Clinical Questions about COVID-19: Questions and Answers

Currently, those at greatest risk of infection are persons who have had prolonged, unprotected close contact (i.e., within 6 feet for 15 minutes or longer) with a patient with confirmed SARS-CoV-2 infection, regardless of whether the patient has symptoms. Persons frequently in congregate settings (e.g., homeless shelters, assisted living facilities, college or university dormitories) are at increased risk of acquiring infection because of the increased likelihood of close contact. Those who live in or have recently been to areas with sustained transmission may also be at higher risk of infection. All persons can reduce the risk to themselves and others by wearing a mask, practicing physical distancing, washing their hands often, and taking other prevention measures. For more information, see Risk Assessment and Your Health.

Among adults, the risk for severe illness from COVID-19 increases with age, with older adults at highest risk. Severe illness means that the person with COVID-19 may require hospitalization, intensive care, or a ventilator to help them breathe, or they may even die. People of any age with certain underlying medical conditions are also at increased risk for severe illness from SARS-CoV-2 infection.

CDC continues to investigate multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19. Children and adolescents with MIS-C have presented with a persistent fever and a variety of signs and symptoms including involvement of multiple organs (e.g., cardiac, gastrointestinal, renal, hematologic, dermatologic, neurologic) and elevated inflammatory markers. CDC is collaborating with domestic and international partners to better understand this new syndrome, including how common it is and its risk factors. For more information, including a full case definition and how to report MIS-C to your health department, visit MIS-C Information for Healthcare Providers.

Some CDC infection prevention and control recommendations for healthcare settings are based on Community Transmission levels. In general, healthcare facilities should consider checking their local Community Transmission level weekly. When a healthcare facility’s Community Transmission level increases and the increase results in a change in the recommended interventions, the new interventions should be implemented as soon as possible. When a healthcare facility’s Community Transmission levels decrease into a category that corresponds with relaxation of an intervention, facilities should consider confirming the reduction is sustained, by monitoring for at least two weeks, before relaxing the intervention.

In situations where the use of a respirator is not required either by the employer or by an Occupational Safety and Health Administration (OSHA) standard, the employer may still offer filtering facepiece respirators or permit employees to use their own respirators as long as the employer determines that such respirator use will not in itself create a hazard. This is considered voluntary use under the Respiratory Protection Standard. CDC encourages employers to permit workers to voluntarily use filtering facepiece respirators like N95s. If an employer allows voluntary use of filtering facepiece respirators, the employer must provide users with 29 CFR 1910.134 Appendix D – Information for Employees Using Respirators When Not Required Under the Standard. See 29 CFR 1910.134(c)(2) for additional requirements applicable to voluntary respirator use.

Healthcare personnel, both paid and unpaid, should be allowed to bring their own highly protective masks (such as N95 respirators) as long as the mask does not violate the facility’s safety and health requirements. They should not be asked to remove their more protective source control device (a well-fitting N95 respirator, for example) for a less protective device (such as a procedure mask) unless the mask or respirator is visibly soiled, damaged, or hard to breathe through. However, devices brought from home may not be appropriate for protecting healthcare personnel from all job hazards, and they should change to recommended personal protective equipment when indicated (for instance, before entering the room of a patient managed with Transmission-Based Precautions). Learn more about the types of masks and respirators and infection control recommendations for healthcare personnel.

CDC recommends that people visiting healthcare facilities use the most protective form of source control (masks or respirators) that fits well and will be worn consistently. Healthcare facilities may choose to offer well-fitting facemasks as a source control option for visitors but should allow the use of a clean mask or respirator with higher level protection by people who chose that option based on their individual preference.  Masks and respirators used for source control should be changed if they become visibly soiled, damaged, or hard to breathe through. Learn more about the types of masks and respirators and infection control recommendations for healthcare personnel.

CDC’s guidance to use NIOSH-approved particulate respirators with N95 filters or higher when providing care for patients with suspected or confirmed SARS-CoV-2 infection is based on the current understanding of SARS-CoV-2 and related respiratory viruses.  Current knowledge about modes of SARS-CoV-2 transmission are described in the Scientific Brief: SARS-CoV-2 Transmission.

Facemasks commonly used during surgical procedures will provide barrier protection against droplet sprays contacting mucous membranes of the nose and mouth, but they are not designed to protect wearers from inhaling small particles. NIOSH-approved particulate respirators with N95 filters or higher, such as other disposable filtering facepiece respirators, powered air-purifying respirators (PAPRs), and elastomeric respirators, provide both barrier and respiratory protection because of their fit and filtration characteristics.

Respirators should be used as part of a respiratory protection program that provides staff with medical evaluations, training, and fit testing.

Although facemasks are routinely used for the care of patients with common viral respiratory infections, NIOSH-approved particulate respirators with N95 filters or higher are routinely recommended for emerging pathogens like SARS CoV-2, which have the potential for transmission via small particles, the ability to cause severe infections, and limited or no treatment options. While the situation is evolving for SARS-CoV-2, CDC continues to recommend respiratory protection while the impact of new variants is being assessed.

