HOUSTON, Texas (KTRK) -- After seeing a significant decrease in COVID-19 cases, doctors say the Houston area is starting to see a slight uptick and they're associating the change with the fast-spread delta variant.
Harris County Public Health said the delta variant could become the dominant variant in Houston, especially since it spreads more easily than previous variant.
Since March 2020, Houston Methodist Hospital has been tracking all of the positive COVID cases that have been registered into its system. Researchers recently found the delta variant to be the most dominant in cases they're tracking and it's increasing quickly.
The hospital's most recent data shows the variant makes up 42% of cases, which is up 20% from the previous week.
Researchers have found the variant is doubling every seven and a half days.
"The delta variant is cause of concern for two main reasons: First, it's more transmissible, meaning it's more easily spread from person to person and second, we know, compared to other variants, it's capable of causing more severe disease and more hospitalizations," said Randall Olsen, an infectious disease pathologist at Houston Methodist.
Olsen said they are already starting to see those hospitalizations increase.
ABC13 spoke with Dr. David Persse, the city of Houston's health authority, and discussed what's called the "R" value, which examines the following: For every one person infected by a virus, how many others will become infected?
When it comes to the flu, Persse said for every person that gets it, they're likely to infect 1.1 additional people. For one of the originally reported COVID strains, for every one person infected, 2.5 people were infected.
As far as the delta variant, for every person infected with the virus, they are likely to infect six more people.
"They think the delta variant has an 'R' value of around six," said Persse. "That's a big jump. So, every one person that's infected, of course, they're going to need to be in an environment of unvaccinated people. But for every one person that's infected, they can then turn around and infect six other unvaccinated folks."
One thing experts know is that vaccinations work.
Persse said since the vaccine became available, there have been 1,983 COVID-related deaths in the city of Houston.
Of those deaths, only five people were vaccinated - that means 99.75% of the people who died from COVID were not vaccinated. Persse's main message is vaccines work and urges people to get vaccinated.
When it comes to the delta variant, doctors have several suggestions. First, make sure everyone in your household who is eligible to get the vaccine gets it.
Also, be mindful about what your children are doing. Are they participating in activities that are indoors with lots of other unvaccinated people?
WATCH: How parents can protect their children from delta variant
Something else to consider is wearing a mask.
Dr. Maria Rivera with Harris County Public Health said children over two should wear a mask.
"We know that masks are no longer mandated in the state of Texas, but they're still strongly recommended, and I would strongly recommend any child over the age of two to continue to mask," said Rivera.