Background: The risk of infectivity is known to be high in contacts of HBeAg positive chronically infected patient. We investigated and compared the frequency and significance of transmission of HBV infection from chronic liver disease patients (CLD) with HBeAg or anti-HBe and HBV DNA positive status.
Material and methods: Four hundred and seventy nine contacts [first degree blood relatives (n=278), second degree contacts (n=139) and sexual contacts (n=62)] of 92 HBV-related, liver biopsy proven, CLD patients were studied. Three hundred and seventy three belonged to 65 index patients with HBsAg+ve, HBeAg+ve, HBV DNA+ve, HBV DNA+ve infection and 106 belonged to 27 index patients with (HBsAg+ve, HBeAg-ve, anti-HBe+ve, HBV DNA+ve infection). One hundred and seventy six family members, age and sex matched, belonging to 38 healthy individuals, with no history of liver disease or HBV positivity, served as controls. Viral serology and quantitative DNA estimation was done in index patients.
Results: Forty nine of 65 (75.4%) families of HBeAg+ve and 63% families of HBeAg-ve index patients had one or more family member exposed to HBV (positive family, p=ns). The chronic HBV infection (HBsAg+ve) and past-exposure (only IgG anti-HBc+ve) rates in the contacts of HBeAg+ve and HBeAg-ve index patients were 17.4% and 19.8% (p=ns), and 31% and 14.2% respectively, both being significantly higher (P < 0.01) than the prevalence rates in the control group (chronic HBV infection 2.3%, past-exposure 10.2%). Overall, 48.5% and 34% (p < 0.05) of contacts in the HBeAg+ve and HBeAg-ve groups had markers of HBV infection. The quantitative HBV DNA levels were comparable between HBeAg+ve and HBeAg-ve index patients (1712 +/- 356 pg/ml vs 1802 +/- 812 pg/ml). First degree relatives had higher chronic HBV infection rates than second degree contacts (29% vs. 0%, p < 0.05). The duration of symptomatic illness of HBeAg+ve index patients was longer than HBeAg-ve (p < 0.05). A significant proportion of HBsAg+ve first degree relatives of HBeAg+ve (33%) and HBeAg-ve (40%) patients, had evidence of CLD.
Conclusions: (i) The frequency of transmission of HBV infection is nearly similar in contacts of HBeAg+ve and HBeAg-ve infected patients, more so in first degree relatives, (ii) these observations make family contacts a very high risk group, requiring priority screening and vaccination against HBV.