Fear and Anxiety Caused by COVID-19 in the Iranian Society and the Influential Factors

authors:

avatar Hassan Bashiri 1 , avatar Fatemeh Dehghan 1 , avatar Rostam Jalali 1 , *

Department of Nursing, School of Nursing and Midwifery, Kermanshah University of Medical Sciences, Kermanshah, Iran

how to cite: Bashiri H, Dehghan F, Jalali R. Fear and Anxiety Caused by COVID-19 in the Iranian Society and the Influential Factors. J Kermanshah Univ Med Sci. 2021;25(4):e119855. https://doi.org/10.5812/jkums.119855.

Abstract

Background:

Due to the changing nature of the spread of emerging infectious diseases, such crises could cause significant fear, especially when the disease is associated with high mortality. Fear and anxiety adversely affect health.

Objectives:

The present study aimed to investigate the fear and anxiety caused by COVID-19 in the Iranian society and the influential factors in this regard.

Methods:

This correlational study was conducted on 458 participants who were recruited for an online survey. Data were collected using a researcher-made questionnaire of COVID-19 fear and Beck's anxiety inventory. Data analysis was performed in SPSS version 23 using descriptive statistics (frequency, percentage, mean, and standard deviation) and inferential statistics, including t-test and multiple comparisons.

Results:

The prevalence of fear and anxiety was less than 20%. The correlations between the anxiety scores and fear of COVID-19 with demographic variables indicated that the COVID-19 fear scores had a weak correlation with an appeal to religion and efforts to prevent COVID-19 (P ≤ 0.05), while no correlation was observed with the other variables. In addition, the anxiety scores had weak, inverse correlations with the effort to prevent COVID-19 and satisfaction with the government’s effort (P ≤ 0.05).

Conclusions:

According to the results, the fear of COVID-19 and the subsequent anxiety is mild in the Iranian society. Low anxiety and fear caused by the disease could lead to negligence and disregarding health standards, which will increase the number of these patients in the community.

1. Background

Attention to mental health following the outbreak of infectious diseases is rooted in history. In recent decades, special attention has been paid to the complex links between common anxiety, mood disorders, and infectious and viral diseases in medical sciences (1). Infectious diseases and mental health issues are considered a significant burden of disease globally (2).

Anxiety and mood disorders include generalized anxiety disorder, acute anxiety disorder, posttraumatic stress disorder (PTSD), fears, panic disorder, bipolar disorder, and other mood disorders (3). The main symptoms of anxiety and generalized anxiety include restlessness, premature fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance. These symptoms often manifest after traumatic events and are similar to the symptoms of PTSD (4). These symptoms occur after experiencing traumatic events such as death threats, severe injuries, or the death of another person. However, it is not only the nature of dealing with such events that leads to anxiety disorders, and the way an individual experiences a specific traumatic event could also cause anxiety. Such an example is exposure to natural disasters and life-threatening pandemics (5).

Previous studies have examined psychological trauma and the associated health consequences (6) and determined the possible mechanism of interaction between the mental state and other health conditions, such as infectious and non-communicable diseases (1), highlighting the importance of biological, social, and cultural factors. In the study of the correlation between the mental state and the underlying causes of death, several biological and behavioral pathways have been identified between mental health and viral diseases, which may differ depending on the type of these diseases. Anxiety and depression are associated with biological complications such as decreased cell-mediated immunity and increased inflammatory processes (7). Furthermore, other viral diseases have been reported to directly affect the brain, thereby leading to mood disorders and cognitive impairment (1). Illness anxiety has long been an issue in every community, and several cases have been reported during health crises such as SARS, Ebola, rubella, and even food poisoning with long-term effects (8-10).

In late December 2019, a new coronavirus, currently known as COVID-19, was reported in Wuhan, China, and spread worldwide (11). The diseases was declared a pandemic by the World Health Organization (WHO) on March 11, 2020 (12). Evidently, there is significant anxiety regarding this health crisis as the coronavirus could be fatal although its mortality rate is directly correlated with a weakened immune system. The rate of coronavirus transmission is extremely high, while the mortality rate is low. Global data indicate that 80% of COVID-19 patients show symptoms that do not require hospitalization. In other words, there is no need to panic about the disease. The estimated mortality rate of the coronavirus is 2% worldwide, while this rate was reported to be 9 - 12% for SARS; the comparison of these infections in terms of mortality rate could help generate new perspectives (13-15).

