Chikungunya fever, epidemiology, cause, clinical features, treatment and prevention

2. CHIKUNGUNYA
PRESENTED BY
IMRAN HOSSAIN
CAPTAIN
ROSTER – 11
MOBC-82

3. I DON’T GET IT
 Chikungunya (has nothing to do with chickens) is
pronounced “Chik-un-goon-ya” or“Chik–un-gun-ya”

6. Introduction
Chikungunya fever (CF) is a viral illness
caused by an arbovirus transmitted by the
Aedes mosquitoes.
The disease was documented first time in the
form of an outbreak in Tanzania.
The name is derived from the ‘makonde’
dialect which means ‘that which bends up’,
indicating the physical appearance of a
patient with severe clinical features. The fever
locally also named as ‘LangraJor’

7. OBJECTIVES
 Historical epidemiology of CHIKUNGUNYA
 What is CHKV
 Clinical presentation
 Vector borne diseases, Differential Diagnosis,
Transmission
 At risk groups ,Dengue /CHIKV dengue snapshot
 Treatment
 Prevention

8. Historical epidemiology
 A viral infection transmitted to humans by the bite
of an infected mosquito
 It has become endemic in south and central India
 Chikungunya (CHIK) virus first isolated from the
serum of a febrile human in Tanzania in 1953.
 Chik virus has caused numerous out breaks in
Africa and South Eastern Asia,

9. A disease of Africa and Asia
www.drsarma.in9

10.  French island of Réunion in the Indian Ocean-
2005
 After an extensive outbreak during the beginning
of current millennium in the French territory of
Reunion Islands in the Indian Ocean, the disease
has been reported from almost 60 countries from
various WHO regions including South-East Asia
 Chikungunya virus strains isolated in India during
the 2004-2006 outbreaks are closely related to
strains isolated from Réunion islands

11. 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*.
*http//medicine.plosjournals.org

12. THE CHIKUNGUNYA
VIRUS

13. The CHIK Virus
 Causative agent is an RNA – VIRUS
 Class – Arbor Virus (Arthropod Borne)
 Family – Togaviridae
 Genus – Alpha Virus
 Species – Chikungunya Virus

14. CHIKUNGUNYA VIRUS
spread by bite of Aedes aegypti
mosquito which usually bite during
day light hours.
 the name is derived from Swahili
word meaning “that which bends
up”.
Describes the posture patient
assumes to relieve the severe joint
pains

15. The Vector
 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

16. Aedes aegypti/alboptycus/Tiger
mosquito

17. 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

18. Transmission

19. CLINICAL FEATURES
CHIKV Infection a disease of two phases
ACUTE :
o Incubation period: 3–7 days (range of
1‒12 days).
o Main symptoms: acute onset of fever and
polyarthralgia
CHRONIC :
o Early exacerbations, inflammatory
relapses, longstanding rheumatism and
loss in quality of life

20. Fever and polyarthralgia
 Fever
 Acute onset
 ≥38.5°C
 Joint pain
 Sometimes serious and debilitating
 Multiple joints
 Bilateral and symmetric (usually)
 Most commonly in hands and feet
http://www.paho.org/hq/index.php?option=com_docman&task=doc_download&gid=16985&Itemid=

22. 22
Subacute stage, persisting distal inflamatory arthralgias
Simon F et coll. Medicine 2007;86: 123-37

23. 23
Subacute stage, tenosynovitis

24. 24
Simon F et coll. Medicine 2007;86: 123-37
Subacute stage, bursitis

25. 25
Subacute stage, associated rheumatic disorders

26. Other signs and symptoms
 Headache
 Myalgia
 Arthritis
 Conjunctivitis
 Nausea and vomiting
 Maculopapular rash
http://wfffun.info/diseases/chikungunya-rash-photos-2/

27. Skin Rash in CHIKV
www.drsarma.in27

28. The Arthralgia
www.drsarma.in28
 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.

29. www.drsarma.in29
The Contorted Posture

30. Outcome
30
 Acute symptoms: resolved in 7-10 days
 Mortality: rare (elderly)
 Some patients have relapses of rheumatic
symptoms in the months following the acute
illness
 Chronic illness of varying degrees, with pain
persisting for months or years
 Life long immunity, once one suffers this infection

31. Who are at greater risk ?
www.drsarma.in31
 Pregnant women
 Elderly people
 Newborns
 Women in general
 Diabetics
 Immuno-compromised patients
 Patients with severe chronic illnesses

