3.1 Features related to HBV infection among rejected blood donors from Luanda, Angola
The putative features related to the hepatitis B virus infection among rejected blood donors from Luanda are shown in Table 1. A total of 164 rejected blood donors fulfilled the inclusion criteria and formed part of the analyses. The mean age of rejected blood donors was 30.9 ± 9.04 years, which varies from 18 to 58 years, of which the age group between 20 - 40 years was predominant with about 79% (130/164). The predominant sociodemographic features in the studied population were male donors (87.8%, 144/164), residents in urbanized areas (54.9%, 90/164), with a low educational level (92.1%, 151/164), employees (82.3%, 135/164), and unmarried (94.5%, 155/164).
Overall, the HBV positivity rate among these rejected blood donors was 63.4% (104/164). Mean age was statistically related to HBV infection with a difference of 4.67 years old (p<0.001), being the mean age of the HBV-infected donors (29.2±8.02 years) lower compared to the HBV-uninfected donors (33.9±10.0 years). None of the demographic characteristics studied was related to HBV infection (p>0.05). Despite that, we observed that blood donors aged between 20–40 years (83.7%, 87/104), male gender (86.5%, 90/104), donors from urbanized areas (56.7%, 59/104), donors with low education (93.3%, 97/104), donors employed in the public and/or private sector (79.8%, 83/104), and unmarried donors (95.2%, 99/104), were the most affected by HBV infection. Univariate logistic analyses showed that donors between 20–40 years [OR: 2.34 (95% CI: 1.02 - 5.34), p=0.045], the male gender [OR: 1.40 (95% CI: 0.51 - 3.86), p=0.516], residents in urbanized areas [OR: 1.23 (95% CI: 0.65 - 2.32), p=0.530], with a low educational level [OR: 1.54 (95% CI: 0.49 - 4.82), p=0.458], unemployed [OR: 1.65 (95% CI: 0.68 - 3.99), p=0.271], and unmarried [OR: 1.41 (95% CI: 0.37 - 5.48), p=0.616], were more likely to contract HBV infection, compared to the other groups.
The clinical features showed that the mean AST, a marker of liver function in the generally rejected blood donors enrolled in this study, was 58.9 ± 53.6 U/L, higher than the maximum expected value established for this study, which ranged from 8 to 48 U/L. Mean AST values were higher in HBV-infected donors (59.7 ± 56.6 U/L) compared to mean values from HBV-uninfected donors (57.6 ± 48.6 U/L), with a mean difference of 2.04 U/L, although no significance was observed (p=0.816). On the other hand, ALT values, another biological marker used to monitor liver function, in the generally rejected blood donors were 34.0 ± 30.2 U/L and were within the range established as the standard for this study. No difference in mean ALT values was observed between HBV negative (33.9±20.4) or positive (34.0±34.7) donors (p=0.972). Also, no relationship between AST and ALT status and HBV infection was observed. Despite that, the mean AST/ALT ratio was higher in HBV-positive donors (2.07±1.42) compared to the mean in uninfected donors (1.90±1.14), although not significant (p=0.430). Donors with AST/ALT ratio <1 presented 1.92 times (95% CI: 0.76 - 4.82) more chances of HBV infection compared to donors with an AST/ALT ratio ≥1.