In general, transport and movement of a patient with suspected or confirmed SARS-CoV-2 infection outside of their room should be limited to medically essential purposes. If being transported outside of the room, such as to radiology, healthcare personnel (HCP) in the receiving area should be notified in advance of transporting the patient. For transport, the patient should wear a well-fitting source control (if tolerated) to contain secretions and their body should be covered with a clean sheet.

If transport personnel must prepare the patient for transport (e.g., transfer them to the wheelchair or gurney), transport personnel should wear all recommended PPE (gloves, a gown, a NIOSH-approved particulate respirator with N95 filters or higher, and eye protection [i.e., goggles or disposable face shield that covers the front and sides of the face]). This is recommended because these interactions typically involve close, often face-to-face, contact with the patient in an enclosed space (e.g., patient room). Once the patient has been transferred to the wheelchair or gurney (and prior to exiting the room), transporters should remove their gown and gloves and perform hand hygiene.

The transporter should continue to wear their respirator. The transporter should also continue to use eye protection  if there is potential that the patient might not be able to tolerate their well-fitting source control device for the duration of transport. Additional PPE should not be required unless there is an anticipated need to provide medical assistance during transport (e.g., helping the patient replace a dislodged facemask).

After arrival at their destination, receiving personnel (e.g., in radiology) and the transporter (if assisting with transfer) should perform hand hygiene and wear all recommended PPE. If still wearing their original respirator and eye protection, the transporter should take care to avoid self-contamination when donning the remainder of the recommended PPE. This cautious approach will be refined and updated as more information becomes available and as response needs change in the United States.

EMS personnel should wear all recommended PPE because they are providing direct medical care and are in close contact with the patient for longer periods of time.

In general, minimize the number of personnel entering the room of patients who have SARS-CoV-2 infection. Healthcare facilities should consider assigning daily cleaning and disinfection of high-touch surfaces to nursing personnel who will already be in the room providing care to the patient. If this responsibility is assigned to EVS personnel, they should wear all recommended PPE when in the room. PPE should be removed upon leaving the room, immediately followed by performance of hand hygiene.

After discharge, terminal cleaning can be performed by EVS personnel. If not wearing all recommended PPE, they should delay entry into the room until time has elapsed for enough air changes to remove potentially infectious particles. After this time has elapsed, EVS personnel can enter the room and should wear  a gown and gloves when performing terminal cleaning; well-fitting source control might also be recommended. Eye protection and a facemask (if not already worn for source control) should be added if splashes or sprays during cleaning and disinfection activities are anticipated or otherwise required based on the selected cleaning products. Shoe covers are not recommended at this time for SARS-CoV-2.

Some procedures performed on patients are more likely to generate higher concentrations of infectious respiratory aerosols than coughing, sneezing, talking, or breathing. These aerosol generating procedures (AGPs) potentially put healthcare personnel and others at an increased risk for pathogen exposure and infection.

Development of a comprehensive list of AGPs for healthcare settings has not been possible, due to limitations in available data on which procedures may generate potentially infectious aerosols and the challenges in determining if reported transmissions during AGPs are due to aerosols or other exposures.

There is neither expert consensus, nor sufficient supporting data, to create a definitive and comprehensive list of AGPs for healthcare settings.

Commonly performed medical procedures that are often considered AGPs, or that might create uncontrolled respiratory secretions, include:

• open suctioning of airways
• sputum induction
• cardiopulmonary resuscitation
• endotracheal intubation and extubation
• non-invasive ventilation (e.g., BiPAP, CPAP)
• bronchoscopy
• manual ventilation

Based on limited available data, it is uncertain whether aerosols generated from some procedures may be infectious, such as:

• nebulizer administration*
• high flow O2 delivery

*Aerosols generated by nebulizers are derived from medication in the nebulizer. It is uncertain whether potential associations between performing this common procedure and increased risk of infection might be due to aerosols generated by the procedure or due to increased contact between those administering the nebulized medication and infected patients.

References related to aerosol generating procedures:

Tran K, Cimon K, Severn M, Pessoa-Silva CL, Conly J (2012) Aerosol Generating Procedures and Risk of Transmission of Acute Respiratory Infections to Healthcare Workers: A Systematic Review. PLoS ONE 7(4); https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338532/#!po=72.2222external iconexternal icon).

The amount of time that the air inside an examination room remains potentially infectious depends on a number of factors including the size of the room, the number of air changes per hour, how long the patient was in the room, if the patient was coughing or sneezing, and if an aerosol-generating procedure was performed.

In general, it is recommended to restrict HCP and patients without PPE from entering the room until sufficient time has elapsed for enough air changes to remove potentially infectious particles.

General guidance is available on clearance rates under differing ventilation conditions.

