when the hiv epidemic peaked in 1993 , aids was the leading cause of death among 25 - 44-year - old men and women and the eighth most common cause of death worldwide ( 1 ) . injection drug use ( idu ) and unprotected sex are considered as major risk factors for the acquisition of retroviral infection ( 2 - 4 ) , and more than half of people living with hiv are women and girls ( 2 , 5 - 7 ) . because of social , economic , and political differences among regions , the epidemic has not been uniform ( 8 , 9 ) . the most common route of hiv transmission in high - income countries such as the united states and the united kingdom is homosexuality . people who engage in high - risk sexual behaviors in sub - saharan africa and idus in eastern europe and southeast asia are the major at - risk groups ( 10 - 14 ) . in 2011 , adolescents , women , homosexuals , and serodiscordant couples ( i.e. one partner is hiv positive , and the other is hiv negative ) were reported to be the populations with the highest risk of infection ( 10 ) . although the aids epidemic is relatively mild in asia , factors such as low condom use , unsafe injections among injection drug users , immigration , lack of education , and misconceptions about hiv / aids could affect the hiv / aids epidemic in all countries that currently have low prevalence ( 15 - 17 ) . according to estimates by the ministry of health and medical education , as of september 21 , 2011 more than 91% of these patients were men , and approximately 4,400 had died ( 18 ) . needle sharing in idus is the most common route of hiv transmission in men in iran , accounting for approximately 70% of established transmissions . however , studies show an increased rate of high - risk behaviors for hiv infection , particularly unprotected sex ( 18 - 22 ) . in addition , it is important to consider the hiv infection prevalence in specific populations in iran , such as patients with tuberculosis ( 23 ) . rapid changes in the epidemiological characteristics of infectious diseases necessitate health practitioners being aware of the current status of these diseases , especially in cases of pandemic diseases such as aids , whose control requires global efforts ( 24 - 26 ) . in this regard , research should serve as a tool to improve the effectiveness of healthcare systems . successful aids prevention and treatment depend on the complete and accurate identification of at - risk populations as well as regular and standardized data collection , analysis , and interpretation ( 1 , 27 ) . one of the best opportunities to combat aids in iran is the use of the healthcare system . however , behavioral research in the general population and high - risk groups is not systematic , integrated , or consistent ( 24 , 28 ) . the present study investigated the epidemiology of hiv / aids in east azerbaijan , iran . the target population was all patients with hiv / aids in east azerbaijan province , including patients who acquired hiv infection through idu , sexual transmission , mother - to - child transmission ( i.e. vertical transmission ) , and contaminated blood products . the vice chancellor of research and technology of tabriz university of medical sciences ethical committee approval was obtained for the study ( decision number : 5.4.328).first , necessary supplies including computers , telephone lines , etc . ( table 1 ) were extracted and entered into microsoft excel software for classification and sorting . next , data were analyzed , and diagrams and tables were created using microsoft excel and spss . among the 371 patients who were identified by healthcare centers in east azerbaijan from 1987 to 2012 ( figure 1 ) , 91% ( n = 338 ) were men and 9% ( n = 33 cases ) were women . the prevalence of hiv / aids increased along with the population growth from 1987 to 2012 ( data not shown ) , the current prevalence of hiv / aids in east azerbaijan is 1/10,000 . the mean ages of the total , male , and female patients were 30.8  12.3 , 31.3  12.1 , and 28  10.3 years , respectively . approximately 54% ( n = 200 ) of patients were single ( table 1 ) . more than one - third ( n = 131 ) of patients had died , and 27% ( n = 99 ) were actively undergoing regular consultation ( figure 2 ) . the most common transmission route was related to idu ( 59% , n = 219 ) ( table 1 ) . approximately 80% ( n = 208 ) of them had high school or lower ( table 1 ) . the occupational status of 36% ( n = 102 ) and 17% ( n = 48 ) of patients was recorded as  self - employed  and  unemployed ,  respectively ( table 1 ) . the rest of the patients were employed in various jobs ( data not shown ) . available : patients who actively undergoing regular consultation ; unavailable : patients who havent referred to council centers since they have diagnosed as hiv positive . the frequencies of coinfection with hepatitis c virus ( hcv ) , hepatitis b virus ( hbv ) , syphilis , and toxoplasmosis with respect to sex are shown in table 2 . thirty - one of 207 patients ( 15% ) were diagnosed with hbv , and 25 of 371 patients were diagnosed with hiv / hbv / hcv co - infection . p : positive , n : negative , ud : undetermined .   