How to MeaslesTransmission

MeaslesTransmission -

Measles is highly contagious and can be spread to others from four days before to four days after the rash appears. Measles is so contagious that if one person has it, 90% of the people close to that person who are not immune will also become infected with the measles virus.

The virus lives in the mucus in the nose and throat of the infected person. When that person sneezes or coughs, droplets spray into the air. The droplets can get into other people’s noses or throats when they breathe or put their fingers in their mouth or nose after touching an infected surface. The virus can live on infected surfaces for up to 2 hours and spreads so easily that people who are not immune will probably get it when they come close to someone who is infected.

Who is at risk?

Unvaccinated young children are at highest risk of measles and its complications, 

including death. Unvaccinated pregnant women are also at risk. Any non-immune person 

can become infected.

Measles is still common in many developing countries – particularly in parts of Africa and 

Asia. More than 20 million people are affected by measles each year. The overwhelming 

majority (more than 95%) of measles deaths occur in countries with low per capita i

ncomes and weak health infrastructures.

Measles outbreaks can be particularly deadly in countries experiencing or recovering 

from a natural disaster or conflict. Damage to health infrastructure and health services 

interrupts routine immunization, and overcrowding in residential camps greatly increases 

the risk of infection.

Structure of Measles Virus...

Structure of Measles-

Structure of Measles Virus

• Structure of Measles Virus-
• 
  
• Measles virus is a member of the genus Morbillivirus of the family Paramyxoviridae
• Measles) virus is a typical paramyxovirus (spherical enveloped particles that contain a non segmented negative strand RNA genome)
• Measles virus have two types of envelope spikes that shows:

    Hemagglutinating activity

Cell fusion and hemolytic activity

• Single serotype i.e. Life long immunity occurs in individuals who have had the disease.
• Hemagglutinin is the antigen against which neutralizing antibody is formed.
• Infants are protected during the first six months of life ( they get maternal antibody as it passes the placenta)

Replication cycle of Measles Virus

• Adsoprtion to the cell surface: via Hemagglutinin. Cellular receptor of measles virus is CD46 molecule.
• Penetrates the cell surface and uncoats
• Virion RNA polymerase transcribes the negative-strand genome to mRNA
• Specific viral proteins are formed
• Assembly to helical nucleocapsid
• Release of virus by budding

Transmission and Epidemiology of Measles

• Worldwide distribution, outbreaks in 2-3 years
• Transmitted via respiratory droplets produced by sneeze or cough during prodromal period which continues up to few days after rash appears
• Measles virus is extremely infectious, most children contract clinical disease on exposure
• More serious outcomes in Malnurished children, people with deficient cell mediated immunity.

Pathogenesis

• Measles virus infects the cells lining the upper respiratory tracts
• Enters blood and infects reticuloendothelial cells and replicates again.
• Spread to skins
• Appearances of rash: (because of cytotoxic T cells attacks measles virus infected vascular endothelial cells in the skin).
• Formation of Multinucleated giant cells.

Clinical features of Measles

• Incubation period: 10-14 days
• Prodromal phase: Characterized by fever, conjunctivitis (causing photophobia), running nose, and coughing
• Appearance of Koplik’s spot (bright red lesions with the white, central dot) # Diagnostic feature
• Appearance  of Maculopapular rashes, common features of which includes:
  
  

  Child infected with Measles
  Source:: CDC
• Occurs 5‐7 days after symptoms    
• Lasts 3 or more days
• Brownish hue
• Progresses from face to body to extremities
• Rash becomes confluent as it progresses
• Rash affects palms and soles
• Soon after the rash appears, the patient is no longer infectious.

Complications  because of Measles infections

• Encephalitis: 1 per 1000 cases
• Subacute sclerosing panencephalitis (SSPE): Fatal disease of nervous system can develop after several years after measles.
• Giant cell pneumonia
• Co-infections:

–     Secondary bacterial pneumonia –     Bacterial otitis media

• Increased risk of still birth in pregnant women infected with measles.
• Measles virus infection of fetus causes fetal death
• Atypical measles develops in some people who were given killed vaccine and subsequently infected with measles virus.