During the current COVID-19 pandemic, the risk of infection is rather high, and a greater understanding of the risk of the disease is associated with a number of behavioral responses that may indicate anxiety in individuals. Although the response to the H1N1 influenza pandemic has been investigated (14, 16-18), such investigations are scarce in the COVID-19 pandemic. Previous studies have evaluated anxiety disorders and their association with infectious diseases, while also discussing multiple bio-behavioral pathways to determine the correlation between mental health and viral diseases, as well as the specific mechanism of viral diseases. The findings of these studies indicate a direct, bivariate correlation between anxiety disorders and viral diseases. Fear of infection leads to anxiety, and anxiety reduces resistance to these diseases through weakening the immune function (19). Therefore, identifying the main influential factors in anxiety regarding viral diseases (especially COVID-19) could largely contribute to proper healthcare planning.

2. Objectives

The present study aimed to investigate the influential factors in the anxiety caused by COVID-19.

3. Methods

This correlational study was conducted on 458 men and women who completed a questionnaire of the influential factors in the anxiety caused by the coronavirus (social, economic, personal, and environmental factors) during March 15-April 15, 2020. The participants were selected from the general population and invited to partake in the study based on the inclusion criteria, which were willingness to participate, age of 15 - 70 years, and Iranian nationality.

The sample size of the study was determined to be 357 based on the Cochran formula with 95% confidence level and the P-value of 50%. Notably, 100 participants were added for more reliable results. Convenience sampling was performed by inviting people via social networks to complete the questionnaire using the provided link. The social networks were public, and the users were from different regions of Iran. The participants were those aged more than 15 years who had access to the internet and completed the questionnaire. They were asked to choose the closest choice to their perception from among the options.

The questionnaire consisted of three sections; the first section included demographic characteristics, economic status, social status, and belief status in 30 items. The second section contained Beck’s anxiety inventory with 21 items, each of which was scored from zero (none) to three (strongly). Scores 0 - 7 indicated minor anxiety, scores 8 - 15 showed mild anxiety, scores 16 - 25 indicated moderate anxiety, and scores 26 - 63 showed severe anxiety. This section of the questionnaire was developed and adapted by Beck et al. (20, 21), and the Cronbach's alpha was estimated at 0.92 in the present study. The third section of the questionnaire consisted of 30 researcher-made items to express the fear of COVID-19 disease by the respondents. The required data for this section were collected by reviewing the current literature and using expert opinions. The content validity of the questionnaire was confirmed, and the convergence validity was estimated at 0.588. In addition, the Cronbach's alpha and Guttman split-half coefficient were used to evaluate its reliability, which were estimated at 0.91 and 0.859, respectively.

The sample size of the study was calculated to be 384 using the Cochran formula and Morgan’s table, and the minimum sample size was determined to be 400. The link to the online questionnaire was provided to the participants.

Data analysis was performed in SPSS version 23, and the influential factors in anxiety were identified in terms of significance using Pearson’s and Spearman’s correlation-coefficients. Notably, completing the questionnaires was voluntary.

4. Results

According to the analysis of the demographic characteristics, 334 participants (72.9%) were female, 124 (27.1%) were male, and 56 (12.2%) were aged 15 - 20 years (Table 1).

Table 1.

Demographic Characteristics of Participants

CharacteristicsPercent
Age (y)
15 - 2012.2
21 - 2533
26 - 3015.3
31 - 3513.8
36 - 4012.4
41 - 456.1
46 - 503.7
≥ 513.5
Education level
High school (or lower)2
High school diploma15.5
Associate degree8.3
Bachelor’s degree40.2
Master’s degree24.9
PhD (or higher)9.2
Marital status
Married 37.3
Single 57
Divorced/widowed 5.7
Financial status
Very poor2
Poor17
Average78.5
Rich2.5
Very rich2

According to the obtained results, more than 85% of the participants had mild or moderate fear, and more than 82% had mild or moderate anxiety (Table 2).

Table 2.

