In addition to their suppressive effects against HIV, these drugs feature excellent antiviral activity against HBV. In clinical practice, appropriate use of these agents in HIV/HBV co-infected patients results in a halt or even regression of liver cirrhosis, improvement of biological markers of disease activity and a reduction of emergence of antiviral resistance of HBV. The World Health Organization guidelines on antiretroviral therapy of HIV recommend screening for HBV by means of HBsAg testing and the inclusion of two dually-active drugs in the antiretroviral treatment combination of co-infected patients. So far, routine screening for HBsAg is not included in the eDNA techniques could be used to form cost-efficient multi-species inventory and monitoring programs for sensitive species majority of national HIV programs in SSA. One reason for this might be that standard testing strategies rely on enzyme immuno assays, which require a critical and costly amount of infrastructure and human resources not available outside of urban centers. Therefore, the implementation of a viable screening strategy to identify co-infected patients is crucial as an effective intervention, i.e. cART with dually active components is already in place. Rapid diagnostic testing has successfully facilitated widespread screening for HIV even in rural Africa. Several point of care products for the detection of HBsAg are currently available but their take-up has been limited so far. The practical evaluation of these RDT devices in HIV-positive patients in an African peripheral setting is key in order to study the utility of including them in diagnostic routines. In this study, we prospectively assessed the diagnostic accuracy and feasibility of a scalable product locally in a large HIV outpatient clinic in rural Tanzania. The reported prevalence of detectable HBsAg of 9.2% in our study in HIV-positive patients in Ifakara lies within the range reported from previous studies in the same area and other African settings. It is significantly below the 17.3% found in an HIV outpatient clinic in Dar es Salaam, the urban hub of Tanzania. The same tendency is observed when comparing the prevalence of anti-HCV antibodies of 18.1% in the urban setting, which is almost five-fold higher than the one we found. This marked variance indicates a difference in the presence and/ or modification of risk factors for acquisition of viral hepatitis between rural and urban settings. Differences between these two settings have been reported in SSA before but there is no clear trend in which setting the odds of being infected with viral hepatitis B are higher. A positive HBsAg status was associated with moderately increased ALT levels, which is to be expected due to the hepatic inflammatory state in patients with active replication of HBV. Of the patients with detectable HBsAg, 28% showed HBeAg positivity. A positive HBeAg status is associated with increased HBV DNA levels, thus being a surrogate marker of high level HBV replication. During HBV infection, HBeAg follows the appearance of HBsAg. In turn, during recovery, HBeAg clearance and seroconversion to anti-HBe precede the loss of HBsAg and detection of anti-HBsAg. Therefore it is likely that almost three quarters of our patients with detectable HBsAg were transitioning from a high replicative state to a low replicative state, with lower risk of progressive liver disease and further transmission. This is one of the first studies prospectively evaluating a rapid test for HBsAg in HIV-infected patients entirely at the point of care.