"Somebody with measles goes to an environment 10 people present with no immunity to measles," Kaiser Permanente Fresno Dr. Samer Saghbini said.
"9 out of the 10 will get infected."
Activity around the country is high right now as the disease is affecting nine states-- including California.
Action News checked in with public health officers in Fresno, Madera, and Tulare Counties, who told us they are closely monitoring the situation.
"We always like to stay on top of whatever trends are going on because we know contagious diseases can travel very quickly in our society," Dr. Rais Vohra with the Fresno County Department of Public Health said.
Measles is one of the most contagious diseases.
In California, there are three confirmed cases so far. Action News reached out to California Department of Public Health, who sent the following statement:
"Measles, one of the most contagious infections, can lead to severe life-long consequences and also be fatal, especially for children. The measles-mumps-rubella (MMR) vaccine is safe and provides long-lasting protection against measles. It's important to check if you and your loved ones are up to date on all of your routine vaccines, including the MMR.
There have been three cases reported in California. All three cases have been linked to travel to countries with recent measles epidemics in the wake of decreased routine immunization. Current cases counts of measles can be found on the CDPH measles page. No fatalities have been reported.
So far, the number of measles cases diagnosed recently in California is similar to pre-pandemic levels. Due to the limited number of cases, the Department is not releasing additional identifiable information, including the counties of residence. Individual California counties may elect to share their case counts.
More information and current data can be found on the CDPH measles webpage."
However, the increased activity around the country has Valley health leaders concerned, especially since they're seeing a drop in vaccinations.
"So rates are lower, we're seeing more cases. And that's not just in the U.S., that's worldwide," Dr. Paul Simon with the Madera County Department of Public Health.
Last year, Merced and Tulare Counties both had measles exposure cases.
However, there are steps to prevent an exposure from turning into an outbreak.
It starts with contact tracing.
"If an individual is, does have measles to contain an exposure, we assess, Who was exposed? Were other people were around them? Were they in a public place?" Dr. Thomas Overton with the Tulare County Health & Human Services Agency said.
Fresno, Tulare, and Madera Counties say so far haven't seen any measles cases or exposures.
Health experts add that the best way to protect yourself and the community from the illness is to make sure you're vaccinated.
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