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Hepatitis B virus (HBV) is a major global health concern, affecting more than 250 million people worldwide. Beyond the well-known, surface antigen–positive infection lies a more elusive challenge: occult HBV infection (OBI) — a condition where HBV DNA persists in the body even when hepatitis B surface antigen (HBsAg) tests negative.

This silent infection can remain undetected for years, allowing HBV to spread within communities, evade early treatment, and reactivate under conditions of immunosuppression, sometimes with severe consequences such as liver failure or hepatocellular carcinoma.

A recent study published in BMC Research Notes¹ examined this phenomenon in northern Uganda, a region with high HBV endemicity. The findings shed light on how OBI can silently sustain HBV transmission within the community and pose a risk of viral reactivation, even in individuals with no overt clinical symptoms.

What the Study Found

Researchers screened 387 HBsAg-negative individuals and found that 5.43% had detectable HBV DNA, confirming occult infection (OBI). Most OBI cases were observed in participants under 30 years old, and the majority were positive for anti-HBc (hepatitis B core antibody), indicating prior exposure or resolved infection. Interestingly, liver enzyme levels (ALT and AST) were largely within normal ranges, highlighting the clinically silent nature of OBI.

Despite the absence of detectable HBsAg, these individuals still carried HBV DNA, meaning they could potentially transmit the virus through blood and were at risk of viral reactivation, particularly under immunosuppressive conditions.

The researchers emphasized the urgent need for more sensitive and accessible diagnostic strategies to identify OBI, especially in regions where routine nucleic acid testing (NAT) is limited or unavailable.

Why Occult HBV Matters

Occult infections carry several important risks:

• Blood safety: OBI can escape standard screening, leading to potential transmission via transfusion or transplantation.
  
• Reactivation: In patients undergoing chemotherapy, HIV treatment, or organ transplantation, latent HBV can reactivate with serious outcomes.
  
• Public health surveillance: Traditional screening programs may underestimate true HBV prevalence if OBI is overlooked.

While this study focused on Uganda, the findings have global relevance, particularly in regions where HBV is endemic and testing infrastructure is limited.

Moving Toward Better Screening

Detecting OBI requires a combination of serological and molecular approaches. While NAT remains the gold standard, serological markers such as anti-HBc can help identify individuals who may require further molecular testing.

Point-of-care (POC) diagnostic tools can play an important role in broadening early screening, particularly when lab-based PCR testing is inaccessible. Rapid screening platforms — including Healgen’s HBsAg and HBcAb tests — provide accessible first-line tools to identify at-risk individuals and guide confirmatory testing strategies.

By combining reliable serological screening with targeted molecular follow-up, healthcare programs can more effectively capture the “hidden” cases that sustain HBV persistence.

Looking Ahead

The study reinforces that HBV control requires more than vaccination and treatment. Addressing the silent reservoir of OBI is essential to reduce transmission, prevent reactivation, and protect vulnerable populations. Expanding access to high-quality diagnostic tools and raising awareness of OBI can strengthen screening programs and public health efforts.

For laboratories and community health programs looking to strengthen HBV screening frameworks, tools like Healgen’s rapid tests can complement national strategies, bridging the gap between initial detection and molecular confirmation.

References

¹ Kafeero, H.M., Ocama, P., Ndagire, D. et al. The status of occult HBV infection in a high endemic region: risk of community HBV transmission and reactivation. BMC Res Notes 18, 255 (2025). https://doi.org/10.1186/s13104-025-07337-6

Disclaimer: This article highlights findings from a peer-reviewed study published in BMC Research Notes (2025). Original study: Kafeero, H.M., Ocama, P., Ndagire, D. et al. “The status of occult HBV infection in a high endemic region: risk of community HBV transmission and reactivation.” https://doi.org/10.1186/s13104-025-07337-6