Exposure to HBV among patients with HCV is common, although coinfection is relatively rare and associated with male sex, younger age and HIV positivity, according to recent results.
Researchers collected data on patients in the National Veterans Affairs HCV Clinical Case Registry who were tested for HCV between 1997 and 2005. The cohort included 168,239 people exposed to HCV and tested for HBV.
Patients with records indicating two positive HCV tests, or one test and an ICD-9 code for HCV were considered exposed; those with positivity for HCV RNA or a genotype were classified as infected. Patients with positive test results for hepatitis B surface antigen (HBsAg), HBV DNA, hepatitis B e antigen (HBeAg) or hepatitis B core or Be antibodies were considered exposed. Those with a positive HBsAg, HBV DNA or HBeAg test within 1 year of HCV diagnosis were considered coinfected.
HBV exposure occurred in 34.7% of the cohort. HCV infection was observed in 102,971 patients, 1.4% of whom were HBV coinfected.
Factors independently associated with HBV/HCV coinfection included patients aged 50 years or younger (OR=0.77; 95% CI, 0.69-0.86 for patients aged 51 to 64 years and OR=0.5; 95% CI, 0.36-0.69 for 65 years and older), male sex (OR=1.76; 95% CI, 1.17-2.64), HIV positivity (OR=2.03; 95% CI, 1.72-2.38), cocaine and other drug use (OR=1.23; 95% CI, 1.09-1.40 for cocaine), having undergone blood transfusion (OR=1.63; 95% CI, 1.28-2.08) and having sicklemia, hemophilia or thalassemia (OR=1.95; 95% CI, 1.04-3.68). Investigators said Hispanics were at reduced risk for coinfection (OR=0.68; 95% CI, 0.51-0.92 vs. Caucasians).
“This is the largest study in the US to examine the prevalence and predictors of HBV coinfection in a cohort of patients with HCV,” the researchers wrote. “Based on these findings, all patients with HCV exposure should be tested for HBV. Additionally, this study identified risk factors more frequent in patients with HBV coinfection than HCV mono-infection. These predictors of HBV coinfection can be used to target screening and prevention programs to those individuals who may be at greatest risk for coinfection.”