We are collaborating with Dr. Fred Campbell, an internal medicine physician and associate professor of medicine at the Long School of Medicine at UT Health San Antonio, to answer listener questions about the coronavirus and their health. You can hear Dr. Campbell on the show each week, and keep up with our questions and answers on this page. Submit your own questions here, or send them to Ask a Doctor via Twitter, or Facebook.
To view an answer, just click the question:
Should I get tested for COVID-19 if I travel across state lines to Louisiana? Is there any reason that trip would put me more at risk?
Louisiana has been a hot spot for the disease, and it has a much higher per capita death rate than Texas. But Campbell says traveling from state to state doesn’t matter so much as what you are doing during your travels.
“Were you in an enclosed area such as a dance hall or a bar? And were there a number of people who were within six feet; whether or not they were using face coverings? All of those things are high-risk behavior in terms of picking up COVID-19.”
If so, he says, get tested.
Should I get tested regularly for COVID-19?
Campbell says testing is only necessary if you develop symptoms, or if you were exposed to someone who has the disease.
Are blood donors being tested for the disease before they donate?
There is no screening for COVID-19 during blood donations, but blood banks are taking donors’ temperatures as a precaution. Also, before any donated blood is used in a patient, hospitals test it for safety.
How long does it take health officials to process a COVID-19 test?
Currently, tests take about 24 hours to process. But eventually, Campbell expects there will be tests that take mere minutes to process and will be widely available.
How reliable are current COVID-19 tests? And how reliable must they be before it’s safe to reopen businesses and resume public life?
There are two types of tests: diagnostic tests specifically look for SARS-CoV-2 – the virus that causes COVID-19. But they haven’t been wholly reliable; they’ve missed some positive cases. The other kind of test looks for COVID-19 antibodies; in other words, it determines whether someone has contracted the virus and their body has fought the disease. With testing still limited, Campbell said reopening the state is risky because many people who have the disease without symptoms will go undetected, and could pass the virus to others. What’s more, testing isn’t a silver bullet, he said; the best way to prevent the spread is still social distancing and hand-washing.
Can more testing help decrease the number of new COVID-19 cases as Texas continues to reopen its economy?
The United States does not yet have a robust testing plan in place. Campbell said effective testing might mean every American would be tested each week until there is a vaccine or treatment for COVID-19. Until then, gatherings endanger public health. What’s more, the behaviors that keep people apart, like social distancing, have been shown to be the most effective at slowing the spread of the virus, in the absence of good testing or treatment.
How soon after the start of the 10 to 14-day incubation period can a test detect COVID-19?
The best COVID-19 diagnostic test can usually detect the virus four days after someone has been infected – so, four days into the incubation period.
“Prior to that time, unfortunately, we really don’t have a reliable test.”
As COVID-19 cases and hospitalizations spike in Texas, and as Gov. Greg Abbott responds with more restrictions on businesses, what can we expect for public life in the near future?
The new coronavirus is “highly virulent and highly infectious,” Campbell said. That means it’s unlikely that we’ll be able to get back to normal life until there’s vaccine.
“I would like to be more optimistic about making more strides toward a normal economy, but I can’t see that that’s a short-term possibility.”
Note: The following question has been updated to include more recent medical findings.
What risks does COVID-19 pose to pregnant women?
Data from Wuhan, China, where the pandemic started, showed that the virus can be passed from mother to child. Three out of 33 children in one study contracted the disease from their mother; all survived but one needed intensive medical care. But a more recent study of over 400,000 women in the U.S., indicated that pregnant women are more likely to experience severe COVID-19 symptoms than women who are not pregnant. The COVID-19 vaccine is now recommended during pregnancy, and for lactating mothers.
Should we be concerned about getting the virus from prepared food?
s long as cooks and restaurant workers follow regular standards for food preparation, ordering takeout is generally safe. The only risk would be if someone were to cough or sneeze into the food; the virus could theoretically survive and be transmitted to the customer. But that likelihood goes down even more if the food is heated.
