Corresponding Author: Patricia F. Walker, MD, DTM&H, Associate Professor, Division of Infectious Disease and International Medicine, Department of Medicine, Staff Physician, HealthPartners Center for International Health, Medical Director, HealthPartners Travel and Tropical Medicine Center, 451 North Dunlap St, St Paul, MN 55104, USA. E-mail: Patricia.email@example.com
In this issue of the Journal of Travel Medicine, Johnson and colleagues review the risk of acquisition of hepatitis B in international travelers. They found that the monthly incidence of hepatitis B virus (HBV) acquisition in long-term travelers to endemic countries ranges from 25 to 420 per 100,000. In the same issue, a study of short-term travelers from Australia to Asia analyzing paired pre-travel and post-travel sera showed a much lower incidence of 2.19 new hepatitis B infections per 10,000 travel days. This is in agreement with a recent study of Danish travelers where the monthly incidence of HBV was estimated to be 10.2 per 100,000. Multiple factors, including HBV prevalence in the destination country, visiting friends and relatives (VFR) status, risk activities, or medical care during travel, all impact risk of HBV acquisition. These at-risk travelers should be offered hepatitis B vaccination.
Pre-travel consultation is also an opportunity to identify previously undiagnosed HBV infection in travelers known to be at risk of HBV infection as underlined in one article published in the 20.1 issue of the Journal. The authors evaluated the behavior of travel medicine practitioners in Boston, MA, as it relates to screening travelers for hepatitis B. In this study, provider behavior in relation to testing for HBV as well as characteristics of those tested and immunized for HBV were analyzed over a 25-month period: 16% of patients were born in HBV-risk countries, only 25% had previous HBV test results at their travel clinic appointment and 11% had tests performed at their travel clinic visit. Among 230 travelers tested during their travel clinic visit, 3.3% were HBV infected (HBsAg-positive), 43.6% immune (anti-HBs-positive), and 59.2% susceptible by serologic testing. The US National Health and Nutrition Survey data from 1999 to 2006 showed an overall prevalence rate in the United States for chronic HBV infection of 0.27%, indicating that in this group of US travel clinics in Boston, patients are more likely to be travelers at higher previous risk of HBV infection. Travel clinics that see a larger proportion of VFR travelers may be predicted to have similar results.
The results of these studies offer some hope for progress in reducing hepatitis B infection and its long-term sequelae, and also reveal that there is significant room for improvement in our educational and clinical practices.
The Importance of Identifying HBV Carriers
Carriers are under diagnosed in the United States. In addition, it is estimated that only 4% to 5% of chronically HBV-infected patients are screened, enter a health system, and obtain treatment. In 2008, the Centers for Disease Control and Prevention (CDC) issued guidelines recommending HBV screening for all persons born in geographic regions with an HBsAg prevalence of >2% (many of whom are VFR or last-minute travelers), all US-born persons who were unvaccinated as infants and whose parents were born in regions of high HBV endemicity (≥8% HBsAg prevalence), and individuals with parenteral risk factors.
Ironically, newly arrived refugees to many countries may have the highest screening rates for hepatitis B of any foreign-born population, as in many countries refugees undergo standardized screening upon arrival to a resettlement country. As one example, in Minnesota, 98% of refugee new arrivals in 2010 were screened for hepatitis B. It is the other large cohort of migrants, ie, those who have lived outside their country of origin for >1 year according to the United Nation's definition, who may be at the highest risk for undiagnosed hepatitis B infection. This includes foreign workers, professionals, the undocumented, adoptees, and others. A recent economic analysis by Eckman and colleagues showed that the 2% HBV prevalence threshold in current CDC/US Public Health Service screening guidelines is cost-effective.
Identifying carriers allows for education and interventions to reduce risk of both vertical and horizontal transmission. For the individual infected with chronic HBV, treatment and routine screening for liver cancer may be offered. Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the third leading cause of cancer-related deaths. Although optimal methods of screening and cost-effectiveness of surveillance for HCC remain to be established, systematic screening still offers the best hope for early diagnosis, treatment eligibility, and improved survival.[12, 13] Guidelines of the American Association for the Study of Liver Diseases suggest that surveillance should be performed using alpha-fetoprotein and ultrasonography at an interval of every 6 to 12 months. Treatment with interferon, nucleoside, and nucleotide analogs reduces the risk of developing HCC in chronic hepatitis B carriers, highlighting the importance of screening for and identifying HBV carriers.
The Need to Educate Providers
The pace of international travel has outpaced medicine's ability to educate clinicians or patients about diseases with higher prevalence in developing countries, such as hepatitis B. For those providers not trained in global health, “You don't know what you don't know” remains a very real clinical problem that worsens health disparities. This knowledge gap can be partially addressed through design and implementation of point-of-care educational tools geared toward patient demographic characteristics. We are currently studying the effectiveness of a best practice alert called the “Global Health Wizard,” which utilizes the electronic medical record (EMR) to remind providers to screen appropriate patients for hepatitis B (Figure 1).
In 2010 for HealthPartners Primary Care Division in Minnesota, 93% of patients had race/ethnicity documented, 99% had language preference documented, and approximately 40% had country of origin documented. We are leveraging this demographic data to implement a point-of-care best practice education and order set for HBsAg testing, including further tests for newly identified carriers, for all patients who should be, but have not been screened for HBV carrier status. The EMR prepopulates best practice order sets for approval, assisting clinicians via a “checklist” approach.
Preliminary results from the study show that hepatitis B screening tests were ordered in 12.2% of encounters in active intervention clinics and 5.5% in passive intervention clinics, indicating that assisting providers with best practice order sets may be more effective than passive educational interventions. Uptake by clinicians on the best practice alert is low, perhaps reflecting time pressure in clinic practice as well as “best practice alert fatigue.” As predicted, we are finding previously undiagnosed carriers for hepatitis B: 8 of 245 (3.26%) of the patients tested in the first 4 months of the study were found to be HBV carriers (PF Walker, E Parker, C Enstad et al., unpublished data). Such levels are significantly higher than the overall US prevalence for HBV of 0.27%, and similar to those found in the Boston study published in the 20.1 issue of the Journal.
For many patients, “Where were you born and where have you traveled?” is a stronger predictor of disease risk than race or ethnicity. A checklist approach, based on country of origin and disease prevalence, can be more broadly applied to many other health issues facing globally mobile populations, and can provide evidence-based best practices that are made available real time, via EMRs or handheld applications, to clinicians caring for globally mobile populations.
In addition, concerted outreach to communities at higher risk of HBV infection, including the last-minute and VFR travelers, may help with improving patient knowledge and uptake of HBV immunization. Ethnic-specific media including print, radio, and television programs have been shown to be effective outreach tools, such as the ECHO program and the Hajj Travelers Outreach Project (C. Bowron, personal communication). Loo and Pryce are piloting a laminated card for patients to carry that would alert providers to the need to screen them for hepatitis B, an ideal intersection of education for both patients and their providers.
Recommendations from travel medicine providers should consider countries with greater than 2% hepatitis B prevalence: if patients were born in such countries, screen to be certain they are not already carriers; if patients are traveling to such countries, they should be offered HBV vaccination. Travel clinicians should work to heighten awareness on the part of patients, primary care providers, and travel medicine colleagues toward screening and immunization for hepatitis B, a vaccine-preventable cancer.
This research was funded by the Program in Health Disparities Research, University of Minnesota, and conducted with the support of HealthPartners Institute for Education and Research staff.
Declaration of Interests
The author states that she has no conflicts of interest.