Communicable Diseases

Question 1

Diptheria

Answer 1

Corynebacterium diphtheria
Endemic
Nasal ; Throat carriers (95% are carriers)
2-6 days incubation period
Spread : droplet+cut. Lesions+fomites
14-28 days infection period
DPT vaccine
Schick Test
Tt: antitoxin dose (10,000-1,20,000 units)

Question 2

Schick Test

Answer 2

Intradermal (diphtheria toxin)
For Immunity + hypersensitivity
Dose 0.2ml
Positive if red flush seen(susceptibility)
Pseudopositive in control arm(susceptibility+hypersensitivity)

Replaced by Hemagglutination test

Question 3

Small pox

Answer 3

Chordopoxvirinae ( orthopoxvirus)
Incubation: 12-14 days
Communicability 3 week from lesion
No animal reservoir
Lifelong immunity
Characteristic rash (centrifugal distribution+non-pleomorphic+deep)
Externsor surface+palms+soles
Scabs 10-14 days after

Question 4

Chickenpox

Answer 4

Varicella zoster virus (herpes-3)
14-16 days incubation
Communicable 1-2 days before to 4-5 days after rash
Secondary attack (90%)
Dew drops on rose petal appearance
Centripetal distribution (Axilla+flexor surfaces)
Pleomorphic rash( inflammation)
Not on palm / soles
Scabs after 4-7 days
Live attenuated vaccine (OKA strain)
Varicella zoster Ig (VZIG)

Question 5

Varicella zoster Immunoglobulin (VZIG)

Answer 5

Within 72 hr of exposure
Dose 1.25-5.0ml (i.m.)
For Immunocompromised + Newborn

Question 6

Koplik spots

Answer 6

In measles

Question 7

Measles / Rubeola /Red measles / Hard measles / First disease

Answer 7

RNA polymyxovirus
Incubation 10-14 days
Source (cases + no carriers)
Secondary attack rate -90%
Trnasmission by air droplets
Communicability - 4 d before -5 d after rash
Rash (retro auricular)
Highly infective in prodromal + eruption
Lifelong immunity
Cyclical trend (2-3 years)
Koplik spots
Otitis media (children)
Vaccine
Active immunization
Live attenuated (MMR)
Strain (Schwarz, Moraten)
Dose 0.5ml subcutaneous
Ig (0.25 ml /kg)

Question 8

Mumps

Answer 8

Myxovirus parotiditis (RNA paramyxovirus)
Incubation14-21 days
Source (clincal +subclinical cases)
Transmission - air droplets
Communicability (4-6d before - 7 d after symptom onset)
Secondary attack rate -86%
Vaccine
Mumps vaccine (active immunity)
Live attenuated
Strain (Jeryl Lynn)
Lifelong immunity
Clinicals
Parotid involved
Aseptic meningitis
Orchitis , oophoritis (adolescents)