In addition to ensuring sufficient time for enough air changes to remove potentially infectious particles, HCP should clean and disinfect environmental surfaces and shared equipment before the room is used for another patient.

Preprocedural mouth rinses (PPMR) with an antimicrobial product (e.g. chlorhexidine gluconate, povidone-iodine) have been shown to reduce the level of oral microorganisms in aerosols and spatter generated during dental procedures. Evidence from recent studies suggest that some PPMR solutions are efficacious and may temporarily decrease the viral load of SARS-CoV-2 in the oral cavity. Targeted clinical studies are currently underway to learn more about the potential role of PPMR and the prevention of SARS-CoV-2 transmission.

Because more research is needed to demonstrate the effectiveness of PPMR in preventing transmission of SARS-CoV-2 in the dental setting, CDC does not provide a recommendation for or against the use of PPMR before dental procedures. However, if PPMR are used before dental procedures, they should be used as an adjunct to other infection prevention and control measures recommended to decrease the spread of infectious diseases in dental settings. Such measures include delaying elective dental procedures for patients with suspected or confirmed SARS-CoV-2 infection until they are no longer infectious or for patients who meet criteria for quarantine until they complete quarantine.

• Clinicians are able to access laboratory testing through state and local public health laboratories, as well as commercial and clinical laboratories across the country. The Association of Public Health Laboratories provides a list of states and territories with laboratories that are using COVID-19 viral tests. For more information, see Testing in U.S. Clinicians should direct testing questions to their state health departments. Commercial reference laboratories are also able to offer a larger volume of testing for SARS-CoV-2.
• CDC has guidance for who should be tested, but decisions about testing are at the discretion of state and local health departments and/or individual clinicians.
• Healthcare providers should report positive  results to their local/state health department CDC does not directly collect these data directly.

Yes. There are commercially developed respiratory panels with multi-pathogen molecular assays that can detect respiratory pathogens, including SARS-CoV-2, influenza, and other human coronaviruses that can cause acute respiratory illness. The U.S. Food and Drug Administration (FDA) maintains a list of tests that includes viral tests with Emergency Use Authorization (EUA).

Patients can be infected with more than one virus at the same time. Coinfections with other respiratory viruses in people with COVID-19 have been reported. Therefore, identifying infection with one respiratory virus does not exclude SARS-CoV-2 virus infection.

Clinicians considering use of chest CT scans for diagnosis or management of COVID-19 patients should consider whether such imaging will change clinical management. The American College of Radiology (ACR) recommends that CT should not be used to screen for COVID-19, or as a first-line test to diagnose COVID-19, and that CT should be used sparingly and reserved for hospitalized, symptomatic patients with specific clinical indications for CT. Appropriate infection control procedures should be followed before scanning subsequent patients. For more information see, ACR Recommendations for the use of Chest Radiography and Computed Tomography (CT) for Suspected COVID-19 Infectionexternal icon.

Healthcare providers should immediately notify infection control personnel at their facility if they suspect COVID-19 in a patient. If a patient tests positive, providers should report that positive result to their local/state health department.

Patients with MIS-C have presented with a persistent fever and a variety of signs and symptoms including multiorgan (e.g., cardiac, gastrointestinal, renal, hematologic, dermatologic, neurologic) involvement and elevated inflammatory markers. Not all children will have the same symptoms. For children who may have MIS-C, further evaluation for signs of this syndrome may include (but are not limited to) chest radiograph, echocardiography, and blood testing to evaluate for evidence of inflammation.

Healthcare providers who have cared or are caring for patients younger than 21 years of age meeting MIS-C criteria should report suspected cases to their local, state, or territorial health department. After hour phone numbers for health departments are available at the Council of State and Territorial Epidemiologists website.  For additional reporting questions, please contact CDC’s 24-hour Emergency Operations Center at 770-488-7100. For more information, including a full case definition, please visit MIS-C Information for Healthcare Providers.

There is currently no FDA-approved post-exposure prophylaxis for people who may have been exposed to COVID-19. For information about registered clinical trials of investigational therapeutics for pre- or post-exposure prophylaxis of SARS-CoV-2 infection, visit ClinicalTrials.gov.

For more information on movement restrictions, monitoring for symptoms, and evaluation after possible exposure to COVID-19, see Interim US Guidance for Risk Assessment and Public Health Management of Persons with Potential Coronavirus Disease 2019 (COVID-19) Exposure in Travel-associated or Community Settings and Interim U.S Guidance for Risk Assessment and Public Health Management of Healthcare Personnel with Potential Exposure in a Healthcare Setting to Patients with Coronavirus Disease 2019 (COVID-19).

The National Institutes of Health recently published guidelines on prophylaxis use for COVID-19 and testing and management of COVID-19 patients. For more information, please visit: National Institutes of Health: Coronavirus Disease 2019 (COVID-19) Treatment Guidelines.

Not all patients with COVID-19 will require medical supportive care. Clinical management for hospitalized patients with COVID-19 is focused on supportive care for complications, including supplemental oxygen and advanced organ support for respiratory failure, septic shock, and multi-organ failure. Empiric testing and treatment for other viral or bacterial etiologies may be warranted.

