Chlamydia trachomatis transmission between the oropharynx, urethra and anorectum in men who have sex with men: a mathematical model.

BACKGROUND: It has been presumed that Chlamydia trachomatis is transmitted between men only through anal or oral sex, but no mathematical models have tested this presumption. METHODS: To test this presumption, we created 20 compartmental mathematical models of different sexual practices that included both oral and anal sex and calibrated these models to the observed rates of Chlamydia trachomatis infection at three anatomical sites from 4888 men who have sex with men (MSM) in Melbourne Sexual Health Centre during 2018-2019. RESULTS: A model that included only oral and anal sex could replicate the observed rates of single-site infection at the oropharynx, urethra and rectum alone, but could not replicate infection at more than one of these sites (multisite). However, if we included transmission from sexual practices that followed one another in the same sexual episode (e.g. saliva contamination of the penis from oral sex transmitting chlamydia to the rectum by anal sex), we significantly improved the calibration of multisite infection rates substantially. CONCLUSIONS: Our modelling study suggests that transmission routes other than just oral and anal sex are necessary to explain the high rate of Chlamydia trachomatis infection at more than one site.

Is There any Association between Urothelial Carcinoma of the Bladder and Human Papillomavirus? A Case-Control Study.

OBJECTIVES: Human papillomavirus (HPV) is a well-known oncogenic virus associated with anogenital carcinomas. Despite the anatomical proximity of the bladder and the anogenital region, the relationship between HPV and urothelial carcinoma of the bladder (UCB) is still a controversial issue. This study aimed to test the urethral swabs and first-void urine samples of patients with UCB for HPV-Deoxyribonucleic acid (DNA) using polymerase chain reaction (PCR) assay and to compare the results with a control group. MATERIALS AND METHODS: Sixty-nine patients who were diagnosed with UCB between January and December 2018 were included in this case-control study. Sixty-nine patients who visited the urology outpatient clinic for non-oncological reasons within the study period were designated as the control group. Urethral swab and first-void morning urine samples were collected from each patient. HPV-DNA presence was investigated using a PCR kit that can detect a total of 22 HPV genotypes, of which 18 are high-risk and 3 are low-risk genotypes. RESULTS: The mean age of the patients included in the study was 63.2 ± 12.6 years and the male to female ratio was 5.3. HPV-DNA was detected in 28.9% (20/69) of the patients in the case group and in 8.7% (6/69) of the patients in the control group. HPV-DNA positivity was significantly higher in the case group (OR 4.24; 95% CI 1.63-12.34). No statistically significant relationship was found between HPV-DNA positivity and tumor grade (p = 0.36). CONCLUSION: A statistically significant relationship exists between HPV infection and UCB, regardless of the tumor grade.

Mucosal stromal fibroblasts markedly enhance HIV infection of CD4+ T cells.

Understanding early events of HIV transmission within mucosal tissues is vital for developing effective prevention strategies. Here, we report that primary stromal fibroblasts isolated from endometrium, cervix, foreskin, male urethra, and intestines significantly increase HIV infection of CD4+ T cells-by up to 37-fold for R5-tropic HIV and 100-fold for X4-tropic HIV-without themselves becoming infected. Fibroblasts were more efficient than dendritic cells at trans-infection and mediate this response in the absence of the DC-SIGN and Siglec-1 receptors. In comparison, mucosal epithelial cells secrete antivirals and inhibit HIV infection. These data suggest that breaches in the epithelium allow external or luminal HIV to escape an antiviral environment to access the infection-favorable environment of the stromal fibroblasts, and suggest that resident fibroblasts have a central, but previously unrecognized, role in HIV acquisition at mucosal sites. Inhibiting fibroblast-mediated enhancement of HIV infection should be considered as a novel prevention strategy.

Prevalence of anal, oral, penile and urethral Human Papillomavirus in HIV infected and HIV uninfected men who have sex with men.

