Table 4.

Factors influencing estimated prevalence of occult HBV infection

Factor	Comment	Reference(s)
Population studied
Risk group	Prevalence rates vary between high-risk groups and low-risk groups	29, 259
Sampling
No. of samples	Occult HBV DNA may be intermittently detected in serum; serial sampling is ideal	113
	HBV DNA may be detected in liver but not in serum	108, 238
Testing
HBsAg testing	Some commercial assays are better suited for detection of HBsAg mutants	147
HBV DNA testing	Targeting multiple regions of the HBV genome improves detection; differences between amplification methods for HBV DNA testing exist	108, 260
Geographical region
HBV prevalence	Endemicity of HBV infection correlates with prevalence of occult HBV infection	166
Coinfections	HCV/HIV coinfections are associated with higher rates of occult HBV infection	29, 170