Washington, DC - More coronavirus cases are expected in the United States amid efforts to ramp up testing for the disease, officials say, after weeks of delays and faulty test kits led the virus to circulate undetected.

Experts said as more people are tested for the COVID-19 virus in the coming weeks, more cases will be confirmed.

"As we expand testing we will certainly pick up additional cases," said Peter Jay Hotez, professor and dean at the National School of Tropical Medicine, in Houston, Texas.

"We will also have to have capacity for isolating those individuals," Hotez told Al Jazeera.

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Nine people have died from the respiratory disease in the US, all in Washington state, and more than 100 have tested positive for the virus, according to the Center for Disease Control and Prevention (CDC). So far, 12 states have confirmed coronavirus cases.

The administration of President Donald Trump has faced widespread criticism for its response to the virus and a delay in the delivery of testing kits to states, slowing the process of detection and isolation of cases - crucial to the containment of the disease.

Delays, faulty kits

The need for more testing became urgent last week after the CDC announced a patient in California who had no travel history and no known exposure to an infected person, tested positive for the virus. Testing that patient had been delayed for four days because of CDC guidelines limiting those who can be tested to Americans returning from China or people close to a confirmed case.

In early February, the CDC said it had shipped about 200 test kits, but two weeks later, the agency announced that the tests were flawed and directed state health departments to send all samples to the central CDC headquarters in Atlanta, Georgia, significantly delaying the process.

"One implication of the delay in testing is not knowing who is contagious if they are asymptomatic or can't distinguish their symptoms from a regular cough or cold," said Bhaskar Chakravorti, dean of Global Business at The Fletcher School of Law and Diplomacy at Tufts University.

"Expanding testing has costs and disruptive effects, but can potentially limit the spread of the contagion earlier and faster," Chakravorti told Al Jazeera.

The CDC has not fully explained why the tests were flawed, but said "performances issues were identified related to a problem in the manufacturing of one of the reagents which led to laboratories not being able to verify the test performance" of the kits.

Researchers working in a lab that is developing testing for the COVID-19 coronavirus at Hackensack Meridian Health Center for Discovery and Innovation in Nutley, New Jersey, US [Kena Betancur/Getty Images/AFP]

Former Food and Drug Administration (FDA) Commissioner Scott Gottlieb said the US's government sole reliance on the CDC for testing was a mistake.

"I think there's some things we did that were very smart," Gottlieb said during an interview with CBS on Sunday.

"One of the mistakes, one of the challenges was getting the diagnostic testing in place, I think what we should have done and I don't want to, you know, armchair quarterback this, we relied on the CDC," he said, adding that the government could have involved other laboratories and manufacturers much sooner.

Expansion of testing capacity

Following the criticism, the Trump administration pledged a "rapid" expansion of the country's testing capabilities. The CDC broadened its guidelines for testing, and the FDA expanded its policy so that hundreds of labs can begin using their own tests after they are validated, instead of waiting until after the agency has completed its reviews of the tests.

US Health and Human Services Secretary Alex Azar told CBS's Face the Nation programme on Sunday that the US had enough kits to test 75,000 people, and additional kits were on the way.

CDC official Anne Schuchat announced on Tuesday that by the end of the week, all US state public health labs should be capable of conducting coronavirus testing. Speaking at a Senate committee hearing, FDA Commissioner Stephen Hahn said 2,500 kits with a capacity of up 500 tests each will be supplied to laboratories by Friday, enabling labs to perform one million coronavirus tests.

But members of Congress expressed scepticism over the estimates.

"I'm hearing from health professionals that's unrealistic," Democratic Senator Patty Murray told Hahn during the hearing.

The FDA later told the New York Times that the estimate includes the anticipated supply of kits by a private company.

About 54 of 100 local and state public health labs across the country are currently able to perform testing, according to the Association of Public Health Laboratories. Those labs have the capacity to test 100 patients a day.

Vehicle Maintenance Utility Service Worker wiping down a bus with disinfectant during a routine cleaning at the King County Metro Atlantic and Central Base in Seattle, Washington, US [Jason Redmond/Reuters]

New York Governor Andrew Cuomo, whose state has two confirmed cases, welcomed the FDA's decision to allow New York to test for the virus.

"I would like to have a goal of 1,000-tests-per-day capacity within one week because, again, the more testing, the better," Cuomo said at a briefing on Monday.

In a news release on Monday, California said it has received additional test kits and 10 labs in the state have begun testing thousands of specimens after Governor Gavin Newsom made the request from the federal government last week.

The coronavirus outbreak, which originated in Wuhan, China, has spread to 70 countries worldwide. More than 90,000 people have been infected with the virus and over 3,100 have died as a result of the disease, according to the World Health Organization. It has affected markets, suspended travel and shuttered schools in dozens of countries.

A real threat

Trump who has accused his political rivals of "fearmongering" about the coronavirus, last week appointed Vice President Mike Pence in charge of overseeing the response and announced restrictions on travel from other countries into the US. Pence said Americans should brace for more cases but that the "vast majority" of those who contracted the disease would recover.

Trump met members of his administration's coronavirus taskforce on Monday, as well as heads of pharmaceutical companies to discuss the development of a vaccine. He said there was no need to declare a national emergency and his administration has maintained that the risk of contracting the virus remains low for the American public.

Health officials, however, have continued to call for readiness against the respiratory disease, whose symptoms includes fever and coughing and, in more severe cases, pneumonia. They say a sustained community transmission in the US remains a real threat.

"We expect the number of cases will continue to increase in the coming days and weeks," Dr Jeff Duchin, health officer for the Seattle and King County Public Health agency said a news conference on Monday, "and we are taking this situation extremely seriously".