Aims of the study were to evaluate Human Papillomavirus (HPV) and type-specific prevalence in four anatomical sites in HIV infected men who have sex with men (MSM) compared with HIV uninfected MSM. Participants were recruited among the attendees of Infectious Diseases Clinics in Central Italy. A trained medical practitioner collected by interview sociodemographic data and information on medical history, sexual behavior, and drug use. Swabs from anal canal, oral cavity, urethral mucosa, and coronal sulcus were tested for HPV DNA and genotyping. Ninety MSM were enrolled, 45 subjects within each group. Overall, 48.9% MSM were HPV positive and prevalence was higher in HIV infected men (60.0% vs 37.8%, P = 0.035). HPV at multiple anatomic sites occurred in 59.1% MSM, with 34.1% and 22.7% at two and three sites, respectively. Prevalence of anal, coronal sulcus, oral, and urethral HPV was 96.3%, 37%, 21.6%, and 18.5% in HIV infected MSM, and 70.6%, 70.6%, 29.4%, and 23.5% among HIV uninfected. A similar proportion of HIV infected and uninfected MSM (59.2% and 58.8%) carried at least one high-risk genotype. Prevalence of types covered by nonavalent vaccine was 77.8% in HIV infected compared with 82.3% in HIV uninfected MSM. HPV 58 and 16 were mostly detected in HIV positive (43.7% and 31.2%) and negative MSM (50.0% and 40.0%). HPV detection rate underlined the high vulnerability of MSM to acquire multisite infections, characterized by various genotype combinations. Since nonavalent vaccine could have prevented 80% of HPV infections, study findings support the implementation of vaccination programs among MSM.

Chlamydia trachomatis and HPV co-infections in HIV negative men from a multi-ethnic area of Northern Italy at high prevalence of cervical malignancies.

Chlamydia trachomatis and HPV coinfections in the male population are often a disregarded issue. We performed a study to evaluate the prevalence of such infections in heterosexual HIV negative men from a Northern Italy multi-ethnic area at high prevalence for cervical malignancies. Urethral swabs (US) or first-voided urine were evaluated retrospectively from 1317 patients attending Sexually Transmitted Infections (STI) clinic and from 3388 outpatients attending private clinics. Informations about participants' demographic characteristics and attributes of C. trachomatis, including chronic infection, and HPV genotypes testing, were collected. Exact Fisher test, bivariate, and multivariate logistic regressions were carried out. The prevalence of C. trachomatis was 1.7% in the outpatients and 16.9% in the STI group (P < 0.0001) in which the highest frequency was observed in men of age ≤25 years. Among patients with C. trachomatis, asymptomatic HPV co-infection was detected in 33% of men from the STI clinic and in 2% of the outpatients. Out of all coinfections, 56% were due to single HPV, with a prevalence of 73% in young STI men. The distribution of HPV genotypes confirmed the increased circulation of LR-HPV42, HR-HPV51, HR-HPV52 and prHR-HPV82, and the decreasing of HR-HPV16. African nationalities and leucorrhea were significantly associated risk factors, while the regular condom use offered an effective protection. This study highlights the high prevalence of C. trachomatis and HPV asymptomatic co-infection in young HIV negative men attending the STI clinic, representing a reservoir of new HPV genotypes with potential oncogenic risk.

Detection of Simian Immunodeficiency Virus in Semen, Urethra, and Male Reproductive Organs during Efficient Highly Active Antiretroviral Therapy.

UNLABELLED: A number of men receiving prolonged suppressive highly active antiretroviral therapy (HAART) still shed human immunodeficiency virus (HIV) in semen. To investigate whether this seminal shedding may be due to poor drug penetration and/or viral production by long-lived cells within male genital tissues, we analyzed semen and reproductive tissues from macaques chronically infected with simian immunodeficiency virus mac251 (SIVmac251) who were treated for 4 months with HAART, which was intensified over the last 7 weeks with an integrase inhibitor. We showed that a subset of treated animals continued shedding SIV in semen despite efficient HAART. This shedding was not associated with low antiretroviral drug concentrations in semen or in testis, epididymis, seminal vesicles, and prostate. HAART had no significant impact on SIV RNA in the urethra, whereas it drastically reduced SIV RNA levels in the prostate and vas deferens and to a lesser extent in the epididymis and seminal vesicle. The only detectable SIV RNA-positive cells within the male genital tract after HAART were urethral macrophages. SIV DNA levels in genital tissues were not decreased by HAART, suggesting the presence throughout the male genital tract of nonproductively infected cells. In conclusion, our results demonstrate that 4 months of HAART induced variable and limited control of viral infection in the male reproductive organs, particularly in the urethra, and suggest that infected long-lived cells in the male genital tract may be involved in persistent seminal shedding during HAART. These results pave the way for further investigations of male genital organ infection in long-term-treated infected individuals. IMPORTANCE: A substantial subset of men receiving prolonged HAART suppressing viral loads in the blood still harbor HIV in semen, and cases of sexual transmission have been reported. To understand the origin of this persistence, we analyzed the semen and male reproductive tissues from SIV-infected macaques treated with HAART. We demonstrated that persistent seminal shedding was not linked to poor drug penetration in semen or semen-producing prostate, seminal vesicle, epididymis, and testis. We revealed that HAART decreased SIV RNA to various extents in all male genital organs, with the exception of the urethra, in which SIV RNA(+) macrophages were observed despite HAART. Importantly, HAART did not impact SIV DNA levels in the male genital organs. These results suggest that infection of male genital organs, and particularly the urethra, could be involved in the release of virus in semen during HAART.

Human papillomavirus infection in male patients with STI-related symptoms in Hanoi, Vietnam.

This cross-sectional study investigated the prevalence, genotypes, and risk factors for human papillomavirus (HPV) infection in Hanoi, Vietnam. The study included 192 males (mean age, 32.9 years) with symptoms related to sexually transmitted infections (STI). Urinary, penile, and urethral samples were collected in April and May, 2014. HPV DNA was detected with PCR, performed with modified and/or original GP5(+)/GP6(+) primers. HPV genotypes were determined with a gene array assay. Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) DNA were detected with loop-mediated isothermal amplification. HPV DNA, NG, and CT were detected in 48 (25.0%), 23 (12.0%), and 41 (21.4%) patients, respectively. HPV DNA appeared in penile samples (21.0%, 39/186) more frequently than in urinary (3.1%, 6/191, P < 0.001) and urethral (9.4%, 18/192, P = 0.002) samples. Among patients with HPV, genotype prevalence was: HPV81 (22.9%), HPV52 (18.8%), HPV18 (16.7%), and HPV16 (6.3%). Multiple-type and high risk-type HPV infections were determined in 33.3% and 64.6%, respectively. Multivariate analysis showed a significant association of HPV infection in urethra with younger sexual debut age. HPV52 was the most prevalent high-risk HPV genotype, whereas HPV16 was less common in the male Vietnamese patients with STI-related symptoms. Younger sexual-debut age was a risk factor for HPV infection in urethra.

Characteristics of adenovirus urethritis among heterosexual men and men who have sex with men: a review of clinical cases.

BACKGROUND: The aim of this study was to characterise the clinical features of adenovirus urethritis in men and to compare the frequency of these between heterosexual men and men who have sex with men (MSM). METHODS: This was a review of the clinical and laboratory information from men diagnosed with PCR-confirmed adenovirus urethritis at the Melbourne Sexual Health Centre between January 2006 and April 2014. RESULTS: 102 adenovirus urethritis cases were reported, among which 61 were heterosexual men and 41 MSM. Eighty-nine per cent (n=91) had signs of meatitis or conjunctivitis: 51% had meatitis only; 32% meatitis together with conjunctivitis and 6% with conjunctivitis only. The distribution of symptoms and signs was similar among heterosexual men and MSM (p values >0.1). Adenovirus was the sole pathogen found in 93% of cases, excluding gonorrhoea, chlamydia, Mycoplasma genitalium and herpes simplex virus. Only 37% had ≥5 polymorphs per high-power field from a urethral smear. Where samples were still available for adenoviral sequencing (n=20), all were subgroup D. CONCLUSIONS: The clinical features of adenovirus urethritis in men can be distinctive and aid diagnosis, distinguishing it from other treatable causes of male urethritis.

Prevalence of HPV Infection in Croatian Men during a 12-year Period: a Comparative Study of External Genital and Urethral Swabs.

AIM: The aim of the study was to compare the prevalence and distribution of both low-risk and high-risk HPV infection of the urethra and outer genital region in Croatian men. Thus far there is a consensus that sampling the coronal sulcus and glans of the penis is essential for adequately assessing HPV status in men but less agreement is noted for urethral sampling. METHODS: External genital brushing and urethral swabs were taken from 1,342 men during a 12-year period and tested with the hc2 HPV DNA Test using Hybrid Capture 2 technology. RESULTS: The overall prevalence of male HPV infection in this study was 36.66%. Infection with high-risk HPV types (44.72%) was significantly more frequent than infection with low-risk HPV types (28.86%) or co-infection with both low-risk and high-risk HPV types (26.42%). HPV was more frequently demonstrated in the outer genital area (58.33%) when compared to the sole infection of the urethra (17.89%) or infection of both genital sites (23.78%). CONCLUSIONS: Results from this study indicate high prevalence of HPV infection in men and suggest that optimal sampling method for the testing of men is the combination of external genital and urethral swabs. Further research about the proper collection of biological samples and testing methods for HPV detection in men is necessary since our future end-goal is to implement standardized guidelines on sampling and diagnostic testing of males.

The Neonatal Fc receptor (FcRn) enhances human immunodeficiency virus type 1 (HIV-1) transcytosis across epithelial cells.

The mechanisms by which human immunodeficiency virus type 1 (HIV-1) crosses mucosal surfaces to establish infection are unknown. Acidic genital secretions of HIV-1-infected women contain HIV-1 likely coated by antibody. We found that the combination of acidic pH and Env-specific IgG, including that from cervicovaginal and seminal fluids of HIV-1-infected individuals, augmented transcytosis across epithelial cells as much as 20-fold compared with Env-specific IgG at neutral pH or non-specific IgG at either pH. Enhanced transcytosis was observed with clinical HIV-1 isolates, including transmitted/founder strains, and was eliminated in Fc neonatal receptor (FcRn)-knockdown epithelial cells. Non-neutralizing antibodies allowed similar or less transcytosis than neutralizing antibodies. However, the ratio of total:infectious virus was higher for neutralizing antibodies, indicating that they allowed transcytosis while blocking infectivity of transcytosed virus. Immunocytochemistry revealed abundant FcRn expression in columnar epithelia lining the human endocervix and penile urethra. Acidity and Env-specific IgG enhance transcytosis of virus across epithelial cells via FcRn and could facilitate translocation of virus to susceptible target cells following sexual exposure.

Potential Contribution of Cytomegalovirus Infection to Prenatal and Early Neonatal Mortality of Monkeys in the Adler Breeding Center.

Scrapings from the cervical canals and uterine cavities of females with a history of miscarriages, pathological deliveries, and stillbirths were tested for the cytomegalovirus DNA. The incidence of the agent in the females with a history of gestosis and abnormal deliveries was significantly higher than in females without anamnesis of this kind. Parenchymatous organs of stillborn neonates and animals dead during the first month of life were studied. This analysis and studies of the umbilical cords and placentas showed generalized cytomegalovirus infection in 22% dead animals, which objectively proved intrauterine infection.

Establishment of a molecular diagnostic system for detecting human papillomavirus in clinical samples in Sri Lanka.

Human papillomavirus (HPV) is associated with variety of clinical conditions that range from innocuous lesions to cancer in both men and women. Consensus primer-mediated PCR assays have enabled screening for a broad spectrum of HPV types. We have established a molecular diagnostic system for detecting HPV DNA in clinical samples from STD clinics in Sri Lanka and compared the efficacy of three different primer sets, MY09/11, GP5+/6+ and CPI/IIG primer sets, to determine which primer set or combination of primers is most efficacious in screening for HPV. Cervical and urethral swabs were obtained from 51 patients who were suspected of having HPV. The presence of HPV DNA in swabs was detected by MY09/11 PCR (33%), GP5+/6+ PCR (72%) and CPI/IIG PCR (57%) primers. HPV DNA was detected in 23% of samples by all three methods, in 43% by any two methods, and in 6% only by GP5+/6+ primer set. GP5+/6+ PCR alone was capable of detecting the most number of HPV positives but, any single PCR method for the detection of HPV may underestimate the true prevalence of HPV in clinical samples. Nested PCR assay with MY09/11 and GP5+/6+ primer sets had higher sensitivity than singleplex PCR but, due to the risk of cross contamination in employing nested PCR, it was concluded that GP5+/6+ PCR is more suitable for HPV DNA detection in epidemiologic and clinical follow-up studies in Sri Lanka.

Prevalence of human papillomavirus infection in the urinary tract of men with urethritis.

OBJECTIVES: To investigate the prevalence of human papillomavirus (HPV) in the genital and urinary tract of men with urethritis. METHODS: Cell samples were collected from the penis, urethra and urine of 142 men with urethritis. A HPV test was performed on the samples using the modified GP5+/6+ polymerase chain reaction method, and the HPV genotype was determined using a HPV GenoArray test. RESULTS: Out of 142 urethritis patients, HPV was detected in 48% (68 cases), and high-risk HPV was found in 32% (46 cases) of patients, on their penis or in the urinary tract (urethra or urine). HPV was detected in 31% in the penis, 20% in the urethra and 24% in the urine, while high-risk HPV was identified in 23% in the penis, 12% in the urethra and 11% in the urine. Among the HPV-positive men, 66% had HPV infection in the urinary tract where the most common HPV types were HPV6, HPV16, HPV18 and HPV58. Single HPV-type infection was more frequently found in the urinary tract (89%) than in the penis (65%) (P < 0.05). CONCLUSIONS: Similar to the penis, the urinary tract represents a common HPV infection site in men with urethritis.

Bacteriophages of the lower urinary tract.

The discovery of bacteria in the female urinary bladder has fundamentally changed current dogma regarding the urinary tract and related urinary disorders. Previous research characterized many of the bacterial components of the female urinary tract, but the viral fraction of this community is largely unknown. Viruses within the human microbiota far outnumber bacterial cells, with the most abundant viruses being those that infect bacteria (bacteriophages). Similar to observations within the microbiota of the gut and oral cavity, preliminary surveys of the urinary tract and bladder microbiota indicate a rich diversity of uncharacterized bacteriophage (phage) species. Phages are vital members of the microbiota, having critical roles in shaping bacterial metabolism and community structure. Although phages have been discovered in the urinary tract, such as phages that infect Escherichia coli, sampling them is challenging owing to low biomass, possible contamination when using non-invasive methods and the invasiveness of methods that reduce the potential for contamination. Phages could influence bladder health, but an understanding of the association between phage communities, bacterial populations and bladder health is in its infancy. However, evidence suggests that phages can defend the host against pathogenic bacteria and, therefore, modulation of the microbiome using phages has therapeutic potential for lower urinary tract symptoms. Furthermore, as natural predators of bacteria, phages have garnered renewed interest for their use as antimicrobial agents, for instance, in the treatment of urinary tract infections.

HIV-1 reservoirs in urethral macrophages of patients under suppressive antiretroviral therapy.

Human immunodeficiency virus type 1 (HIV-1) eradication is prevented by the establishment on infection of cellular HIV-1 reservoirs that are not fully characterized, especially in genital mucosal tissues (the main HIV-1 entry portal on sexual transmission). Here, we show, using penile tissues from HIV-1-infected individuals under suppressive combination antiretroviral therapy, that urethral macrophages contain integrated HIV-1 DNA, RNA, proteins and intact virions in virus-containing compartment-like structures, whereas viral components remain undetectable in urethral T cells. Moreover, urethral cells specifically release replication-competent infectious HIV-1 following reactivation with the macrophage activator lipopolysaccharide, while the T-cell activator phytohaemagglutinin is ineffective. HIV-1 urethral reservoirs localize preferentially in a subset of polarized macrophages that highly expresses the interleukin-1 receptor, CD206 and interleukin-4 receptor, but not CD163. To our knowledge, these results are the first evidence that human urethral tissue macrophages constitute a principal HIV-1 reservoir. Such findings are determinant for therapeutic strategies aimed at HIV-1 eradication.

Development of a repeat-exposure penile SHIV infection model in macaques to evaluate biomedical preventions against HIV.

Penile acquisition of HIV infection contributes substantially to the global epidemic. Our goal was to establish a preclinical macaque model of penile HIV infection for evaluating the efficacy of new HIV prevention modalities. Rhesus macaques were challenged once or twice weekly with consistent doses of SHIVsf162P3 (a chimeric simian-human immunodeficiency virus containing HIV env) ranging from 4-600 TCID50 (50% tissue culture infective dose), via two penile routes, until systemic SHIV infection was confirmed. One route exposed the inner foreskin, glans and urethral os to virus following deposition into the prepuce (foreskin) pouch. The second route introduced the virus non-traumatically into the distal urethra only. Single-route challenges resulted in dose-dependent rates of SHIV acquisition informing selection of optimal SHIV dosing. Concurrent SHIV challenges via the prepuce pouch (200 TCID50) and urethra (16 TCID50) resulted in infection of 100% (10/10) animals following a median of 2.5 virus exposures (range, 1-12). We describe the first rhesus macaque repeat-exposure SHIV challenge model of penile HIV acquisition. Utilization of the model should further our understanding of penile HIV infection and facilitate the development of new HIV prevention strategies for men.

The bacterial microbiota in first-void urine from men with and without idiopathic urethritis.

BACKGROUND: Non-gonococcal urethritis (NGU) is a common syndrome in men. NGU may have several causes, but many cases are caused by sexually transmitted infections that may also cause complications in their female partners. Chlamydia trachomatis and Mycoplasma genitalium are the most common causes of NGU, but in up to 35% of the cases, none of the known viral or bacterial causes are found. Traditionally, pathogens have been detected using various culture techniques that may not identify all species present in the urethra. To address this, we used culture-independent methods for analysis of the male urethral microbiota. METHODS: This case-control study analysed first void urine samples, collected at STD clinics in Stockholm, Sweden from men with idiopathic urethritis (IU), i.e. negative for Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis, adenovirus, and herpes simplex virus type 1 and -2 together with samples from men without urethritis. Forty-six controls and 39 idiopathic urethritis patients were analysed. RESULTS: The microbiota was highly diverse: None of the 302 operational taxonomic units (OTUs) found in negative controls and IU patients were found in all of the samples or even in all of the samples in one group. More than 50% of the OTUs were only found in one or two of the total of 85 samples. Still the most dominant 1/6 of the genera constituted 79% of the sequences. Hierarchical clustering in a heatmap showed no specific clustering of patients or controls. A number of IU patient samples were dominated by a single genus previously related to urethritis (Gardnerella, Haemophilus, Ureaplasma). CONCLUSION: The male urethra contain a very diverse composition of bacteria, even in healthy controls. NGU may be caused by a number of different bacteria but more studies including a higher number of samples are needed for elucidation of the role of each species.

Carcinoma of the urethra.

Primary carcinomas of the urethra are rare and poorly understood lesions; hence, their clinical and pathologic spectrum is not completely defined. We analyzed a series of 130 primary urethral tumors and classified 106 of them as primary urethral carcinomas. The age at diagnosis of patients with primary urethral carcinomas ranged from 42 to 97 years (mean, 69.4 years; median, 70 years). There were 73 male and 33 female patients with a ratio of 2.2:1. In male patients, the tumors most frequently developed in the bulbous-membranous segment of the urethra. In female patients, the entire length of the urethra was typically involved. Microscopically, they were poorly differentiated carcinomas with hybrid squamous and urothelial features and developed from precursor intraepithelial conditions such as dysplasia and carcinoma in situ, which were frequently present in the adjacent urethral mucosa. High-risk human papilloma virus infection could be documented in 31.6% of these tumors. Follow-up information was available for 95 patients. Twenty-three patients died of the disease with a mean and median survival of 39 and 21 months, respectively. Urethral carcinomas are aggressive tumors with a high propensity for regional and distant metastases with mean and median survival of 39 and 21 months, respectively. Our observations have important implications for the management of patients with primary carcinoma of the urethra by defining them as a unique entity linked to human papilloma virus infection.

Human papillomavirus assay in genital warts--correlation with symptoms.

Our purpose was to investigate the human papillomavirus (HPV) type distribution using the Hybrid Capture 2 (HC2) Microplate assay in males. We tested a urethral swab from 550 HIV-negative males with genital warts and 64 HIV-negative males clinically free of genital warts, partners of HPV-infected females, using the HC2 Microplate assay. A perianal swab was also obtained from patients with perianal warts. In the first group, HPV DNA of any type was detected in 280 (50.9%) patients. Relatively few patients with urethral or perianal warts demonstrated a negative test (both P < 0.0001). Low-risk types were commoner, accounting for 60.0% of the HPV cases, high/intermediate-risk types accounted for 23.6%, while 46 men (16.4%) were infected with both types. Of 13 subjects (20.3%) of the second group who tested positive for HPV DNA, 61.5% were infected by low-risk types, 23.1% by high/intermediate-risk types and 15.4% had a dual infection. In conclusion, male partners of infected females and males with genital warts are predominantly infected by low-risk HPV types, but a substantial proportion is also or only affected by high-risk types.