The National Institutes of Health has published interim guidelines for the medical management of COVID-19 prepared by the COVID-19 Treatment Guidelines Panel.

For information on investigational therapies, see Therapeutic Options for Patients with COVID-19.

Not all patients with COVID-19 require hospital admission. Patients whose clinical presentation warrants in-patient clinical management for supportive medical care should be admitted to the hospital under appropriate Transmission-Based Precautions.

Some patients with initial mild clinical presentation may worsen in the second week of illness. The decision to monitor these patients in the inpatient or outpatient setting should be made on a case-by-case basis. This decision will depend not only on the clinical presentation, but also on the patient’s ability to engage in self-monitoring, the feasibility of safe isolation at home, and the risk of transmission in the patient’s home environment. For more information, see Interim Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19) in a Healthcare Setting and Interim Guidance for Implementing Home Care of People Not Requiring Hospitalization for Coronavirus Disease 2019 (COVID-19).

References related to hospitalization and outcomes among patients with COVID-19:

Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506.

Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. JAMA 2020.

Dong Y, Mo X, Hu Y, et al. Epidemiology of COVID-19 Among Children in China. Pediatrics 2020.

Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72 314 Cases From the Chinese Center for Disease Control and Prevention. JAMA 2020.

Patients can be discharged from the healthcare facility whenever clinically indicated. Meeting criteria for discontinuation of Transmission-Based Precautions is not a prerequisite for discharge from a healthcare facility. Isolation should be maintained at home if the patient returns home before the time period recommended for discontinuation of hospital Transmission-Based Precautions.

Decisions to discontinue Transmission-Based Precautions or in-home isolation should be made according to the following guidance:

• For hospitalized persons, see Discontinuation of Transmission-Based Precautions and Disposition of Patients with SARS-CoV-2 Infection in Healthcare Settings.
• For non-hospitalized persons, see Interim Guidance for Implementing Home Care of People Not Requiring Hospitalization for COVID-19 and Discontinuation of Isolation for Persons with COVID-19 Not in Healthcare Settings.

Many recovered persons do not have detectable SARS-CoV-2 RNA in upper respiratory tract specimens. However, viral RNA can be persistently detected by reverse transcription polymerase chain reaction (RT-PCR) in respiratory tract samples in some persons after apparent clinical recovery.  In some persons, after testing negative by RT-PCR in two consecutive samples, later samples can test positive again. These persistent detections of viral RNA usually are associated with higher cycle threshold (Ct) values (i.e., fewer RNA copies) than Ct values found in RT-PCR results from samples collected shortly before or during clinical illness. Studies that have examined how long SARS-CoV-2 RNA can be detected in adults have demonstrated that, in some persons, it can be detected for weeks.

Whether the presence of detectable but low concentrations of viral RNA after clinical recovery represents the presence of potentially infectious virus is unknown. Based on experience with other viruses, it is unlikely that such persons pose an important infectious risk to others. However, whether this is true for SARS-CoV-2 infection has not been definitively established.

After the onset of illness, the detectable viral burden usually declines. After a week or more, anti-SARS-CoV-2 immunoglobulin becomes detectable and then antibody levels increase. Some of these antibodies may prevent the virus from infecting cells in cell culture. A decline in viral RNA is associated with a decreased ability to isolate live virus. For most patients with COVID-19, efforts to isolate live virus from upper respiratory tract specimens have been unsuccessful when specimens are collected more than 10 days after illness onset. Recovery of live virus between 10 and 20 days after symptom onset has been documented in some persons with severe COVID-19; in some cases, these persons were in an immunocompromised state.

Persons who have tested persistently or recurrently positive for SARS-CoV-2 RNA have, in some cases, had their signs and symptoms of COVID-19 improve. When viral isolation in tissue culture has been attempted in such persons in South Korea and the United States, live virus has not been isolated. There is no evidence to date that clinically recovered persons with persistent or recurrent detection of viral RNA have transmitted SARS-CoV-2 to others.

Despite these observations, it’s not possible to conclude that all persons with persistent or recurrent detection of SARS-CoV-2 RNA are no longer infectious. There is no firm evidence that the antibodies that develop in response to SARS-CoV-2 infection are protective. If these antibodies are protective, it’s not known what antibody levels are needed to  protect against reinfection.

These data and experience with other viral respiratory infections indicate that most persons recovered from COVID-19 who test persistently or recurrently positive by RT-PCR are likely no longer infectious. Isolation and precautions may be discontinued for persons with COVID-19  10 days after symptom onset (the date on which symptoms first began, including non-respiratory symptoms), provided their fever has resolved for at least 24 hours, without the use of fever-reducing medications, and their other symptoms have improved. For some persons with severe or critical illness, or who are severely immunocompromised, isolation and precautions may be maintained for up to 20 days after symptom onset.