Fear and Anxiety Levels of Participants a

VariablesCOVID-19 FearCOVID-19 Anxiety
None/mild65 (14.2)239 (52.2)
Mild and moderate329 (71.8)137 (29.9)
63 (13.8)46 (10.0)
Severe1 (0.2)36 (7.9)
Total458 (100.0)458 (100.0)

The correlations between the scores of COVID-19 anxiety and fear with the variables of employment status, number of family members, type of residential home, mental state, place of residence, education level, type of job, economic status of individual/family, type of religion, religiosity, trust in praying, individual/family income levels, travel, exercise, physical health, COVID-19 disease, COVID-19 prevention, and treatment preference indicated that the COVID-19 fear scores were poorly correlated with religion and efforts for COVID-19 prevention, while no correlations were observed with the other variables (P ≤ 0.05). Furthermore, the anxiety scores had weak, inverse correlations with efforts to prevent COVID-19 and satisfaction with the government’s efforts (P ≤ 0.05).

The mean score of COVID-19 fear was estimated at 78.64 ± 18.77 in the male subjects and 82.36 ± 19.22 in the female subjects. The results of independent t-test showed no significant difference between the male and female subjects regarding the score of COVID-19 fear. The mean score of COVID-19 anxiety was 8.12 ± 9.83 in the male subjects and 10.84 ± 9.9.9 in the female subjects, and no significant difference was observed between these groups in this regard (P ≤ 0.254) (Table 3).

Table 3.

t-Test for Equality of Means between Male and Female Participants

FtdfMean DifferenceStd. Error DifferenceP-Value
COVID-19 fear0.009-1.85456-3.7120.924
COVID-19 anxiety1.306-2.611456-3.711.980.254

According to the multiple comparison of the difference between the levels of COVID-19 fear and COVID-19 anxiety with the marital status of the participants indicated that the single participants had less fear and anxiety about COVID-19 with a significant difference with the married subjects in this regard (P = 0.022). However, no significant correlation was denoted between the level of anxiety and marital status of the participants (Table 4).

Table 4.

Multiple Comparisons Between Married, Single, and Divorced/Widowed Participants

Dependent Variable(I) Marital Status(J) Marital StatusMean Difference (I-J)Std. ErrorP-Value
COVID-19 fearMarriedSingle4.98 a1.870.022
Divorced/widowed3.344.000.682
SingleMarried-4.98 a1.870.022
Divorced/widowed-1.633.910.908
Divorced/widowedMarried-3.344.000.682
Single1.633.910.908
COVID-19 anxietyMarriedSingle0.930.970.607
Divorced/widowed-2.012.090.602
SingleMarried-0.930.970.607
Divorced/widowed-2.942.040.321
Divorced/widowedMarried2.012.090.602
Single2.942.040.321

The comparison of the levels of COVID-19 fear and anxiety based on the source of information about the disease indicated that the participants who received information from other sources had a different fear of COVID-19 from other groups (P ≤ 047). However, no significant difference was observed in the anxiety variable between those who received information from different sources (Table 5).

Table 5.

Multiple Comparisons of Information Sources About COVID-19

Dependent Variable(I) Source of Information About COVID-19(J) Source of Information About COVID-19Mean Difference (I-J)Std. ErrorP-Value
COVID-19 fearNational TVInternational TV-2.443.370.888
International social media-1.092.070.953
Other9.284.170.119
International TVNational TV2.443.370.888
International social media1.353.130.973
Other11.721864.794720.070
International social mediaNational TV1.090232.072970.953
International TV-1.351633.133410.973
Other10.37023 a3.987940.047
OtherNational TV-9.280004.179510.119
International TV-11.721864.794720.070
International social media-10.37023 a3.987940.047
COVID-19 anxietyNational TVInternational TV-2.421231.757580.514
International social media-2.242181.07989.162
Other-0.867742.177270.979
International TVNational TV2.421231.757580.514
International social media0.179051.632321.000
Other1.553492.497760.925
International social mediaNational TV2.242181.079890.162
International TV-0.179051.632321.000
Other1.374442.077480.911
OtherNational TV0.867742.177270.979
International TV-1.553492.497760.925
International social media-1.374442.07748.911

5. Discussion

The present study aimed to investigate the fear and anxiety caused by COVID-19. According to the obtained results, more than 80% of the participants experienced mild-to-moderate anxiety and fear, and moderate-to-severe anxiety was observed in less than 20%. A study by Cowling et al. indicated that although people understood the importance of the H1N1 pandemic, they experienced less anxiety (22). Studies have also shown several emotional disorders due to diseases such as AIDS at the beginning of its outbreak although these disorders decreased with antiviral therapies (23).

