human papillomavirus ( hpv ) infection is considered as the most common sexually transmitted virus infection ( 1 ) . cervical cancer is the second / third leading cause of cancer in females , with an estimated 493,000 cases and 273,000 deaths , annually ( 2 ) . the human papillomavirus genotypes 6 , 11 , 16 and 18 are transmitted sexually and considered as the most common cause of anogenital warts and cervical cancers ( 3 , 4 ) . human papillomavirus are small , non - enveloped , double - stranded circular dna , 8 kb in size , surrounded by a 55-nm capsid . so far , more than 150 genotypes of the virus have been identified ( 5 ) . low risk hpvs result in benign tumors , while high - risk hpvs generate malignant tumors . human papillomavirus types 6 and 11 have low malignant potential ; however , some studies have introduced these types as risk factors for vulvar malignancy ( 1 , 2 ) . genotypes 16 and 18 of hpv are high risk hpvs and responsible for 70% of all cervical cancer cases ( 3 - 5 ) . a high prevalence of hpv genotypes 16 and 53 has been reported in iran ( 6 , 7 ) . the pap smear , cytological evaluations , serological and immunohistochemical staining methods for identification of hpv variants are insensitive . on the other hand , a highly specific and sensitive test for hpv genotyping determination is the polymerase chain reaction ( pcr ) ( 3 ) . thus , the pcr can be a screening test for detection of hpv dna in precancerous lesions of genital warts ( 4 , 5 ) . the present study was conducted to determine the frequency of hpv genotypes in patients with anogenital warts . this study was a cross sectional research designed with 54 patients with anogenital warts referred and registered at the dermatology department of imam hospital of ahvaz city , southwest iran , during 2011 to 2012 . patients with anogenital warts who under treatment , those with severe systemic diseases , and immunocompromised ( cancerous and organ transplanted ) individuals were excluded from the study . the ethical committee of ahvaz jundishapur university of medical sciences approved this study ( eth-488 ) and all patients signed an informed consent form . a questionnaire was set up and completed based on the patients data such as age , gender , marital status , characteristic of lesions ( duration , location and shape ) and physical examination . laboratory tests including venereal disease research laboratory ( vdrl ) , human immunodeficiency virus ( hiv ) , and hepatitis c virus ( hcv ) antibodies as well as hbs ag were carried out for all patients . the warts were diagnosed based on clinical findings for typical lesions while histopathological assessment was performed for suspicious lesions . the samples were then fixed in 10% formalin and sent to a virology laboratory affiliated to ahvaz jundishapur university of medical sciences . the dna was extracted from the patients tissue sample using a high pure pcr template kit ( roche , germany ) , according to the manufacturer s instruction . 5 - tttgttactg tggta gatactac - 3 , and reverse , gp6 5 - gaaaaataaactgtaaa tcatattc - 3 . the pcr reaction mixture was then prepared containing : 5 l template , 1 l dntp 10 mm , 0.3 l enzyme taq polymerase 5 u / ul , 5 l pcr buffers 10x , 1 l of each primer ( gp5 and gp6 ) at a concentration of 30 picomoles and 36.7 l of dnase free water with a final volume 50 l . the pcr reaction mixture including patient samples , positive and negative control was subjected to a thermocycler ( teqlab , germany ) and the following thermal cycles were set up : initial denaturation at 95c for five minutes , followed by 35 cycles of denaturation at 95c for 40 seconds , annealing at 40c for 40 seconds , extension at 72c for 45 seconds , and final extension 72c for three minutes . an amount of 6 l of positive pcr product was electrophoresed on 1.5% agarose and the presence of a 150 bp band indicated a positive reaction . the positive pcr product was then sequenced ( abi sequencer , bioneer co. south korea ) . the results of sequences were blasted using the national center for biotechnology information ( ncbi ) site . for the analysis of variable mean and standard division , this study was a cross sectional research designed with 54 patients with anogenital warts referred and registered at the dermatology department of imam hospital of ahvaz city , southwest iran , during 2011 to 2012 . patients with anogenital warts who under treatment , those with severe systemic diseases , and immunocompromised ( cancerous and organ transplanted ) individuals were excluded from the study . the ethical committee of ahvaz jundishapur university of medical sciences approved this study ( eth-488 ) and all patients signed an informed consent form . a questionnaire was set up and completed based on the patients data such as age , gender , marital status , characteristic of lesions ( duration , location and shape ) and physical examination . laboratory tests including venereal disease research laboratory ( vdrl ) , human immunodeficiency virus ( hiv ) , and hepatitis c virus ( hcv ) antibodies as well as hbs ag were carried out for all patients . the warts were diagnosed based on clinical findings for typical lesions while histopathological assessment was performed for suspicious lesions . the samples were then fixed in 10% formalin and sent to a virology laboratory affiliated to ahvaz jundishapur university of medical sciences . the dna was extracted from the patients tissue sample using a high pure pcr template kit ( roche , germany ) , according to the manufacturer s instruction . 