Demographic Factors Among HIV Confirmed Blood Donors from 2013 to 2021 in Shenzhen

Introduction

Blood transfusion medicine is an evolving discipline that is developed using a multidisciplinary approach. It focuses on the transfusion of blood from donors to patients for treatment and conducts research, development, and application. The most important of transfusion is to ensure the safety and efficacy of clinical blood transfusions. However, in 1981, after HIV was first reported in the world, it quickly became one of the most serious health challenges.¹ HIV can be spread via unprotected sex with an infected partner, sharing unsterilized injection tools used by an infected person with others, and transfusion of blood products from the infected person. Due to the characteristics of HIV transmission by blood transfusion, blood donors who test positive for HIV are more likely to infect recipients and become a threat to blood security. In addition, Donors who are more likely to cause HIV transmission are those with HIV but are in the window period (tested negative for HIV).

Before 1978 in China, blood for clinical use was mainly collected from paid individual donations, donating blood became an effective way to earn money for blood donors, which led to the widespread of HIV on the central plain of China. In 1998, the establishment and implementation of the Chinese national blood policy significantly reduced the spread of HIV,² as unpaid blood donors reduce the risk for HIV infection through transfusion.^3,4

In 2020, COVID-19 spread around the world and severely impacted health systems.⁵ In many countries, the COVID-19 pandemic had a serious impact on blood donation and led to changes in the prevalence of HIV.⁶ This article aims to study the prevalence of HIV among blood donors in Shenzhen before the COVID-19 pandemic and the impact of COVID-19 on HIV prevalence, which provides scientific strategies for preventing HIV from getting into the blood supply chain, even during an epidemic.

Methods

Shenzhen Blood Center is a public health institution, which carries out blood collection and supply. To provide blood consumption, testing services and medical blood service guidance for nearly 50 clinical medical institutions in Shenzhen.

From January 1, 2013, to December 31, 2021, samples from 735,247 blood donors at Shenzhen Blood Center were collected. Samples of blood donations screened reactive for HIV by ELISA or NAT were sent to Shenzhen Chronic Disease Prevention Center for confirmatory testing by WB. All blood donors in Shenzhen Blood Center are volunteers, and all tests were performed in strict accordance with the instructions regarding the reagents and equipment. Specimens with positive results in all tests were considered HIV-positive, and these blood donors were considered HIV-infected blood donors. The prevalence of HIV among blood donors was equal to the number of blood donors who tested positive for HIV divided by the total number of blood donors. All data were statistically analyzed by the Chi-square test.

Blood donors were grouped by different criteria. Blood donors with a higher education background were defined as those who were in the process of or have completed university studies. Blood donors with a lower education background were defined as those without a college education. Local blood donors were those whose household registration is in Shenzhen. Foreign blood donors were those whose household registration was not in Shenzhen, but who traveled, worked, or studied in Shenzhen during this study period. First-time blood donors were defined as those who made no blood donations prior to the study period. Repeat donors were defined as donors who had made at least one donation prior to the study period and one or more during the study period.

Results

As shown in Figure 1, during nine years, the prevalence of HIV among blood donors in Shenzhen showed a fluctuating trend. The highest prevalence of HIV was 0.073% in 2014 and the lowest prevalence of HIV was 0.027% in 2018.

Figure 1 The prevalence of HIV among unpaid blood donors from 2013 to 2021.

In Table 1, from 2013 to 2021, the prevalence of HIV among males was higher than that of females (Figure 2), there were significant differences between males and females (P < 0.01). It indicated that in Shenzhen, the prevalence of HIV among blood donors was associated with gender. In 2019, the prevalence of HIV among repeat blood donors was higher than that of first-time blood donors (P<0.05), but in 2021, the prevalence of HIV among repeat blood donors was lower than that of first-time blood donors (P < 0.001). Only HIV prevalence among repeat blood donors in 2020 was statistically decreased compared to that in 2019 (P < 0.05) in Table 2. It may indicate that COVID-19 have an effect on HIV prevalence among blood donors with different history of blood donation.

Table 1 The Prevalence of HIV Among Unpaid Blood Donors from 2013 to 2021

Table 2 The Impact of COVID-19 on the Prevalence of HIV Among Different Blood Donors

Figure 2 The prevalence of HIV among male and female blood donors from 2013 to 2021.

In Table 3, we found that the characteristics of blood donors changed in 2020 compared to 2019 and 2021. The percentage of males increased significantly from 2019 to 2020 (P < 0.05), although there was no significant difference between 2020 and 2021. From 2019 to 2021, there were more foreigners than locals, and the lowest percentage of foreigners was observed in 2020 (P < 0.001). In 2019 and 2021, there were more first-time blood donors than repeat blood donors, but in 2020, it was the first time that there were more repeat blood donors than first-time blood donors and the percentage of repeat blood donors was the highest (P < 0.001). In 2019, there were more blood donors with a lower education background than those with a higher education background, but in 2020 and 2021, there were more blood donors with a higher education level than those with a lower education level, especially in 2020, the percentage of blood donors with a higher education level was the highest (P < 0.05). From 2019 to 2021, there were more blood donors aged 30–65 years old than those aged 18–29 years old, and compared to 2019, the percentage of blood donors aged 18–29 years old decreased significantly in 2020 (P < 0.001), but in 2021, it increased (P < 0.001). Overall, this may indicate that the character of blood donors, including education, age and so on, has been affected by COVID-19.