No. Although attempts to culture virus from upper respiratory specimens have been largely unsuccessful when Ct values are in high but detectable ranges, Ct values are not a quantitative measure of viral burden. In addition, Ct values are not standardized by RT-PCR platform nor have they been approved by FDA for use in clinical management. CDC does not endorse or recommend use of Ct values to assess when a person is no longer infectious. However, serial Ct values may be useful in the context of the entire body of information available when assessing recovery and resolution of infection.

Prospectively collecting serial respiratory samples and attempting to isolate live virus in tissue culture from multiple persons testing positive by RT-PCR following illness recovery is needed. If repeated attempts to recover replication-competent virus in culture from such serial samples are unsuccessful, that data would be sufficient evidence that infectious virus is absent. Then we would be sure that persons continuing to test positive do not pose an infectious risk to others.

Yes. However, viral culture is not widely performed for SARS-CoV-2. It must be conducted in Biosafety Level 3 (BSL-3) laboratories using BSL-3 practices by experienced virologists and culture results can take a week or more. Therefore, while persons whose specimens do not yield live virus are considered no longer infectious, the complexity of such testing and the time required to complete it mean that culture cannot be used routinely to guide management of infected persons.

For persons who remain asymptomatic following recovery from COVID-19, retesting (e.g., as part of a contact tracing investigation) is not necessary during the first 3 months after the date of symptom onset. When a positive test occurs less than 3 months after the person’s symptom onset of their most recent illness, it is possible that the positive test represents a new infection or a persistently positive test associated with the previous infection. If a positive test occurs more than 3 months after a person’s symptom onset, clinicians and public health authorities should consider the possibility of reinfection. Until we have more information, the determination of whether a patient with a positive test in these situations is contagious to others should be made on a case-by-case basis. Consider consultation with infectious diseases specialists and public health authorities to review all available information (e.g., medical history, time from initial positive test, RT-PCR Ct values, and presence of COVID-19 signs or symptoms).  Persons who are determined to be potentially infectious should undergo evaluation and remain isolated until they again meet criteria for discontinuation of isolation or discontinuation of transmission-based precautions, depending on their circumstances.

If a previously infected person experiences new symptoms consistent with COVID-19 3 months or more after the date of the previous illness onset (or date of last positive viral diagnostic test [RT-PCR or antigen test] if the person never experienced symptoms), the person should undergo repeat viral diagnostic testing. However, serologic testing should not be used to establish the presence or absence of SARS-COV-2 infection or reinfection. These people who have a positive test result should be considered infectious and remain isolated until they again meet criteria for discontinuation of isolation or of transmission-based precautions. Contact tracing during the person’s second episode of symptoms is warranted.

For persons who have recovered from laboratory-confirmed SARS-CoV-2 infection and who experience new symptoms consistent with COVID-19 within 3 months since the date of symptom onset of the previous illness episode (or date of last positive viral diagnostic test if the person never experienced symptoms), repeating viral diagnostic testing may be warranted if alternative etiologies for the illness cannot be identified. If reinfection is suspected and retesting is undertaken, the person should follow isolation recommendations for cases of COVID-19 pending clinical evaluation and testing results. Results of repeat testing should also be interpreted in consultation with an infectious disease specialist with consideration of cycle threshold values (if available) and clinical presentations. The determination of whether a patient with a subsequently positive test is contagious to others should be made on a case-by-case basis, in consultation with infectious diseases specialists and/or public health authorities, after review of available information (e.g., medical history, time from initial positive test, RT-PCR Ct values, and presence of COVID-19 signs or symptoms).

Note: Serologic testing should not be used to establish the presence or absence of SARS-CoV-2 infection or reinfection.

If a person has clinically recovered from SARS-CoV-2 infection and is then identified as a contact of a new case 3 months or more after the date of symptom onset of their previous illness episode (or date of positive viral diagnostic test [RT-PCR or antigen test] if the person never experienced symptoms), then they should follow general quarantine recommendations for contacts and undergo repeat viral diagnostic testing.

The following applies to a person who has clinically recovered from  SARS-CoV-2 infection that was confirmed with a viral diagnostic test and then, within 3 months since the date of symptom onset of the previous illness episode (or date of positive viral diagnostic test if the person never experienced symptoms), is identified as a contact of a new case.  If the person remains asymptomatic since the new exposure, then they do not need to be retested for SARS-CoV-2 and do not need to be quarantined. However, if the person experiences new symptoms consistent with COVID-19 and an evaluation fails to identify a diagnosis other than SARS-CoV-2 infection (e.g., influenza), then repeat viral diagnostic testing may be warranted, in consultation with an infectious disease specialist and public health authorities for isolation guidance.

No. The symptom-based strategy is intended to replace the need for repeated testing.

