According to the study of Zhenzhen Pan et al. (2023) on the efficacy of various serologic assays for hepatitis D antibodies, regardless of the availability and quantity of sensitive and specific hepatitis D antibody serologic tests, obstacles in conducting epidemiological studies on hepatitis D persist. This study has multiple of challenges due to its limited data available for each serological test, exclusion of non-english articles, high heterogeneity of the meta-analysis, and lastly HDV diagnosis is generally based on HDV RNA detection as the gold standard, but this gold standard has some problems. On the one hand, in clinical practice, HDVRNAdetection is usually only performed when the HDV serological test is positive, which results in a sensitivity much higher than the actual value. On the other hand, the sensitivity of the dot hybridization method used to detect HDV RNA in early included studies is much lower than that of the RT-PCR method used in recent years. If this standard is used, a higher than actual serological detection sensitivity will be obtained. As there is no fully standardized PCR detection technique to date, results from different laboratories are also not comparable. Since there is still no standard reference, relevant regulatory agencies should develop relevant standards as soon as possible to standardize HDV diagnosis. In addition, the study included a large time span, which included a period of rapid development of serological detection methods. The early literature included relatively ancient serological detection methods, which cannot represent the accuracy of serological diagnosis at the present stage, and therefore led to less reliable results.

The challenges of studying the epidemiology of hepatitis D include its dependence on hepatitis B infection, limited understanding of transmission routes, asymptomatic cases, and the need for specialized testing methods.