2. 2
īChikungunya 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.
īCHIKV Fever
īBuggy Creek virus infection
īKnuckle fever
īMe Tri virus infection
īSemliki Forest virus infection
Synonyms
6. īFirst reported in India in 1963 â 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.
īIn 2006, there was a big outbreak in the Andhra Pradesh state in
India.
īIn Bangalore, the state capital of Karnataka (India), there seems
to be an outbreak of CHIK now (May 2006)
ī In the 3rd week of May 2006 the outbreak of Chikungunya in
North Karnataka is severe.
īA separate outbreak of chikungunya fever was reported from
Malegaon town in Nasik district, Maharashtra state,
īIn Orissa state, amost 5000 cases of fever with muscle achesand
headache were reported between February 27 and March 5, 2006.
7. CHIKV and Travelers
ī1995-2009: 109 lab-confirmed cases in US
īĄ Adult travelers, mean age 48 yrs
īĄ 57% female
Gibney et al. CID 2011; 0:1-6
10. History (Its story)
10
īA viral infection transmitted to humans
īBy the bite of an infected mosquito
īIt has become endemic in south and central India
īFirst outbreak in 1952 on the Makonde Plateau
īBorder between Tanganyika and Mozambique
īFirst published report is from Africa in 1955 by
īMarion Robinson and W.H.R. Lumsden
īRecent large epidemic occurred in Malaysis in 1999
11. What is this virus ?
11
īCausative agent is an RNA â VIRUS
īClass â Arbor Virus (Arthropod Borne)
īFamily â Togaviridae
īGenus â Alpha Virus
īSpecies â Chikungunya Virus
īSimilar to Semliki Forest Viruses (SFV) in Africa and Asia.
12. Chikungunya Virus (CHIKV): Alphavirus
īâThat which bends upâ
in Swahili
īTogaviridae family
īSingle strand RNA virus,
mosquito-transmitted
īNew World: Fever, rash,
encephalitis
īĄ Western equine
encephalitis
īĄ Eastern Equine
encephalitis
īOld World: Fever, rash,
arthralgias
īĄ Chikungunya
īĄ Ross River Virus (Oceana)
īĄ Barmah Forest Virus
(AUS)
īĄ Oânyong-nyong (Africa)
īĄ Semliki Forest Virus
(Africa)
īĄ Mayoro (South America)
īĄ Sindbis virus (AUS, Africa,
Europe, Asia minor)
www.cdc.gov/ncidod/dvbid/arbor/alphavir.htm
14. Transmission
14
īReservoir â Non-human primates in Africa
īNo animal reservoir is found in India
īMaintained in nature by man â mosquito â man cycle
īVector â Aedes aegypti, Ae. albapticus mosquito
īSame vector as for Dengue and Yellow fevers
īVehicle of transmission â None
īNo known mode - other than mosquito bite
īIncubation Period â 2 days to 12 days
16. The Vector
16
īAedes aegypti mosquito, flight range < 100 meters
īAggressive daytime biter â under lights â bites ankles
īOnce infected â it has the virus until death (30 days)
īIt is a man made mosquito â prefers its owner
īBreeds in man made household containers
īIndoor, peridomestic, fresh water mosquito
īMetallic, plastic, rubber, cement and earthen containers
- open, left or unused - get filled with water
īAir coolers, ACs, Old oil drums, Over head tanks
21. Transmission: Aedes mosquito
īAedes aegypti
īĄ Urban mosquito
īĄ Needs standing water for larvae
īĄ Prefers cool, dark areas for resting
īĄ Feeds through the day, most active at dawn/dusk
īĄ Eggs do not survive winter in temperate climates
īAedes albopictus: Asian Tiger Mosquito
īĄ Urban, periurban, rural habitats
īĄ Feeds through the day, most active dawn/afternoon
īĄ Eggs survive winter in temperate climates
īĄ Invasive- spreading in Europe and Americas
www.cdc.gov
25. Why only Aedes Mosquito ?
īScanning Electron Micro-graph
of the mid gut cells of the
mosquito
īLocation of the Chik Virus
binding proteins.
