"We are potentially facing a very serious public health threat," he said.
He told ABC13's Mayra Moreno he began noticing the numbers going up after the Memorial Day holiday.
During a briefing on Monday, Mayor Sylvester Turner reported 1,789 new COVID-19 cases, adding to Houston's total of 14,322. Monday's total is the most the city has reported in one day so far.
READ MORE: Houston mayor says city 'moving very fast in the wrong direction' as record cases reported
"I have never reported these type of numbers," said Turner.
Continuing down this path could mean Houston will then see what happened in New York, said Hotez.
"Where there is a big surge and it becomes difficult to manage patients and that's where death rate goes up," he said.
He said he's most concerned with low-income neighborhoods where he said there may be more crowds and people with comorbidities.
He hopes people take the message and proceed with caution.
"We will get a better sense if this is trending over next few days," he said.
FULL VIDEO: Could Houston look like New York City when it comes to COVID-19?
This message comes hours after Gov. Greg Abbott said COVID-19 is "spreading at an unacceptable rate in Texas" after an alarming spike in cases across the state.
During his briefing on Monday, the governor announced infection rates have gone from 4.5 percent in May to 9 percent.
"Hospitalizations for COVID-19 average just over 1,600 a day in the latter part of May," explained the governor. "In the last four or five days, hospitalizations have averaged more than 3,200 a day. To state the obvious, COVID-19 is now spreading at an unacceptable rate in Texas, and it must be corralled."
However, Abbott said there is now more testing being conducted in hot spots across the state, and said they're working with hospitals to make sure anyone with COVID-19 receives the proper treatment.
"Closing down Texas again will always be the last option," said Abbott.
Abbott continues to push for Texans to stay at home, wash their hands and practice safe social distancing.
WATCH: Would Gov. Abbott consider scaling back on his reopening plan?
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