measles
An acute highly communicable viral disease with prodromal fever, conjunctivitis, coryza, cough & small spots with white or bluish white centers on erythematous base on the buccal mucosa (Koplike spots).
A characteristic red rash appears
on the third to seven day, the
rash begin on the face then become generalized last 4-7 days, leucopenia
is common.
The disease is more severe in infant
& adult than in children.
The case fatality rate in developing countries are estimated to be 3-5% & may reach 10-30% in some localities.
Diagnosis: usually made on clinical & epidemiological ground & confirmation by detection of measles specific IgM Abs which appear 3-4 day after rash, detect of viral antigen in nasopharyngeal mucosal swab.
Children with clinical or subclinical vit A deficiency are at particular high risk to severe disease.
The children who are border line nourished, measles often precipitate acute kwashiorkor & exacerbate vit A deficiency, that lead to blindness.
Complications
otitis media
*pneumonia
*larangeotracheobronchitis (croup)
*diarrhea
*encephalitis
Infectious agent: measles virus, paramyxoviridae
Occurrence:
Before the immunization, measles was common in childhood, more than 90% of people had been infected by age of 20 years old.
Measles was endemic in many countries & appear as epidemic every second or third year .
In smaller communities and areas Outbreak tend to be more wildly spaced & more severe with longer interval between outbreaks.
In temperate climate, measles occur in late winter & early spring .
In tropical climate , measles occur in dry season.
Reservoir: human
Mode of tranismission
() Air borne by droplet spread
() Direct contact with nasal or throat secretions of infected person
() By articles freshly soiled with nose &
throat secretion (less common)
Measles is one of the most highly communicable diseases.
() incubation period: about 10 days, but may be 7-18 days from the exposure to onset of fever, usually 14 days until rash appears.
Rarely as long as 19 -21 days
() period of communicability:
Usually about 4 days before rash onset to 4 days after the rash
()susceptibility & resistance:
- all persons who not had
the disease
- all persons not succefully
immunized
Acquired immunity after illness is permanent
Infants borne to mothers who had the disease are protected for 1st 6-9 months or more .
Immunizations at 12-15 months induces immunity in 94-98%
Methods of control
A- preventive measures:
1- public education by health department to encourage measles immunization for all susceptible infant, children , adolescent & young adult.
Those for whom vaccine is contraindicated & un immunized persons identified more than 72 hr after exposure to measles may be partially or completely protected by IG given within 6 days after exposure.