Early identification of CHB-LTBI co-infection could guide clinicians to modify management of both CHB and LTBI to reduce the risk of drug-induced liver injury.

Chronic hepatitis B (CHB) and latent tuberculosis (LTBI) remain major infectious diseases that contribute to significant morbidity and mortality worldwide. While both CHB and LTBI manifest with different clinical phenotypes, with one being primarily a liver disease and the other primarily a pulmonary disease, there are important overlaps with the epidemiology of these two conditions, including demographics and risk factors. In the United States, screening for CHB and LTBI remains primarily risk-based, although recent data continue to support discussions on expanding hepatitis B virus (HBV) screening to a universal approach. Despite the overlapping epidemiology, there is a lack of data on understanding CHB-LTBI co-infection, particularly among US populations. Understanding prevalence of CHB-LTBI co-infection, as well as practice patterns as it relates to HBV and LTBI testing, is particularly important given that underlying CHB increases the risk of drug-induced liver injury from anti-tuberculosis therapies. Thus, early identification of CHB-LTBI co-infection could guide clinicians to modify management of both CHB and LTBI to reduce the risk of drug induced liver injury.

In our current study published in the Journal of Public Health Management and Practice, we utilized Quest Diagnostics clinical laboratory data from 2016 to 2020 to evaluate practice patterns as it relates to laboratory testing to evaluate for CHB-LTBI co-infection. Among our cohort of over 89,000 CHB individuals identified, only 10.7% of individuals had laboratory testing to evaluate for LTBI. These low rates of testing are particularly concerning, given that many CHB patients in the US, who are predominantly immigrant populations, have co-existing risk factors that would warrant testing for LTBI. Even more striking, the prevalence of CHB-LTBI co-infection among individuals that were tested was 19.6%, more than two times higher than LTBI prevalence in a comparator cohort of individuals without CHB. These data emphasize two concerning patterns – 1) Individuals with CHB have higher risk of concurrent LTBI, and 2) low rates of testing for LTBI were observed among this representative cohort.

When we flipped the question around and asked it slightly differently – among individuals with LTBI, what proportion were tested for HBV – similarly concerning findings were observed. Among nearly 395,000 individuals with LTBI identified, less than one-third of patients were tested for HBV. As previously discussed, testing for HBV in patients with LTBI is clinically relevant not only because of similar risk factors but also because existing data suggest an increased risk of drug- induced liver injury with certain anti-tuberculosis therapies. Thus knowing if underlying CHB is present is critical to guide clinicians to modify their treatment approach to avoid the potentially preventable liver injury that can occur with certain medications such as isoniazid. Among individuals with LTBI that were tested for HBV, we observed HBV prevalence of 1.5%, which is three times higher than a comparator cohort without LTBI. These data emphasize the need for greater awareness and vigilance towards ensuring routine testing for CHB-LTBI co-infection among individuals with CHB or LTBI.

While both LTBI and CHB are disease states for which asymptomatic screening remains a risk-based approach, our data highlight the importance of ensuring routine testing for CHB-LTBI co-infection among CHB and LTBI populations. Furthermore, while current advocacy efforts and discussions towards expanding HBV screening to a universal approach may further address these gaps in testing we have identified, we must be cognizant that new policies to expand HBV screening must be accompanied by adequate public health resources and innovative approaches to effectively implement any new recommendations so that underserved and resourced-limited settings and individuals are not left behind.

Read the Research Report:

• Prevalence of Hepatitis B Virus and Latent Tuberculosis Coinfection in the United States

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