Measles Lecture final yr MBBS 2017
-
Upload
sajjad-sabir -
Category
Health & Medicine
-
view
90 -
download
2
Transcript of Measles Lecture final yr MBBS 2017
MEASLESDr. Muhammad
Sajjad Sabir DCH , MCPS, FCPS
Assist Prof of Paediatrics
DEFINITION Measles is an acute highly contagious viral disease
caused by measles virus characterized by Fever Cough , coryza ,conjunctivitis Koplik spots Maculopapular rash
ETIOLOGY Measles Virus RNA virus ( Paramyxo virus family) One antigenic type
Rapidly inactivated by heat and light
Source of infection Patients of measles, No carriers No animal reservoir
Routes of transmission air-borne / droplet
immunity permanent acquire after disease Incidence equal in both sexes Epidemic features season: winter and spring age: 6 months to 5 years old
EPIDEMIOLOGY
Measles is one of the most highly infectious
diseases known Highly infectious during prodromal period and at
the time of eruption
90% of people without immunity sharing a house with an infected person will catch it.
Communicability
Spread of Virus-droplet infection
The highly contagious virus is spread by coughing and sneezing, close personal contact or direct contact with infected nasal or throat secretion-
INFECTIVITY It lasts from 4 days
before to 5 days after the onset of the rash
INCUBATION PERIOD
The infection has n average incubation period of 10 days (range 6-19 days)
Measles Pathogenesis● Respiratory transmission of virus ● Replication in nasopharynx and regional
lymph nodes ● Primary viremia 2-3 days after exposure ● Secondary viremia 5-7 days after exposure
with spread to tissues
Incubation period (from exposure to onset of symptoms)
Approximately 10 days( 6~18days) after the initial exposure to the virus, the classic viral prodrome occurs
Beginning of Illness in Measles
The prodromal phase is marked by malaise, fever, anorexia, and conjunctivitis, cough, and coryza (the "3 Cs")
Koplik’s spotsAdditional prodromal symptoms may include
malaise, myalgias, photophobia, and periorbital oedema
Beginning of Illness in MeaslesProdromal phase 3~4 days
Koplik Spots leading clue to Measles With in 2-3 days,
the pathognomonic Koplik spots typically arise on the buccal, gingival, and labial mucosa
KOPLIK SPOTSource: http://phil.cdc.gov/PHIL_Images/20040908/4f54ee8f0e5f49f58aaa30c1bc6413ba/6111_lores.jpg
Time: the3~5 days after fever ; but the 4th day is most common
Shape: maculopapular Sequence: face → trunk→ limbs The temperature rise continuously and
accompanied with toxic symptoms Persists 5-6 days Fades in order of appearance
Measles Eruption stage
Rash is a Prominent Feature
Sequence: behind the ear → along the hairline →face → neck → chest → back→ abdomen → limbs→ hand and feet
Convalescent stage
brown staining fine branny desquamation course:10-14 days complete healing
Atypical measles
1 . mild measles; 2 . severe measles (toxic and shock type
measles); 3. hemorrhagic measles; 4 . variant measles.
Duration of Symptoms in Measles
The entire course of uncomplicated measles, from late prodrome to resolution of fever and rash, is 7-10 days.
Cough may be the final symptom to appear
Risk factors for severe measles
Malnutrition Immunodeficiency Pregnancy Vitamin A deficiency
Mortality Rate in Measles Low mortality rate associated with
uncomplicated measles in immunocompetent, well nourished children
The mortality rate high with malnourishment immunocompromised, and to lesser extent with age
Modified Measles Modified measles occurs in children who have
received serum immunoglobulin after their exposure to measles
The measles symptom complex may still occur, but the incubation period is as long as 21 days, with the same symptoms as measles but milder
Atypical Measles When they are exposed to the measles virus, a mild or
nonexistent prodrome of fever, headache, abdominal pain, and myalgias precedes rash
Rash begins on the hands and feet and spreads
centrally.
