NEW YORK, March 5 (Xinhua) -- The total number of confirmed COVID-19 cases from some 20 U.S. states has topped 200 with at least 12 deaths by Thursday evening, according to the databases set up by several major U.S. media outlets.

The numbers updated by the U.S. Centers for Disease Control and Prevention (CDC) as of 4 p.m. on Thursday show a total of 148 confirmed COVID-19 cases and a death toll of 10.

"With more and more testing done at states, these numbers (persons under investigation) would not be representative of the testing being done nationally...states are reporting results quickly and in the event of a discrepancy between CDC and state case counts, the state case counts should always be considered more up to date," said the CDC.

States are scrambling to get approval from the federal government to conduct tests locally so as to speed diagnosis. In the state of Texas, Houston's public health lab on Wednesday gained a single test kit to analyze samples, and reported on Thursday two more confirmed cases in Harris County.

These are the second and third cases in Greater Houston Area as well as in Texas. The two cases, a man and a woman, are travel-related and have shown no evidence of community spread, Harris County Public Health Department said in a release.

The test kit has the capacity to test 700 specimens suspected of carrying the virus, enough for about 200 to 400 patients, health officials said.

Also on Thursday, Illinois authorities reported the fifth COVID-19 patient in the Midwestern state. Governor J.B. Pritzker told a press conference that the patient is a man in his 20s who was probably infected during a recent travel to Italy.

The patient has been hospitalized in isolation and is reportedly in stable condition.

"The state of Illinois is working around the clock to contain COVID-19 and educate the public," said the governor, adding that the risk of COVID-19 to the general public in Illinois "remains low."

"But we encourage the public to be vigilant and take extra care with the normal precautions you should take during flu season," said Pritzker.

In Los Angeles, a medical screener who worked at Los Angeles International Airport (LAX) for checking passenger's health situation, has tested positive for COVID-19, prompting more tests for other workers.

The local NBC news channel reported Thursday that the patient was described by the Department of Homeland Security (DHS) as a medical screener who "wore all the correct protective equipment and took necessary protections on the job."

The DHS noted that they did not know if this case was a result from community spread or through their work as a medical screener, saying "there have been no positive COVID-19 detections reported from the LAX screened travelers. "

In the state of New York, the number of confirmed cases doubled that of the previous day, reaching 22. Eight of the new cases are in Westchester County and all related to the state's second case reported on Tuesday, who is an attorney living in Westchester County and working in Manhattan.

During a press conference on Thursday morning, New York City Mayor Bill de Blasio noted that the newly added COVID-19 cases have shown more evidence of community spread.

"What we do know is when you have a community spread dynamic, you have to assume it could be anywhere in the city. So we're going to work on an assumption of intense vigilance," said the mayor.

He called on all New Yorkers who returned from a country or a region where there is a COVID-19 outbreak to isolate themselves for 14 days as a precaution.

Currently in New York City, over 2,700 people are in home isolation and self-quarantine, city health officials have said.

On Thursday evening, the state of Maryland declared a state of emergency as three Montgomery County residents tested positive for COVID-19.

State officials said the patients, a couple in their 70s and a woman in her 50s, contracted the virus while traveling abroad. They are in good condition and are isolated in their homes.

These cases could be the closest so far to Washington, D.C., which has not reported any cases yet.