Key Facts about Measles

Key facts-

• Measles is one of the leading causes of death among young children even though a safe and cost-effective vaccine is available.
• 
  
• In 2012, there were 122 000 measles deaths globally – about 330 deaths every day or 14 deaths every hour.
• Measles vaccination resulted in a 78% drop in measles deaths between 2000 and 2012 worldwide.
• 
  
• In 2012, about 84% of the world's children received one dose of measles vaccine by their first birthday through routine health services – up from 72% in 2000.
• Since 2000, more than 1 billion children in high risk countries were vaccinated against the disease through mass vaccination campaigns ― about 145 million of them in 2012.

signs and symptoms measles

 The classic signs and symptoms of measles include four-day fevers [ the 4 D's ] and the three Cs—cough, coryza (head cold), andconjunctivitis (red eyes)—along with fever and rashes. The fever may reach up to 40 °C (104 °F). Koplik's spots seen inside the mouth arepathognomonic (diagnostic) for measles, but are not often seen, even in confirmed cases of measles, because they are transient and may disappear within a day of arising. Their recognition, before the affected person reaches maximum infectivity can be used to reduce spread of epidemics.
The characteristic measles rash is classically described as a generalized, maculopapular, erythematous rash that begins several days after the fever starts. It starts on the back of the ears and, after a few hours, spreads to the head and neck before spreading to cover most of the body, often causing itching. The measles rash appears two to four days after the initial symptoms and lasts for up to eight days. The rash is said to "stain", changing color from red to dark brown, before disappearing.

History-


The Antonine Plague, 165–180 AD, also known as the Plague of Galen, who described it, was probably smallpox or measles. The epidemic may have claimed the life of Roman emperor Lucius Verus. Total deaths have been estimated at five million.[83] Estimates of the timing of evolution of measles seem to suggest this plague was something other than measles. The first scientific description of measles and its distinction from smallpox and chickenpox is credited to the Persian physician Rhazes (860–932), who published The Book of Smallpox and Measles.[84] Given what is now known about the evolution of measles, this account is remarkably timely.


16th century Aztec drawing of someone with measles
Measles is an endemic disease, meaning it has been continually present in a community, and many people develop resistance. In populations not exposed to measles, exposure to the new disease can be devastating. In 1529, a measles outbreak in Cuba killed two-thirds of the natives who had previously survived smallpox. Two years later, measles was responsible for the deaths of half the population of Honduras, and had ravaged Mexico, Central America, and the Inca civilization.


Between roughly 1855 to 2005 measles has been estimated to have killed about 200 million people worldwide Measles killed 20 percent of Hawaii's population in the 1850s. In 1875, measles killed over 40,000 Fijians, approximately one-third of the population.[88] In the 19th century, the disease decimated the Andamanese population.] In 1954, the virus causing the disease was isolated from an 11-year old boy from the United States, David Edmonston, and adapted and propagated on chick embryo tissue culture. To date, 21 strains of the measles virus have been identified.[91] While at Merck, Maurice Hilleman developed the first successful vaccine. Licensed vaccines to prevent the disease became available in 1963.[93] An improved measles vaccine became available in 1968.

About Measles...........

*MEASLES*

Measles, also known as morbilli, English measles, or  is an infection of the respiratory system, immune system and skin caused by a virus, specifically a paramyxovirus of the genus Morbillivirus.[1][2] Symptoms usually develop 7–14 days  after exposure to an infected person and the initial 

symptoms usually include a high fever Koplik's spots (spots in the mouth, these usually appear 1–2 days prior to the rash and last 3–5 days), malaise, loss of appetite, hacking cough (although this may be the last symptom to appear), runny nose and red eyesAfter this comes a spot-like rash that covers much of the body.[1 The course of measles, provided there are no complications, such as bacterial infections, usually lasts about 7–10 days.

