Uncovering the silent threat in life-saving blood donations and the factors driving infection rates
In many parts of the world, donating blood is a routine act of civic responsibility—a simple gesture that saves millions of lives each year. But in some regions, this life-giving resource carries hidden dangers that threaten to undo its healing power. Yemen, a country with a rich history stretching back millennia, now faces a modern health challenge: high rates of hepatitis B and C infections among its population, including those who selflessly donate blood to help others.
The World Health Organization estimates that millions of Yemenis may be living with viral hepatitis, often without knowing it. These silent infections can persist for years before causing symptoms, all while being potentially transmissible to others.
This article explores the scientific detective work that uncovered the extent of this problem in Aden City, Yemen, and examines the factors that make these viruses so persistent in this population. Through understanding comes power—the power to prevent, screen, and ultimately eliminate these threats to public health.
Hepatitis B virus (HBV) and hepatitis C virus (HCV) are both viruses that primarily attack the liver, but they differ in important ways. Hepatitis B is a hepadnavirus that can cause both acute and chronic infection, while hepatitis C is a hepacivirus that more often leads to chronic conditions 1 2 .
HBV and HCV spread through various routes, with some important differences in transmission efficiency:
Sharing needles, blood transfusions, and exposure to blood products
Unsafe injections, surgical procedures, and dental treatments
Sharing personal items, traditional healing methods like cupping 9
In 2007, researchers conducted a systematic investigation at the national blood bank service in Aden to determine the precise prevalence of HBV and HCV among blood donors and identify the factors that increased infection risk 9 .
Hepatitis B prevalence among blood donors
24 out of 469 donors tested positive for HBsAg
Hepatitis C prevalence among blood donors
6 out of 469 donors tested positive for anti-HCV
| Infection Type | Number of Cases | Prevalence Rate | Demographic Notes |
|---|---|---|---|
| Hepatitis B (HBsAg positive) | 24 out of 469 donors | 5.1% | All donors were male, reflecting cultural norms |
| Hepatitis C (Anti-HCV positive) | 6 out of 469 donors | 1.3% | Higher than rates in developed countries |
The study found that the prevalence of HBV and HCV among blood donors in Yemen remains significantly higher than in many developed countries 9 . This disparity highlights the unequal global distribution of viral hepatitis and the need for targeted interventions in high-prevalence regions.
The 5.1% HBV prevalence observed in the Aden study classifies Yemen as a country with intermediate endemicity for hepatitis B 1 . This means the virus is firmly established in the population, though not as widespread as in "high endemicity" countries where rates can exceed 8%.
For hepatitis C, the 1.3% rate may seem modest at first glance, but it represents a substantial disease burden when applied to the broader population. Furthermore, this rate is significantly higher than what's typically observed in blood donors from developed countries, where extensive screening and prevention measures have dramatically reduced transmission.
The Aden study went beyond simply counting cases—it investigated the specific factors that made infection more likely. Through statistical analysis, researchers identified several variables that significantly increased the risk of hepatitis infection.
| Risk Factor | Adjusted Odds Ratio | Interpretation |
|---|---|---|
| History of blood transfusion | 22.8 | Those with prior transfusions had nearly 23 times higher risk |
| Malaria infection | 6.8 | Previous malaria increased risk nearly 7-fold |
| Dental treatment | 3.6 | Dental procedures tripled the risk |
| Cupping | 3.9 | Traditional healing practice increased risk 4-fold |
| History of blood donation | 0.17 | Repeat donors had lower risk, suggesting effective screening |
The dramatically elevated risk associated with blood transfusion history (OR=22.8) highlights the challenges Yemen has faced in ensuring blood safety 9 . Before implementation of rigorous screening protocols, the blood supply itself could transmit infections, creating a vicious cycle of transmission.
This traditional healing technique, which involves creating suction on the skin, can transmit bloodborne viruses if the equipment isn't properly sterilized between sessions 9 .
Surprisingly, routine dental care emerged as a significant risk factor, suggesting infection control in dental settings may need strengthening.
The strong association with malaria may reflect shared risk factors or possibly the effect of malaria on the liver, making it more susceptible to other infections.
Understanding these local contextual factors is essential for designing effective, culturally appropriate prevention programs.
The Aden study employed a cross-sectional design with systematic sampling of all blood donors attending the national blood bank service in Aden between June and October 2007 9 . This approach provided a representative snapshot of the blood donor population during this period.
Researchers selected donors every other day, resulting in a final sample of 469 male donors. The exclusive participation of men reflects cultural norms around blood donation in Yemen.
Participants completed a structured questionnaire gathering information on:
Using a hepatitis B antigen detection kit with enzyme immunoassay
Using the IMx HCV version 3.0 system
All testing followed manufacturer instructions to ensure reliability.
The laboratory results revealed 24 HBsAg-positive cases and 6 anti-HCV-positive cases among the 469 donors. But the crucial insight came from connecting these infection statuses with the questionnaire data through multivariate analysis.
| Characteristic | Category | HBV Prevalence | HCV Prevalence |
|---|---|---|---|
| Education | Less than high school | 5.8% | 1.5% |
| High school or more | 4.2% | 1.0% | |
| Residence | Urban (Aden) | 4.8% | 1.2% |
| Rural | 5.9% | 1.4% | |
| Donation History | First-time | 7.1% | 2.1% |
| Repeat | 3.2% | 0.6% |
The findings provide a roadmap for targeted interventions—by focusing on the identified risk factors, public health authorities can maximize the impact of limited resources.
Implement rigorous screening protocols for all donated blood
Enhance infection control in dental and healthcare settings
Train cupping practitioners in proper sterilization techniques
Modern hepatitis research and screening depend on specialized reagents and laboratory materials. Here are the key components of the viral hepatitis detection toolkit:
| Reagent/Material | Primary Function | Application in Hepatitis Research |
|---|---|---|
| Enzyme Immunoassay Kits | Detect viral antigens or antibodies | Initial screening for HBsAg and anti-HCV |
| Nucleic Acid Testing Systems | Amplify and detect viral genetic material | Confirm active infection; detect window period infections |
| Recombinant Immunoblot Assay | Confirm antibody specificity | Verify positive screening results; reduce false positives |
| Viral RNA Extraction Kits | Isolate viral genetic material | Prepare samples for molecular detection methods |
| PCR Primers and Probes | Target specific viral sequences | Amplify HBV DNA or HCV RNA for detection |
These tools represent the evolution from first-generation hepatitis tests—which had limited sensitivity and specificity—to modern high-precision detection systems that can identify even low-level infections.
The Aden study utilized standard enzyme immunoassays, which were the cornerstone of hepatitis screening in 2007 9 . Today, many blood screening programs have added nucleic acid testing (NAT), which can detect infections during the "window period" before antibodies appear, further enhancing blood safety.
The 2007 Aden study provided invaluable insights into the silent epidemic of viral hepatitis in Yemen. The findings revealed an intermediate endemicity for HBV and a concerning prevalence of HCV among blood donors, with specific medical and cultural practices driving transmission.
Perhaps the most encouraging finding was that repeat blood donors had dramatically lower infection rates, demonstrating that effective donor education and screening can significantly reduce transmission risk 9 . This suggests that expanding these practices to the general population could similarly reduce infection rates community-wide.
In healthcare and dental settings
Traditional therapy providers about sterilization
Against hepatitis B
Tests for the blood supply
While challenges remain, the scientific evidence provided by studies like the Aden investigation lights the path forward. Through continued research, targeted interventions, and global cooperation, a future free of these silent killers may be within reach for Yemen and similar regions struggling with high hepatitis prevalence.