We are on the right track for the worst measles epidemic of this century

With six states among seven separate epidemics, 2019 is one of the worst years of measles in a long time. The United States has a total of 626 cases. That's about 250 more than what happened in all 2018, making it the second worst year for measles since the United States declared it eradicated in 2000. We have only 41 left to break the record for most cases since 1995.

Meanwhile, we continue to accumulate new outbreaks, some in places where researchers predicted they were at risk because of low vaccination rates. Portland, Houston and Kansas City all had small outbreaks and were identified as risk areas in 2018 PLoS Medicine study. The epidemic in Clark County, Washington, just across the Portland-Oregon border, was the most widely covered. At present, the Detroit area is also experiencing a substantial situation in the county precisely predicts.

Many of these cases have occurred in highly unified communities with low vaccination rates. The outbreak in Washington State originated in a Slavic community and the two current situations in New York – in Rockland County and Brooklyn – are both located largely within Jewish groups Orthodox living in the area. This is the case of many recent years of severe measles. In 2014, more than half of the total cases came from a single home among the Amish in Ohio. A small, concentrated group of Americans of Somali origin in Minnesota was the epicenter of the main epidemic of 2017, and Orthodox Jews were the focus of 2018.

But there is also the growing problem of vaccine exemptions. Many states allow parents to quote religious or philosophical exemptions to prevent their children from being vaccinated. These lax laws have allowed some communities to create pockets with vaccination rates low enough to allow the spread of an extremely contagious disease such as measles. To prevent the virus from spreading from one person to the other, 95% of the population must be immunized. But in many states, kindergarten children have a vaccination rate well below that figure.

Such epidemics can expose people who can not get vaccinated, have immune system problems or just too young, and it is these people who really worry public health officials. These are the most vulnerable among us that we try to protect.

Here are answers to other questions that you are likely to ask yourself as these epidemics evolve.

Where are these epidemics?

As of April 19, 22 states had reported measles cases at the Center for Disease Control: Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Maryland, Massachusetts, Michigan, Missouri, Nevada , New Hampshire, New Jersey, New York, Oregon, Texas, Tennessee and Washington. Seven of these countries – Arizona, Colorado, Oregon, Texas, Michigan, Missouri and Washington – admit philosophical objections to vaccination and have counties with dangerously low vaccination rates.

Not all of these countries are affected by epidemics – some have isolated cases, which is not uncommon. Only parts of New York, Washington, New Jersey, California, and Michigan have outbreaks, defined as 3 or more cases in a cluster. But we have already seen one outbreak trigger another. Michigan's public health officials confirmed that the outbreak had begun when a man had caught measles in Brooklyn and then went to the Detroit area.

Most other current situations result from international travel. Since the virus is no longer endemic in the United States, it is the main means of triggering a measles epidemic: an unvaccinated person travels and then brings the virus back to the states. And when you have pockets of low vaccination rates, these singular events can spread quickly.

Thus, many cases of measles reported each year in the United States come from the Philippines. In the Philippines, an outbreak is underway, where more than 200 people (most children) have died since January out of 12,700 cases. This is quite an increase over last year and, according to Al Jazeera, was largely blamed for lower vaccination rates. In the Philippines, health officials said coverage in some areas was only 30 percent and the overall rate has already fallen to 60 percent.

How many people are sick so far?

Here is the most recent information for each state (updated 23 April):

California: Out of a total of 21 cases this year (the same number as in 2018), 13 have been associated with outbreaks in different counties, although the situation is continuing in the Butte County region of Northern California .

New York: There have been 359 cases in Brooklyn and Queens since October 2018 and 199 in Rockland County during the same period – all in the Orthodox Jewish community, where vaccination rates are particularly low.

Oregon: There are now 10 cases in Multnomah County, four of which are related to the main outbreak (Patient Zero seems to have caught the virus while he was in Washington State). There are also four other cases that are not related to the epidemic.

Texas: 15 cases up to now, the largest grouping around the Houston area and a bit more of the rest of the state.

Washington: There are 74 cases, one in King County and the others in Clark County, the vast majority of which are unvaccinated. Only a handful of these cases involve adults over 18 years of age.

Michigan: 43 people have been sick so far, all with one exception near the New York outbreak. Public health officials confirmed that a man had returned from the city in southeastern Michigan while it was contagious but before it showed any symptoms .

New Jersey: There are currently 13 cases, 11 of which are associated with the outbreak. This is in addition to the previous outbreak of October 2018 to January 2019, in which 33 people became ill.

How did all this begin?

For the last 20 years, measles epidemics in the United States have generally started in the same way: a person gets measles from a foreign country and spreads it to unvaccinated Americans.

More generally, this happens because we have allowed vaccination rates to decline. Although the national vaccination rate is 91.9%, there are areas where rates fall below, especially for young children who are most vulnerable to the virus. These pockets allow measles to spread and eventually spread to the general population, exposing people who can not receive the MMR vaccine for medical reasons. Although lawmakers in the state of Washington have just passed a bill banning personal and philosophical exemptions, Arizona lawmakers are doing the exact opposite: they have introduced numerous bills which would make vaccinations even easier. According to CNN, at least 19 other states have tried to introduce similar bills, although that does not necessarily mean that they will be passed.

Should I do something?

If you or your children have not had both doses of the MMR vaccine, this should be your top priority. Children from the age of 9 months can be vaccinated for the first time. Unless you have a medical problem (your doctor needs to know if you have one that prevents you from being vaccinated), all teenagers and healthy adults can also be vaccinated. The only exception is women who are currently pregnant.

Some minors began to seek immunization without the permission of their parents. In most states, you can not do much before age 18 because many laws prevent minors from making their own health decisions. But there are 15 states where you can get vaccines without parental consent: Alabama, Alaska, Arkansas, Delaware, Idaho, Illinois, Kansas, Louisiana, Maine, Massachusetts, Montana, Nevada, Oregon, Pennsylvania, South Carolina, Tennessee, Washington and West Virginia. If you live in one of these states, you should be able to ask a doctor to give you a vaccine, provided that he finds you mature enough to understand the procedure.

If you live in or near one of the areas affected by epidemics, you can check the list of potential exposure sites on the website of your state's Department of Health. Washington and Oregon, for example, have a long list that is constantly updated. If you discover that you may have been exposed to measles (or if you think you may be), the CDC recommends that you call your doctor immediately to determine if you are immune to the virus. You are considered immune if you received both doses of MMR or were born before 1957 because the virus was so prevalent that virtually all children were exposed. If you were born right after that and were vaccinated in the 60s or 70s, you may need another vaccine. We have more information about this here.

If you are not immune, the CDC asks you to stay away from areas where there may be people who are immunocompromised or too young to be vaccinated – such as in a school or hospital – until that your doctor allows you. You must also take special care to avoid contact with pregnant people and newborns. Some parents of young babies who have not yet been vaccinated choose to stay out of the public as often as possible to reduce the risk of exposure.

Bottom line: get vaccinated and encourage others to do the same.

This story is updated regularly as new cases and information arrive.