Everything About the Measles: Causes, Symptoms, Diagnosis | Healthiy B|


Measles is one of the most contagious infectious diseases and remains a leading cause of death, particularly among young children, especially in areas with low rates of vaccination. Measles is also called Ruby which can easily get confused with German measles which is also called rubella, similar sounding names but very different viruses.

Regular measles is caused by the measles virus. Seriously, the species is the measles virus of the genus Morbillivirus and the family Paramyxoviradi. The reason why this guy is so contagious is that it's airborne and spreads via tiny liquid particles that get flung into the air when someone sneezes or coughs and can live for up to 2 hours in that airspace or nearby surfaces.

How does it effects to our body?

If someone breathes in that air or touches the surface and then touches their eyes, their nose or their mouth, they can become infected. Measles is so contagious that if one person has it,90% of nearby nonimmune people will also become infected. Once the measles virus gets onto the mucosa of an unsuspecting person it quickly starts to infect the epithelial cells in the trachea or bronchi. 

Measles virus uses a protein on its surface called hemoglobin not just H protein to bind to a target receptor on the host cell which could be CD 46 which is expressed on all nucleated human cells CD 150 Akasignaling lymphocyte activation molecule or Slam which is found on immune cells like BRT cells and antigen-presenting cells or Neptune IV, a cellular adhesion molecule.

Once bound, the fusion or F protein helps the viruses with the membrane and ultimately get inside the cell. Now, this virus is a single-stranded RNA virus and it's also negative sense, meaning it first has to be transcribed by RNA polymerase into a positive sense mRNA strand. After that, it's ready to be translated into viral proteins, wrapped in the cells lipid envelope and sent out of the cell as a newly made virus.

Within days, the measles virus spreads through local tissue and is picked up by dendritic cells in alveolar macrophages and carried from that local tissue in the lungs to the local lymph nodes. From there it continues to spread, eventually getting into the blood and spreading to more lung tissue as well as other organs like the intestines and the brain.


Now, it typically takes ten to 14 days from the time that the virus enters the body to the start of symptoms and this is the incubation period. Once the symptoms start, we've entered the prodromal period which typically lasts around three days and starts with a high fever and the three C's cough, conjunctivitis or inflammation and redness of the white part of the eye and mycorrhiza swelling in the mucous membrane of the nose, essentially a stuffy nose. 

One to two days later comes the enanthem which is a rash in the mucous membranes that looks like salt grains on a wet background. These are called complex spots and are these small white spots that are commonly seen on the inside of the cheeks opposite the molars.

 After these initial Prodromo symptoms come the Xanthamphase, which is where a red blotchy maculopapular rash spreads in a cephalocaudal progression. In other words, the exams start at the head or cephalopod and spread to the extremities or the ends of the body or coddle. This rash fades after about four days and leads into the recovery phase which can last for another ten to 14 days, with the final symptom usually being a persistent cough. 

In general, infected people are most contagious starting from the final day of the incubation period through the Prodromos and Xanthum phase which roughly works out to be four days before to four days after the onset of the rash. 

Causes By The Measles

Now, the good news is that once all this is over and someone's recovered from measles, they have life long immunity. Since measles affects various organs like the lungs, and the intestine in the brain, it can lead to complications like pneumonia, diarrhea and on rare occasions, encephalitis, all of which can lead to death. In addition, measles can suppress the immune system for up to six weeks and this can contribute to bacterial superinfections like otitis media and bacterial pneumonia. 

Who Is At Highest Risk?

All of these complications are worst among young infants, who typically have the highest rates of mortality during a measles outbreak. Another severe and often fatal complication for children under two years old is the development of subacute sclerosing panencephalitis, which can happen seven to ten years later and this is thought to be caused by persistent measles virus infection, possibly due to an abnormal immune response or a mutated strain of the measles virus, which leads to chronic inflammation of the entire brain. 

The symptoms of SSPE 

The symptoms of SSPE are initially pretty subtle like, for example, mood changes, but eventually, become severe and dramatic and can include seizures, coma and, if left untreated, death. For people who are immunocompromised, for example, people with HIV or AIDS, their immune-mediated responses are impaired. That being said, if they get measles they might not develop some symptoms that are a result of the immune system responding to the measles virus, like the anthem or the complex spots or the ex anthem, the rash. These people, though, also have higher rates of pneumonia and encephalitis, which contribute to a higher mortality rate. 


Diagnosis of measles is usually done via serology looking for measles antibodies in the blood serum and the disease is usually most likely to happen in unvaccinated individuals. That said, the measles vaccine is alive attenuated immunization, essentially meaning it's been weakened and it's given between twelve and 15 months of age and again between four and six years of age and it has an impressive 95% vaccine efficacy rate, which means that out of 100 cases of measles among unvaccinated people, 95 would have been prevented by the vaccine. 


In addition to the vaccine, another source of protection for young infants is their mother's antimaselsantibody or immunoglobulin, which the fetus gets transplacental and lasts until about nine months of age. When measles does develop, there isn't a specific antiviral treatment. Instead, the medications are generally aimed at treating superinfections, maintaining good hydration with adequate fluids, and pain relief. 

Some groups are also given vitamin A, like young children in the severely malnourished, which acts as an immunomodulator that boosts the antibody responses to measles and decreases the risk of serious complications. Finally, in outbreak settings, the measles vaccine can be given to household contacts and measles immunoglobulin can be given to pregnant women and young infants to help prevent others from getting sick. 

All right, so quick review of measles. Measles is an airborne pathogen that is highly contagious and causes cough, conjunctivitis and coryza, as well as complications like pneumonia and encephalitis, and can be prevented through vaccination, helping current and future clinicians focus, learn, retain and thrive.