NEW YORK (Reuters) - Investment-advisers are increasingly worried that U.S. authorities are not be doing enough to prevent a widespread outbreak of coronavirus in the country, potentially adding further downside to already-battered markets.

FILE PHOTO: A woman wearing a mask to prevent the coronavirus is reflected in the mirrors, in Seoul, South Korea, February 24, 2020. REUTERS/Heo Ran/File Photo

Their criticisms include the number of people so far tested by the U.S. Centers for Disease Control and Prevention (CDC), which some say is too small, the possible difficulties of imposing lockdowns on U.S. cities and concerns that the White House could bungle containment efforts.

The worries have magnified the uncertainty that has accompanied the coronavirus outbreak over the last several weeks, as investors scramble to adjust their portfolios to price in the virus’ potential for damage to the global economy and assess its further impact on asset prices.

The CDC states on its website that “as of Feb. 24, CDC teams are working with the Department of Homeland Security at 11 airports where all flights from China are being directed to screen travelers returning to the United States, and to refer them to U.S. health departments for oversight of self-monitoring.”

U.S. Health and Human Services (HHS) Secretary Alex Azar said as of Thursday morning the CDC had tested 3,625 specimens for the fast-moving virus.

For some investors and analysts, those assurances ring hollow.

“Much of what we’ve seen about this virus has shaken confidence in governments,” said James Bianco, head of Chicago-based advisory firm Bianco Research.

His list includes doubts over China’s accuracy in counting cases, criticism over Japan’s handling of a cruise ship quarantine at one of its ports, and the comparatively small number of people that U.S. authorities have so far tested.

Worries over the growing number of cases outside China sent the S&P 500 into intraday correction territory on Thursday morning. Stocks took an earlier hit on Wednesday after health officials in Nassau County, New York, said they were monitoring 83 people who visited China and may have come in contact with the coronavirus. Governor Andrew Cuomo said the state has had no confirmed cases so far. [L2N2AQ192]

On Wednesday evening, U.S. President Donald Trump told Americans that the risk from coronavirus remained “very low,” and appointed Vice President Mike Pence to run the U.S. response to the looming global health crisis.

Bianco said he fears many investors are still complacent about how quickly the number of cases could multiply in the United States, as it has in countries such as Iran, Italy and South Korea.

He is advising his clients to tread lightly until the full extent of the outbreak is known.

“I would rather risk a lost opportunity by being out of the market or underweight and finding out that this is not a big deal, than being fully invested and worrying that this will get worse,” Bianco said.

‘TREMENDOUS AMOUNT OF RISK’

Others are concerned over the consequences if the United States were forced to implement a lockdown similar to the one imposed by Chinese authorities on Hubei Province, the epicenter of the coronavirus outbreak.

Wuhan, Hubei’s capital, imposed strict controls on movement of residents, then eased them, then later announced that the relaxation had been revoked. Such measures could be more difficult to enforce in the United States.

“Those of us sitting here in Hong Kong looking at financial markets think there is a tremendous amount of risk in the system,” said Simon Powell, equity strategist at Jefferies in Hong Kong.

Powell is particularly worried that there could be spread of the virus from people from countries outside China which were not subject to travel restrictions coming into the United States. He is particularly concerned about the outbreak in Iran.

Iran said on Thursday that its coronavirus death toll had risen to 26, by far the highest number outside China. The death rate among confirmed cases of the virus has been running at around 10% in Iran compared to around 3% elsewhere.

Powell also thinks that a Trump government is unlikely to choose reduced economic activity , writing in a recent research note that “our base case hypothesis is that a Trump government is unlikely to choose reduced economic activity, and supply chain disruption, so spread of the virus, if it were to emerge in the US, would be more likely.”

Others have pointed to what they believe are shortcomings in the CDC’s approach.

“The initial response from the U.S. has been targeted to mount a response to confirmed high-risk or infected cases, not directed to a more generalized public health containment,” said Wouter Jongbloed, head of policy and risk analysis at New York-based Exante Data.

With coronavirus having spread well outside China, CDC testing was “likely insufficiently effective in preventing a potential outbreak in the U.S.,” Jongbloed said.