Many different viruses, bacteria and parasites have been associated with disease outbreaks over the years.
Surprisingly, just what constitutes an outbreak and how many cases depend on what is making people sick. For example, a few cases of flu in the winter wouldn't be considered an outbreak because you expect people to get sick with influenza during cold and flu season. On the other hand, since most children in the United States are vaccinated against measles, even a single case of measles would be considered an outbreak.
The World Health Organization (WHO) states that an outbreak generally occurs "when the number of cases observed is greater than the number normally expected in the same geographic area for the same period of time."
Some of the most common outbreaks have included:
- Norovirus and other viral infections that cause diarrhea
- Bacteria that cause food poisoning, such as E. coli, Salmonella and Listeria
- Vaccine-preventable diseases like measles, pertussis and mumps
- Influenza viruses, including seasonal flu, avian flu (bird flu) and H1N1 flu (swine flu)
Outbreak NewsWhether it is an outbreak of norovirus on a cruise ship, a large measles outbreak in a small community or a nationwide outbreak of Salmonella or Listeria, it is important to be aware of the latest outbreak news:
- Multi-state food-borne outbreaks
- Travel notices and outbreaks
- WHO disease outbreak news
- Emerging and re-emerging infectious diseases
- ProMED-mail (Program for Monitoring Emerging Diseases)
You can also look for news from your local and state health departments for the latest outbreaks that are close to you where you live. Visit their websites regularly.
Recent Outbreaks and EpidemicsIn addition to staying up-to-date on current outbreaks and epidemics, being aware of recent outbreaks may help you avoid them in the future. Recent outbreaks include:
- An outbreak in which at least 3,774 people got sick with E. coli O104:H4 from eating raw sprouts. Most of the cases were in Germany, and there were 44 deaths and 750 cases of hemolytic uremic syndrome (HUS) (2011)
- A Listeria outbreak in which 146 people in 28 U.S. states got sick from eating contaminated cantaloupes (2011).
- A Salmonella outbreak in which about 1,939 people got sick and which was linked to shell eggs, which led to the recall of millions of eggs (2010).
- An outbreak that caused 72 people in 30 states to get sick with E. coli O157:H7 from eating raw cookie dough (2009).
- The 2009 H1N1 influenza (swine flu) pandemic, which led to between 8,870 and 18,300 flu deaths in the United States.
- Measles outbreaks that led to record numbers of cases in 2008 (140 cases) and 2011 (at least 223 cases).
- An outbreak of mumps from June 2009 to January 2010 in New York and New Jersey in a tradition-observant Jewish community, which led to at least 1,521 cases of mumps.
- An increase in pertussis cases in California in 2010, with at least 9,143 cases and 10 deaths in infants too young to be vaccinated.
- An outbreak of cryptosporidiosis that led to almost 3,000 cases in Texas, with more than half in north Texas, causing diarrhea and vomiting in kids who had been swimming in contaminated water.
- A large outbreak of hepatitis A that sickened at least 555 people and killed three, which was linked to green onions served at a restaurant in Pennsylvania.
- An outbreak of avian influenza A (H5N1), commonly referred to as bird flu, in Asia, Europe, the Near East and Africa, with at least 584 cases since 2003 and 345 deaths.
- An epidemic of severe acute respiratory syndrome (SARS) in 2003, which sickened about 8,098 people and led to about 774 deaths in 29 countries (including 29 in the United States).
- Legionnaire's disease is estimated to sicken between 8,000 and 18,000 people each year with pneumonia-like symptoms.
- Lyme disease was initially discovered in the late 1970s after a large number of children were diagnosed with juvenile rheumatoid arthritis in Connecticut. The outbreak was eventually linked to a bacterial infection caused by tick bites.
Avoiding OutbreaksOne easy way to avoid outbreaks is to check for any travel health warnings from the federal Centers for Disease Control and Prevention and the U.S. Department of State.
It can also help to:
- Teach your kids the correct way to wash their hands, and encourage them to frequently wash their hands
- Encourage your kids to wash fruits and vegetables
- Follow food safety guidelines to cook and store food properly
- Avoid people who are obviously sick
- Use insect repellent and take other precautions to avoid mosquito and tick bites
- Avoid ingesting water while swimming in pools, rivers and lakes.
- Avoid unfamiliar dogs and wild animals. Wash your hands carefully after touching any animals, whether it's the family cat or the animals in a petting zoo
- Make sure your kids don't swim when they have diarrhea, pink eye, hepatitis A or other contagious diseases. They should practice other healthy swimming tips, such as showering before getting in the water
- Teach your kids to turn their heads and cough or sneeze into a disposable tissue or the inside of their elbow if they don't have a tissue
Finally, make sure your child's vaccines are current. Several recent outbreaks involved vaccine-preventable diseases, including recent flu, hepatitis A and measles outbreaks.
CDC. Health Information for International Travel (Yellow Book) 2012.
CDC. Manual for the Surveillance of Vaccine-Preventable Diseases. 5th Edition, 2011.
WHO. WHO Guidelines for Epidemic Preparedness and Response to Measles Outbreaks. Geneva, Switzerland, May 1999.