Sero-epidemiological Study of Hepatitis B, C, HIV and Treponema pallidum among Blood Donors in Hodeida city - Yemen

Infections transmitted in blood transfusions are the most significant concern associated with blood donation. The purpose of this study was to establish the current prevalence of hepatitis viruses (B and C), HIV and T.pallidium among blood donors at National Blood Transfusion and Research Center (NBTRC) Hodeida Branch, Hodeida city, Yemen. Serological markers of HBV, HCV, HIV 1, 2, T.pallidium antibodies were studied in 25446 (males) using commercially available kits, over a period of 3 years from January 2016 to April 2018 at National Blood Transfusion and Research Center (NBTRC) Hodeida Branch , Hodeida city, Yemen. Also, the prevalence of confirmed-positive test results of these infections was evaluated among different ages. The sero-prevalence of HBV and HCV, HIV, T.pallidium infections based on confirmation tests, were 0.74%, 0.19%, 0.38% and 0.18% respectively. The prevalence of HBV was significantly higher in age groups 37-46 years and 47-56 years with significant associated OR equal to 2.3 (p<0.001) and OR=2.7 (p=0.02) respectively. The prevalence of HCV was significantly higher in age groups 47-56 years with significant associated OR equal to 6.5 (p=0.003). The prevalence of T.pallidium was significantly higher in age group 37-46 years with significant associated OR equal to 3.6 (p<0.001). In conclusion: this study highlights the prevalence of HBV, HCV, HIV, and T.pallidium among different male ages. The prevalence varies from one age group to another, being the lowest among younger and very older age groups. Therefore, extensive recruitment of young donors should help ensure a long-term increase in the blood supply without jeopardizing safety.


Introduction
Blood transfusion is one of the most important tools in modern medical therapy, and saving patients is its aim. If the safe blood supply is not considered, it can be lifethreatening. However, the blood has its potential risks causing serious side effects in the recipients. It is known that bacteria, viruses and parasites can be transmitted through blood transfusions 1,2 . Choosing healthy donors with low risk of blood contamination is one of concerns around the world. The World Health Organization (WHO) recommends that all donated blood be tested for transfusion transmissible infections. These include HIV, Hepatitis B, Hepatitis C, Treponema pallidum (syphilis) and, where relevant, other infections that pose a risk to the safety of the blood supply, such as Trypanosoma cruzi (Chagas disease) and Plasmodium species (malaria) 3 .
According to the WHO, 25 countries are not able to screen all donated blood for one or more of: HIV; Hepatitis B; Hepatitis C; or syphilis. One of the main reasons for this is because testing kits are not always available. However the prevalence of transfusiontransmitted infections is much higher in low income countries compared to middle and high income countries 4,5 . HBV, HCV, HIV and Treponema pallidium (syphilis) infections are important causes of morbidity and mortality worldwide and pose problems in the safety of blood transfusion. Because of the shared modes of transmission, HBV/HCV/HIV/T.pallidium co-infection is not uncommon in highly endemic areas and among subjects with a high-risk of parenteral transmission.
Prolonged vascular exposure and multiple blood transfusions increase the risk of acquiring these blood-borne infections in endemic areas as Yemen. According to the Yemeni National Infectious Viral Hepatitis Control Programme, Yemen was recognized as HBV-endemic area 6 . In 1998 the WHO recommended the entrance of hepatitis B vaccine in the national immunization programmes of Yemen 7 , particularly among neonates, where vertical transmission is common, regardless of the HBsAg prevalence. The incidence of acute HBV has declined dramatically during the past decade after the vaccination programme, especially among young individuals, although, it still may take several decades until the effect of vaccination will be translated into reduced transmission and morbidity in general. The purpose of this study was to establish the current prevalence of hepatitis viruses (B and C), HIV and T.pallidium among blood donors at National Blood Transfusion and Research Center (NBTRC) Hodeida Branch, Hodeida city, Yemen.

Subjects and Methods
This was a retrospective study. : Spacing male donors and it is rare for female to be blood donors. Also blood donation is semivoluntary by friends and relatives of patients but voluntary donation is not the role.

Blood Testing:
The blood donors sera were tested by rapid immunochromatographic assay (RICA) kits and confirmed by ELISA test (ABON )for diagnosis of Hepatitis B surface Antigen (HBsAg ), antibodies to HCV, antibodies to HIV, and antibodies (IgG and IgM) for Treponema Pallidum (TP).

Inclusion Criteria of blood donors:
Potential donors were accept for donation if they are clinically healthy individuals between 18-60 years of age, with body weight of above 45Kgs, Hemoglobin more than 12.5gm/dl and no significant medical or surgical history.

Exclusion Criteria
Potential donors were excluded if they were below 17 years old, weighed less than 45 kg, had anemia and a history of jaundice within the past six months, engaged in highrisk behavior (i.e., unsafe intercourse, drug use etc), or donated blood within the past three months .

