

• A few deaths have been reported - Examples
• It was thought to be due mainly to
• Inappropriate use of antibiotics and NSAIDs
• Virus can cause thrombocytopenia
• These drugs can cause gastric erosions - thus
• Leading to fatal upper GI bleed
• Use of steroids for the joint pains
  inflammation
• This is dangerous and completely unwarranted

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Pregnancy and CHIKV
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Pregnancy and CHIKV

• Mother to fetus transmission can occur
• Reported between 3 to 4.5 months of gestation
• Maternal IgG develops in 2 weeks after CHIKV
• This passes through placenta confers protection
• Intra-partum risk is 48 if mother has viremia
• Neonatal infections are very mild fully recover
• No miscarriages or congenital malformations

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Vertical Transmission

• Vertical maternal-fetal transmission of the
  Chikungunya virus. Ten cases in newborns
  among 84 pregnant women

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Pregnancy - CHIKV

• June 2005 to Jan 2006, 84 pregnant women with
  CHIKV
• In 88 cases the newborns are asymptomatic
• 10 newborns had severe attacks, 4
  meningo-encephalitis
• 3 with intravascular coagulations No infants
  died
• One case of severe intra cerebral hemorrhage
• Had severe thrombocytopenia
• All confirmed by specific serology or PCR or both
• Women had severe intra-partum viremia fever

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Differential Diagnosis

• Dengue fever, DHF, DSS
• Onyong-nyong viral fever
• Sindbis viral fever
• Other non specific viral fevers
• Any other acute fever like malaria, UTI etc.

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Differential Diagnosis
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Laboratory Diagnosis
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Laboratory Diagnosis

• Four fold or more rise of HI Antibody
• IgM capture ELISA using MAbs
• Indirect Immuno Flourescence Test (I IFT)
• On infected cells from tissues
• Virus Isolation Infant Swiss Albino mice
• Vero BHK-21 cell lines are used
• Nucleic acid amplification by PCR RT PCR

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Laboratory Diagnosis

• IgM capture ELISA Good serological test
• Not commercially available
• NIV Pune, NICD Delhi only
• Positive after 5-10 days lasts up to 6 months
• HI Antibody appears on day 3 or 4
• RT PCR confirmatory before the 5th day

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Value of RT -PCR

• Real Time PCR scores over conventional PCR
• Positive in the phase of viremia up to 5 days
• Transportation of sample to be at 2o to 8o c
• It is a confirmatory test with high specificity
• Its sensitivity is very high detects even 1 copy
• After the viremia ceases it will be negative
• We do not have the HI Ab or Ig M capture

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Treatment of CHIKV
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Treatment

• There is no specific treatment for CHIKV
• No vaccine or preventive pill is available
• The illness is usually self-limiting
• It will resolve with time over a week to 10 days
• No relapses occur no second attacks
• Convalescence may take longer
• Symptomatic treatment only

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Management of cases

• Rest in bed will help hasten recovery
• Infected persons should be protected
• from further mosquito exposure
• staying indoors and/or under a mosquito net
• during the first few days of illness
• This is to reduce transmission to others

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Pregnancy and Lactation
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NSAIDs in Pregnancy

• Using NSAIDs during early or late stages of
  pregnancy is not associated with congenital
  anomalies, prematurity, or low birth weight, but
• There is a significant link between NSAID use and
  miscarriage in the first trimester.
• In third trimester may cause premature delivery
• Recommend stopping NSAIDS 6 to 8 weeks before
  delivery to prevent premature closure of fetal
  ductus arteriosus.

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Lactating Women

• Q. Can a woman suffering from early signs of
  Chikungunya breast feed her month old baby?
• A. It is better if you do not. During very early
  stages fever there is viremia. And some of the
  virus may be present in the breast milk. As in
  newborns the immune system is not mature
  particularly monocyte-macrophages system, these
  cells may not be able to take care of the
  ingested virus absorbed through mucous membranes.

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Prevention of Mosquito bite
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Avoid Mosquito Menace
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Prevention from mosquito bites

• Use insect repellent such as DEET on exposed
  skin.
• Wear long sleeves pants, treat clothes with
  permethrin
• Have secure screens on windows and doors
• Get rid of mosquito breeding sites by
• Emptying standing water from flower pots, buckets
  etc.,
• Change the water in pet dishes in bird baths
  weekly
• Drill holes in tire swings so water drains out
• Keep children's wading pools empty

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Perfect Protection
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Vector Control Measures

• Cover all tanks, cisterns, barrels, containers
• Remove old tyres, tins, buckets and bottles
• Clogged gutters and drains need to be cleared
• Change water in dip trays, plant pots twice week
• Tanks need to be covered and cleaned - 2 weeks
• Weeds and tall grass to be cut short ? hiding
• Temephos 1 ppm for large water tanks

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Correct leaking taps
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Cover overhead tanks
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Domestic Water Collections
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Properly close the garbage bins
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Peri domestic fumigation
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Out door fumigation
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Mosquito Magnet
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IEC Activities

• Awareness of CHIKV
• Mass media, TV, Radio, News papers
• Awareness of vector and its control
• Involvement of NGOs
• Special campaigns
• Punishment for non-compliance