Risk of Hepatitis B transmission by healthcare workers - a systematic review.

BACKGROUND

The risk of transmission of hepatitis B virus (HBV) to healthcare workers (HCW) is well known. However, evidence for supporting guidelines with respect to exclusion of infected HCW from exposure prone procedures (EPP) remains poorly characterized.

METHOD

A systematic review of studies published providing serological data for transmission of HBV infected HCW to patients was performed. Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) we searched MEDLINE, Scopus and Cochrane databases to identify publications prior to September 2024.

RESULTS

The literature search yielded 311 studies and 39 from nine countries met the inclusion criteria. A total 53 of HCW were considered as source cases of transmission and 25,000 individuals tested for at least one HBV marker. 66 transmissions by HCW to patients were confirmed through DNA analysis; in 100 patients HBV transmissions were considered probable and in 480 patients at least possible. Of the 36 studies in which HBeAg in HCW was determined, the antigen was positive in 29 studies (80.6%), and negative only in seven studies (19.4%), comprising a total of only 31 and 17 HCW, respectively. The HBV viral load of the transmitting HCW was conducted in only 8 studies including 18 HCW, of those four were HBeAg-positive and 14 HBeAg-negative. Although the viral load in HBeAg-negative sources generally was 10 times lower than in HBeAg-positives, considerable variability was seen in HBeAg-negatives with overlapping values up to 1.5×10 copies/mL. A HBV DNA value of 4×10 copies/mL represents the lower threshold for transmissibility for 18 source cases in all studies, however, for the other 35 no measurements were available. Due to the low evidence on defining an HBV DNA viral load below which HBV transmission from HCW to patients appears unlikely, the safety thresholds for excluding infected HCW from performing EPP in most recent national guidelines (UK, Germany, the Netherlands and the US) still differ by factors of as much as 5 (200 IU/mL to 1,000 IU/mL).

CONCLUSIONS

The published literature on HBV transmission from HCW to patients is sparse and offers only limited guidance on national prevention guidelines.