data are presented as no . the prevalence of hiv infection among injection drug users is reported to be 15.07% ( 18 ) . the results of the present study show that idu is the most common hiv transmission route in east azerbaijan province , which is similar to national reports on hiv / aids ( 18 ) . in a study conducted in tehran and kermanshah provinces , unsafe needle sharing was the reported cause of 83% of hiv infections ( 29 ) . another study performed in 2007 in imam khomeini hospital in tehran reports idu as the most common hiv transmission route ( 31% ) ( 30 ) . furthermore , a study conducted by researchers at shiraz university of medical sciences reports 76% of patients had a history of idu . however , in the present study , idu was not the only route of hiv acquisition ( 31 ) , 15% of patients simultaneously had a history of idu and other high - risk behaviors . a study conducted in china in 2008 found that the most common hiv transmission route is idu ( > 43% of transmissions ) ( 32 ) . meanwhile , a study in the us reports the most common hiv transmission route is homosexual contact in men , whereas idu is ranked third ( 1 ) . thus , it seems that educating prisoners and injection drug users , reducing jail time , focusing on public education , making more efforts to provide methadone for people unable to quit their drug addiction , and doing research counseling methods and behavioral disorders at healthcare centers and prisons may improve the current status of the hiv epidemic ( 24 , 33 - 36 ) . many studies conducted in iran report the prevalence of hiv / aids is higher in men than in women ( approximately 85 - 95% higher ) ( 29 , 31 , 37 , 38 ) . however , the 2010 joint united nations programme on hiv / aids global report states that more than 50% of people living with hiv worldwide are women and girls ( 39 ) . the higher prevalence of hiv infection among men in iran and east azerbaijan could be due to a lack of precise data on the number of sex workers , which may partly explain the low rate of hiv / aids in women . hbv and hcv coinfection among patients infected with hiv is common ; and severe complications can occur in these patients ( 40 ) . severe complications can occur in patients with coinfection via the same transmission route of hiv ( 40 - 44 ) . the present results show that 53% of patients with hiv / aids were coinfected with hcv , hbv , or both . in a study conducted in southwestern iran , hcv or hbv however , the prevalence of coinfection with hepatitis viruses in patients with hiv / aids varies among studies as well as populations with respect to exposure to different risk factors , geographic region , and ethnicity ( 41 , 46 ) . one limitation of the present study is that the sample may not be representative of the total population in east azerbaijan province . furthermore , the paper - based records of some patients were incomplete , preventing us from analyzing some variables ( associated to the clinical features ) ( e.g. some laboratory parameters ) . however , the present study is one of the few studies on this topic that have been conducted in iran ; there are no reports from many other provinces . the findings of this study highlight the information gap in this area and help fill in a small part of it . it is noteworthy that some countries have had success in controlling and preventing contagious diseases such as hiv through healthcare systems set up for the general population ; thus , the development of effective methods on the basis of evidence and data is clearly possible ( 22 , 24 , 28 , 47 - 50 ) .
background : this study was performed in response to the rapid propagation of hiv / aids across iran and its status in this region . 
 accordingly , an evidence - based program is required to combat this disease.objectives:the present study estimated the prevalence of hiv / aids in east azerbaijan ( population : 3,724,000).materials and methods : we created a database of all positive cases from 1987 to 2012 . 
 we also analyzed and described the epidemiological status of hiv / aids during a 25-year period by using spss.results:in east azerbaijan , 371 hiv / aids cases have been reported , i.e. 1 case per 10,000 population . 
 the vast majority of reported cases ( 91% , n = 338 ) were men , whereas only 9% ( n = 33 ) were women . the mean age of patients was 30.8  12.3 years . 
 unsafe drug injection ( 59% , n = 219 ) and sexual interaction ( 13% , n = 48 ) were the two major modes of hiv transmission . 
 in addition , 7% ( n = 25 ) of patients have been diagnosed with hiv , hepatitis b virus , and hepatitis c virus simultaneously . 
 moreover , 60% ( n = 205 ) of men were infected via drug injection , while 82% ( n = 27 ) of women were infected via unprotected sexual interaction ( p < 0.001).conclusions : the results indicate a rapid increase in the number of hiv / aids cases in east azerbaijan , necessitating immediate attention and strategies to combat the rapid spread of the disease . 
 development of provincial and national hiv / aids strategies demands more accurate and comprehensive hiv / aids surveillance .