Measles outbreak in Clark County: 9 things everyone should know about the virus

The measles virus is one of the most infectious diseases known to man. A person with measles can cough in a room and leave, and a few hours later, if you are not vaccinated, you can catch the virus by the droplets in the air that the infected person has left behind.

No other virus can do it.

If your parents were born before 1960, they have a good chance of getting measles. They lived to talk about it, but maybe they had friends who did not have one. In the United States, before the introduction of a vaccine in 1963, there were 4 million cases of measles with 48,000 hospitalizations and 500 deaths in the United States each year. Measles was also one of the leading causes of death in children.

The beauty of the vaccine is that people who receive the right doses will never get measles, even if they are exposed. And in 2000, because of a widespread vaccination, the virus was declared eliminated in the United States: enough people were immunized so that outbreaks were rare and deaths from measles were barely heard.

New England Journal of Medicine

Yet, pockets of intense transmission remain in the world, especially in low-income countries such as the Philippines and Vietnam.

In the United States, Canada, and Europe as a whole, there has been a slight increase recently because too many people forget to get vaccinated. In the first half of 2018, Europe recorded more than 41,000 cases, a record in the postvaccination era.

In the United States, in 2018, there were 17 outbreaks totaling 349 cases. One of these outbreaks, in the state of New York, has spread this year, with more than 180 cases occurring in ultra-Orthodox Jewish communities.

Now, a measles outbreak in Washington State has prompted the governor to declare a public health emergency.

As of Monday, there were 35 cases in Washington County, Portland, Oregon border Most cases involved children aged 1 to 10 years who had not been vaccinated. There is also an adult case in nearby King County, whose largest city is Seattle. And health officials believe that the epidemic will become much larger and faster.

The health system and a generation of doctors who have never seen measles weigh heavily on the world, a disease that could have been absolutely prevented through routine immunization. Here are eight big questions about measles, answered.

1) How did the measles outbreak in Washington occur?

In the United States, measles outbreaks generally begin when one traveler contracts the virus in another country where measles is still common and brings it back to an unvaccinated community here. We do not yet know who is the "zero patient" in the Washington epidemic, but we do know that people living with the virus in Clark County have visited public places, including health care facilities. health, schools and churches, as well as Ikea and Dollar Tree – potentially measles to others.

Even more troubling: there will likely be more children at risk in these public places than in the rest of the country. This is because Oregon and Washington are more permissive than other states when it comes to allowing parents to opt out of vaccines – and many parents have benefited from it.

In Clark County, 7.9 percent of children received a vaccine exemption to enter kindergarten in the 2017-2018 school year, according to the Washington Post. And on the other side of Oregon, the vaccine exemption rate has risen sharply from 5.8% in 2015 to 7.5% in 2018. That's a lot higher than the national average, suggesting that 2% of children are not vaccinated for non-medical reasons.

These waivers have made Oregon and Washington more vulnerable to entirely preventable outbreaks, said Peter Hotez, an infectious disease researcher at Baylor College of Medicine.

"[They] are now a major anti-vaccine hot spot because of non-medical vaccine exemptions that have nothing to do with religion, "he said. Although Oregon has not yet reported any cases, the geographic proximity of the Washington outbreak is worrisome, he added. And "as this is a large and unvaccinated cohort, this epidemic could last for a while."

2) What does measles look like and is it deadly?

Measles is a deadly infectious disease that usually strikes children. After an incubation period of 10 to 12 days, measles is manifested by fever, cough, stuffy nose, bloodshot eyes and watery eyes. Loss of appetite and discomfort are also common. Several days after these first symptoms, a mottled and uncomfortable rash begins to spread all over the body, starting with the face and neck and going down. The rash usually lasts for three to five days and then gradually disappears.

In simple cases, people who contract measles begin to recover from the onset of the rash and return to normal after two to three weeks.

But up to 40% of patients have complications due to the virus. These usually occur in very young people (children under 5 years of age), adults over 20 years of age, and other undernourished or immunocompromised people. Children under 5 have the highest probability of death.

The most common complication of measles is pneumonia, which is responsible for most measles-related deaths. Less commonly, measles can lead to blindness, croup, mouth ulcers, ear infections or severe diarrhea. Some children develop encephalitis (swelling of the brain) that can lead to seizures, loss of hearing and mental retardation. Again, these complications occur primarily in people whose immune systems are already weakened by age, pre-existing conditions, or malnutrition.

According to the Centers for Disease Control and Prevention, the horrific mathematics of measles looks like this: one in 20 children with measles has pneumonia; encephalitis (swelling of the brain) in 1,000; one or two children out of 1000 will die.

3) What does a measles rash look like?

4) How do we know that measles vaccine is safe?

The MMR combination vaccine (measles, mumps and rubella) prevents measles. The CDC recommends that children receive two doses:

• The first dose between 12 and 15 months
• The second dose between 4 and 6 years

The immunity against the vaccine lasts for decades, but you should ask your health care provider about booster shots if you are an adult.

The vaccine is known to be extremely safe and effective: it contains a live but weakened version of the virus, which causes your immune system to produce antibodies against the virus. If you are exposed to measles, these antibodies will trigger to protect you from the disease.