Yes. It is recommended that all persons, with a few exceptions, wear cloth face coverings in public.¹ The primary purpose of cloth face coverings is to limit transmission of SARS-CoV-2 from infected persons who may be infectious but do not have clinical symptoms of illness or may have early or mild symptoms that they do not recognize. Cloth face coverings may provide reassurance to others in public settings and be a reminder of the need to maintain social distancing. However, cloth face coverings are not personal protective equipment (PPE) and should not be used instead of a respirator or a facemask to protect a healthcare worker.

[1] Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or anyone who is unconscious, incapacitated, or otherwise unable to remove the mask without assistance.

Although current understanding of reinfection remains limited, CDC is working with its partners to characterize the clinical features, transmissibility, and immunological profile around reinfection with SARS-CoV-2. Therefore, the guidance remains the same to reinfections as to primary infection with SARS-CoV-2. To further our shared understanding of reinfection, CDC has released the Investigative Criteria for Suspected Cases of SARS-CoV-2 Reinfection as well as the Common Investigation Protocol for Investigating Suspected SARS-CoV-2 Reinfection. This protocol is to support public health investigations conducted by interested institutions and jurisdictions. Clinicians with available specimens for suspected cases of reinfection meeting the above investigative criteria are also invited to contact CDC at eocevent461@cdc.gov after consulting with their local health department to pursue investigations with CDC support.

Several patients with COVID-19 have been reported to present with concurrent community-acquired bacterial pneumonia. Decisions to administer antibiotics to COVID-19 patients should be based on the likelihood of bacterial infection (community-acquired or hospital-acquired), illness severity, and antimicrobial stewardship issues. For more information, see Diagnosis and Treatment of Adults with Community-acquired Pneumonia: An Official Clinical Practice Guideline of the American Thoracic Society and Infectious Diseases Society of Americaexternal icon.

The National Institutes of Health (NIH) has published guidelines on testing and management of patients with COVID-19. For more information, please visit the NIH Coronavirus Disease 2019 (COVID-19) Treatment Guidelines. The recommendations are based on scientific evidence and expert opinion and are regularly updated as more data become available.

Current clinical management of COVID-19 includes infection prevention and control measures and supportive care, including supplemental oxygen and mechanical ventilatory support when indicated. The U.S. Food and Drug Administration (FDA) has approved one drug, remdesivir (Veklury), for the treatment of COVID-19 in certain situations.

Persons seeking information about registered clinical trials for COVID-19 in the United States can search for such information here: ClinicalTrials.gov.

For more information on investigational therapies, see Therapeutic Options for Patients with COVID-19.​

CDC is currently not aware of scientific evidence establishing a link between NSAIDs (e.g., ibuprofen, naproxen) and worsening of COVID‑19. FDAexternal icon, the European Medicines Agency, the World Health Organization, and CDC are continuing to monitor the situation and will review new information on the effects of NSAIDs and COVID-19 disease as it becomes available. For those who wish to use treatment options other than NSAIDs, there are other over-the-counter and prescription medications approved for pain relief and fever reduction. Patients who rely on NSAIDs to treat chronic conditions and have additional questions should speak to their healthcare provider for individualized management. Patients should use NSAIDs, and all medications, according to the product labels and advice of their healthcare professional.

People with moderate to severe asthma, particularly if not well controlled, might be at higher risk of getting very sick from COVID-19.

Based on what we currently know about COVID-19, the selection of therapeutic options through guideline-recommended treatment of asthma has not been affected. National asthma guidelines are available. Continuation of inhaled corticosteroids is particularly important for patients already using these medications because there is no evidence of increased risk of COVID-19 morbidity with use of inhaled corticosteroids and an abundance of data showing reduced risk of asthma exacerbation with maintenance of asthma controller therapy.

Patients with asthma but without symptoms or a diagnosis of COVID-19 should continue any required nebulizer treatments.

Selection of therapeutic options through guideline-recommended treatment of asthma exacerbations has not been affected by what we currently know about COVID-19.

Systemic corticosteroids should be used to treat an asthma exacerbation per national asthma guidelines and current standards of care, even if it is caused by COVID-19. Short-term use of systemic corticosteroids to treat asthma exacerbations should be continued. There is currently no evidence to suggest that short-term use of systemic corticosteroids to treat asthma exacerbations increases the risk of developing severe COVID-19, whereas there is an abundance of data to support use of systemic steroids for moderate or severe asthma exacerbations.

Patients with asthma but without symptoms or a diagnosis of COVID-19 should continue any required nebulizer for treatments, as recommended by national professional organizations, including the American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI). If healthcare providers need to be present during nebulizer use among patients who have either symptoms or a diagnosis of COVID-19, use CDC’s recommended precautions when performing aerosol-generating procedures (AGPs).

Clinicians may be concerned that an asthma exacerbation is related to an underlying infection with COVID-19. Clinicians can access laboratory testing for COVID-19 through a network of state and local public health laboratories across the country. Lists of states and territories with laboratories that are using COVID-19 viral tests are available. For more information, see Testing in U.S. Clinicians should direct testing questions to their state and local health departments.