īNot transmitted to the progeny
of the mosquito
25
27. Notable Outbreaks
27
ī1963 to 1965 - An epidemic was reported in Calcutta â
ī4.37% of the people were later found to be seropositive
ī1973 â An epidemic 37.53% in Barsi - Sholapur district
ī2006 â Present epidemic after 33 years is the largest
ī9,06,360 or more cases in Andhra Pradesh
ī5,43,286 cases from Karnataka; 66,109 from Bâlore
īMaharashtra 2,02,114 cases; Gujarat 2,500 cases
īTamil Nadu 49,567 cases; Orissa 4,904 cases,
īMadhya Pradesh 43,784 and Pune 138 cases
28. Distribution in India
28
īThe disease is common with periodic epidemics
īSporadic outbreaks described in Madras and Vellore
īCases were reported in Chennai, Pondicherry, Vellore
īVizag in 1964; Rajahmundri, Kakinada, Nagpur in 1965
īThe last epidemic in India was in 1973
īFrom Yavat village (Pune) in 2000
ī2.9% in the Andaman & Nicobar Islands are seropositive
īInfected mosquitoes seen in Pune, Maharastra State
29. Most Recent Epidemics
29
īEpidemic of CHIKV occurred in Malaysia â 1999
īFrench island of RÊunion in the Indian Ocean- 2005
īEpidemic was recorded in Mauritius â 2005
īMadagascar, Mayotte and Seychelles â 2005
īHong Kong and Malaysia early 2006
īPresent indian epidemic is the largest -from Dec â05
īMaximum # of cases from Andhra Pradesh so far
30. The Indian Epidemic
30
īPresent epidemic has started in Nov 2005
īAndhra Pradesh, Karnataka, Maharashtra, Madhya Pradesh,
Orissa, Gujarat, Tamilnadu, Rajasthan, Kerala are under its
onslaught
īThis is spreading far and wide at a rapid rate
īNot much spread to the northern states like Delhi, Haryana,
Punjab as yet.
īNot much cry from U.P. and Bihar
31. Attack Rates
31
īIn urban localities it is more â why ?
īUsual age group is above 15 years
īLess common in children and infants
īFamily clustering of cases usual
īAttack rates vary from 3 to 40% of population
īAverage attack rate is 10%
īHerd immunity restricts further spread
32. Why is this sudden epidemic ?
32
ī 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 virusâ coat protein, which
potentially allows it to multiply more easily in mosquito
cells*.
33. Why is this quasi-pandemic ?
33
īSeveral distinct variants of the virus
īA change at position 226 of the E1 coat protein
īThis A226V mutation caused the virus to more easily
invade and multiply in the mosquitoes
īThree protein changes in non-structural proteins
īĄ nsP1 (T301I), nsP2 (Y642N), and nsP3 (E460 deletion)
īĄ This mutant virus - from a neonatal encephalopathy case
35. Symptoms
35
īSudden onset of fever, chills
īHeadache, nausea, vomiting, abdominal pain
īJoint pain with or without swelling,
īLow back pain and rash
īVery similar to those of Dengue but
īUnlike in Dengue, no hemorrhagic or shock syndrome
37. Clinical Features
37
īIncubation period is 2-12 d; usually 3-7 days
īViremia last for 5 days (infective period)
īSilent CHIKV â inapparent infections in children
īFlu-like symptoms, Severe headache and chills
īHigh grade fever (40°C or 104°F),
īArthralgia or arthritis â lasting several weeks
īConjunctival suffusion and mild photophobia
īNausea, vomiting, abd. pain, severe weakness
38. The Arthralgia
38
īThe small joints of the lower and upper limbs
īMigratory poly arthralgia â not much effusions
īLarger joints may also be affected (knee, ankle)
īPain worse in the morning â less by evening
īJoints may be swollen & painful to the touch
īSome patients have incapacitating joint pains
īArthritis may last for weeks or months.
42. CLINICAL
SIGNS
CHIKUNGUNYA DENGUE
Fever Common Common
Rash Day 1 â Day 4 Day 5 â Day 7
Retroorbital pain Rare Common
Arthralgia Constant Rare
Arthritis Common, edematous Absent
Myalgia Common Common
Tenosynovitis Common Absent
Hypotension Possible Common, Day 5 â Day 7
Minor bleeding Rare Common, Day 5 â Day 7
Outcome Possible Raynaud syndrome,Month2-
Month3
Possible Tenosynovitis,Month2-
Month3.
Common persistence of arthralgia for
months to years.