Again, the side effects are rare and usually very mild. According to the CDC, for example, fevers after MMR vaccine occur in one in six people and mild rashes in one in 20. More serious problems are virtually non-existent: severe allergic reactions occur in less than one person. case on a million. Deafness, long-term seizures and permanent brain damage are "so rare that it is difficult to know if they are caused by the vaccine". Thus, the benefits of the vaccine – the protection of children and the communities in which they live – far outweigh the harms.

5) Is it easy to get measles?

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If you are not vaccinated, it is extremely easy to get measles. In a non-immune population, a person with measles can infect 12 to 18 others. This is much higher than other scary viruses like Ebola, HIV or SARS. (With Ebola, one case usually leads to another 2. With HIV and SARS, one case usually leads to four others.)

Measles is a virus suspended in the air, transmitted by the respiratory droplets of the nose, mouth or throat of an infected person, usually by coughing or sneezing.

Small particle aerosols of a person with measles can remain suspended in the air for long periods after the person has left a room, and the virus can survive on surfaces up to two hours.

What Health officials fear that the measles virus will be transmitted to a person four days before the onset of the rash, so that people infected with the virus begin to be contagious even before they know they have measles. (They stop being contagious about four days after the appearance of the rash.)

Exceptionally In rare cases, even if you are vaccinated, you can still get measles. In less than 5% of vaccinated people, their immune system is not responsive, even with vaccines. The researchers do not know why.

Having only one dose of the vaccine instead of the two recommended also appears to increase the risk of getting measles if exposed to the virus.

6) Is there a treatment for measles?

Unfortunately no. Doctors can help patients avoid more serious complications (blindness, pneumonia) by providing them with good nutrition and enough fluids.

Doctors may prescribe antibiotics for eye and ear infections that may occur. And as measles depletes vitamin A levels of its victims, doctors usually give patients two doses of vitamin A supplements.

7) To what extent do parents refuse the MMR vaccine for their children?

Overall, the refusal of the MMR vaccine is not so common in the United States. According to the latest CDC data, 91% of young children received the MMR vaccine in 2016. This is almost enough for what is known as "group immunity": for any vaccine to be effective, it is necessary to vaccinate a certain percentage of people in a population. This means that diseases can not spread very easily in populations and even protects people who are not or can not be vaccinated, such as newborns and people allergic to the vaccine. And for measles, 90 to 95% of the population must be vaccinated.

But statistics on national and national averages hide geographic clusters of unvaccinated people. They are not guided by any particular ideology. It may be Amish reluctant to the vaccine in Ohio or Orthodox Jews in New York, Californians who do not want to put "unnatural" things in the bodies of their children or parents who simply want to delay immunization of their children.

PLOS

In these groups, vaccine refusal rates can be very high. According to a 2018 badysis, published in PLOS Medicine, dozens of counties across the country had non-medical vaccine exemption rates of between 5.1 and 30 percent in 2016-17. Camas County, Idaho, led the country with a dropout rate of 27%.

Although the 50 state laws provide for vaccines for students, almost all states allow exemptions for people with religious beliefs against immunization, and 18 states grant philosophical exemptions to vaccine opponents because of personal or moral beliefs. . (The exceptions are Mississippi, California, and West Virginia, where the country's strictest vaccine laws do not allow for any philosophical or religious exemptions.)

Perhaps unsurprisingly, areas of the country that facilitate the withdrawal of vaccines tend to have a higher rate of … people who choose not to be vaccinated.

Oregon and Washington are among the 18 US states allowing philosophical exemptions from vaccines for people who wish to withdraw because of their moral or personal beliefs. In 12 of the 18 Member States, the number of such exemptions has increased since 2009.

8) Are we going to one day completely eradicate measles?

The measles virus could theoretically be scratched from the surface of the planet to never infect another human being again. This is because it corresponds to the profile of diseases that can be eradicated: people, not animals, are the only vectors of the virus (so that eradication does not require killing an entire animal species), we have an effective vaccine and we have accurate and readily available diagnostic tests to identify the disease.

Globally, there is good news in this regard: in 2017, about 85% of children worldwide received one dose of measles vaccine on their first birthday, up from 72% in 2000, according to the World Health Organization.

But that is not enough for total eradication. While most of today's epidemics occur in developing countries, particularly in Africa and Asia, as we have seen in Washington and Europe, measles can take off anywhere, provided that enough people have not been vaccinated.

In the United States, researchers have found that recent outbreaks of measles and whooping cough are closely linked to people who refuse vaccines. Unvaccinated people are often "zeros of the patient", which means that they have triggered epidemics by creating pockets of susceptibility to the diseases that caused the disease. Again, these outbreaks typically occur when travelers infected with the virus encounter groups of people in the United States who are not vaccinated.

To increase vaccination rates, many European countries have cracked down on parents refusing to be vaccinated, experimenting with fines and penalties.

In 2015, Oregon state lawmakers made it a bit more difficult for parents to exempt their children from vaccination. They asked parents to look at an online vaccination program or to consult a doctor or nurse to obtain a "vaccine education certificate". has not deterred parents, according to a recent badysis of the state. After an initial decline in the non-medical exemption rate, it has steadily increased in recent years.

"Measles was eliminated from the United States in 2000, but it was allowed to come back," said Hotez, in part because of "ignorant and cowardly legislatures and the failure of governments to organize a campaign." defense of vaccines ".