Due to their evolving nature, the prevalence of emerging infectious diseases may be associated with considerable public fear and in specific communities, especially when the disease and its mortality are significant. Reducing fear and discrimination against patients with infectious diseases could be effective in controlling disease transmission. Individuals with the fear and stigma of becoming infected may not seek treatment and remain anonymous in society, which delays their treatment (24). On the other hand, low anxiety and fear caused by diseases could lead to negligence and disregarding standard health regulations, thereby increasing the number of patients in the community. This is particularly important in Iran, which has led to the relatively higher incidence rate of COVID-19 in this country.

The comparison of fear and anxiety between the male and female participants in the present study indicated that the married and single subjects and different information sources caused women to be more afraid of developing COVID-19 compared to men. This is in line with the results obtained by Davoudi et al., which were focused on gender differences in health anxiety (25). Our findings in this regard are also consistent with the research by Modara et al., who determined the mean score of anxiety in Iran in a systematic review and meta-analysis (26). The higher susceptibility of women to anxiety could be attributed to gender roles and the socialization of women in society (27) as women are often encouraged to express their emotions more frequently and seek social support due to their sexual role. On the other hand, men are more likely to deny stressful situations and are often inclined toward independence. This difference may be associated with women's communication style as they have more extensive communication networks compared to men, and these communication traits and interdependencies encourage women to express their emotions and health-seeking behaviors more easily. Moreover, women are more encouraged than men owing to their health-seeking and supportive behaviors in society (28). According to Ginsberg, symptoms of anxiety (including health anxiety) are more common in women compared to men. He believes that based on the social learning model, reassuring behaviors and expressing concern are more acceptable in women. Therefore, accepting the role of the patient is more common among women compared to men (28). High anxiety levels in women could also be associated with more health and preventive behaviors (22).

In the current research, a significant difference was observed in the levels of fear and anxiety of the married subjects compared to the singles. In a similar study, Juliao identified the factors associated with the tendency to die in patients with advanced disease stages, stating that this tendency was not correlated with gender, which is inconsistent with the results of the present study. Meanwhile, it is in line with our findings in terms of the lack of a correlation between other variables, such as education level, religion, and the number of family members (29).

According to the results of the present study, the level of fear of developing COVID-19 differed among the participants with various sources of information apart from domestic, international, and social networks. Anxiety of COVID-19 is highly common and may mostly be due to the unknown nature of the disease and cognitive ambiguity about the virus. Fear of the unknown causes anxiety in humans and disturbs their perception of immunity. As scientific knowledge remains scarce regarding COVID-19, the anxiety of the disease will likely exacerbate (30).

Currently, people are constantly seeking information to relieve their anxiety of COVID-19. Anxiety may render people unable to distinguish between right information and misinformation, and they may be exposed to false news as a result (31). Since stress and anxiety may weaken the immune system and increase susceptibility to diseases such as COVID-19, it is recommended that anxiety be managed by proper strategies, such as the use of special techniques to reduce anxiety and manage stress. In addition, individuals must learn to change and improve their lifestyle to effectively control COVID-19.

5.1. Limitations of the Study

One of the main limitations of our study was the Iranian culture, which differs with the cultural background of other countries. Moreover, the small sample sizes restricts the generalizability of the results, and further investigations in this regard should be conducted on larger sample sizes.

5.2. Conclusions

According to the results, the fear and anxiety caused by COVID-19 were mild in the Iranian society. Therefore, it is recommended that the importance of the disease be further emphasized and fear and anxiety be controlled properly by using special techniques to reduce anxiety and manage stress. Lifestyle changes could also be significantly effective in the management of COVID-19.

Acknowledgements

References

  • 1.

    Coughlin SS. Anxiety and Depression: Linkages with Viral Diseases. Public Health Rev. 2012;34(2):7. [PubMed ID: 25264396]. [PubMed Central ID: PMC4175921]. https://doi.org/10.1007/BF03391675.

  • 2.

    Prince M, Patel V, Saxena S, Maj M, Maselko J, Phillips MR, et al. No health without mental health. Lancet. 2007;370(9590):859-77. https://doi.org/10.1016/s0140-6736(07)61238-0.

  • 3.

    Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005;62(6):593-602. [PubMed ID: 15939837]. https://doi.org/10.1001/archpsyc.62.6.593.

  • 4.

    American Psychiatric Association. Association, AP Diagnostic and statistical manual of mental disorders. Arlington, VA, US. American Psychiatric Publishing; 1995.

