Outbreaks
Disease Outbreaks
Outbreaks of vaccine-preventable diseases can happen in communities with low vaccination rates when an infected person spreads the disease to others. An outbreak occurs when there are more cases of a disease than normally expected within a certain geographic area, time period, or population.
Thanks to vaccines, many diseases that used to be common in the U.S. (like whooping cough, measles, and polio) have been dramatically reduced. Unfortunately, many communities are now seeing outbreaks, especially where vaccination rates have gone down.
While preventable diseases may not be circulating in your community, they exist around the globe in places where people don’t have access to vaccines or are not getting vaccinated. Most of the time, a disease is introduced to a community from somewhere else, brought in by someone who may or may not know they are sick.
To avoid bringing a vaccine-preventable disease back into your community, check that you have all recommended vaccines and are aware of any outbreaks before traveling.
Vaccines Stop Measles from Spreading
Measles is very contagious. Exposure to an infected person with measles will cause infections in 9 in 10 people who are not protected. Measles is serious and can be deadly, even in otherwise healthy children.
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When an outbreak is declared, each sick person must be evaluated to see if their illness is part of the outbreak. Since each outbreak is unique, public health officials develop a definition of the typical sick person. If someone is ill but doesn’t fit the definition, they will most likely not be counted as sick due to the outbreak.
When healthcare professionals are determining if a sick person fits the outbreak definition, they will ask themselves questions such as:
- Does the person fit the population (age, vaccination status, risk factors, etc.) most affected?
- Did the person get sick in the place or season where the outbreak is occurring?
- How long did it take for the person to get sick from exposure to the disease?
- Does the sick person have the features of the disease?
When cases pop up, they are investigated according to the definition and categorized as “confirmed” (definitely a case), “probable” (likely a case without laboratory confirmation), or “suspected” (maybe a case). Note that these classifications can change. A suspected case may later be reclassified as confirmed once laboratory results become available.
This definition is essential in determining which cases are part of the outbreak and gives officials important data that are necessary to contain the outbreak
You can find information about disease outbreaks in the United States and internationally on the Johns Hopkins Center for Outbreak Response Innovation web page.
When deciding to travel nationally or internationally, check the CDC’s Destinations web page to see which vaccines you may need in order to avoid getting sick and bringing disease back into your community.
Plan ahead when traveling and make sure you get all the necessary vaccines at least 4–6 weeks before travel. You can find out which vaccines you need on the CDC’s Travelers’ Health web page.
Measles is causing worrisome outbreaks across the globe. Due to outbreaks in the United States, check the Johns Hopkins Measles Cases and Outbreaks web page weekly for information on measles outbreaks and cases in your area. It’s essential to get vaccinated against measles, as the highly contagious disease is preventable with a very effective vaccine. Two doses of the measles vaccine are 97% effective at preventing measles.
If you suspect you or a family member in your home may have a vaccine-preventable disease, stay home, call your healthcare provider, and follow instructions. If you don’t have a healthcare provider and you believe you have a disease that’s part of an outbreak, call the number for your local health department.
Vaccines need to be given before disease circulates in the community, because it takes around two weeks for the body to become immune. Children should be vaccinated according to the recommended schedule before they enter school and should continue to be vaccinated into adulthood to avoid serious consequences, including death, from vaccine-preventable diseases.
Adults need vaccines, too. Be diligent about keeping yourself and your family up to date on vaccines.
By the time an outbreak has occurred, it will be too late. Don’t wait to protect yourself and your family from vaccine-preventable diseases.
To prevent an outbreak, enough people in an area need to have immunity, which can be achieved through vaccination. The more people who are vaccinated, the more difficult it is for the disease to spread. If enough of the population is immune to a disease, people who are not vaccinated due to medical reasons or age restrictions are better protected. This is called community immunity.
You can help prevent outbreaks and sickness in your family by ensuring your entire family is up to date on their vaccines. Check out the following recommended vaccine schedules and talk to your healthcare provider about which vaccines you and your family need to get to be up to date on vaccines.
- AAP’s recommended schedule for children and adolescents (18 years and younger)
- AAFP’s recommended schedule for adults (19 years and older)