Possible fatigue for
weeks
Thrombocytopenia Early and mild Delayed and possible
deep.
46. Rare Clinical Features
46
īA petechial or maculo papular rash usually involving the
limbs may occur.
īHemorrhage is rare
īNasal blotchy erythema, freckle-like pigmentation over
centro-facial area,
īFlagellate pigmentation on face and extremities
īLichenoid eruption and hyper pigmentation in exposed
areas
47. Rare Clinical Features
47
īMultiple aphthous-like ulcers over
īĄ scrotum, crural areas and axilla
īUnilateral or bilateral lympoedema of the limbs
īLymphadenopathy not common
īMultiple ecchymotic spots in children
īVesiculo-bullous lesions in infants and
īSub-ungual hemorrhages
īSevere menigo-encephalitis â rare; may be fatal
48. Course of Illness
48
īFever typically lasts for 2 - 3 days and comes down
īFever may reoccur after 3 days â âsaddle backâ fever
īSome rare cases - fever lasts up to a couple of weeks
īPatients do have prolonged fatigue for several weeks
īHigh fever & crippling joint pain marked this epidemic
īJoint pain, intense headache, insomnia and an extreme
degree of prostration may last for 5 to 7 days
īLife long immunity, once one suffers this infection
49. Who are at greater risk ?
49
īPregnant women
īElderly people
īNewborns
īWomen in general
īDiabetics
īImmuno-compromised patients
īPatients with severe chronic illnesses
50. CHIKV Morbidity
50
īChikungunya is a self-limiting illness
īCauses of prolonged morbidity are
īĄ Severe dehydration
īĄ Electrolyte imbalance and
īĄ Loss of glycemic control
īRecovery is the rule
īIn about 3 to 5%
īĄ Incidence of prolonged arthritis
51. Mortality
51
īA few deaths have been reported - Examples
īIt was thought to be due mainly to
īĄ Inappropriate use of antibiotics and NSAIDs
īĄ Virus can cause thrombocytopenia
īĄ These drugs can cause gastric erosions - thus
īĄ Leading to fatal upper GI bleed
īĄ Use of steroids for the joint pains & inflammation
īĄ This is dangerous and completely unwarranted
53. Pregnancy and CHIKV
53
īMother to fetus transmission can occur
īReported between 3 to 4.5 months of gestation
īMaternal IgG develops in 2 weeks after CHIKV
īThis passes through placenta â confers protection
īIntra-partum risk is 48% if mother has viremia
īNeonatal infections are very mild; fully recover
īNo miscarriages or congenital malformations
54. Vertical Transmission
54
īVertical maternal-fetal transmission of the
Chikungunya virus. Ten cases in newborns among
84 pregnant women
Robillard PY, Boumahni B, Gerardin P, Michault A,
Fourmaintraux A, Schuffenecker I, Carbonnier M,
Djemili S, Choker G, Roge-Wolter M, Barau G.
Pub Med. 2006 May; 35(5 Pt 1):785-8.
55. Pregnancy - CHIKV
55
īJune 2005 to Jan 2006, 84 pregnant women with
CHIKV
īIn 88% cases the newborns are asymptomatic
ī10 newborns had severe attacks, 4 meningo-
encephalitis
ī3 with intravascular coagulations; No infants died
īOne case of severe intra cerebral hemorrhage
īHad severe thrombocytopenia
īAll confirmed by specific serology or PCR or both
īWomen had severe intra-partum viremia & fever
56. Differential Diagnosis
56
īDengue fever, DHF, DSS
īOânyong-nyong viral fever
īSindbis viral fever
īOther non specific viral fevers
īAny other acute fever like malaria, UTI etc.