Table 3 The Impact of COVID-19 on the Structure of Blood Donors

Discussion

HIV infections remain a global public health concern, especially for the safety of transfusion. According to one report, the national-level prevalence of HIV in China is 0.09%, and the prevalence of HIV among blood donors is different from that of general population. From 2010 to 2017, the HIV prevalence among blood donors is about 0.025% in Guangdong province,⁷ which is lower than the national-level prevalence and the prevalence of blood donors in Shenzhen in our study. Demographic factors are shown to be associated with HIV prevalence.^8,9 In the past, there were many articles about the seroprevalence of HIV among blood donors.^10,11 But in recent years, many researchers have focused on the prevalence of HIV based on the positive result for NAT or WB.^12–14 Because the positive result of ELISA is not sufficient to indicate that the blood donor is HIV-infected, the positive result of WB can prove that the blood donor is infected with HIV. In this article, the prevalence of HIV among blood donors was determined based on the positive results of WB.

In many countries, the majority of blood donors are men.^15,16 In Shenzhen of China, from 2013 to 2021, there were more male blood donors than females. It may because of the existence of menstrual period, which limits women to donate blood. As for the prevalence of HIV among blood donors, we found that the prevalence of HIV among females was significantly lower than among males each year (P < 0.01), which was consistent with the results of many studies about the HIV prevalence of male and female blood donors,¹⁷ and we also found that COVID-19 had no significant effect on HIV prevalence among male and female blood donors. An appropriate increase in the proportion of female blood donors in Shenzhen may reduce the HIV positive rate of blood donors, whether or not in times of other epidemics.

In Shenzhen of China, the year 2019 was considered pre-pandemic while 2020 was during the pandemic and 2021 was post-acute-pandemic. Shenzhen is a city with a large number of migrants, and there are more foreigners than locals donating blood. Population migration has been reported to be an obstacle to controlling and managing HIV infection.¹⁸ Due to the COVID-19 pandemic, the Chinese government enforced a blockade policy. So there was a decline in the number of foreign blood donors in 2020 compared to 2019 and 2021. The pandemic led to changes in the percentage of foreign and local blood donors. The decrease of foreign blood donors may be conducive to controlling HIV infection among blood donors in Shenzhen. In addition, the proportion of blood donors with different ages was changed. The lowest percentage of blood donors aged 18–29 years old was observed in 2020. This may be due to the COVID-19 epidemic, the school’s closure strategy banned students from going out. Students are the majority of blood donors younger than 30 years old. In our results, the HIV prevalence of blood donors aged younger than 30 years old was higher than those aged over 30 years old from 2013 to 2018 (P < 0.05). The increasing HIV risk among young people is posing potential threats to blood safety in China,^19,20,27,28 which may be closely related to the lack of sex education.^21,29 Some studies show that there is a certain correlation between the level of education and the incidence of HIV.^19,20,22,23 Some researchers’ conclusions mean that HIV is related to lower education levels,^21,22,24,25 but others mean that the prevalence of HIV among blood donors with >8 years of education was higher than those with < 8 years of education.^23,26 However, in our results, we did not find significant differences in the HIV prevalence between higher-educated blood donors and lower-educated blood donors and the impact of COVID-19 on the HIV prevalence in these two groups. We only found that the percentage of blood donors with a higher educational background increased in 2020. It may due to that the highest educated people usually have better economic conditions, which can facilitate their access to services. Besides this affirmation causes constraints, the lowest educated people could be more affected by COVID-19 pandemic restrictions, impacting their access to services. So, during the COVID-19 pandemic, blood donors with a higher education background may be more willing to donate blood to help others than those with a lower education background.

Incidence in first-time and repeat blood donors is an important measure of transfusion-transmitted HIV infection risk.^24,27 First-time blood donors usually have different motivations for blood donation, some of which provoke the donors to hide risk factors of transfusion-transmissible infections (TTIs).^25,28 It has been reported that the HIV prevalence among first blood donors greatly exceeded that in repeat blood donors.^26,29 In this study, we observed the same trend in 2019, but in 2020, the prevalence of HIV among repeat blood donors decreased and the prevalence of HIV among first-time blood donors was higher than that among repeat blood donors in 2021. We also found that COVID-19 had a significant effect on the proportion of first-time and repeat blood donors, it was the first time in 2020 that there were more repeat blood donors than first-time blood donors from 2013 to 2021. During the COVID-19 epidemic, the main group of blood donors changed from first-time blood donors to repeat blood donors. An increased number of repeat blood donors can not only help ensure blood supply but also reduce the risk of HIV transmission through blood transfusion. It is well known that blood bank managers have the opportunity to receive more information about prevention and discuss repeat blood donors vulnerabilities and so, mitigate this group risks.

There are some limitations in this article. Many other factors associated with HIV infections among blood donors, including sexual behavior and injecting drugs, are not mentioned in our study. Instead of deriving information from all blood donors, we used some programming techniques to extract information, which also prevented us from further analyzing various factors related to HIV. In the future, we will consider further in-depth export data and analysis.

Conclusion

Overall, the data from this study showed that a higher prevalence of HIV among male blood donors than females, the prevalence of HIV decreased among repeat blood donors from 2019 to 2020, and the demographics of blood donors changed in 2020 compared to 2019 and 2021. We concluded that a higher proportion of female blood donors would help decrease HIV positive units in the blood supply, the COVID-19 pandemic affected the demographics of blood donors as well as the prevalence of HIV among repeat blood donors.