HEV infection is a major public health concern. Large-scale epidemics and sporadic cases of acute viral hepatitis in developing countries are caused by Hepatitis E Virus. The infection is generally mild and self-limiting. HEV during pregnancy, especially in the third trimester, is a potential risk factor for fulminant hepatic failure and maternal death. Out of 100 antenatal women screened for HEV antibodies, nine ( 9%) of them were found to be positive in our study. All participants are asymptomatic, no signs of liver involvement are noticed. Overall seropositivity is 9%. Totally, six of them were positive for IgM and five for IgG. This type of low positivity was reported by many authors in their studies. In our country, many studies have been done to find out the seroprevalence of HEV infection and some studies specifically targeted pregnant women as they are more vulnerable to this infection. Most of the studies were aimed to detect IgG antibodies. Our study coincides with a previous study performed in Chennai, Tamil Nadu study where a prevalence rate of 14% was reported Sivasangeetha et al.¹¹ This explains that the lifestyle of Chennai people are not much different from our region in relation to their educational status, sanitation practice and the quality of drinking water. A study from France showed a 7.7% prevalence, which is also similar to our finding. None of the HEV IgG positive women reported a history of liver disease.¹²

A high seropositivity, 33.67% is reported in a study carried out in Delhi, where the investigated population was also represented by asymptomatic women.¹³ In a study from Bangladesh, out of the 255 asymptomatic pregnant women, 96 (37.6%) tested positive for anti-HEV IgG antibodies.

Higher seroprevalence of anti-HEV IgG (57.4%) was observed among pregnant women of lower middle class compared to the upper middle class (15.1%) by Sultana, G et al. from Bangladesh.¹⁴ Higher prevalence was associated with low socioeconomic status, which is considered as one of the risk factors.¹³ Educational status has no significance observed in our study. Studies show significantly higher prevalence among the urban population than  in the rural population. A report from Vellore proved that 19.91% positive in urban population, but only 9.09% seen in the rural population. In our study, the same finding was  observed, 27.7% and 4.9% positivity seen among the urban & rural population respectively. “There is an increasing trend in HEV antibody seroprevalence, which was observed in some studies but that result was not significant according to the authors.”

As far as IgM 6% of samples tested were found to be positive. The presence of IgM indicates acute infection, but all participants in our study were asymptomatic. There was no signs of jaundice. Past history of jaundice had given by 9 antenatal mothers. Out of the six positive cases, two of them had jaundice during their school days. There are wide range in seroprevalence reported from national and global studies. A study performed in Nigeria showed 0.4% positive for HEV IgM among pregnant women. Singh et al.¹⁵ from “All India Institute of Medical Sciences” (AIIMS), Delhi, studied in symptomatic patients suspected of AVH. A very high positivity (40%) for IgM noticed. In 2003 another study from same centre showed 36.6% positivity for IgM anti-HEV antibodies among suspected antenatal women.¹⁶ In both the above mentioned studies, study subjects were suspected patients. So the positivity was high. A study performed at the Red Crescent General Hospital and Saint Elizabeth Hospital, Hyderabad, showed 48.9% of HEV infected pregnant women were having severe complications.¹⁷ Our study subjects are asymptomatic women, so we have not aimed to know about the complications. HEV infection during pregnancy, especially in the third trimester, leads to poor fetomaternal outcomes due to fulminant hepatitis.

Anuradha et al.¹⁸ reported a high (60%) prevalence of HEV IgM, which is very high compared to our study. In their study they have used Rapid test (ICT) for the detection of IgM. Also majority of participants use open sanitation practice, which is one of the risk factors associated with the HEV prevalence.¹⁸

In our study majority of participants are well educated (59%). Previous studies have reported that HEV IgG seropositivity was more common in women who did not complete their higher secondary level of education.¹⁴ Our study found that 20% positivity in people who have not completed higher secondary which is little higher (14.6%) than those who have done graduation and post graduation. Study by Bigna et al., from Cameroon, reported seroprevalence of 3.5% in asymptomatic pregnant women.¹⁹ Another similar study from China, 6.0% of pregnant women were positive for anti-HEV IgG antibody, 0.3% were anti-HEV IgM antibody positive and 0.3% were positive for both anti-HEV IgG and anti-HEV IgM antibodies, which was well in concordance with our study.²⁰ Mustafa et al.²¹ in their study reported high prevalence of 40% for IgG antibodies and 6% positive for IgM antibodies, access to healthy food and clean water is almost impossible for study participants. Such conditions provide a great environment for disease.

In our study all participants belong to third trimester. It was reported that prevalence rate is more among pregnant women in third trimester than first and second trimester.¹⁴

The reason for these variation in prevalence rate as reported from various part of country could be due to early childhood HEV exposures producing long lasting immunity. Positivity also noted in close contacts of patients in some studies.