Introduction

The Coronavirus Disease 2019 (COVID-19) pandemic is still posing a global health threat with a sudden spurt of cases in some regions, such as India, U.S.A and UK. In China, there have recently been some small-size outbreaks in its northern parts, such as Shijiazhuang municipality and Wangkui county, although the pandemic has been well controlled in China since May, 2020. At present, COVID-19 vaccines are only allowed for emergency use in high-risk populations, such as the staff of the departments of Disease Control and Prevention Centers and front-line healthcare professionals in China. Therefore, precautionary measures are still the most effective way to prevent the viral infection of COVID-19 among the general population (Chinese Center for Disease Control & Prevention, 2020). As recommended by the World Health Organization (WHO), effective preventive measures include social distancing, quarantining, hand washing, and wearing disposable medical masks (World Health Organization, 2020).

In China, universities have resumed Zoom, face-to-face and/or hybrid classes after the successful containment of COVID-19 in fall of 2020 (Ministry of Education of the People’s Republic of China, 2020). However, it should be noted that the risk of COVID-19 cluster outbreak is still potentially high, since universities have large number of students in confound areas, such as small classrooms, shared rooms in dormitories and common facilities (Zhai et al., 2020). Therefore, it is of particularly importance to have students maintain correct precautionary behaviors during the outbreak and post-outbreak periods. To this end, it is necessary to assess students’ knowledge of COVID-19 prevention, since there is evidence that good knowledge of COVID-19 preventive measures is associated with appropriate practices towards COVID-19 outbreak (Zhong et al., 2020).

The Macao Special Administrative Region (SAR) and Zhuhai are two major bordering municipalities in Guangdong-Hong Kong-Macao Greater Bay Area (GBA) with distinct cultural, socio-economic, and educational backgrounds, as well as COVID-19 control measures. Universities in Macao also have resumed classes since fall of 2020 (Education & Youth Development Bureau, 2020), so universities of both municipalities face similar challenges of COVID-19 prevention. The differences in the knowledge level of COVID-19 prevention in undergraduate students between two municipalities and identification of underlying reasons for such differences may facilitate the development of more suitable campus-based COVID-19 prevention programs. Therefore, the present study compared Macao and Zhuhai undergraduate students’ knowledge of COVID-19 prevention measures.

Methods

Measures

The COVID-19 preventive knowledge inventory (including the version of simplified Chinese and traditional Chinese) was adapted from the questionnaire on Chinese residents’ knowledge towards COVID-19 (Table 1) (Panjin Municipal People’s Government, 2020). It had five single-choice questions on heat inactivation conditions for SARS-CoV-2, disinfectants for SARS-CoV-2, transmission ways of SARS-CoV-2, etiquette when coughing and sneezing, and use of disposable masks.

Table 1

Questionnaire of COVID-19 preventive knowledge.

		Question list
Question 1: the time condition and temperature condition that can inactivate the SARS-CoV-2.
	Option A. Maintain 56 °C for 30 min Option B. Maintain 56 °C for 15 min Option C. Maintain 56 °C for 20 min Option D. Maintain below 0 °C for 10 min
Question 2: the type of disinfectant that cannot inactivate the SARS-CoV-2.
	Option A. Peroxyacetic acid Option B. 75% ethanol Option C. Iodophor Option D. Bleach powder
Question 3: the non-transmission pathways of the SARS-CoV-2.
	Option A. Contact transmission Option B. Droplet transmission Option C. Soil transmission Option D. Aerosol transmission
Question 4: the wrong precaution when coughing and sneezing.
	Option A. Cover your nose and mouth with a tissue or elbow when coughing and sneezing. Option B. Cover your nose and mouth with both hands when coughing and sneezing. Option C. Put the sneezing tissue in the dustbin with cover. Option D. It’s best to clean your hands thoroughly after sneezing and coughing.
Question 5: the wrong precaution for the use of disposable medical masks.
	Option A. It is recommended to replace the mask every 2–4 h. Option B. It should be replaced immediately once the mask has contaminated. Option C. When wearing masks, avoid touching the inner side of the mask. Option D. The thicker the mask, the better the anti-virus effect.

The survey questionnaire also collected demographic variables, including gender, age, and type of students (medical vs. non-medical).

Results

Characteristics of the study population

A total of 3,840 participants took part in the survey initially, but 3,795 (98.8%) completed the questionnaire, with 977 from Macao and 2,818 from Zhuhai. As shown in Table 2, in comparison to Zhuhai participants, Macao participants were overrepresented by male students with age younger than 20 years and medical students.

Table 2

Characteristics of the respondent.

Variable	n (%)		χ2-value	P-value
	Macao (n = 977)	Zhuhai (n = 2,818)
Gender
Female	530 (54.2%)	1,663 (59.0%)	6.755	0.009
Male	447 (45.8%)	1155 (41.0%)
Age
<20	355 (36.3%)	602 (21.4%)	86.247	<0.001
≥20	622 (63.7%)	2,216 (78.6%)
Major
Medical	217 (22.2%)	268 (9.5%)	104.984	<0.001
Non-medical	760 (77.8%)	2,550 (90.5%)

Correct rates of COVID-19 preventive knowledge

As displayed in Table 3, Macao and Zhuhai participants had similar correct rates in terms of heat inactivation conditions for SARS-CoV-2 (76.8% vs. 76.9%, P = 0.950), etiquette when coughing and sneezing (75.9% vs. 75.0%, P = 0.562), and use of disposable masks (92.2% vs. 90.6%, P = 0.126), while Macao sample had significantly higher correct rates of disinfectants for SARS-CoV-2 (24.6% vs. 17.5%, P < 0.001) and transmission ways of SARS-CoV-2 (84.5% vs. 79.6%, P < 0.001) than Zhuhai sample.

