CDC LECTURES Learning Objectives: By the end of the lecture, the students should be able to describe: 1- The disease, its occurrence & susceptibility. 2- Causative agent, incubation period & communicability. 3- Mode of transmission , reservoir of infection & carrier state if any. 4- Principles of management (diagnosis & treatment). 5- Main preventive & control measures.
COMMUNICABLE DISEASES MEASLES
Professor Qayser Sahib Al Habeeb Specialist in Internal and Community Medicine Department of Family and Community Medicine College of Medicine University of DuhokMEASLES: ( ( Rubeola , Morbilli It is a highly communicable acute viral disease caused by measles virus a member of the --- genus : Morbillivirus --- family : Paramyxoviridae
■ The disease remains one of the leading causes of death among young children globally, despite the availability of a safe and effective vaccine. ■ In 2014, there were 114 900 measles deaths globally “ ~ 314 deaths / day or 13 deaths / hour ”.
Key Facts
■ During 2000-2014, vaccination 79% drop in measles deaths (~ 17.1 million deaths) making measles vaccine one of the best buys in public health ■ > 95% of measles deaths occur in low-income countries with weak health infrastructures.◙ I. P : 10 days ( 7-18 days )◙ MOT : ♦ airborne by droplets ♦ contact with sick children. ♦ less commonly by articles freshly soiled with nose and throat secretions. The virus remains active and contagious in the air or on infected surfaces for up to 2 hours.
◙ Reservoir : humans.◙ Endemicity : worldwide --- In the pre vaccination era, measles was near universal infection of childhood ◙ C.P : Usually about 4 days before rash onset to 4 days after appearance of the rash. --- Common and often fatal in developing countries
Clinically: It starts with: ► a prodromal catarrhal stage (3-4 days ) fever, dry cough, running nose+ conjunctivitis( red watery eyes & photophobia) + koplik’s spots (small with white/bluish center) on an erythematous base on the buccal mucosa
► Exanthematous stage (6 -7 days):starts with dusky maculo papular rash at the hairline, behind the ears and on the face, then spreads downwards slowly to the lower limbs ► Fever settles and the rash begins to fade (sometimes with brawny desquamation.)
Measles tends to be:◙ Less severe in: - older children and teenagers ◙ More severe in: - adults > 20 yrs of age - children < 5 yrs of age ◙ A serious disease in: malnourished, vit.- deficient or immuno compromised pregnant women are also at risk of severe complications and the pregnancy may end in miscarriage or preterm delivery.
Complications: ► may result from viral replication or secondary bacterial infection and include: otitis media, pneumonia,laryngo tracheo bronchitis diarrhea & encephalitis.► In children who are borderline nourished, measles often precipitates acute kwashiorkor and exacerbates “vitamin A” deficiency, that may lead to blindness.
Deaths occur mainly in children < 5 yrs of age primarily from pneumonia & occasionally from encephalitis
Those who recover from measles are immune for the rest of their lives.
Diagnosis: ◙ Clinical suspicion + koplik’s spots ◙ Can be confirmed by: - IgM antibodies or rising titer - PCR can detect the virusTreatment ◙ symptomatic ◙ antibiotics are used for complications ◙ vitamin A may improve outlook in uncomplicated disease
All children in developing countries diagnosed with measles should receive 2 doses of vitamin A supplements, given 24 hours apart.
This treatment 1- can help prevent eye damage and blindness. 2- has been shown to reduce the number of deaths from measles by 50%.
Preventive and Control Measures:◙ Active immunization ( L.A.V.) ◊ key public health strategies to reduce global measles deaths are routine measles vaccination combined with mass immunization campaigns in countries with high case and death rates. ◊ Measles vaccine is often incorporated with rubella and/or mumps vaccines in countries where these illnesses are problems.(equally effective in the single or combined form) ◊ Two doses of the vaccine are recommended to ensure immunity. ( ~ 15% failure after the first dose ) ◊ An aerosol-administered vaccine has been successfully developed & a heat stable vaccine is under development
◙ Improvement of nutrition of children Vitamin A supplementation : single dose of 100000 I.U orally for children above 1 year and 50000 I.U for those 6-12 months of age.
◙ Isolation: of limited value◙ Exclusion from school : for 4 days after the appearance of the rash.◙ Contacts : ♦ Immunization within 72 hours of exposure may provide protection ♦ Passive immunization within 6 days of exposure may be used for contacts whose risk of complications is very high e.g. ---- contacts < 1 yr. ---- pregnant women ---- immuno compromised persons
The Measles & Rubella Initiative Launched in 2001, is a global partnership led by -- the American Red Cross, -- United Nations Foundation, -- Centers for Disease Control and Prevention (CDC), -- UNICEF and WHO. The Initiative is committed to ensuring that : -- No child dies from measles or is born with congenital rubella syndrome; -- Reducing measles deaths by 95% by 2015; and -- Achieving measles and rubella elimination in at least 5 WHO regions by 2020.