* Chicken pox
* 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.* Acute generalized viral disease characterized by:Sudden onset of fever, mild constitutional symptoms, &skin rashMaculo-papular rash.. few hours.. vesicles…. 3-4days.. granular crustsLesion commonly occur in successive groups with several stage of maturity present at the same time.
* 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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* 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. Reservoir : Human
* Mode of transmission:Direct contact person-to –person * Droplet * airborne spreadvesicle 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
* Period of communicability 1-2 days before the Rash and 5 days after.
* Susceptibility &resistance: general More sever from occur among adults Infection gives life long immunity Second attacks are rare
* 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
* 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 contacts
* Acyclovir week of exposure 80mg/kg/day/qds Specific Rx : Antiviral drag Zovirax( Acyclovir), Vidarabine
* Smallpox (Variola) Last naturally acquired case in word occur in October 1977 in Somalai Global eradication was certified two years later by WHO
* It is systemic viral disease
* 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).* In the previously vaccinated the rash stage was significantly modified. Infectious agent: Variola virus a species of orthopox virus.
* 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%.
* 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.
* Mumps
Infectious parotistis* 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).
* 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 )
* Infectious agent: Mumps virus: a member of the Paramyxoviradae
* Occurrence: Less regularly recognized than other common communicable childhood diseases 1/3 of the exposed susceptible may have inapparent infection 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* 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
* 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.
* Contra-indication of the vaccine: Immune suppression. Pregnancy &planning of pregnancy in the next 3 months
* 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.