Table 3

Correct rates of COVID-19 preventive knowledge in undergraduates of Macao and Zhuhai, China.

Question Subject	n (%)		χ2-value	P-value
	Macao	Zhuhai
Inactivation conditions for SARS-CoV-2	750 (76.8%)	2,166 (76.9%)	0.004	0.950
Disinfectants for SARS-CoV-2	240 (24.6%)	493 (17.5%)	23.271	<0.001
Transmission ways of SARS-CoV-2	826 (84.5%)	2,244 (79.6%)	11.334	0.001
Etiquette when coughing and sneezing	742 (75.9%)	2,114 (75.0%)	0.336	0.562
Use of disposable masks	901 (92.2%)	2,553 (90.6%)	2.342	0.126

After adjusting for demographic variables (Table 4), the regional differences in correct rates of disinfectants for SARS-CoV-2 (P < 0.001) and transmission ways of SARS-CoV-2 (P = 0.001) remained statistically significant.

Table 4

Logistic regression on the association of correct COVID-19 knowledge with region, adjusted for demographic variables.

Variable§	Question Subject
	Inactivation Conditions for SARS-CoV-2				Disinfectants for SARS-CoV-2				Transmission Ways of SARS-CoV-2				Etiquette When Coughing and Sneezing				Use of Disposable Masks
	OR*	95% CIΔ		P	OR	95% CI		P	OR	95% CI		P	OR	95% CI		P	OR	95% CI		P
		Upper	Lower			Upper	Lower			Upper	Lower			Upper	Lower			Upper	Lower
Region	1.086	0.910	1.297	0.360	0.713	0.595	0.855	<0.001	0.704	0.576	0.861	0.001	0.978	0.821	1.166	0.807	0.809	0.615	1.064	0.130
Age	1.123	0.941	1.342	0.199	1.169	0.975	1.403	0.092	0.855	0.712	1.027	0.094	1.117	0.938	1.329	0.214	1.236	0.944	1.620	0.124
Gender	1.022	0.877	1.191	0.777	1.123	0.951	1.325	0.172	0.754	0.638	0.891	0.001	1.671	1.440	1.939	<0.001	2.123	1.692	2.663	<0.001
Type of students	1.650	1.278	2.131	<0.001	1.957	1.579	2.425	<0.001	1.117	0.872	1.431	0.381	1.391	1.092	1.772	0.008	1.122	0.784	1.606	0.529

Discussion

This study compared university students’ knowledge of COVID-19 prevention between Macao and Zhuhai. Students of both cities had more than 75% rate of correct knowledge of heat inactivation conditions for SARS-CoV-2, transmission ways of SARS-CoV-2, etiquette when coughing and sneezing, and use of disposable masks. Although Macao students had statistically significant higher correct rates of disinfectants for SARS-CoV-2 and transmission ways of SARS-CoV-2 than Zhuhai students, which remained statistically significant after demographic variables including age, gender, and types of students were adjusted, the correct rates of disinfectants were still low in students of both cities. Our study results were similar to previous studies (Chang, Yuan & Wang, 2020; Puspitasari et al., 2020).

The higher percentage of medical students in Macao than Zhuhai students cannot fully explain the regional difference in knowledge of disinfectants for SARS-CoV-2 and transmission ways of SARS-CoV-2. The possible reason may be the students in Macao have more hygienic habits, such as wearing masks, good etiquette when coughing and sneezing, and ventilating. Nevertheless, the correct rates of disinfectants for SARS-CoV-2 were low in both cities, because the use of disinfectants requires professional knowledge and lack of students’ knowledge about disinfectants.

The present study has some limitations. First, the two university students were recruited online, so the representation of participants might be limited and need to take caution in generalizing the findings from the current study. Second, the knowledge measures covered in the questionnaire are limited. Items, such as social distancing and hand hygiene, were not included. Finally, although three possible confounding factors were adjusted, the possibility of residual confounding could not be excluded.

Still, findings of the present studies suggest that health education programs are warranted to further improve undergraduates’ knowledge of COVID-19 prevention because approximately 10–15% (Macao SAR) and 25% (Zhuhai) of the students of the two cities were unaware of the transmission ways of SARS-CoV-2 and correct etiquette when coughing and sneezing, respectively. There is also a need to educate students on the correct use of disinfection products during the pandemic. Given that opinion leaders and role models appear to have a key function among students (Abdi & Simbar, 2013), the peer education approach based on social media platforms may be an ideal form of health education among university students. Popular social media platforms, such as WeChat, TikTok, and Weibo, may be a good avenue to spread correct COVID-19 preventive knowledge, similar conclusion drawn in previous study in Pakistani university populations (Salman et al., 2020).