HPV is closely correlated to a variety of diseases and is one of the more frequent DNA oncoviruses at present. Furthermore, 5.5% of cancers worldwide are associated with HPV infection [5]. HPV infection is commonly detected in clinics and is one of the most common sexually transmitted diseases, especially in the skin and anal genitalia. Considering the severity of HPV, the rapid and accurate detection of HPV infection through genotyping is of great significance for the prevention and treatment of HPV-related diseases. These amplified products were crossed with 17 types of high-risk type and six types of low-risk typing probes on the fixed membrane strip by PCR-reverse blot hybridization. A total of 23 kinds of HPV subtypes common in clinic can be typed simultaneously. This method has the advantages of high accuracy, strong specificity, and high sensitivity. This has been widely used in the typing detection of HPV infection [6].
HPV was epitheliophilic and preferentially infects squamous epithelium rather than columnar, cubed, or transitional epithelium. Therefore, the head of the penis, the body of the penis and the scrotum, the urethral orifice were common sites of HPV infection. A previous study by Ni et al. [7] identified 43.7% HPV infection rate in the tumor tissues of male patients with head and neck squamous cell carcinoma. Chen et al. [8] reported that the male HPV infection rate in a clinic in Shanghai was 47.8% by sampling scrotum or penis. In addition, Luo et al. [9] reported that the infection rate of male HPV in the Guangdong area was 57.8%. In this paper, the HPV-typing of urethral epithelium or scraped penile epidermis from 1044 male outpatients in Qingyuan District was carried out and the total infection rate was 54.31% under our sampling methods.
Among the 567 HPV-infected subjects, the single HPV-type infection was dominant (56.61%) and significantly higher than that of the double infection (26.63%) and multiple infection (16.75%). HPV6 and HPV11 were most common HPV subtypes.Although HPV6 and/or HPV11 are mostly latent infections in the genitalia and usually do not show clinical symptoms, these are the dominant genotypes that cause condyloma acuminata in countries around the world [10,11,12,13]. The high-risk subtypes of HPV play an important role in the development of penis cancer [11]. Infection with multiple HPV subtypes would increase the risk of abnormal proliferation and canceration of infected cells [14,15,16]. Therefore, it is necessary to reduce the risk of carcinogenesis of infected tissues by increasing the frequency of follow-ups, performing regular pathological examinations for pathological tissues, or strengthening the treatment for high-risk HPV-infected subjects and multiple HPV subtypes (including high-risk subtypes) [17].
In the present study, it was found that the positive rate of HPV in vegetation was the highest, followed by prepuce glans and uremitis. It was reported that the initial clinical manifestations of HPV virus in Chinese men are often condyloma acuminata, which is vegetations on the genital surface. Condyloma acuminata are most common in the genitals and anus. The color and size of skin lesions vary according to the course of disease [18]. At first, it presents as small, reddish papules. Then, the size gradually expands, the number increases, and the color gradually changes to grayish white or brown-black. The incubation period varies from two weeks to eight months, with an average incubation period of 2–3 months. There are three routes of infection: sexual contact infection, indirect contact infection, and mother-to-child vertical infection [19]. In order to cut the routes of transmission, controlling the source of HPV infection is the key step. Only foreign vaccines have been approved for use in China. Preventive vaccines produced in China have not yet been listed, and phase III clinical trials are still under way. HPV patients also need secondary prevention, and there is no specific method to cure HPV virus. At present the most important mode of treatment is to remove the local hyperplastic warts, which is effective, simple, safe, and scar-free [20]. HPV can also be treated by physical therapy, medicine, and vaccine. In China, in addition to a healthy lifestyle and vaccination, the prevention of HPV infection is performed mainly through uterine screening for primary prevention [21]. However, whether this would be applicable to men and cover the most prevalent genotypes remains unknown and requires further research in the future.
The infection rate of HPV in male patients with venereal disease in the Qingyuan District was high and mainly consisted of low-risk HPV or single-type HPV infections. Patients who were positive for HPV were mainly in the age group of 21–50 years old, and the detection rate was higher in the age group of over 50 years old. HPV52, HPV16, and HPV51 were the three main high-risk HPV types in the region. HPV6, HPV11, and HPV42 were the three main low-risk HPV types in the region. Since there are regional differences in the distribution of male HPV infection types [22, 23], mastering the HPV infection of male patients in local sexually transmitted disease (STD) clinics plays an important role in the monitoring of diseases caused by HPV. In clinical work, in addition to actively treating skin lesions, such as condyloma acuminate, in HPV-infected subjects, especially those with high-risk and multiple HPV infections, close follow-ups should be conducted for a long period of time. This can not only reduce the incidence of penile cancer but also effectively reduce the risk of condyloma acuminatum or cervical cancer.
There remain limitations in the present study. First, the present study was a retrospective study, and not a randomized controlled trial, and no blinding method was established. Therefore, there is still a risk of bias due to causes such as the differing severity of the patient’s disease, the differing duration of the disease, and the previous use of various drugs. Second, the present study is a single-center clinical study. Hence, there is still a need to carry out multicenter clinical studies.