Epidemic hepatitis E: serological evidence for lack of intrafamilial spread.

INTRODUCTION

Hepatitis E presents as epidemic as well as sporadic disease. Fecal contamination of drinking water results in epidemics of hepatitis E. The extent of intrafamilial spread needs to be assessed employing serological assays.

AIMS: To understand the dynamics of intrafamilial spread of the disease.

METHODS

The study was conducted using blood samples collected during the 1988 and 1989 epidemics of viral hepatitis in Kudal and Atit villages of Maharashtra state; the epidemics were subsequently shown to be due to hepatitis E virus (HEV). The one-time collection carried out at the end of the Kudal epidemic was from 184 apparently healthy individuals irrespective of family history of jaundice during the epidemic. In the Atit epidemic, 153 family contacts of 49 IgM anti-HEV positive patients were bled. An additional 151 blood samples were collected from apparently healthy individuals irrespective of family history of jaundice during the epidemic. One month later, blood samples were collected from 64 of the 153 family contacts. Relevant history was recorded each time. All serum samples were tested for ALT levels and for IgM and IgG antibodies to hepatitis E virus employing ELISA.

RESULTS

IgM anti-HEV positivity among persons with family history of jaundice was not different from those without such a history (8/62 [12.9%] and 11/122 [9%] at Kudal; 9/57 [15.8%] and 22/94 [23.4%] at Atit; p > 0.1). Excluding IgG anti-HEV positive samples from the analysis also yielded non-significant results. Of the 32 follow-up samples collected from family contacts without IgG or IgM antibodies to HEV in the initial blood sample, 31 remained IgM and IgG anti-HEV negative at the end of 1 month. One of the family contacts was found to be IgG anti-HEV positive in the second blood sample. The disease was not related to the index case.

CONCLUSION

Intrafamilial spread of HEV is negligible.