Statistical Analysis
To relate age as possible risk factor for HBV, HCV, HIV and T.pallidium infections, the data were examined in a case-control study format. With confirmed positive tests of HBV, HCV, HIV and T.pallidium were matched up with those who were HBV, HCV, HIV or T.pallidium negative. The chi square was used to see the association Odds ratios (OR) and their 95% confidence intervals (CI). Values (OR, CI, χ 2 ) were estimated using 2x2 tables to identify possible odds ratio on occurrence of HBV, HCV, HIV or T.pallidium and their significance. The result at p-value 0.05 was considered as statistically significant.

Ethical Consideration
Ethical clearance for the study was taken from the Faculty of Medicine and Health Sciences Research Review Committee.

Results
A total number of 25446 blood donors were included in this study. The prevalence of HBV, HCV, HIV, and T.pallidium were 0.74%, 0.19%, 0.38%, and 0.18%, respectively with total prevalence of tested infectious agents equal to 1.52% (table 1). When age groups of blood donors were considered, there was significant increase in HBV rate in age group 47-56 years (1.94% with associated OR equal to 2.7; 95% CI=1.1-6.6, χ 2 =5.1, and p=0.02), followed by age group 37-46 years (1.44%, OR=2.3; 95% CI=1.6-3.1, χ 2 =5.1, p=0.02. However, lower rate of HBV was found in younger age groups (table 2). Also, a high prevalence of HCV was in age group 47-56 years (1.2%) with associated OR equal to 6.5; 95% CI =1.9-20.9, χ 2 =12.8,and p=0.003. However, low  (table 3). On other hand, there was no significant variation of the prevalence of HIV among the different age groups of the blood donors; and zero prevalence of HIV was found in older age groups (47-56 years and >56 years) (table 4). A higher prevalence of T.pallidium was found in age group 37-46 years (0.49%) with associated OR equal to 3.6 (95% CI=1.9-6.8, χ 2 =19.4, p<0.001). However, low rate of T.pallidium was found in younger age groups and 0% was found in age group >56 years (table 5).

Discussion
The prevalence of HBV (0.74%) and HCV (0.19%) in the current study are lower than previously reported in Yemen (4-20%, 1.5% respectively) 8 . The differences in the prevalence between our study and previous studies in Yemen may be attributed to differences in the sensitivities of the assays used, the criteria of positivity, types of donors as well as in the degree to which individuals with risk factors for blood-borne viral infections may have been excluded. In most of the earlier studies, an earlier generation of anti-HCV ELISA (which was less sensitive and less specific) was used.
However, in our study a fourth generation ELISA was used for confirmation, which was more sensitive and more specific.
In general, the prevalence of hepatitis B and C were lower among young donors than older donors in the current study. This confirm the results reported earlier by other investigators 9,10 this may be explained on the basis of increased exposure with age and on the fact that a high awareness of blood-borne viral infections has developed and a comprehensive vaccination program against hepatitis B has been implemented in Yemen. It should be noted that the carrier rate of HBV was higher than the carrier rate of HCV in this study and in other studies [8][9][10][11][12] . These data suggested that the mode of transmission and the efficiency of transmission of HBV may be different from that of HCV. Also, the prevalence of HCV among Yemeni donors was shown to be relatively low (0.19%), this was in an agreement with other studies carried in USA (0.29%) 13 , Central America (0.19%) 14 , Germany (0.1%) 15 , Australia (0.29%) 16 , Singapore (0.37%) 17 and Iran (0.09%) 18 . This can be explained by an introduction of newer generation of anti-HCV testing in BT service has contributed to control and reduction of transmission of HCV as this virus is primarily parenterally transmitted.

Human immunodeficiency virus infection is a major health problem in sub-Saharan
Africa where the prevalence of HIV among blood donors ranges between 2-20% in

Conclusion
In conclusion, this study has shown that prevalence of hepatitis B and C (0.74% and 0.19%) has reduced in Yemen. Further educational programs should target both public and hospital personnel to increase awareness concerning these pathogens. It should be noted that the prevalence of hepatitis B and hepatitis C markers was lower among young donors than among older donors, hence, young people should be encouraged to donate blood to help ensure a long-term increase in the blood supply without jeopardizing safety. Finally, implementation of more sensitive tests (such as nucleic acid amplification testing [NAT] for HIV, HBV and HCV) that detect infection earlier (reduce the window period) will further decrease risks of transfusion-transmitted viral infections. Also, further study can be carried out performing NAT on sero-negative blood donor samples to determine the risk of transfusion-transmitted.

Aacknowledgements
Authors acknowledge the financial support of Hodeidah University, Hodeidah city, Yemen.

Conflict of interest
"No conflict of interest associated with this work".  Chi-square = 3.9 or more significant pv Probability value = 0.05 or less significant Chi-square = 3.9 or more significant pv Probability value = 0.05 or less significant Chi-square = 3.9 or more significant pv Probability value = 0.05 or less significant