Teens might face less risk for COVID-19 because of their age, but what about those with virus-induced asthma?
Asthma is a serious condition, and anyone who experiences wheezing should seek medical care immediately – even young people. Young people with underlying health conditions have died from COVID-19, Campbell said.
The spread of viruses sometimes slows in summer because of the heat. Will that be the case this year with the coronavirus?
The influenza virus, for example, tends to spread more slowly in summer. But Campbell said that doesn’t seem to be the case with the new coronavirus; it is currently spreading in warm-weather countries. And when cold weather sets in again later this year, Campbell worries the regular flu season will compound existing problems associated with the COVID-19 pandemic.
How should Texans conduct themselves now that the state is starting to reopen? Have we “flattened the curve”?
Follow closely the guidance from public health officials even as businesses start to reopen; Campbell said public health expertise is more important than ever right now because the number of cases and deaths are still rising in Texas.
“As someone who respects the opinion of experts in controlling what has been a very, very dangerous kind of situation … it would be important to follow the recommendations of experts in waiting at least a two-week period of time with decreasing cases before we would consider the situation in the community to be safe,” Campbell said.
How do you convince someone about the risks of COVID-19 if they don’t believe they’ll get sick and aren’t taking safety precautions like social distancing?
The risk is real. COVID-19 has infected over 1 million people and killed thousands in the United States alone. In light of that, Campbell said all Americans “must consider the consequences of their behavior.”
How important is individual behavior versus government intervention when it comes to slowing the spread of the coronavirus?
It’s a mix. When people practice social distancing, that helps flatten the curve – in other words, it slows how quickly the virus spreads. But when the government removes restrictions, individual behavior starts to change back toward activities that could put their health, and public health, at risk. Campbell said that with fewer restrictions, Texas faces another spike in COVID-19 cases.
Is it safe to get a haircut once restrictions on salons and barbershops are lifted?
Until a vaccine or treatment is available, getting a haircut is risky. Regular testing could help customers make an informed decision about when and where to get their hair cut, but Campbell says “we are far from that at the present time.”
Should business owners always take patrons’ temperatures, and should people avoid businesses where temperatures are not taken?
Campbell said he would insist that business owners take customers’ temperatures before entering an establishment because it reduces the statistical likelihood that an infected person would pass the virus to someone.
Is it safe to send kids back to youth sports this summer?
There’s no guarantee that children are safe from COVID-19, especially if they go back to group activities where it’s harder to practice social distancing. Many kids who get the disease don’t have symptoms, or only mild symptoms. But in rare instances they can develop multisystem inflammatory syndrome in children, or MIS-C. Meanwhile, they can spread the coronavirus to other more vulnerable people like the elderly or those with compromised immune systems.
Though social-distancing practices and precautions like masks are important for everyone to follow, Campbell said adults need to model that behavior so that kids follow suit.
How can a parent tell if it’s safe to send kids to summer camp? Should they even go?
Look for camps that keep kids in small, isolated groups.
“That minimizes exposure,” Campbell said.
Also look for camps that follow masking and other social-distancing guidelines.
But participating in any group activity right now means that kids will be more susceptible to the coronavirus, and more likely to spread it to others when they return home.
Should I self-quarantine if I came in contact with someone who recently traveled by airplane?
A self-imposed 10- to 14-day quarantine is a good idea when coming into contact with someone who’s recently been in higher-risk situation like air travel. That’s because at least 25% of people who get the coronavirus don’t show any symptoms. Campbell said that despite airlines’ assurances that they’re making adjustments to protect passengers’ health, air travel still puts passengers at greater risk for contracting COVID-19.
In general, how safe is it to be out in public right now?