  • 5.

    Coughlin SS. Post-Traumatic Stress Disorder and Chronic Health Conditions. Washington DC, USA: American Public Health Association; 2013. https://doi.org/10.2105/9780875530161.

  • 6.

    Schnurr PP, Green BL. Understanding relationships among trauma, posttraumatic stress disorder, and health outcomes. Trauma and health: Physical health consequences of exposure to extreme stress. American Psychological Association; 2004. p. 247-75. https://doi.org/10.1037/10723-010.

  • 7.

    Schuster R, Bornovalova M, Hunt E. The influence of depression on the progression of HIV: direct and indirect effects. Behav Modif. 2012;36(2):123-45. [PubMed ID: 22089635]. https://doi.org/10.1177/0145445511425231.

  • 8.

    Sharma J, Malakar M, Gupta S, Dhandar AR. Food Poisoning: A cause for anxiety in Lakhimpur district of Assam. Ann Biol Res. 2014;5(1):46-9.

  • 9.

    Ajdacic-Gross V, Aleksandrowicz A, Rodgers S, Muller M, Kawohl W, Rossler W, et al. Social Phobia Is Associated with Delayed Onset of Chickenpox, Measles, and Mumps Infections. Front Psychiatry. 2016;7:203. [PubMed ID: 28082921]. [PubMed Central ID: PMC5186793]. https://doi.org/10.3389/fpsyt.2016.00203.

  • 10.

    Kaputu-Kalala-Malu C, Musalu EM, Walker T, Ntumba-Tshitenge O, Ahuka-Mundeke S. PTSD, depression and anxiety in Ebola virus disease survivors in Beni town, Democratic Republic of the Congo. BMC Psychiatry. 2021;21(1):342. [PubMed ID: 34238249]. [PubMed Central ID: PMC8265146]. https://doi.org/10.1186/s12888-021-03343-7.

  • 11.

    Xu Z, Shi L, Wang Y, Zhang J, Huang L, Zhang C, et al. Pathological findings of COVID-19 associated with acute respiratory distress syndrome. Lancet Respir Med. 2020;8(4). https://doi.org/10.1016/s2213-2600(20)30076-x.

  • 12.

    Aslanbek A. Social-Political and Ethnocultural Situation in the Republic of Daghestan in 2020 (Event Analysis). Russia Moslem World. 2021;(2 (312)):27-52.

  • 13.

    Connerton P, Vicente de Assuncao J, Maura de Miranda R, Dorothee Slovic A, Jose Perez-Martinez P, Ribeiro H. Air Quality during COVID-19 in Four Megacities: Lessons and Challenges for Public Health. Int J Environ Res Public Health. 2020;17(14):5067. [PubMed ID: 32674410]. [PubMed Central ID: PMC7400368]. https://doi.org/10.3390/ijerph17145067.

  • 14.

    Lau JT, Griffiths S, Choi KC, Tsui HY. Widespread public misconception in the early phase of the H1N1 influenza epidemic. J Infect. 2009;59(2):122-7. [PubMed ID: 19592114]. https://doi.org/10.1016/j.jinf.2009.06.004.

  • 15.

    Jha RK, Jain P, Ambad RS. The Origin, Transmission and Mortality of Corona Virus. J Critic Rev. 2020;7(10):93-6. https://doi.org/10.31838/jcr.07.10.23.

  • 16.

    Kamate SK, Agrawal A, Chaudhary H, Singh K, Mishra P, Asawa K. Public knowledge, attitude and behavioural changes in an Indian population during the Influenza A (H1N1) outbreak. J Infect Dev Ctries. 2009;4(1):7-14. [PubMed ID: 20130372]. https://doi.org/10.3855/jidc.501.

  • 17.

    Goodwin R, Haque S, Neto F, Myers LB. Initial psychological responses to Influenza A, H1N1 ("Swine flu"). BMC Infect Dis. 2009;9:166. [PubMed ID: 19807908]. [PubMed Central ID: PMC2765446]. https://doi.org/10.1186/1471-2334-9-166.

  • 18.

    Jones JH, Salathe M. Early assessment of anxiety and behavioral response to novel swine-origin influenza A(H1N1). PLoS One. 2009;4(12). e8032. [PubMed ID: 19997505]. [PubMed Central ID: PMC2779851]. https://doi.org/10.1371/journal.pone.0008032.

