Sero-prevalence and mother-to-infant transmission of hepatitis E virus among pregnant women in the United Arab Emirates.

OBJECTIVES: (1) To study the prevalence of HEV infection in a cohort of pregnant women in the United Arab Emirates (UAE). (2) The rate of mother-to-infant transmission.

METHOD: Sera of 469 pregnant women residing in the UAE was tested for anti-HEV with ELISA and for HEV-RNA by polymerase chain reaction (PCR). Neonatal cord-blood and infant blood was similarly tested for anti-HEV and HEV-RNA. Out of these 469 women, 33% were UAE nationals (Group A) and Egyptians (Group B), respectively, and 34% were from the Indian sub-continent (Group C).

RESULTS: Out of 469 mothers 93 (20%) were anti-HEV positive and 28 (30%) of these 93 were HEV-RNA positive and symptomatic with on-going infection. The prevalence of anti-HEV was significantly increased amongst Groups B and C (Group A:B, P<0.001; Group A:C, P<0.001). Twelve of these 28 symptomatic women developed acute hepatic disease and two died undelivered, thus, were excluded from further study. Six of the remaining 10 women had non-fulminant acute viral hepatitis and four developed fulminant hepatic failure, of which one died in the early post-partum period. The remaining 16 women had mild symptomatic disease with complete recovery as did the remaining nine women with acute illness. Of the 10 babies born to mothers with acute disease, two were pre-term, three had anicteric hepatitis and two babies were born with hypothermia and hypoglycaemia and died within 48h. Noteworthy is the fact that, the 26 infants born to the 26 HEV-RNA positive mothers developed acute/on-going clinical infection and were HEV-RNA positive. Apart from the two early neonatal deaths, the remaining 24 infants had full recovery. No infant of the other mothers were symptomatic or had HEV-RNA. Thus, the mother-to-infant transmission was 100%. The remaining 65 sero-positive women remained asymptomatic with no evidence of clinical infection, continued to be HEV-RNA negative and delivered at term. Their infants had no evidence of infection and were sero-negative by 9 months of age, suggesting transplacental transmission of IgG antibodies.

CONCLUSIONS: There is a high prevalence of anti-HEV among pregnant women residing in the UAE. Twelve of infected women developed fulminant/acute hepatitis resulting in three fatalities. Evidence suggests significant vertical transmission of HEV among HEV-RNA positive mothers with appreciable perinatal morbidity and mortality. Excluding mothers with acute hepatic disease, Breast-feeding appears to be safe in HEV sero-positive mothers.