The rash is most prominent in the body creases and may be macular
Atypical measles occurs in individuals who were previously immunized with incomplete immunity
BronchopneumoniaMyocarditisLaryngitisDiarrheaOtitis mediaEncephalitis
COMPLICATIONSSSPEHaemorrhagic
MeaslesMalnutrition Death
Haemorrhagic Measles Sever form of measles Rash is confluent rash is hemorrhagic or
petechial Bleeding from
mouth,nose or bowel Death may occur before
rash
Subacute Sclerosing Panencephalitis (SSPE)
a history of primary measles infection
usually before the age of 2 years followed by several asymptomatic years (6–15 on average) and then gradual, progressive psycho neurological
deterioration, consisting of personality change, seizures, myoclonus, ataxia, photosensitivity, ocular abnormalities, spasticity, and coma
Diagnosis of Measles
Most cases of Measles are diagnosed clinically
Direct Virological confirmation is difficult in most of the Developing countries
Laboratory confirmation Multinucleated giant cells are detected
in nasopharynx mucosa secretions
Measles virus can be isolated in tissues culture
Antibody titer--measles-specific IgM (ELISA tests)
CBC--- WBC is relative low
DIFFERENTIAL DIAGNOSIS Rubella (German measles) Roseola infantum (exanthem subitum) Meningococcemia Scarlet fever Erythema infectiosum/ slapped cheek
(parvovirus B-19) Other viral exanthems Drug rashes
Management General therapy:
rest Good nursing diet
Symptomatic therapy: fever and cough Support therapy Vitamin A treatment of complications
Treatment options in Developing Countreis
All children in developing countries diagnosed with measles should receive two doses of vitamin A supplements, given 24 hours apart 6mo-12mo 1,00,000 U Blue Cap Above 1 yr 2,00,000 U Red Cap
This can help prevent eye damage and blindness
Vitamin A supplements have been shown to reduce the number of deaths from measles by 50%
PREVENTION
Control source of infection
Interruption of transmissions
Protection of the susceptible person
Measles VaccineActive immunization Lived attenuated measles vaccine at 9 months ( can be after 6mo) post exposure : with in 2 days Passive immunization Immunoglobulin <5 days prevent onset >5 days relieve symptoms
VACCINATION
The Vaccines are Live attenuated seroconversion rate of 90%
The immunity produce may be life long
Two doses of Measles Vaccine
All children receive two doses of measles vaccine
First dose at 9 months
Second dose at 15 months The measles vaccine (in use for 40
years) is safe, effective and relatively inexpensive
Measles vaccine as MMR Vaccine
The measles vaccine is often incorporated with rubella and mumps vaccines in countries where these illnesses are problems
The combination proved to be equally effective and safe
Measles vaccine is given as MMR Vaccine
Doses of MMR vaccine
First dose at 12-15 months
Second dose after 6 months
Third dose between 4-6 yrs age
Vaccination for Measles continues to be a Top Priority
QUIZ
Measles Clinical Case Definition
Cough, coryza, or conjunctivitis
Temperature >38.3 C (101 F)
Generalized rash lasting >3 days
3 Cs of Measles
Clinical features 3 Cs (Cough, Coryza & Conjunctivitis) Koplik spots Four days fever (400c) Generalized, maculopapular,erythematous rash.
Coryza catarrhal inflammation of the mucous
membrane in the nose with discharge of mucus
Measles Clinical Features● Incubation period 10-12 days ● Prodrome 2-4 days ■ stepwise increase in fever to 103°F–105°F■ cough, coryza, conjunctivitis ■ Koplik spots (rash on mucous membranes) ● Rash ■ 2-4 days after prodrome, 14 days after exposure ■ persists 5-6 days ■ begins on face and upper neck ■ maculopapular, becomes confluent ■ fades in order of appearance
Measly Look
Measly Look Red eyes Puffy eyelids Swollen bridge of nose Copious nasal discharge Toxic look Maculopapular , erythematous rash.
Post Exposure Immunization Active immunization with Lived attenuated measles vaccine
should be done with in 2 days post exposure
WHY?