  • 19.

    Serrano-Ripoll MJ, Meneses-Echavez JF, Ricci-Cabello I, Fraile-Navarro D, Fiol-deRoque MA, Pastor-Moreno G, et al. Impact of viral epidemic outbreaks on mental health of healthcare workers: a rapid systematic review and meta-analysis. J Affect Disord. 2020;277:347-57. [PubMed ID: 32861835]. [PubMed Central ID: PMC7443314]. https://doi.org/10.1016/j.jad.2020.08.034.

  • 20.

    Beck AT, Epstein N, Brown G, Steer RA. An inventory for measuring clinical anxiety: psychometric properties. J Consult Clin Psychol. 1988;56(6):893-7. [PubMed ID: 3204199]. https://doi.org/10.1037//0022-006x.56.6.893.

  • 21.

    Julian LJ. Measures of anxiety: State-Trait Anxiety Inventory (STAI), Beck Anxiety Inventory (BAI), and Hospital Anxiety and Depression Scale-Anxiety (HADS-A). Arthritis Care Res (Hoboken). 2011;63 Suppl 11:S467-72. [PubMed ID: 22588767]. [PubMed Central ID: PMC3879951]. https://doi.org/10.1002/acr.20561.

  • 22.

    Cowling BJ, Ng DM, Ip DK, Liao Q, Lam WW, Wu JT, et al. Community psychological and behavioral responses through the first wave of the 2009 influenza A(H1N1) pandemic in Hong Kong. J Infect Dis. 2010;202(6):867-76. [PubMed ID: 20677945]. https://doi.org/10.1086/655811.

  • 23.

    Arendt G. Affective disorders in patients with HIV infection: impact of antiretroviral therapy. CNS Drugs. 2006;20(6):507-18. [PubMed ID: 16734500]. https://doi.org/10.2165/00023210-200620060-00005.

  • 24.

    Person B, Sy F, Holton K, Govert B, Liang A. Fear and stigma: the epidemic within the SARS outbreak. Emerg Infect Dis. 2004;10(2):358. [PubMed ID: 15030713]. [PubMed Central ID: PMC3322940]. https://doi.org/10.3201/eid1002.030750.

  • 25.

    Davoudi I, Nargesi F, Mehrabizadeh HM. Gender differences in health anxiety and its related dysfunctional beliefs: With control of age. Q J Health Psychol. 2012.

  • 26.

    Modara F, Sarokhani D, Valizadeh R, Sarokhani M. The Average Review Score of Anxiety in Iran: Systematic Review and Meta-Analysis. Sci J Ilam Univ Med Sci. 2017;25(2):181-210. https://doi.org/10.29252/sjimu.25.2.181.

  • 27.

    Tamres LK, Janicki D, Helgeson VS. Sex Differences in Coping Behavior: A Meta-Analytic Review and an Examination of Relative Coping. Pers Soc Psychol Rev. 2016;6(1):2-30. https://doi.org/10.1207/s15327957pspr0601_1.

  • 28.

    Ginsberg DL. Women and Anxiety Disorders: Implications for Diagnosis and Treatment. CNS Spectrums. 2014;9(9):1-3. https://doi.org/10.1017/s1092852900001978.

  • 29.

    Juliao M, Barbosa A, Oliveira F, Nunes B. Prevalence and factors associated with desire for death in patients with advanced disease: results from a Portuguese cross-sectional study. Psychosomatics. 2013;54(5):451-7. [PubMed ID: 23465741]. https://doi.org/10.1016/j.psym.2013.01.006.

  • 30.

    Bajema KL, Oster AM, McGovern OL, Lindstrom S, Stenger MR, Anderson TC, et al. Persons Evaluated for 2019 Novel Coronavirus - United States, January 2020. Morb Mortal Wkly Rep. 2020;69(6):166. [PubMed ID: 32053579]. [PubMed Central ID: PMC7017962]. https://doi.org/10.15585/mmwr.mm6906e1.

  • 31.

    To KK, Tsang OT, Yip CC, Chan KH, Wu TC, Chan JM, et al. Consistent Detection of 2019 Novel Coronavirus in Saliva. Clin Infect Dis. 2020;71(15):841-3. [PubMed ID: 32047895]. [PubMed Central ID: PMC7108139]. https://doi.org/10.1093/cid/ciaa149.