Use of Chlorhexidine to Eradicate Oropharyngeal SARSCoV-2 in COVID-19 Patients

Research Article

J Fam Med. 2021; 8(2): 1243.

Use of Chlorhexidine to Eradicate Oropharyngeal SARSCoV-2 in COVID-19 Patients

Huang YH¹ and Huang JT²*

¹University of Southern California, Keck School of Medicine, USA

²Division of Infectious Diseases, Good Samaritan Hospital, USA

*Corresponding author: Jong T Huang, Division of Infectious Diseases, Good Samaritan Hospital, Los Angeles, California, USA

Received: February 13, 2021; Accepted: March 19, 2021; Published: March 26, 2021


Objective: As public distribution of a vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is in underway, prevention of coronavirus disease 2019 (COVID-19) relies on minimizing spread. In this study, chlorhexidine gluconate was investigated as a topical antimicrobial agent against SARS-CoV-2.

Methods: This was a randomized, prospective cohort study using chlorhexidine as an oral rinse and posterior oropharyngeal spray in hospitalized COVID-19 patients. The primary outcome was presence or absence of laboratory-confirmed SARS-CoV-2 in the oral and oropharyngeal cavities after four days of chlorhexidine use and standard of care (study group) or standard of care only (control group).

Results: SARS-CoV-2 was eliminated from the oropharynx in 62.1% of patients who used chlorhexidine as an oral rinse, versus 5.5% of the control group patients. In patients who used a combination of oral rinse and oropharyngeal spray, 86.0% eliminated oropharyngeal SARS-CoV-2, versus 6.3% of control patients.

Conclusions: Chlorhexidine is a simple and safe addition to current COVID-19 prevention guidelines and may play a significant role in reducing disease spread.

Keywords: SARS-CoV-2; COVID-19; Disinfectants


Since the emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, there have been over 105.4 million confirmed cases of coronavirus disease 2019 (COVID-19) worldwide resulting in over 2.3 million deaths [1,2]. In the absence of effective systemic antimicrobial agents, prophylaxis is crucial for disease control. The gold standard of epidemic disease prophylaxis is a combination of vaccine immunization, use of prophylactic antimicrobial agents, and isolation from the causal microorganism. As public distribution of a SARS-CoV-2 vaccine is in underway, prophylactic recommendations currently focus on isolation from the virus via social distancing, mask wearing, hand washing, and disease tracing [3]. There is emerging evidence that topical antimicrobial agents may also be useful in preventing the disease spread [4,5]. In this study, the authors investigated the use of chlorhexidine gluconate as an oropharyngeal antimicrobial agent against SARS-CoV-2 infection.

Materials and Methods

This was a prospective cohort study performed at four community hospitals in Los Angeles, CA. All patients were consented prior to their participation. Patients with COVID-19 infection between May 20, 2020, and December 15, 2020 who were admitted to the COVID-19 wards were identified. All COVID-19 diagnoses were confirmed via detection of SARS-CoV-2 in nasopharyngeal swab specimens by real-time reverse Transcription Polymerase Chain Reaction (rRT-PCR). The study population included patients who were able to follow instructions to use chlorhexidine as an oral rinse. Patients with nasogastric or endotracheal tubes placed were excluded from the study. Patients who were symptomatic for over a week prior to admission were also excluded.

From this population, patients were randomly assigned to the study and control groups. Both groups received the standard of care in their treatment plans. The study group was given chlorhexidine to use as an oropharyngeal rinse while the control group was not. For each administration of chlorhexidine, a unit dose cup containing ½ ounce (15 milliliters) of commercially available chlorhexidine gluconate (0.12%) was provided to each patient. Patients were then observed to self-administer the solution as a thorough oral rinse for 30 seconds twice a day. After 4 days, the oropharynx was swabbed and tested for the presence of SARS-CoV-2 by rRT-PCR.

Since an oral rinse alone would not reach the posterior oropharynx effectively, a chlorhexidine spray was added to the oral rinse regimen in the second study group. After the patient used chlorhexidine as an oral rinse as stated above, a provider used a spray applicator to deliver 3 sprays (a total of approximately 1.5 milliliters) of the chlorhexidine solution to the posterior oropharynx. To open the posterior pharynx, the patient was instructed to vocalize “ah” for 5 seconds while the solution was sprayed. This process was performed twice a day for 4 days. After four days of chlorhexidine administration, the oropharynx was swabbed and tested for presence of SARS-CoV-2 by rRT-PCR. A paired T-test was used to compare findings.


684 patients with positive SARS-CoV-2 infection were identified. The average onset of symptoms was 2-6 days prior to admission. Among the total study population, 294 patients were included in analysis, with 159 patients receiving chlorhexidine and 135 patients in the control group.

Oropharyngeal specimens after oral rinse only

A total of 121 patients were included in the analysis of using chlorhexidine as an oral rinse in COVID-19 patients (Table 1). Of the 66 patients in the chlorhexidine-treated group, 41 (62.1%) were found to be negative and 25 (37.9%) were found to be positive for SARS-CoV-2 in the oropharynx. On the same testing in the control group of 55 patients, 3 (5.5%) tested negative and 52 (94.6%) tested positive. The differences in the results were statistically significant between the two groups (P<0.01).

Citation:Huang YH and Huang JT. Use of Chlorhexidine to Eradicate Oropharyngeal SARS-CoV-2 in COVID-19 Patients. J Fam Med. 2021; 8(2): 1243.