Measles is spread through respiration (contact with fluids from an infected person's nose and mouth, either directly or through aerosol transmission), and is highly contagious—90% of people without immunity sharing living space with an infected person will catch it. An 
asymptomatic incubation period occurs nine to twelve days from initial exposure.

The period of infectivity has not been definitively established, some saying it lasts from two to four days prior, until two to five days following the onset of the rash (i.e., four to nine days infectivity in total),[6] whereas others say it lasts from two to four days prior until the complete disappearance of the rash. The rash usually appears between 2–3 days after the onset of illness.

Routine Immunization Program Background-

Immunization Programme is one of the key interventions for protection of children from life threatening conditions, which are preventable. It is one of the largest immunization programme in the world and a major public health intervention in the country.

Immunization Programme in India was introduced in 1978 as Expanded Programme of Immunization 

The programme gained momentum in 1985 and was expanded as Universal Immunization Programme (UIP) to be implemented in phased manner to cover all districts in the cou try by 1989-90.

UIP become a part of Child Survival and Safe Motherhood Programme in 1992 Since, 1997, immunization activities have been an important component of National Reproductive and Child Health Programme and is currently one of the key areas under National Rural Health Mission (NHM) since 2005

Under the Universal Immunization Programme, Government of India is providing vaccination to prevent seven vaccine preventable diseases i.e.

Diphtheria, Pertussis, Tetanus, Polio, Measles, severe form of Childhood Tuberculosis and Hepatitis B

The vaccination schedule under the UIP is:

BCG (Bacillus Calmette Guerin) 1 dose at Birth (upto 1 year if not given earlier)

DPT (Diphtheria, Pertussis and Tetanus Toxoid) 5 doses; Three primary doses at 6,10,14 weeks and two booster doses at 16-24 months & 5 Years of age

OPV (Oral Polio Vaccine) 5 doses; 0 dose at birth, three primary doses at 6,10 and 14 weeks and one booster dose at 16-24 months of age

Hepatitis B vaccine 4 doses; 0 dose within 24 hours of birth and three doses at 6, 10 and 14 weeks of age.

Measles 2 doses; first dose at 9-12 months and second dose at 16-24months of age

TT 2 doses at 10 years and 16 years of age

TT – for pregnant woman two doses or one dose if previously vaccinated within 3 Year

In addition, Japanese Encephalitis (JE vaccine) vaccine was introduced in 112 endemic districts in campaign mode in phased manner from 2006-10 and has now been incorporated under the Routine Immunization Programme

~26 million new born are targeted for vaccination each year through ~9 million immunization session held annually

There are ~25,000 cold chain points in the country to store vaccine under required temperatur.

Routine immunization

Routine immunization-



A cornerstone of the polio eradication strategy is the need to ensure high (more than 80%) immunization coverage of children in the first year of life with at least three doses of oral polio vaccine as part of national routine immunization schedules.

While routine immunization alone cannot eradicate the disease, good routine oral polio vaccine coverage increases population immunity, reduces the incidence of polio and makes eradication feasible.

If uniformly high immunization coverage is not maintained, pockets of non-immunized children build up, favouring continued spread and outbreaks of the poliovirus. 

According to WHO/UNICEF immunization coverage estimates, 86% of infants received three doses of oral polio vaccine in 2010, compared with 75% in 1990.

Polio-free countries must continue to ensure high levels of immunization coverage to prevent the re-establishment of poliovirus through importations from other countries. This can happen through international travellers, migrant populations or population sub-groups who refuse immunization.


An increasing number of industrialized, polio-free countries are using inactivated polio vaccine (IPV) in routine immunization schedules. IPV is not recommended for routine use in polio-endemic countries or in developing countries at risk of poliovirus importations as it does not stop transmission of the virus, and is more complex to administer and costly than oral polio vaccine. - See more at: