HPV
prevalence and genotype distribution in Liaocheng men between 2016 and
2022
Lili Zheng1, * , Jieyu Qi 2,
Liyuan Zheng3, Shuangfeng Chen1,
Wenhui liu4, * , and Ke Li1, *
1Central Laboratory of Liaocheng Peoples’ Hospital,
Liaocheng, 252000, Shandong, China;
2 Clinical Laboratory of Liaocheng Peoples’ Hospital,
Liaocheng, 252000, Shandong, China;
3School of Rehabilitation Sciences and Engineering,
University of Health and Rehabilitation Sciences, 266071, Shandong,
China;
4Department of dermatology Liaocheng Peoples’
Hospital, Liaocheng, 252000, Shandong, China;
*Correspondence: Ke Li, 2385677237@qq.com;
Wenhui liu, 215197617@qq.com;
Lili Zheng,lily20060306@126.com* Contributed equally to this work.
ABSTRACT
HPV infection can lead to HPV-related cancer in men, including the anus,
penile, and oropharyngeal cancers and precancerous lesions. This study
retrospectively investigated HPV prevalence and genotype distribution in
Liaocheng men between 2016 and 2022. The total HPV positive rate was
64.87% (2388/3681, 95% CI: 63.32%-66.40%), where HR-HPV and LR-HPV
accounted for 42.49% (1564/3681, 95% CI: 40.90%-44.09%) and 69.71%
(2566/3681, 95% CI: 68.20%-71.17%), respectively. The mixed HPV
infection rate of two and more genotypes was 35.72%. The infection rate
of HR-HPV increased with the number of positive cases annually from 2016
(16.91%) to 2022 (46.59%). The most common HR-HPV genotypes were HPV16
(11.60%), HPV52 (6.95%), and HPV59 (6.28%), whereas the least common
HR-HPV was HPV26. The most common LR-HPV genotypes were HPV6 (56.99%),
HPV11 (23.79%), and HPV43(6.37%). The 9v HPV vaccine preventable for
LR-HPV and HR-HPV accounted for 80.78% and 30.40%, respectively, in
this study. Most HPV-positive patients aged 1-86 were in the 30-39 age
group. This study confirmed that HPV prevalence in Liaocheng men was
common and diverse. HPV16, HPV52, and HPV59 are widely distributed in
Liaocheng men, and the male HR-HPV infection rate remained high in this
region. Regarding public health and cancer prevention, it is recommended
and effective to include the HPV vaccination in the national vaccination
program for men.
KEYWORDS
Human papillomavirus, Male, Prevalence, Penile Neoplasms/virology,
Vaccine
1. INTRODUCTION
Human papillomavirus (HPV) is a common sexually transmitted virus
[1]. It can also be transmitted nonsexually through horizontal
(fomites, fingers, mouth, and skin contact) and vertical
(mother-to-child) routes [2]. The global HPV infection rate among
males (3.5%-45%) was similar to that among women (2%-44%) [3].
The incidence ratio for infection transmission was also similar, 0.59
(95% CI, 0.16-2.20) for male-to-female transmission and 0.77 (95% CI,
0.37-1.60) for female-to-male transmission [4].
HPV-attributable
cancer predominated in women [5]. However, HPV-attributable cancer
in men cannot be ignored, including anal, penile, and oropharyngeal
cancers [6-8] and certain tumor tissues [9], such as finger
multiple invasive squamous cell carcinomas [10]. A large proportion
of penile cancers and penile intraepithelial neoplasias are associated
with HPV DNA infection [11]. HPV infection is responsible for 50.8%
of penile cancers globally, 79.8% of penile intraepithelial neoplasia,
and 90% genital warts [12]. Even Germany launched a campaign: HPV
prevention is man’s business [13].
Approximately 450 kinds of HPV have been isolated and sequenced to date
[14]. HR-HPV is generally considered to be an oncogenic HPV type.
The most frequent cancer-causing HR-HPV genotypes are HPV16, HPV18,
HPV31, HPV33, HPV35, HPV39, HPV45, HPV51, HPV52, HPV56, HPV58, and
HPV59, which are frequently associated with penile cancer [15, 16].
The second most frequent genotype associated with potential
carcinogenicity is HPV68, and several other HR-HPV types (HPV26, HPV53,
HPV66, HPV67, HPV70, HPV73, HPV82, HPV30, HPV34, HPV69, HPV85, and
HPV97) have been thought to be potentially carcinogenic [17]. HR-HPV
and LR-HPV are different in promoter localization, promoter regulation,
and messenger RNA splicing patterns, and these differences affect the
expression of E6/E7 genes [18]. LR-HPV cause benign and localized
lesions but can also cause cancer in certain conditions, such as severe
combined immunodeficiency and epidermohypoplasia verruciformis (EDV)
[19]. Persistent LR-HPV infection can also lead to complex diseases,
such as recurrent respiratory papilloma, for which the management and
treatment impose a considerable socioeconomic burden [20]. HPV
epidemiology varied by race/ethnicity, age at first sexual intercourse,
city/urban residence, and sex life [21]. The HPV vaccination rates
differed in men because of gender and social background factors
[22]. The male HPV infection status of Liaocheng (China) has not
been reported as of yet. The city of Liaocheng is located on the border
of the Hebei-Shandong-Henan provinces and is a densely populated
regional medical center of Shandong Province. Understanding the
ecological diversity of HPV prevalence and genotype distribution in men
at different times and locations is crucial for optimizing HPV
vaccination and maximizing vaccination efficacy.
2. MATERIALS AND METHODS
2.1 Ethical consideration
The present study was approved by the Ethics Committee of LiaoCheng
People’s Hospital with approval
number 2023004. No informed consent or other action from the patients
was required because of the anonymity of the data analyses. All
experiments followed the laboratory biosafety guidelines in a lab
certified by the National Center for Clinical Laboratories.
2.2 Sample collection
The study retrospectively analyzed male patient
samples collected between January
201 and December 2022 from the Liaocheng People’s Hospital dermatology
clinic. The analyses included urinary tract infection (UTI), genital
warts, condyloma, balanitis, penis neoplasm, and eczema. The samples
were obtained by gently rubbing saline-soaked nylon tips around the
penile squamous areas, including the shaft and glans. The samples were
suspended using a mixing tip into a tube containing 1 mL of
physiological saline and stored at 4°C until use.
2.3 HPV DNA amplification and
genotyping
HPV positivity was identified using polymerase chain reaction (PCR), and
the HPV PCR-flow fluorescence assay was used for HPV genotyping.
Twenty-seven HPV genotypes were
tested using the Nucleic Acid genotyping Kit for Human Papillomavirus
(Tellgen, China), including 17 HR-HPVs (HPV16, 18, 31, 33, 35, 39, 45,
51, 52, 56, 58, 59, 66, 26, 53, 68, and 82) and 10 LR-HPVs (HPV6, 11,
40, 42, 43, 44, 55, 61, 81, and 83).
2.4 Data analysis
All data were analyzed using the SPSS17.0 statistical software (SPSS,
IBM, USA). The chi-square test was used to compare the infection rates
of different groups; statistical significance was tested at P
< 0.05. Positive predictive value with 95% confidence
intervals (CIs) was calculated using the binomial distribution.
3. RESULTS
3.1 HPV prevalence in 3681
males
Between 2016 and 2022, 3681 males were enrolled at the Liaocheng
People’s Hospital. As shown in Figure 1a,
the
total positive rate of HPV was 64.87% (2388/3681, 95% CI:
63.32%-66.40%), where HR-HPV and LR-HPV accounted for 42.49%
(1564/3681, 95% CI: 40.90%-44.09%) and 69.71% (2566/3681, 95% CI:
68.20%-71.17%), respectively. Table 1 presents the clinical diagnosis
data of 2388 HPV-positive males. Most HPV-positive patients exhibited
symptoms, such as a penis-genital wart, common wart, urethritis,
dermatitis, and rash. Only a few males were examined physically
(9.92%), and penis-genital wart accounted for 45.48%, higher than
other diagnostic types (Table 1).
As shown in Figure 1b, the single infection rate was 64.28%, and the
mixed infection rate of two and above genotypes was 35.72%. The double
infection rate was 22.71%, followed by the trebling infection (8.92%),
quadruple infection (2.55%), and other multiple infections (1.51%).
Priority was given to the single and double infection rates over other
kinds of mixed infection (P < 0.01).
3.2 HPV prevalence between 2016 and
2022
From 2016 to 2022, as the number of male patients tested for HPV
increased, the prevalence of HPV-positive patients each year was
analyzed. As shown in Figure 3, the number of positive males increased
annually, and the overall positive detection rate was 39.7%–77.6%.
The two relatively low positive rates were 39.7% and 59.4% in 2016 and
2022, respectively. The highest infection rate appeared in 2017
(77.59%). In each year between 2018 and 2021, there was no significant
difference in the positive rate for each HPV type
(x2 = 5.25, P = 0.26). The annual
infection rate of each HPV type was further analyzed (Table 2). The
infection rate of HR-HPV increased annually (Figure 3) from 2016
(16.91%) to 2022 (46.59%) (P < 0.01,x2= 20.33, P = 6.5e-6)
(Table 2). The LR-HPV infection rate increased significantly from 2016
(37.50%) to 2020 (85.82%) (P <0.01,x2 = 49.38, P =
2.1e-12), then decreased in 2021 (74.59%) and 2022
(59.13%) (P < 0.01, x2=5.39, P = 0.02).
3.3 HPV genotype distribution among 2388 HPV-positive
patients
Seventeen HR-HPV and ten LR-HPV genotypes
were retrospectively analyzed
from the HPV-positive patients (n = 2388). As evident from Table 3,
LR-HPV6, LR-HPV11, and HR-HPV16 were the major infection types in this
study. The top ten HR-HPV genotypes are as follows in descending order:
HPV16 (11.60%), HPV 52 (6.95%), HPV59 (6.28%), HPV66 (5.36%), HPV56
(5.23%), HPV39 (5.07%), HPV58 (4.27%), HPV51 (4.15%), HPV53
(4.19%), and HPV18 (4.02%). There was no significant difference among
the top ten HR-HPV types (x2 = 5.24, P =
0.26), and the least prevalent HR-HPV type was HPV26 (0.17%). The most
common LR-HPV genotypes were
HPV
6 (56.99%), HPV 11 (23.79%), HPV 61 (6.37%), and HPV 43 (6.28%); the
least LR-HPV was HPV 83 (0.54%).
As shown in Table 2, the primary benefit of each infection type annually
varied slightly. The distribution of common HPV genotypes in 2016-2022
was further analyzed in Figure 4. A subsequent analysis was performed
from 2017 because of the low reliability caused by the small amount of
data (Samples < 100) in 2016. The prevalence of total HR-HPV
genotypes increased from 2017 (16.91%) to 2022 (46.95%) (Figure 4a).
Among the HR-HPV genotypes, the prevalence of HPV 52 increased from 2017
(0.70%) to 2022 (10.47%). The prevalence of total LR-HPV genotypes
increased from 2017 (67.76%) to 2022 (85.82%), which was higher than
that of total HR-HPV genotypes (Figure 4b). The infection rate of HPV6
increased from 2017 (47.18%) to 2022 (63.11%), and that of HPV11
increased from 2017 (16.89%) to 2022 (32.62%) (Table 2).
3.4. Analysis of the prevalence of 9-valent HPV vaccine
targeting
genotypes.
The currently approved 9-valent HPV vaccine (9v HPV vaccine) is the
highest potency vaccine, which contains LR-HPV (HPV 6 and 11) and HR-HPV
(HPV 16, 18, 31, 33, 45, 52, and 58). The prevalence of 9v HPV vaccine
targeting genotypes was analyzed (Figure 5), where the 9v vaccine
preventable for LR-HPV and HR-HPV accounted for 80.78% and 30.40%,
respectively. The detailed prevalence of these nine genotypes of HPV was
analyzed. As shown in Table 3, in addition to HPV 16 (11.6%), the
prevalence of three other vaccine targeting types—HPV31 (1.34%),
HPV33 (1.13%), and HPV45 (1.09%)—was extremely low. Notably, 69.60%
of HR-HPV types (for instance, the main genotypes HPV52, HPV59, HPV66,
HPV56, and HPV39) were not included in the 9v HPV vaccine protecting
range.
3.5 Age Distribution in 2388 HPV positive
patients
As shown in Figure 6, 2388 HPV-positive patients ranged from 1 to 86
years old, with a mean age of 34.23 (SD = 12.49). The number of
HPV-positive males in the <20 age group was the lowest
(7.20%), and the youngest was 1. The number of HPV-positive males in
the 30-39 age group was the highest (34.09%) among all age groups,
followed by the 20-29 age group (28.52%). There were no significant
differences between the 20-29 and 30-39 age groups (P> 0.05, x2 = 0.72, P = 0.40). The
positive rate decreased as the age of the >40 age group
increased. Among them, the 40-49 age group accounted for 17.38%, the
50-59 age group accounted for 8.12%, and the >60 age group
was the least (4.69%).
4. DISCUSSION
In this study, we reported the prevalence and genotype distribution of
HPV infection in men who visited Liaocheng People Hospital with STI
(sexually transmitted infection) symptoms between 2016 to 2022, and the
total positive rate of HPV was 64.87%. The prevalence of HPV among men
varied between countries and crowds. The male HPV infection rates in
Czech, Brazil, and Hong Kong were 96.8%, 80%, and 90%, respectively
[23-25], which were higher than that mentioned in our study.
Furthermore, the infection rates of any genital HPV type in men were in
Brazil (60.2%), Mexico (49.2%), and the United States (46.9%)
[26]. In 2014, 9% of healthy men from Africa, the United States,
Asia, and Europe were HPV carriers [27]. In China, the average anal
HPV positivity rate of any genotype among MSM (men who have sex with
men) was 62.1% [28], and it varied by region, for instance,
Shanghai (65.5%) [29], Qingyuan area of Guangzhou (54.3%)
[30], and Beijing (50.9%) [31]. The HPV prevalence of our study
(64.87%) was similar to that of Shanghai and higher than the average of
China [28, 30]. In our study, the prevalence of HR-HPV and LR-HPV
accounted for 42.28% and 72.32%, respectively, higher than Shanghai
(28.0% and 57.6%, respectively) [30].
Various
mixed infections related to the degree of pathological changes were
further analyzed, with most single infections accounting for 64.28%,
nearly double the rate of 35.72% for mixed infections. The rate of two
or more mixed infections decreased with the increase in HPV type. In
Japan, a single HPV-type infection was found in the urinary tract (89%)
[32]. The multiple infection rate was 42.9% in Vietnam males
[33]. In our study, the two or more mixed infection rate was
35.72%, higher than in Shanghai (25.8%) [25]. A high rate of
multiple infections may be associated with the risk of cervical cancer
in women [34], whereas men are likely to be infected with multiple
HPV strains [35].
Genotype distribution of HPV infection in males differs among countries.
Between 1995 and 2009, the five most prevalent types worldwide were
HPV16, HPV18, HPV52, HPV31, and HPV58 [36]. Similar to our result,
HPV16 was the most prevalent HR-HPV type in the Czech [23], Vietnam
[33],
and Japan [32]. In Shanghai, China, HPV16, HPV59, and HPV52 were the
most popular HR-HPVs, whereas the three most frequent LR-HPVs were HPV6,
HPV11, and HPV43 [30]. This result is consistent with our result of
the top three common HR-HPV genotypes (HPV16, HPV52, and HPV59) and the
top three LR-HPV genotypes (HPV6, HPV11, and HPV43). HPV6 and HPV11 are
more commonly related to the carcinogenesis of condylomatous lesions and
cause 90% of all external genital warts [37, 38]. The high positive
rates of HPV6 and HPV11 in our study could be because most male patients
had inflammation and warts. Moreover, the most prevalent genotypes
differed between males and females in this region, especially HPV-59 was
more prevalent in males (6.28%) than in females (2.09%) [39], and
a similar difference is also reported in Lebanon, where HPV-59
prevalence was higher in men (6.6%) than in women (2.1%) [35].
Moreover, each year’s analysis revealed that the infection rate of
HR-HPV increased annually, especially HPV52, so HR-HPV infection in
LiaoCheng men cannot be ignored.
The 9v HPV vaccine (Gardasil 9TM) has been proven to
protect against seven HR-HPV (HPV16, 18, 31, 33, 45, 52, and 58) and two
LR-HPV genotypes (HPV6 and 11) infections. A widespread 9v HPV
vaccination program and early vaccination were supported by clinical
studies [40]. Chinese clinical studies have confirmed that HPV
vaccines for women are highly effective and safe [41]. Based on the
prevalence of vaccine-protected genotypes, it can be predicted that the
9v HPV vaccine can effectively prevent 80% LR-HPV and 30% HR-HPV
infections in LiaoCheng males. However, 69.60% of HR-HPV types were not
protected by the 9v HPV vaccines, especially the prevalence of the top
genotypes (HPV59, HPV66, HPV56, HPV39, HPV51, and HPV53) in this region.
Therefore, these HR-HPV genotypes should be prioritized in future
vaccine optimization.
In our study, HPV prevalence was highest in the 30-39 (34.09%) and
20-29 (28.52%) age groups and decreased in the >40 age
group. These findings are similar to the age distribution of Vietnamese
male patients, with the highest HPV infection rate in the 20-39 age
group, and the rate decreased in the >40 age group
[33]. Notably, children also have HPV infection risk through the
placenta, the amniotic fluid, or via contact with maternal genital
mucosa during natural birth [2]. Our study’s age analysis revealed
that those under 20 were mainly composed of those aged 15 to 19,
including each aged 1, 5, 6, and 9. Generally, males in early adulthood
are deemed too old to be vaccinated against HPV, although studies have
suggested that HPV infection rates are not correlated with male age
[40, 41]. In Germany, neutral HPV vaccination is recommended for all
children aged 9 to 14 years to prevent HPV-related diseases [13].
Given that four children were found to be HPV carriers in our study, we
must recommend vaccination for male children in this area.
5. CONCLUSION
The present study demonstrated the HPV prevalence and the genotype
distribution in Liaocheng men. It is essential to know the prevalence of
HPV infection in Shandong Liaocheng and serves as a supplement to the
data on HPV infection in women, consistent with the current prevalence
of HPV in China. In addition to HPV16 and HPV52, the prevalence of
HPV59, HPV66, HPV56, HPV39, HPV58, HPV51, HPV53, and HPV18 was also high
in this region. This study indicated the urgent need for enhanced HPV
prevention and control measures in the male population, which is crucial
in optimizing and advancing vaccine research.