MUSC infectious disease director advises caution
By Liv Osby
With the number of new cases of Covid-19 trending upward in recent weeks, an MUSC infectious disease specialist cautions that the state could be facing an escalation of the virus - especially in the aftermath of mass demonstrations over the killing of George Floyd in Minneapolis.
The number of new cases per day, or epicurve, hit 1,601 on June 26 - up from 507 on June 5 - the highest number since the state began to track the virus as of that date, according to the state Department of Health and Environmental Control.
And as of June 28, 712 South Carolinians had died from the virus, while the cumulative number of cases topped 33,221, the agency reported. The state currently projects 1,172 deaths by Oct. 1.
In addition, the number of positive tests increased from 9.6 percent on June 14 to 20.1 percent on June 27, according to DHEC, while about 75 percent of hospital beds were being used.
The trend has tracked the reopening of the state after a two-month shut down of schools and businesses, said Dr. Cassandra Salgado, hospital epidemiologist for the Medical University of South Carolina and division director for infectious diseases.
"When I look at specific indicators ... it's more than just the number of cases per day. The more important number is maybe what is the proportion of new cases each day compared to the previous day or total case number. And when that starts to get higher, more than 4 or 5 percent, I start to get concerned that we're hitting a threshold in a state or a certain area where cases could start to escalate," she said.
"South Carolina went from 5 percent to 10-plus percent over the (May 30-31) weekend," she added. "Most people would say you want to see ... the number of positive cases, the proportion of positive cases and rate of rise - we want to see them very, very low before we consider reopening."
Salgado said she's concerned that reopening might cause people to think that there's no longer a need for social distancing. And that the mass protests around the state since the death of George Floyd could also fuel a spike in cases.
"The large groups getting together in close proximity, even outdoors, bringing together people who don't normally spend time together, makes one worry. Not everyone participating in the protests are wearing masks," she said. "When I put all that together, we are still in a bit of a vulnerable state and need to keep a close eye on these numbers."
After shut-down, the rate of increase in positive cases was less than 1 percent, Salgado said. And after a limited reopening around mid-April, the numbers held steady until mid-May, then began to rise again, she said.
But that also coincided with increased testing, she said, so it's hard to pinpoint the cause definitively.
"It was not until we further reopened the state - in my mind the week of May 18 - where we started to see in a predictable fashion 10 days later a rise in the number of cases," she said. "One could speculate that people just have not practiced good social distancing. But I feel it's the biggest tool in our toolbox to prevent spread."
Greenville in particular has seen an increase. The number of new cases on May 30 was reported at 9, according to the state Department of Health and Environmental Control. On May 31, it was 89. Memorial Day weekend ran May 23-25.
As of June 28, there were 4,733 confirmed cases in Greenville County, the state reports.
DHEC says it can't say for sure why certain areas experience an increase in cases.
But spokeswoman Laura Renwick said that increased testing, the wrap-up of universal testing at nursing homes, and reduced social distancing could be at play.
"We're currently investigating the data associated with recent Greenville cases, such as the ZIP code information for positive cases, to identify any other factors that could be contributing to an increase so that we can immediately address them," she said via email.
That's how Greenville was identified as a hotspot, said Dr. Brannon Traxler, an epidemiologist and DHEC consultant. The testing allowed health officials to track an increase in cases over a week, then analyze the cases further.
"For the Greenville area, we've determined about half a dozen instances where multiple positive cases were coming from single-family dwellings, most likely meaning that family members had passed the virus among each other," she said via email. "We've also targeted some specific ZIP codes that had numerous cases reported to help identify situations where community spread could be occurring within those areas."
About 30 percent of the increased cases were among Hispanics, she said. So DHEC immediately ramped up efforts to increase testing in Hispanic communities, have bilingual staff on hand, and spread the word about the virus on Latino radio stations.
Salgado said she's concerned. "Overall .... I worry that people in general have a difficult time practicing good social distancing," she said. "I wish people would not equate the word opening up with 'I don't need to be careful.'"
Meanwhile, Salgado said MUSC is preparing for a surge.
"We're making sure we're all prepared for patients seeking care and getting testing sites fully staffed. I don't have a crystal ball, but it feels like things are heating up again," she said. "And just because we're reopening, it doesn't mean people don't have to be careful."
Renwick said the virus can spread in any setting where people are less than 6 feet from each other, especially if they aren't wearing face masks or cloth face coverings. The risk grows when people are speaking loudly, cheering or yelling - like at demonstrations - which can produce more respiratory particles containing virus, she said.
"Anytime individuals take part in mass gatherings and don't adhere to social distancing and mask-wearing guidance," she said, "we can expect to see an increase in the number of people diagnosed with Covid-19."
Renwick said that as the weather warms and the country reopens, it's imperative that people take precautions to protect themselves and others, such as wearing a mask in public, avoiding crowds, and frequent hand washing.
Salgado said she recently went out to dinner for the first time since the pandemic hit and thought the restaurant did a good job of limiting the number of customers and keeping them apart from one another, going so far as to turn patrons away. There was hand sanitizer on the tables and all the staff wore masks and gloves.
"But I feel like ... we need to be very cautious and watch the numbers over the next several weeks before making any decision about further reopening and large gatherings from a public health perspective," she said.
"And as a health care provider, I'm concerned we're seeing more cases."
Regularly updated data on Covid-19 in South Carolina is available at:
Dr. Cassandra Salgado: A Closer Look
A native of West Virginia and one of five children in a blended family, Salgado says she always wanted to be a doctor.
"I just never really wanted to do anything else," she said. "I don't know why."
She attended the West Virginia University School of Medicine and the University of Virginia. Because of her love of working with her hands and sculpting, she initially thought she'd specialize in plastic surgery.
But she found that she connected with patients during clinical rotations in medical school, which "made me much happier."
And as a natural puzzle solver, she decided the fascinating and often enigmatic world of infectious disease and health care epidemiology was a better fit.
"I've often thought that if I wasn't doing this, I would be a detective," she said with a chuckle.
"I'm not sure I thought I'd be involved in a global pandemic. We've had some things happen, like H1N1 and Ebola and Zika," she said. "But it's been 100 years since we've seen anything like this."
Since 2004, she's been with MUSC in Charleston, a perfect home base for a breast cancer survivor who loves the outdoors, bird watching and water sports like kayaking and dragon boating.