5 - tttgttactg tggta gatactac - 3 , and reverse , gp6 5 - gaaaaataaactgtaaa tcatattc - 3 . the pcr reaction mixture was then prepared containing : 5 l template , 1 l dntp 10 mm , 0.3 l enzyme taq polymerase 5 u / ul , 5 l pcr buffers 10x , 1 l of each primer ( gp5 and gp6 ) at a concentration of 30 picomoles and 36.7 l of dnase free water with a final volume 50 l . the pcr reaction mixture including patient samples , positive and negative control was subjected to a thermocycler ( teqlab , germany ) and the following thermal cycles were set up : initial denaturation at 95c for five minutes , followed by 35 cycles of denaturation at 95c for 40 seconds , annealing at 40c for 40 seconds , extension at 72c for 45 seconds , and final extension 72c for three minutes . an amount of 6 l of positive pcr product was electrophoresed on 1.5% agarose and the presence of a 150 bp band indicated a positive reaction . the positive pcr product was then sequenced ( abi sequencer , bioneer co. south korea ) . the results of sequences were blasted using the national center for biotechnology information ( ncbi ) site . for the analysis of variable mean and standard division , chi - square and t student test were used . all patients had negative test results for vdrl , hbs ag , hiv and hcv antibodies . out of 54 samples , 46 ( 85.18% ) cases showed positive results for hpv dna . a total of 26 ( 56.6% ) samples were from males and 20 ( 43.4% ) from females while eight ( 14.81% ) showed negative results for hpv dna ( table 1 ) . the patients age ranged from 19 to 44 years with a mean age of 29.6  6.8 years . overall , 37 ( 80% ) patients had multiple sexual partners , and nine ( 20% ) had one sexual partner . duration of disease in 16 participants was less than one month whereas in 18 participants this duration was equal or more than three months , and in 12 patients it was one to three months . the lesions in males were detected on the penis ( 24 cases ) , scrotum ( 1 case ) , penis - scrotum ( 11 cases ) and suprapubic area ( 1 case ) . the lesions in females were found in vulva ( 12 cases ) and anus ( 7 cases ) . a total of 32 ( 70% ) patients with flat condylomata and 14 ( 30% ) with condylomata acuminate were found . condylomata acuminata was found in 19 females and 13 males whereas flat condyloma was observed in six females and eight males . the hpv genotypes were found in 46 samples including 26 ( 48.14% ) males and 20 ( 37.03% ) females . the results of sequencing revealed that frequency of hpv16 , hpv11 and hpv6 was 58.69% , 26.08% and 15.21% , respectively . furthermore , hpv16 was observed in 17 ( 31.48% ) males and 10 ( 18.51% ) females . human papillomavirus 11 was found in seven ( 12.96% ) males and five ( 9.25% ) female , while hpv6 was detected in two ( 3.7% ) males and five ( 9.25% ) females . in the present study , 46 patients with anogenital warts showed positive results for hpv . a higher rate of positive hpv was found in male patients , which is in accordance with the results of ciconte et al . it is likely that more frequent anal intercourse was the reason behind this finding . in the current study , 76% of married patients had positive hpv results , which was in accordance with the study of nassiri et al . the most probable reason for the higher rate of genital warts in married individuals might be multiplicity of sexual partners . genital ( 85.18% ) and anal ( 15.2% ) areas were the most common anatomical locations of the warts . the most common sites of involvement were the penis in males and the vulva in females . in some studies , involvement of genital locations was found more than anal sites ( 3 , 10 ) . in our investigation , the single female patients had only anal involvement . in the iranian culture , proof of a girls virginity prior to her marriage is required , thus anal sexual contact is preferred by some unmarried girls . in our study , out of 54 patients with anogenital warts , 46 ( 85% ) samples showed a strong positive pcr for hpv . aubin et al . from france ( 2008 ) , studied acuminata condylomata among 214 females and 209 males . they detected hpv - dna with dominant genotypes of hpv6 ( 69% ) , and low prevalence of hpv11 ( 16% ) and hpv16 ( 9% ) ( 11 ) . in the present study , hpv 16 and 6 showed the highest and lowest frequencies in both genital and anal locations , respectively . wang et al . in 2012 , studied a total of 120 , 772 samples from female cervical in 37 chinese cities and reported that the most prevalent genotypes were hpv16 ( 4.82% ) and hpv52 ( 4.52% ) , followed by hpv58 ( 2.74 % ) . two genotypes hpv6 ( 4.01% ) and hpv11 ( 2.29% ) were predominant in the low - risk hpv ( lrhpv ) type , while the mixed genotypes hpv16 + 52 and hpv52 + 58 were most common in females with multiple infections ( 12 ) . detected hpv 6 or 11 in 79% of the specimens , and hpv 16 or 18 in 21% of samples ( 3 ) . reported that most cases of anogenital warts were associated with high prevalence of hpv 6 and 11 followed by low prevalence of hpv 16 and 18 , which were not consistent with our results ( 9 ) . in our study , one couple with genital warts shared the hpv 11 strain and the other couple shared hpv 16 infection . in the study of konno et al . on 12 couples with genital warts , 78% of couples had the same hpv dna , detected by dna hybridization ( 13 ) . in conclusion , our findings revealed that the most prevalent genotypes in anogenital warts were hpv 16 , 11 and 6 , respectively .
background : human papillomavirus ( hpv ) infection is considered the most prevalent sexually transmitted virus infection . 
 human papillomavirus 16 and 18 have been documented as high - risk hpv infections and responsible for 70% of all cervical cancers.objectives:the aim of this study was to determine hpv genotypes in patients with anogenital warts.patients and methods : in this study lesion samples were collected from 54 patients with an age ranged of 19 to 44 years . 
 initially , dna extraction was carried out for all samples followed by detection of hpv dna by the polymerase chain reaction . 
 the positive pcr products were sequenced and the results were blasted to determine hpv genotypes.results:out of 54 samples , 46 ( 85.18% ) cases showed positive results for hpv dna . 
 a total of 26 ( 56.6% ) samples were males and 20 ( 43.4% ) females while eight ( 14.81% ) showed hpv negative results . 
 overall , 37 ( 80% ) patients had multiple sexual partners , and nine ( 20% ) had one sexual partner . 
 the frequency of anogenital warts was higher in married patients . 
 the results of sequencing revealed that frequency of hpv16 , hpv11 and hpv6 was 58.69% , 26.08% and 15.21% , respectively.conclusions:human papillomavirus 16 as a high risk hpv was found to have the highest frequency among patients with anogenital warts .