Campbell said outside spaces are safer than inside ones when it comes to the coronavirus. When inside, it’s important to wear a mask to prevent spreading the virus. That even applies when working out at a gym, for instance. But even when outside, if you’re spending time in closer proximity to others, you need to wear a mask.
“There are a lot of things that apply to being inside, I think, that could be a whole lot stricter than outside. But still, social distancing is very important.”
Is it safe right now for kids to play with their neighborhood friends?
Exercise and play is crucial for kids, so if they are playing with others during the pandemic it’s best for them to do it outside. But they are still at risk for getting the virus, especially if they aren’t practicing social distancing or wearing masks. And when it comes to whether they play in the yard or a swimming pool, Campbell said it isn’t so much about where they play but how.
“Somebody that goes out and swims laps probably is at low risk. [But] people maybe playing games or in very close quarters … need to be concerned about acquiring the virus, even outside.”
Do the protests put people at greater risk of contracting COVID-19, even if they’re outside?
Masks do help, but they only provide some protection against the coronavirus. It can still spread between people, even those who don’t show symptoms, and especially when they’re less than 6 feet apart.
“The larger the protest and the more confined the area is where the protests are being conducted will increase the likelihood of acquisition of the virus.”
Campbell said he expects another spike in positive COVID-19 cases and deaths soon, not only because of the protests, but because people are gathering again as the state reopens.
Do you always develop antibodies after a COVID-19 infection? And can those antibodies be used to create a vaccine?
People with healthy immune systems develop antibodies to the disease. Some of those antibodies are “neutralizing” ones, which means they attack the coronavirus, and they theoretically could be used in vaccine development. But not all antibodies are neutralizing.
Do you need to sanitize groceries after bringing them home from the store?
Remove food packaging when possible – you can even wipe down packaging with disinfectant wipes or a sanitizing solution. And don’t forget to thoroughly rinse produce before eating it.
How effective are homemade cloth face masks?
Masks do help prevent the transmission of the coronavirus through a cough or sneeze, especially if they’re made of a thicker material like denim. But Campbell said they’re not a silver bullet; they’re most effective when combined with other preventive behaviors like social distancing and hand-washing.
How do you know if there are COVID-19 cases in your neighborhood?
It’s difficult to know who has the disease, or who might have it but not have symptoms. Campbell said there are lots of cases in more dense, urban areas, but smaller cities and rural areas have cases too. Regardless of where you live, assume you can get the disease from anyone; take precaution with a mask, hand-washing and social distancing.
Are gloves useful?
Gloves are used by medical workers, especially those working with COVID-19 patients. But they’re not especially helpful for the general public. Campbell said they may even give someone a “false sense of security” that they’re safe from the coronavirus; it can still be transmitted if they touch their face with a contaminated glove. Instead of relying on gloves for protection, he said regular hand-washing with soap and water is best.
Can freezing food packaging kill the coronavirus?
In theory, it could work, but without research Campbell can’t say for certain. Instead, he said, if you’re concerned about contaminated packaging you can clean it with a diluted bleach solution.
Can zinc supplements boost your immune system to make your body less susceptible to the coronavirus?
There have been many unsubstantiated claims of coronavirus “cures” since the pandemic started, which can endanger the lives of people who take those claims seriously. Campbell said zinc supplements haven’t been tested to see if they help fight off a new coronavirus infection, so taking one could give someone a “false sense of security.”
How can someone protect themselves if someone in their household isn’t practicing social distancing and insists it’s safe to go out without a mask?
Campbell said living with a person who engages in “reckless” behavior with regard to the virus puts everyone in the residence, including those most vulnerable to infection, at risk.
“Virtually everyone will develop the infection if they’re exposed long enough,” Campbell said.
Does the annual flu shot or the pneumonia vaccine help protect against COVID-19?
Flu shots need to be repeated annually because flu viruses change every year, so that vaccine wouldn’t make someone immune to the new coronavirus. As for the pneumonia vaccine, it protects against a bacteria, not a virus, so it also wouldn’t protect against COVID-19.
