In the most alarming sign that New York may be on the cusp of a resurgence or second wave, coronavirus cases are skyrocketing in two communities in suburban Rockland County.

Spring Valley and Monsey, two small communities in the town of Ramapo with large numbers of Orthodox Jewish residents, have respective single-day positivity rates of 30% and 25%, according to Governor Andrew Cuomo. As of Friday, there have been over 370 cases over the last two weeks in Spring Valley and Monsey, according to the local health officials.

In his second telephone press briefing of the day, Cuomo read a list of 10 ZIP codes that he said represent 2.9% of the state's population but now account for 25% of its cases statewide.

The state's positivity rate was 1.5% on Sunday, up from 1.02% on the prior day. In Rockland County, nearly 13% of all tests came back positive.

Back in April, Rockland County was reported as having the highest per capita rate of coronavirus infection in the state. Local officials at the time attributed the high caseload to ultra-Orthodox Jewish residents refusing to comply with social distancing rules. In response, Jewish leaders accused authorities of overstating the problem and spurring anti-Semitism.

This is not the first time the county has had to contend with a public health crisis affecting Orthodox communities. Last March, a measles outbreak prompted a local state of emergency, where those under 18 who had not been vaccinated were banned from public places. Many of the measles cases were said to be concentrated in areas with high numbers of Orthodox residents, who had not vaccinated their children.

After the two Rockland County areas, Brooklyn's Borough Park had the third highest positivity, that of 17%, followed by Midwood, at 11%.

On Monday, Mayor Bill de Blasio also reported a dramatic jump in positivity to 1.93%. The figure was last reported on Friday as being at 1.3%.

A spokesperson for the mayor did not immediately respond to a request for comment.

Cuomo said the state would immediately make 200 rapid testing machines available to schools, both public and private, in the 10 high positivity rate ZIP codes as well as to local governments.

"I strongly encourage them to request a rapid testing machine and have them start testing their students," Cuomo said, of schools.

Rockland County Executive Ed Day on Monday said local officials were in conversations with the state about securing additional testing and that he was directing further enforcement actions.

"I am both privately and publicly urging local municipalities to utilize their employees such as building and fire inspectors and police in educational efforts. It is my expectation that appropriate enforcement action will be taken, as necessary," he said, in a statement.

On Friday, Day said that 70% of the uptick was coming from Spring Valley and Monsey, according to News12.

"In this case it's a unique situation," Day said. "It has nothing to do with the Phase 1-4 reopenings. This is something that really goes back to the way a religious group practices. It's communal in nature and now it's a matter of getting them to understand that and getting all these folks to understand what they need to do to minimize the spread."

New York City has been using a rapid test, which can deliver results in as little as 15 minutes, since around early July in certain hotspot neighborhoods. Unlike conventional diagnostic tests, the test is performed on a machine the size of a toaster that can process four specimens within an hour. The downside of the test is its high false negative rate, where it misses some positive cases. To address that weakness, all individuals must also submit to the more widely used polymerase chain reaction (PCR) diagnostic test.

City health officials last week threatened to impose greater restrictions across a swath of South Brooklyn and two neighborhoods in Queens as early as Tuesday. Since Friday, they have focused some of their efforts on ultra-Orthodox communities, by making robocalls and broadcasting messages on ambulances and other city vehicles in Yiddish.

The news about the upticks come on Yom Kippur, which marks the holiest day in the Judaism.

Cuomo did not cite a source for the infections, but asked about the "elephant in the room," he replied, "I know what you're referring to but we’ll have a conversation with the local governments."

But the state's coronavirus restrictions, he added, "applies to everyone equally. Public health is public health."

Under New York's rules, houses of worship are limited to 33% capacity and social distancing must be maintained inside. However, Dr. Jay Varma, the mayor's senior health advisor, said Friday that the city was not currently enforcing that rule, explaining that, "The city needs to walk a delicate line between disease control and recognizing people's religious and cultural practices."

Mayor Bill de Blasio has stumbled with his attempts to enforce social distancing in the Orthodox community. In April, following a crowded funeral that drew thousands of mourners in Brooklyn, he issued a stern warning on Twitter to "the Jewish community" that was criticized for both painting an ethnically and culturally diverse community in broad strokes and for singling them out.

"Threatening to lock up people in a crowded cell in order to prevent them from attending a crowded funeral (or congregating in a crowded park) is a cruel and counterproductive policy," Brooklyn Councilman Brad Lander told Gothamist at the time.

Denis Nash, an epidemiology professor at CUNY, on Monday acknowledged the challenges of getting a public health message across to a specific community.

"It’s a very fine line. I don’t think stigmatizing communities is going to work ever," he said, adding, "When we rely on individuals to adopt behaviors that are protective of themselves, there's a lot of work that needs to go into understanding what people’s baselines attitudes are."

Unfortunately, he said, given the signs of increasing transmission, there may not be much time left for that kind of considered and collaborative messaging.

"By the time our city could do that, it may be too late," he said.