Patients can be referred to CDC’s recommendations for caring for themselves or someone else at home sick with COVID-19.

If nebulizer use at home is necessary for patients with asthma who have symptoms or a diagnosis of COVID-19, use of the nebulizer in a location that minimizes and preferably avoids exposure to any other members of the household, and preferably a location where air is not recirculated into the home (like a porch, patio, or garage) is recommended by national professional organizations, including the American College of Allergy, Asthma & Immunology (ACAAI) by the ACAAI and the Allergy & Asthma Network (AAN). Limiting the number of people in the room or location where the nebulizer is used is also recommended by the Asthma & Allergy Foundation of America (AAFA). Nebulizers should be used and cleaned according to the manufacturer’s instructions.

If nebulizer use in a healthcare setting is necessary for patients who have either symptoms or a diagnosis of COVID-19, use CDC’s recommended precautions when performing aerosol-generating procedures (AGPs).

Many patients with severe illness from COVID-19 have underlying hypertension.¹ Hypertension is common in the United States. Hypertension is more frequent with advancing age and among non-Hispanic blacks and people with other underlying medical conditions such as obesity and diabetes. At this time, people whose only underlying medical condition is hypertension might be at increased risk  for severe illness from COVID-19.²

1. Garg S, Kim L, Whitaker M, et al. Hospitalization Rates and Characteristics of Patients Hospitalized with Laboratory-Confirmed Coronavirus Disease 2019 — COVID-NET, 14 States, March 1–30, 2020. MMWR Morb Mortal Wkly Rep 2020;69:458–464. DOI: http://dx.doi.org/10.15585/mmwr.mm6915e3.
2. Killerby ME, Link-Gelles R, Haight SC, et al. Characteristics Associated with Hospitalization Among Patients with COVID-19 — Metropolitan Atlanta, Georgia, March–April 2020. MMWR Morb Mortal Wkly Rep 2020;69:790–794. DOI: http://dx.doi.org/10.15585/mmwr.mm6925e1.

No. The American Heart Association, the Heart Failure Society of America, and the American College of Cardiology recommend continuing ACE-I or ARB medications for all patients already prescribed those medications for indications such as heart failure, hypertension, or ischemic heart disease. At this time, available evidence demonstrates no indication of COVID-specific harm from these agents. Several randomized controlled trials are under way to better answer this important clinical question. Cardiovascular disease patients diagnosed with COVID-19 should be fully evaluated by a healthcare professional before adding or removing any treatments, and any changes to their treatment should be based on the latest scientific evidence. Patients who rely on ACE-Is or ARBs to treat chronic conditions and have additional questions should speak to their healthcare provider for individualized management

Waste generated in the care of PUIs or patients with confirmed COVID-19 does not present additional considerations for wastewater disinfection in the United States. Coronaviruses are susceptible to the same disinfection conditions in community and healthcare settings as other viruses, so current disinfection conditions in wastewater treatment facilities are expected to be sufficient. This includes conditions for practices such as oxidation with hypochlorite (i.e., chlorine bleach) and peracetic acid, as well as inactivation using UV irradiation.

Wastewater workers should use standard practices including basic hygiene precautions and wear the recommended PPE as prescribed for their current work tasks when handling untreated waste. There is no evidence to suggest that employees of wastewater plants need any additional protections in relation to COVID-19.

Medical waste (trash) coming from healthcare facilities treating COVID-2019 patients is no different than waste coming from facilities without COVID-19 patients. CDC’s guidance states that management of laundry, food service utensils, and medical waste should be performed in accordance with routine procedures. There is no evidence to suggest that facility waste needs any additional disinfection.

More guidance about environmental infection control is available in section 7 of CDC’s Interim Infection Prevention and Control Recommendations for Patients with Confirmed COVID-19 or Persons Under Investigation for COVID-19 in Healthcare Settings.

Surfaces can become contaminated with microorganisms and potential pathogens. However, many of these surfaces are generally not directly associated with transmission of infections to either healthcare workers or patients.  The transfer of pathogens from environmental surfaces is largely due to hand contact with the surface (e.g., frequently touched surfaces). Touch contamination may lead to cross contamination of patient care items, other environmental surfaces, self-contamination, and possible infection after touching one’s face or mouth.

Both hand hygiene and the cleaning and disinfection of environmental surfaces are fundamental practices to reduce the incidence of healthcare-associated infections.

For more information see our guidelines for healthcare facilities that cover cleaning, disinfection, sterilization, and hand hygiene:

• Guideline for Environmental Infection Control, 2003
• Guideline for Disinfection and Sterilization, 2008
• Guideline for Hand Hygiene in Healthcare Settings

Cleaning is an important first step for any process that involves disinfection or sterilization because the presence of organic and inorganic soils may cause disinfection or sterilization to fail.  Cleaning is the process of removing both organic and inorganic matter from surfaces with the use of detergents (e.g., anionic, cationic, non-ionic, and zwitter ionic) or enzymatic cleaners.  Cleaning may involve manual, automated, or a combination of manual and automated methods.

