EPIDEMIOLOGY OF CHICKEN POX

2. EPIDEMIOLOGY OF
CHICKEN POX
DR. MAHESWARI JAIKUMAR.
maheswarijaikumar2103@gmail.com

4. INTRODUCTION
•CHIKEN POX or VARICELLA
is an acute, highly
infectious disease caused
by VARICELLS ZOSTER (V-Z)
virus.

5. • It is characterized by vesicular
rash that may be
accompanied by fever and
malaise.

8. AGENT
• The causative
agent of
chicken pox, V-
Z virus is also
called “Human
(alpha) herpes
virus”.

10. SORCE OF INFECTION
• 1. Usually a case of chikenpox.
• 2.The virus occurs in the
oropharyngeal secretions and
lesions of the skin and
mucosa.

11. • 3. The virus can be isolated
from vesicular fluid during the
first three days of illness.
• 4. The scabs are not infective.

12. VESICLE

13. INFEECTIVITY
• Ranges from 1 to 2 days before
the appearance of rash and 4 to
5 days thereafter.
• The virus tends to die out before
the pustular stage.

15. • The patient ceases to be
infectious once the lesions have
crusted.

16. SECONDARY ATTACK RATE
• Chickenpox is highly
communicable.
• The secondary attack rate in
household contacts approaches
90%.

18. AGE
• Chicken pox primarily occurs
among children under 10 years
of age.
• The disease can be severe in
normal adults.

19. IMMUNITY
• One attack gives durable
immunity.
• Secondary attacks are rare.

20. PREGNANCY
• Infection during pregnancy
presents a risk for the foetus and
the neonate.

22. • Chicken pox shows seasonal
trend in India.
• The disease mostly occurs during
the first six months of the year.
• Overcrowding favours it’s
transmission.

23. TRANSMISSION
• Chickenpox is transmitted from person
to person by droplet infection and by
droplet nuclei.
• Most persons are infected by face – to
– face contact.
• The portal of entry of the virus is
respiratory tract.

24. INCUBATION PERIOD
• Usually 14 to 16 days, although
extreme as wide as 10 to 21 days
have been reported.

25. CLINICAL FEATURES

27. • The clinical spectrum of
chickenpox may vary from child
to child.
• The clinical course of chickenpox
may be divided into two stages.

28. PRE ERUPTIVE STAGE
• Onset is sudden with mild or
moderate fever, pain in back,
shivering and malaise.
• This stage is brief, lasting about 24
hrs.

29. • In adults, the prodromal illness is
usually more severe and may last
for 2 to 3 days before the rash
appears.

30. ERUPTIVE STAGE
• In children the rash is often the
first sign.(The rashes are
prurutic)
• It comes on the day the fever
starts.

31. • The distinctive features of rash
are:
1. DISTRIBUTION.
2. RAPID EVOLUTION.
3. PLEOMORPHISM.
4. FEVER.

32. DISTRIBUTION
• The rash is symmetrical.
• It first appears on the trunk
where it is abundant and then
comes on the face, arms and legs
where it is less abundant.

33. • Axilla may be affected but palms
and soles are not usually
affected.
• The density of the eruption
diminishes centrifugally.

34. RAPID EVOLUTION
• The rash advances quickly through
the stages of macule, papule,
vesicle and scab.
• The vesicles look like dew drops on
the skin. Scabbing begins 4 to 7
days after the rash appears.

35. PLEOMORPHISM
• A characteristic feature of the
rash in chickenpox is its
pleomorphism (ie, all the stages
of the rash may be seen
simultaneously at one time in
the same area)

36. FEVER
• The fever does not run high but
shows exacerbations with each
fresh crop of eruption.

37. COMPLICATIONS
• In most cases, chickenpox is self
limiting.
• However it may be accompanied
by severe complications in
immunosuppressed individuals.

38. • These include haemorrrhage,
pneumonia, encephalitis,
secondary bacterial infections
and DIV (Desseminated
Intravascular Coagulation).

39. LAB DIAGNOSIS
• 1. Examination of the vesicular
fluid.
• 2. Scrapings of floor of vesicles
shows multinucleated giant cells
coloured by Giemsa)

40. TREATMENT
• Antiviral
compounds :
Acyclovir,
Valaclovir,
Famiclovir and
Foscarnet.

42. CONTROL
• The usual measures are :
• Notification.
• Isolation of case for about 6 days
after onset of rash.
• Disinfection of articles soiled by
nose and throat discharges.

43. PREVENTION
• 1. Varicella Zoster immunoglobulin
(VZIG) is given within 72 hrs of
exposure.
• A live attenuated Varicella Virus
vaccine is for children (12-18 Mo),
who have not had chickenpox.

48. HOW TO KILL CHICKEN POX
• Bath the child with soap and
warm water.
• Apply cool clothes soaked in
water from boiled and strained
oatmeal in order to calm itching..

49. • Cut finger nails very short.
• If the scabs get infected, apply
Gentian violet (GV paint) or an
antibiotic ointment over them.

53. THANK YOU