“I don’t see a chance, unfortunately, of cross-immunization.”
Symptoms and Treatment
Speaking of vaccines, how long until one is available?
Experts at the National Institutes of Health say an approved vaccine could be available by early 2021. But we won’t see the benefits until large numbers of people are vaccinated. Nor will we know exactly how effective it is until it’s used on a large scale. Still, Campbell says expecting a vaccine by early next year is realistic.
“The idea of being able to expect an effective vaccine at the first of the year makes a whole lot of sense,” he said.
Are so-called viral loads different in asymptomatic versus symptomatic people with COVID-19? And does that even matter when it comes to treatment?
Knowing a person’s “viral load” – the amount of a virus in someone’s blood – is essential for treating and monitoring people with HIV or hepatitis C, for example. But since COVID-19 is not a chronic illness, as far as we know, viral load might not matter as much.
“COVID-19, being a more acute situation, wouldn’t necessarily be aided by knowing things like viral loads,” Campbell said.
What is the drug ivermectin, and does it help with COVID-19?
Ivermectin is normally used to treat parasitic infections in humans and animals. There’s some research into its possible use for treating COVID-19, but nothing has yet been proven. Campbell says it’s one of many treatments that people tout as a possible cure, without evidence.
“I can’t think of a situation where ivermectin has been helpful for something similar to COVID-19.”
What’s the latest news about asymptomatic carriers of the coronavirus?
Researchers are learning new things every day about the coronavirus and COVID-19. Campbell says it’s possible that almost half of people with COVID-19 might never have symptoms. And for those who do develop symptoms, they are most likely to spread the virus during the 24 hours before those symptoms appear.
“[It’s] a very, very high-risk time for transmitting that virus to other people.”
That means nothing has really changed in terms of protecting yourself from getting the virus. Maintain social distance, wear a mask in public and wash your hands frequently.
How do I tell the difference between allergies and COVID-19?
Some individuals have experienced a COVID-19 infection with symptoms similar to allergies – that includes a stuffy nose or a mild cough – without “red flag” symptoms, which are a fever of 100 degrees or more, shortness of breath or a severe dry cough. Sneezing is a possible symptom of COVID-19, but it’s more closely associated with other illnesses. In mild cases of COVID-19, it may be difficult to distinguish it from allergies. But doctors only recommend seeking medical attention if you experience the more severe, red flag symptoms.
Is it possible to have contracted COVID-19 in the United States before the start of the pandemic? What if I, or someone I know, had symptoms as early as the beginning of February?
It’s possible, but unlikely, because the new coronavirus is believed to have originated in China in late 2019 and spread from there. It’s more likely that such a person had the seasonal flu.
Can over-the-counter medication exacerbate COVID-19 symptoms?
There is no evidence that common medicines used for pain, inflammation or fever, like ibuprofen, will cause an adverse reaction in someone with COVID-19.
When it comes to treatment for COVID-19, what are the options for people who have tested positive but have only mild or moderate symptoms?
Pain relievers like Tylenol or ibuprofen can help with the fever and body aches. But Campbell said check with your doctor first if you have other health conditions like kidney disease that might require a different approach.
Why is temperature-taking done so often when it can’t identify asymptomatic carriers or someone in the early stages of a COVID-19 infection?
Public health workers often take a person’s temperature when interacting with them in a high-risk situation. In those cases, having a fever makes an individual statistically more likely to be infected with COVID-19.
“Quite often we take temperatures in situations that are very high risk where individuals could rapidly spread the infection,” he said.
But having a normal temperature doesn’t indicate, definitively, that an individual is free of the coronavirus.
If a person has mostly complied with stay-at-home orders, worn a mask when going to the grocery store and otherwise followed health guidelines, what’s the appropriate response to feeling a little under the weather? Should they ride it out or seek medical attention?