• Depending on the cleaning method and the surface being cleaned, a 10²-10⁶ log reduction of microorganisms may be possible.
• Proper cleaning may be enough to make an environmental surface safe to handle and to prevent transmission of pathogens.
• Currently, no cleaning guidelines apply to all devices or surfaces, nor is there a single accepted standard method to measure the effectiveness of cleaning (examples include adenosine triphosphate (ATP), fluorescent markers, blood, protein, carbohydrate, RODAC^TM plates, or touch plates).
• See the CDC Environmental Toolkit for additional information on developing a cleaning evaluation program.

Many cleaners used in healthcare settings for routine cleaning of the general environment are cationic detergents, with many of these being quaternary ammonium compounds which are also low- to intermediate-level disinfectants. For EPA registered detergent disinfectants, refer to the label to determine if the product is a one-step or multiple-step product, and follow the product label instructions for use.

• One-step disinfection product and process combine cleaning and disinfection of a noncritical environmental surface or item into a single step. Depending on the instructions for product use, some do not have to be rinsed off.
• Multi-step products and processes require the user to clean the surface before it is disinfected. In some cases, the disinfectant must be rinsed from the surface following the wet contact time listed on the product label.

• Cleaning guidelines vary based on devices and surfaces being cleaned. Multiple methods are used to measure the residual bioburden or effectiveness of cleaning (e.g., ATP, fluorescent markers, blood, protein, carbohydrate, and RODAC^TM plates, or touch plates)
• See the CDC Environmental Toolkit for additional information on developing a cleaning evaluation program.

• No-touch devices (NTDs) are sometimes used in healthcare settings as an adjunct to terminal room cleaning (i.e., after patient discharge or transfer). They are not currently able to replace existing cleaning and disinfection processes. These devices use a variety of different disinfection technologies such as ultraviolet germicidal irradiation (UVGI) and chemical agents. They are called no-touch devices because they use a pre-determined program that allows the device to run unmanned in an unoccupied, pre-cleaned room (e.g., patient room) for a defined period.
• Chemical disinfectants used for NTDs vary according to the specific device. Examples include vapor phase hydrogen peroxide, dry mist hydrogen peroxide, combined hydrogen peroxide + antimicrobial silver, dry fog hydrogen peroxide + peroxyacetic acid, ionized hydrogen peroxide, and chlorine dioxide gas.
• The effectiveness of NTDs is still under investigation; most data are laboratory demonstrations of pathogen inactivation. Thus far, only one study of NTD use has shown a decrease in patient infection rates, the Duke BETR Disinfection Study (Andersen DJ, et al. Lancet Infect Dis 2018; 18(8): 845–853).

These devices are typically used as an adjunct technology to terminal room cleaning. This means that the patient has been transferred or discharged and is no longer occupying the space.  So that EVS may begin cleaning and disinfecting the room in preparation for a new patient (e.g., terminal cleaning).

For information about the application of EPA List N disinfectants with electrostatic sprayers and foggers, refer to the EPA’s Frequent Questions about Disinfectants and Coronavirus (COVID-19). If a product does not have an electrostatic spraying or fogging use on a label, the EPA has not evaluated the safety and efficacy of using that product with an electrostatic sprayer or a fogger.

• Foggers can be hand-held or no-touch devices (NTDs).
• When using an electrostatic sprayer or a fogger to apply disinfectants, always follow manufacturer directions for operation and maintenance of the sprayer or fogger and the disinfectant label’s use directions (e.g., application rate, distance to surface while applying, and contact time).
• Follow the disinfectant’s label recommendations for appropriate personal protective equipment (PPE) for the operator, and adhere to any recommended re-entry times for bystanders, other staff members, or patients.

• UVGI can be used as a supplemental treatment for disinfection of air in HVAC systems or above people in occupied spaces (upper-room or upper-air systems) and for supplemental disinfection of surfaces following routine cleaning and disinfection. UVGI, also known as Germicidal Ultraviolet (GUV), uses ultraviolet energy in the UV-C band (wavelengths of 220-280 nanometers), which is effective against SARS-CoV-2 under laboratory conditions. Efficacy of the applied dose (a function of irradiance and time) is highly dependent on many factors, such as the concentration of the virus, inoculum size (in experimental studies), the virus medium, contours and type of material being treated, as well as what the virus is suspended in (e.g., culture media, respiratory droplets, other proteinaceous material). These complex variables may explain the range of results presented in the published literature.
• For more information on these technologies see the CDC Business FAQs under the heading “Cleaning and Disinfection in the Workplace”
• UV-C can be applied on healthcare environmental surfaces using robots as NTDs following terminal cleaning and is still considered investigational; one study mentioned above the Duke BETR Disinfection Study (Andersen DJ, et al. Lancet Infect Dis 2018; 18(8): 845–853) has shown a decrease in Healthcare-associated infections.