57. Differential Diagnosis
57
Feature CHIKV DENGUE
Presentation A+F Âą mild rash A+F+Rash
Arthralgia Moderate Severe
Arthritis Not common Frequent
Bone pains None Break bone fever
Thrombocytopenia Mild (Not < 1K) May be severe
Hemorrhage None May be present
Shock syndrome Never May occur
Immunity (IgG) Life long 2nd
attack
fatality
59. Laboratory Diagnosis
59
1. Four fold or more rise of HI Antibody
2. IgM capture ELISA using MAbs
3. Indirect Immuno Flourescence Test (I IFT)
īĄ On infected cells from tissues
1. Virus Isolation â Infant Swiss Albino mice
īĄ Vero BHK-21 cell lines are used
1. Nucleic acid amplification by PCR & RT PCR
60. Laboratory Diagnosis
60
īIgM capture ELISA â Good serological test
īNot commercially available
īNIV â Pune, NICD â Delhi only
īPositive after 5-10 days & lasts up to 6 months
īHI Antibody appears on day 3 or 4
īRT âPCR confirmatory â before the 5th
day
61. Value of RT -PCR
61
īReal Time PCR scores over conventional PCR
īPositive in the phase of viremia â up to 5 days
īTransportation of sample to be at 2o
to 8o
c
īIt is a confirmatory test with high specificity
īIts sensitivity is very high; detects even 1 copy
īAfter the viremia ceases â it will be negative
īWe do not have the HI Ab or Ig M capture
63. Treatment
63
īThere is no specific treatment for CHIKV
īNo vaccine or preventive pill is available
īThe illness is usually self-limiting
īIt will resolve with time over a week to 10 days
īNo relapses occur â no second attacks
īConvalescence may take longer
īSymptomatic treatment only
64. CHIKUNGUNYA DRUG
France develops a new drug to treat
64
"We are confident today that a drug to treat Chikungunya will
be made available and we are hopeful that this drug will be
available at the very end of this year or at the very start of
2007"
- French Health Minister - Xavier Bertrand
- September 11th
2006
65. Treatment
65
īRest to the patient and mild movements of joints
īCold compresses to inflamed joints
īLiberal fluid intake or IV fluids
īAnalgesics and NSAIDS
īĄ Paraetamol Âą Ibuprofen or aceclofenac or diclofenac
īĄ Naproxen sodium (Naprasyn, Xenobid)
īĄ Aspirin should be avoided
īHydroxy chloroquine sulphate (HCQS) 200 mg/od
īChloroquine phosphate 250 mg/od
66. What not to give ?
66
īNo indication for antibiotics
īNever use costly, large spectrum drugs
īNo indication for long acting steroids
īNo indication for short term steroids also in the
acute phase of illness
īRarely, if the joint swelling persists â we may
consider use of steroids in short burst.
67. A Y U S H
67
īA Ayurvedic or Acupuncture
īY Yoga and or Naturopathy
īU Unaani
īS Siddha
īH Homeopathy
No comments on these alternative medicines
If no pathy works, finally
Venkatapathy or Tirupathy
68. Management of cases
68
īRest in bed will help hasten recovery
īInfected persons should be protected
īĄ from further mosquito exposure
īĄ staying indoors and/or under a mosquito net
īĄ during the first few days of illness
īĄ This is to reduce transmission to others
70. NSAIDs in Pregnancy
70
īUsing NSAIDs during early or late stages of pregnancy is
not associated with congenital anomalies, prematurity, or
low birth weight, but
īThere is a significant link between NSAID use and
miscarriage in the first trimester.
īIn third trimester may cause premature delivery
īRecommend stopping NSAIDS 6 to 8 weeks before delivery
to prevent premature closure of fetal ductus arteriosus.
71. Lactating Women
71
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.
74. Prevention from mosquito bites
74
īUse insect repellent such as DEET on exposed skin.
īWear long sleeves & pants, treat clothes with permethrin
īHave secure screens on windows and doors
īGet rid of mosquito breeding sites by
īĄ Emptying standing water from flower pots, buckets etc.,
īĄ Change the water in pet dishes in bird baths weekly
īĄ Drill holes in tire swings so water drains out
īĄ Keep children's wading pools empty
76. Vector Control Measures
76
īCover all tanks, cisterns, barrels, containers
īRemove old tyres, tins, buckets and bottles
īClogged gutters and drains need to be cleared
īChange water in dip trays, plant pots twice week
īTanks need to be covered and cleaned - 2 weeks
īWeeds and tall grass to be cut short â hidingâ
īTemephos 1 ppm for large water tanks
85. IEC Activities
85
īAwareness of CHIKV
īMass media, TV, Radio, News papers
īAwareness of vector and its control
īInvolvement of NGOs
īSpecial campaigns
īPunishment for non-compliance
Editor's Notes
Cdc data plus 2 commercial labs performing chik serologies
Recent Italy data: 42% imported cases from Indian ocean Islands 42% Asia