32. 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 outbreak

33. WHO case definitions

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

35. Pregnancy and CHIKV
www.drsarma.in35
 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
 Neonatal infections are very mild; fully recover
 No miscarriages or congenital malformations

36. Differential Diagnosis
 (1) Dengue fever: Severe backpain with purpuras or
active bleeding might suggest dengue fever.
Confirmatory laboratory diagnosis is possible.
 (2) Reactive Arthritis: In general, any arthritis that
follows a febrile gastrointestinal or genitourinary
infection (triggering microbes) is considered a reactive
acute inflammatory arthritis if it lasts less than six
months. The hallmark feature is enthesitis Oral
mucosal ulcers are seen.
 (3) Serum sickness illness: Polyarthritis may be
associated with a serum sickness type reaction
caused by vaccine, medication or other viral infections
 (4) Rickettsial disease can present with fever, rash
and joint pains. Confirm by serology.

37. Differential Diagnosis
 (5) Rheumatic fever: More common in the children and
presents with fleeting (migratory) polyarthritis
predominantly affecting the large joints. Modified Jones
criteria should be the basis for diagnosis. Raised ASO titre
and a history of recurrent sore throat are other points to be
noted.
 (6) Malaria: patient can present with high fevers and may
also complain of joint pains. Periodicity of fever and
alteration of consciousness / seizures should prompt a
diagnosis for malaria
 (7) Leptospirosis: Severe myalgia localized to calf
muscles with conjunctival congestion/ or subconjunctival
haemorrhage with or without oliguria or jaundice in a
person with history of skin contact to contaminated water
would suggest Leptospirosis

38. 38
MALARIA
DENGUE
FEVER
CHIKUNGUNYA FEVER
Jaundice
Renal failure
Fever
Myalgia
Rash
Bleedings
Retro-orbital pain
Transient arterial
hypotension
Acute polyarthritis
Tenosynovitis
Anemia
LEPTOSPIROSIS
Adapted from Simon et al, Schwartz, Infections in travelers, Ed 2009
BACTERIAL
SEPSIS
Myalgia
Myocarditis
ADRS
Chikungunya outbreak, high risk for misdiagnosis

39. Dengue and CHIK
 Virus transmitted by the same mosquitos
 Similar clinical picture
 The viruses can circulate in the same
areas–- co-infection
 Discarding dengue is important, for an
adequate clinical care that improves the
prognosis of dengue

41. Differential Diagnosis
www.drsarma.in41
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

42. Treatment

43. Treatment
www.drsarma.in43
 There is no specific treatment for
CHIKV
 No vaccine or preventive pill is
available
 The illness is usually self-limiting
 Symptomatic treatment only

44.  Mild movements of joints

45.  Rest to the patient

46.  Cold compresses to inflamed joints

47.  Liberal fluid intake or IV fluids

48.  Analgesics and NSAIDS
 Paraetamol ± Ibuprofen or aceclofenac or
diclofenac
 Naproxen sodium (Naprasyn, Xenobid)
 Aspirin should be avoided

49. PREVENTION

50. ANTI-LARVAL MEASURES
 SOURCE REDUCTION OF BREEDING
PLACES
o Elimination of stagnant water at home, schools
and work place to avoid breeding of
mosquitoes.

51. BREEDING SOURCES

54. BIOLOGICAL CONTROL
 Introduction of larvivorous fish, namely
Gambusia and Guppy in water tanks and
other water sources.

55. ANTI-ADULT MEASURE
 The organophosphorous insecticide ABATE is
being used in a large scale
 It does not affect man or the taste of water
 Aerosol spray of ultra low volume [ULV] of
MALATHION or SUMITHION 250 ml/hectare is
effective in interrupting transmission and
stopping epidemics

56. • Wearing the long sleeved clothes like long
trousers of a light shade for protection against
mosquitoes.

57.  Using insect repellents over the exposed parts of the
body.
• Using mosquito screens or nets in non – Air-
conditioned rooms

58. CONCLUSION
 Chikungunya disease is expanding throuout
the world;
 The spread of the disease depends on the
distribution of its vectors;
 The disease is rarely fatal, but can impose a
heavy burden on the health systems.
 Prevention is the target as it has no specific
treatment.
 Vector reduction is the ultimate way to prevent
Chikungunya