2. 2
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.
CHIKV Fever
Buggy Creek virus infection
Knuckle fever
Me Tri virus infection
Semliki Forest virus infection
Synonyms
6. 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.
In Bangalore, the state capital of Karnataka (India), there seems
to be an outbreak of CHIK now (May 2006)
In the 3rd week of May 2006 the outbreak of Chikungunya in
North Karnataka is severe.
A separate outbreak of chikungunya fever was reported from
Malegaon town in Nasik district, Maharashtra state,
In Orissa state, amost 5000 cases of fever with muscle achesand
headache were reported between February 27 and March 5, 2006.
7. CHIKV and Travelers
1995-2009: 109 lab-confirmed cases in US
Adult travelers, mean age 48 yrs
57% female
Gibney et al. CID 2011; 0:1-6
10. History (Its story)
10
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
11. What is this virus ?
11
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.
12. Chikungunya Virus (CHIKV): Alphavirus
“That which bends up”
in Swahili
Togaviridae family
Single strand RNA virus,
mosquito-transmitted
New World: Fever, rash,
encephalitis
Western equine
encephalitis
Eastern Equine
encephalitis
Old World: Fever, rash,
arthralgias
Chikungunya
Ross River Virus (Oceana)
Barmah Forest Virus
(AUS)
O’nyong-nyong (Africa)
Semliki Forest Virus
(Africa)
Mayoro (South America)
Sindbis virus (AUS, Africa,
Europe, Asia minor)
www.cdc.gov/ncidod/dvbid/arbor/alphavir.htm
14. Transmission
14
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
16. The Vector
16
Aedes aegypti mosquito, flight range < 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
21. Transmission: Aedes mosquito
Aedes aegypti
Urban mosquito
Needs standing water for larvae
Prefers cool, dark areas for resting
Feeds through the day, most active at dawn/dusk
Eggs do not survive winter in temperate climates
Aedes albopictus: Asian Tiger Mosquito
Urban, periurban, rural habitats
Feeds through the day, most active dawn/afternoon
Eggs survive winter in temperate climates
Invasive- spreading in Europe and Americas
www.cdc.gov
25. 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
25
27. Notable Outbreaks
27
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 B’lore
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
28. Distribution in India
28
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
29. Most Recent Epidemics
29
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
30. The Indian Epidemic
30
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
31. Attack Rates
31
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
32. Why is this sudden epidemic ?
32
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*.
33. Why is this quasi-pandemic ?
33
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
35. Symptoms
35
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
37. Clinical Features
37
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 (40°C or 104°F),
Arthralgia or arthritis – lasting several weeks
Conjunctival suffusion and mild photophobia
Nausea, vomiting, abd. pain, severe weakness
38. The Arthralgia
38
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.
42. CLINICAL
SIGNS
CHIKUNGUNYA DENGUE
Fever Common Common
Rash Day 1 – Day 4 Day 5 – Day 7
Retroorbital pain Rare Common
Arthralgia Constant Rare
Arthritis Common, edematous Absent
Myalgia Common Common
Tenosynovitis Common Absent
Hypotension Possible Common, Day 5 – Day 7
Minor bleeding Rare Common, Day 5 – 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
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
47. Rare Clinical Features
47
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
48. Course of Illness
48
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
49. Who are at greater risk ?
49
Pregnant women
Elderly people
Newborns
Women in general
Diabetics
Immuno-compromised patients
Patients with severe chronic illnesses
50. CHIKV Morbidity
50
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
51. Mortality
51
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
53. Pregnancy and CHIKV
53
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
54. Vertical Transmission
54
Vertical 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
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
56. Differential Diagnosis
56
Dengue fever, DHF, DSS
O’nyong-nyong viral fever
Sindbis viral fever
Other non specific viral fevers
Any other acute fever like malaria, UTI etc.
57. Differential Diagnosis
57
Feature CHIKV DENGUE
Presentation A+F ± 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)
On infected cells from tissues
1. Virus Isolation – Infant Swiss Albino mice
Vero BHK-21 cell lines are used
1. Nucleic acid amplification by PCR & RT PCR
60. Laboratory Diagnosis
60
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
61. Value of RT -PCR
61
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
63. Treatment
63
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
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
Rest to the patient and mild movements of joints
Cold compresses to inflamed joints
Liberal fluid intake or IV fluids
Analgesics and NSAIDS
Paraetamol ± Ibuprofen or aceclofenac or diclofenac
Naproxen sodium (Naprasyn, Xenobid)
Aspirin should be avoided
Hydroxy chloroquine sulphate (HCQS) 200 mg/od
Chloroquine phosphate 250 mg/od
66. What not to give ?
66
No indication for antibiotics
Never use costly, large spectrum drugs
No indication for long acting steroids
No indication for short term steroids also in the
acute phase of illness
Rarely, if the joint swelling persists – we may
consider use of steroids in short burst.
67. A Y U S H
67
A Ayurvedic or Acupuncture
Y Yoga and or Naturopathy
U Unaani
S Siddha
H Homeopathy
No comments on these alternative medicines
If no pathy works, finally
Venkatapathy or Tirupathy
68. Management of cases
68
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
70. NSAIDs in Pregnancy
70
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.
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
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
76. Vector Control Measures
76
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
85. IEC Activities
85
Awareness of CHIKV
Mass media, TV, Radio, News papers
Awareness of vector and its control
Involvement of NGOs
Special campaigns
Punishment for non-compliance
Notas del editor
Cdc data plus 2 commercial labs performing chik serologies
Recent Italy data: 42% imported cases from Indian ocean Islands 42% Asia