Many cases of COVID-19 are not fatal, or even serious. But it’s difficult to predict which people who become infected are likely to develop a severe case, based on initial symptoms.
“Look for red flag problems … [including] shortness of breath, or if there’s a possibility of doing an oxygen percentage [test], which could be done either at home or in a doctor’s office,” Campbell said.
An oxygen percentage below 90% is a significant symptom, and would require immediate medical attention. Absent severe symptoms, COVID-19 looks like a lot of other infections, including influenza.
“But I would always err on the side of contacting health professionals,” Campbell said.
It’s particularly important to seek help if you have chronic heart, lung or kidney disease, or are elderly, and experience COVID-19 symptoms.
How can someone measure their blood oxygen level? Are phone apps a good method?
Campbell suggested seeking a test from a health professional instead of relying on an app. Tests can be done quickly and easily at a doctor’s office.
“Actually, for people [who] are very, very high risk, like people who already have chronic, severe lung disease, what’s called [a] pulse oximeter is available for purchase at about $40, and would be an excellent tool for those already chronically ill people,” Campbell said.
Once someone tests positive for COVID-19, what is the criteria for their release from self-quarantine or the hospital?
The medical community is using information from China’s epidemic to determine how to handle this situation. Campbell said Chinese patients could leave the hospital after symptoms improved and they had no fever for about three days. They also needed to have had two negative COVID-19 tests at least two days apart. And even after release, they still need to practice social distancing and wear masks, just like the general public. In the United States, however, the testing pipeline is strained, so it’s harder to determine quickly whether someone is suitable for release.
Can you contract COVID-19, recover, and then contract it again?
Data concerning this question is limited for COVID-19. However, it’s unusual for people who have contracted influenza, or other coronaviruses – the common cold is one – to relapse once they are completely over the illness. It is possible though, particularly for people who have a compromised immune system.
Are those who’ve recovered from COVID-19 still able to spread the disease?
It’s unclear the degree to which the “recovered” population could still be infectious. The best way to tell is through antibody testing, which is still limited but growing in availability. Campbell said eventually, patients who have recovered might be able to share their antibodies with those who are sick through blood plasma donation.
Are there tests to determine whether people who’ve had COVID-19 have developed antibodies that protect them from the disease in the future?
Antibody tests are starting to emerge for the new coronavirus, and they will become even more important as the pandemic continues. They could help determine who should self-quarantine and who is safe to move about. They could also help initiate donations of plasma from those with antibodies to help others fighting the disease. The efficacy of plasma donation is currently being evaluated by researchers.
How effective are ventilators at helping COVID-19 patients?
Efficacy depends on whether a patient has other medical conditions in addition to COVID-19. Some otherwise healthy patients have died even after reaching a point when they needed a ventilator. But the people who seem to have the greatest risk of dying once the disease is severe enough to need intubation and a ventilator are those with kidney, heart or lung diseases, cancer and the elderly. Without a cure for COVID-19, ventilators can only help so much by aiding a patient’s breathing.
Without a vaccine, how can we be sure that the pandemic has passed?
Based on past outbreaks and epidemics, there could be a “rebound effect” if life goes back to normal without a cure. There might be a dip in the number of new cases during the summer because of warmer weather, but they could spike again when temperatures drop.
In light of reports from South Korea, how common is it for someone to recover from COVID-19 and then become reinfected with the coronavirus – and does that have any implication for vaccine development?
It is possible to become reinfected with the coronavirus after recovering from COVID-19. As for vaccines, antibodies the immune system produces after a vaccination could potentially protect against reinfection. But since COVID-19 vaccines are still in development, Campbell said it’s unclear how much antibody is needed for a protective effect. Existing vaccines for other diseases often keep people immune for months or even years, but it’s too soon to tell in this case.
When is someone without symptoms, who tested positive for COVID-19, no longer contagious?
After a 14-day quarantine, that person should no longer be contagious.
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