chicken pox small pox mumps

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Chicken pox

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Instructional Objectives:At the end of the lecture the student would be able to:1-Demonstrate the main clinical characteristics of Chicken pox, Small pox, and Mumps.2-Point out the occurrence of the diseases.3-List the causative agent, mode of transmission, incubation period, and period of communicability of Chicken pox, Small pox, and Mumps.4-List the main preventive measures of Chicken pox, and Mumps.5-Describe the control measures of Chicken pox, and Mumps.

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Acute generalized viral disease characterized by:
Sudden onset of fever, mild constitutional symptoms, &skin rash
Maculo-papular rash.. few hours.. vesicles…. 3-4days.. granular crusts
Lesion commonly occur in successive groups with several stage of maturity present at the same time.

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More abundant on covered than exposed parts of the body
Lesions may appear high in the axilla &on the scalp ,MM of the mouth and R.T., &on the conjunctivae




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They may be so few as to escape attention

Mild, atypical, & inapparent infection can occur





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Sever form can occur in adults.

Children with acute leukemia are at high risk of severe disseminated form with CFR of 5-10 %

Neonates (5-10days)have a CFR of up to 30%

Infection early in pregnancy may be associated with (CVS) in 0.7 % &if infection occurs at 13-20 weeks in may be associated with CVS in 2%

Herpes zoster is a local manifestation or reactivation of varicella infection in dorsal root ganglia.

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Infectious agent:
Human (alpha) herpes virus 3
(V-Z virus)

Occurrence:

World wide, in temperate climates at least 90% of the population has had chicken pox by the age of 15 years &at least 95% by young adulthood.
Zoster occurs more commonly in older groups.
In temperate zones occurs most frequently in winter &spring

Reservoir : Human

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Mode of transmission:
Direct contact person-to –person
* Droplet
* airborne spread
vesicle fluid or secretion of the URT of chicken pox case or vesicle fluid of patient with HZ can transmit infection.
Indirect
* Soiled articles
Scabs are not infectious
Incubation period:
2-3 weeks , commonly 14-16 days


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Period of communicability
1-2 days before the Rash
and 5 days after.

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Susceptibility &resistance:
general
More sever from occur among adults

Infection gives life long immunity

Second attacks are rare

sub clinical re-infection is common

Viral infection remain latent &disease may occur later as HZ in about 15%of older adults &some times in children

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• Prevention:
• Live attenuated Variclla vaccine (Varivax). A single dose of 0.5 ml sc is recommended for children age 12m-12 yrs who have not had chicken pox . This vaccine had cumulative efficacy at 70-90 % in preventing varicella in children. It is protective if it is given within 3 days of exposure
• Protect high risk individuals from exposure
• VZIG is effective in preventing or modifying the disease .if given within 96 hours of exposure


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• Control :
• Reporting is not necessary
• Isolation :Exclude children from school for 5 days after appearance of rash
• Disinfection of articles soiled by discharge from nose & throat
• Protection of contact:
• VZIG within 96 hrs of exposure
• Varivax vaccine within3 days of exposure
• Newborns of mothers exposed who develops varicella 5 days before or 2 days after delivery.

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• VZIG given to pregnant does not prevent CVS
• Acyclovir week of exposure 80mg/kg/day/qds
• Specific Rx :
• Antiviral drag
• Zovirax( Acyclovir), Vidarabine

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Smallpox (Variola)
Last naturally acquired case in word occur in October 1977 in Somalai
Global eradication
was certified two years
later by WHO





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It is systemic viral disease

Onset sudden fever,
malaise, prostration,
severe backache,
&occasional abdominal
pain &vomiting
within (2-4 days).



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Then Fever began to fall deep seated rash developing in which individual lesions containing infectious virus macules papules vesicles pustules crusted scrabs
Which fell off after 3-4 weeks
Appeared on the successive stages of maturity
Abundant on the exposed parts (centrifugal distribution).


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Two types of smallpox were recognized during the 20th century :
Variola minor (alastrim) CFR <1%
Variola major (ordinary) CFR 20-40%
(among unvaccinated )

In the previously vaccinated the rash stage was significantly modified.

Infectious agent:

Variola virus a species of orthopox virus.

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Occurrence :
Formerly a world wide disease. it is eradicated.

Reservoir :

Naturally human, officially, only in designated freezers.

Mode of transmission :

Air borne
Secondary attack rate among unvaccinated population was about 50%.


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Incubation period:
7 to 19days
Communicability From the first day of the development of the earliest lesion to the disappearance of all scabs (about 3 weeks).

Susceptibility & resistance:

Among unvaccinated is universal.

Method of control:

Immunization with vaccinia virus vaccine.

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Mumps
Infectious parotistis



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An acute viral disease characterized by: Fever, swelling &tenderness of one or more salivary glands (usually the parotid &some times the sublingual or sub maxillary glands).







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Complications:

Orchitis, most commonly unilateral (20-30%) of post pubertal males
OOpheritis and or mastitis can occur in females >15 years of age
Sterility is extremely rare
Sensoneural hearing loss in children(5:100.000
cases).
Encephalitis (1-2 :10,000 cases)
Pancereatitis usually mild (4% of cases )

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Infection during first trimester increase the rate of spontaneous abortion
No firm evidence of congenital anomalies
Permanent sequelae & deaths are rare

Infectious agent:

Mumps virus: a member of the Paramyxoviradae

Antigenically relates to the parainflunza virus


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Occurrence:
Less regularly recognized than other common communicable childhood diseases
1/3 of the exposed susceptible may have inapparent infection
Winter &spring are seasons of greatest incidence
By the use of effective vaccination program (MMR) the incidence has dramatically decline &the greater risk of infection has shifted toward older children, adolescence &young adults

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Reservoir: Human.
Mode of transmission:
Direct contact with saliva
Airborne
Droplet
Incubation period:
15-18 days
period of communicability :
Before Onset of illness After
6-7 days parotitis 9 days

2days Maximum 4days

before infectiousness after


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• Susceptibility &resistance:
• Immunity is life long after clinical or inapparent infection
• Inapparent infection is communicable
• Prevention:
• Public education
• Vaccination (Jerky Lynn strain) live attenuated vaccine (MMR). more than 95%develop long-lasting or probably life long immunity. Administered at any time after 12 months .
• Special efforts to vaccinate before puberty all persons with no definite history of mumps or mumps immunization.

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• Contra-indication of the vaccine:
• Immune suppression.
• Pregnancy &planning of pregnancy in the next 3 months

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• Control:
• Reporting: It is reportable disease.
• Isolation: respiratory isolation &private room for 9 days from onset of swelling. Also school exclusion for the same period
• Disinfection of all articles soiled with throat secretion.
• Protection of contact
• * Active not effective
• * Passive not effective
• No specific Rx.


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Thank you all