hepatitis e virus ( hev ) infection is commonly an acute hepatitis infection caused by a non - enveloped , single - stranded rna virus belonging to genus hepevirus , family hepeviridae ( 1 ) .
this virus remains infectious in sewage ; therefore , it can be transmitted by fecal - oral route , especially faeces - contaminated water in developing countries ( 1 , 2 ) .
blood transfusion and zoonotic hev infection have a role in the spread of the virus in developed countries where sporadic cases of hev infection have been reported ( 3 ) .
there is some evidence suggesting that persons who receive blood from hev infected blood donors experience acute hepatitis after blood transfusion ( 4 ) .
the clinical symptoms of hev infection are acute , self - limited hepatitis in healthy individuals ( 6 ) .
pregnant women and patients with underlying liver disease are at high risk of fulminant and fatal hev infection ( 1 , 7 - 9 ) . according to what was said ,
hev is a considerable public health problem all around the world , especially in developing countries due to poor sanitation and lack of sewage infrastructures ( 10 ) .
although epidemiological data shows that hev infection is endemic in developing countries of asia , africa , and the middle east , it has been proved that this infection is also increasing in developed countries ( 10 ) .
there has been relatively little research on the prevalence of hev in iran ; therefore , this study was an attempt to address the issue of the high seroprevalence of hev among voluntary blood donors in bushehr , iran .
this study was approved by the ethics committee of bushehr university of medical sciences and bushehr blood transfusion organization to estimate the presence of hev in voluntary healthy blood donors .
based on previous studies and the reported prevalence ( 11.5% ) in other areas in southwest of iran ( 2 ) as well as the confidence level of 95% and an estimated error of 2.5% , the required sample size was 626 . in the present study , 628 anonymized blood samples during a cross - sectional study were collected from iranian blood transfusion organization from september to october 2013 .
blood samples were collected after completing the standard questionnaires ( 11 ) and obtaining the formal written consent of bushehr university of medical sciences .
the presence of anti - hev antibody in human sera was tested by a commercial enzyme - linked immunosorbent assay ( elisa ) kit ( hev igg , pasto , iran ) according to the manufacturer s instructions .
all of the reactive samples were analyzed by liver functional tests including albumin , bilirubin , serum glutamic oxaloacetic transaminase ( sgot ) , and serum glutamic pyruvic transaminase ( sgpt ) to determine acute hev infection and were rechecked by second elisa kit ( hev igg / igm ; dia.pro srl , milan , italy ) .
all the samples were negative for hiv - antibody ( ab ) , hepatitis b surface antigen ( hbs - ag ) , and hepatitis c virus antibody ( hcv - ab ) .
all the statistical analyses were carried out by spss 16 program ( spss inc . , chicago , il , usa ) .
descriptive indices , chi - squared and t - test were also used to analyze the data .
all the statistical analyses were carried out by spss 16 program ( spss inc . , chicago , il , usa ) .
descriptive indices , chi - squared and t - test were also used to analyze the data .
a total of 628 blood donors participated in this study ; 598 ( 95.2% ) were male and 30 ( 4.8% ) were female with a mean age of 36.3 years ( ranging from 19 to 65 years ) . of the 628 blood donors , 76 ( 12.1% )
were first - time donors , 450 ( 71.7% ) were regular donors , and others ( 16.2% ) had a record of donation ; 401 ( 63.9% ) donors were younger than 40 , while 220 ( 35% ) were between 40 - 60 years old and 7 ( 1.1% ) were older than 60 years .
all the donors were normal for liver function tests which indicated the absence of acute hepatic infection .
with regard to age , anti - hev igg antibodies were positive in 14 ( 3.5% ) in the group younger than 40 , 86 ( 39.1% ) in the group 40 - 60 years , and 5 ( 71.4% ) in the group older than 60 years .
therefore , it indicated that the anti - hev prevalence increased by increase of age and there was a significant difference between the age groups regarding hev seropositivity ( p = 0.001 ) .
regarding the analysis of the subjects according to gender , 100 ( 16.7% ) in the male group and 5 ( 16.7% ) in the female group were positive for anti - hev igg antibodies .
however , the difference between males and females was not significant ( p = 0.614 ) .
overall , 105 blood samples ( 16.7% ) showed positive hev - specific - igg antibodies while 523 ( 83.8% ) donors were negative ( table 1 ) .
anti - hev igg antibody is a demonstrator of past infection and can be used for studying the hev epidemiology .
hev prevalence has been determined in different parts of iran which is considered as an endemic country for hev infection ( 4 , 6 ) . however , there are no documented data regarding the hev prevalence in bushehr province . therefore , we measured the anti - hev seroprevalence among healthy blood donors in bushehr and noticed a prevalence of 16.7% , which was higher than what was reported among iranian blood donors ( table 2 ) .
the hev seroprevalence among the general population of developed countries is low ( 0.4% - 3.9% ) ( 6 ) .
according to our results , a high hev seroprevalence rate of 16.7% was observed among volunteer the blood donors in bushehr province , which was higher than those obtained among the blood donors in switzerland ( 4.9% ) ( 9 ) , brazil ( 2.3% ) ( 16 ) , and france ( 3.20% ) ( 17 ) .
however , it was less than the reported values of blood donors in china ( 27.42% and 32.60% ) ( 18 , 19 ) , saudi arabia ( 18.7% ) ( 20 ) , and the netherlands ( 27% ) ( 21 ) .
we noticed that the hev seroprevalence increased with age and there was a significant association between age and higher hev prevalence .
this finding agrees with a similar study in isfahan , iran , which showed that hev seropositivity increased with age from 0.9% in children to about 8% in subjects aged over 50 years ( 22 ) .
seropositivity was 3.5% in people aged below 40 years and 71.4% in people over 60 years old . in the present study ,
no association between gender and hev seroprevalence was detected and none of the suited samples were positive for hiv , hbv , and hcv infectious markers .
similar results were reported by most other studies ( 4 , 6 , 9 , 21 ) . in conclusion ,
the high hev seroprevalence of 16.7% was observed among the blood donors in bushehr province , iran . according to our results
, we came to this conclusion that bushehr province is an endemic area for hev infection .
it appears that exposure to hev increases with the increase of age ; although , more people should be examined .
however , further studies are needed to assess this matter with studying more populations and considering similarity of numbers of each studied group according to gender and age .
 background : although so far several studies have determined the hepatitis e virus ( hev ) prevalence in some parts of iran , no data exists regarding the hev seroprevalence in bushehr province as the southernmost point in iran yet.objectives:the aim of this study was to evaluate the seroprevalence of anti - hev igg among the blood donors in bushehr.patients and methods : a total of 628 blood donor samples were collected from september to october 2013 , after obtaining informed written consents , and analyzed for the presence of anti - hev igg using commercial hev enzyme - linked immunosorbent assay ( elisa ) kit . 
 all the samples were tested by two elisa kits and evaluated for liver function test.results:overall , 105 ( 16.7% ) blood samples were positive for hev - specific - igg antibodies , while 523 ( 83.8% ) were negative . 
 the presence of anti - hev igg was not associated with gender ; however , it was correlated with age . 
 it was indicated that the anti - hev prevalence increases by age and there was a significant difference between the age groups regarding hev seropositivity.conclusions:high hev seroprevalence ( 16.7% ) was observed among the blood donors in bushehr province . 
 it appears that exposure to hev increases with age ; although , more people should be examined . 
1. Background
2. Objectives
3. Patients and Methods
3.1. Statistical Analysis
4. Results
5. Discussion