Male circumcision and the risk of gonorrhoea, syphilis, HIV and human papillomavirus among men in Tanzania

Association between male circumcision and human papillomavirus infection in males and females: a systematic review, meta-analysis, and meta-regression

BACKGROUND

Previous studies have suggested a protective effect of male circumcision on human papillomavirus (HPV) infections in males, and that this protection may be conferred to their female sexual partners.

OBJECTIVES

To synthesize the available evidence on the association between male circumcision and HPV infections in males and females.

DATA SOURCES

We searched MEDLINE, Embase, Scopus, Cochrane, LILACS, and ProQuest Dissertations & Theses Global for records published up to 22 June 2022.

STUDY ELIGIBILITY

We considered observational and experimental studies that assessed male circumcision status and HPV prevalence, incidence, or clearance in males or females for inclusion.

PARTICIPANTS

Males and their female sexual partners who were tested for genital HPV infection.

INTERVENTIONS

Male circumcision compared to no circumcision.

RISK OF BIAS ASSESSMENT

The Newcastle-Ottawa scale was used for observational studies and the Cochrane risk-of-bias tool was used for randomized trials.

DATA SYNTHESIS

We estimated summary measures of effect and 95% confidence intervals (CI) for the prevalence, incidence, and clearance of HPV infections in males and females using random-effects meta-analysis. We assessed effect modification of circumcision on HPV prevalence by penile site in males using random-effects meta-regression.

RESULTS

Across 32 studies, male circumcision was associated with decreased odds of prevalent HPV infections (OR 0.45, CI 0.34-0.61), a reduced incidence rate of HPV infections (IRR 0.69, CI 0.57-0.83), and an increased risk of clearing HPV infections (RR 1.44, CI 1.28-1.61) at the glans penis among male subjects. Circumcision conferred greater protection against infection at the glans than shaft (OR 0.68, 95% CI 0.48-0.98). Females with circumcised partners were protected from all outcomes.

CONCLUSIONS

Male circumcision may protect against various HPV infection outcomes, suggesting its prophylactic potential. Understanding site-specific effects of circumcision on HPV infection prevalence has important implications for studies of HPV transmission.

The role of the genital microbiota in the acquisition and pathogenesis of sexually transmitted infections

PURPOSE OF REVIEW

There are an estimated 374 million new sexually transmitted infections (STIs) worldwide every year. Our review article examines the current evidence of how STI acquisition, transmission, and pathogenesis is impacted upon by the genital microbiota, with a focus on epidemiological, biochemical, and immunological features.

RECENT FINDINGS

At least in women, a genital microbiota dominated by lactobacilli has long been considered optimal for reproductive health, while depletion of lactobacilli may lead to a genital microenvironment dominated by anaerobic pathogens, which can manifest clinically as bacterial vaginosis. Recent research efforts have characterized genital microbiota composition in greater resolution, sometimes at species-level, using proteomics, metabolomics, and deep sequencing. This has enhanced our understanding of how specific microbiota members influence acquisition or clinical manifestation of STI pathogen infection. Other advances include a steady, though still slow, increase in the number of studies that sought to determine the genital (penile or urethral) microbiota of males and how it may impact that of their female partners' genital microbiota and risk of STI acquisition. Altogether, these data enabled us to explore the concept that genital microbiota may be sexually transmitted and influence pathogenesis and clinical presentation of other STI.

SUMMARY

With STI infection rates increasing worldwide, it is important now more than ever to find novel STI prevention strategies. Understanding if and how the genital microbiota is a modifiable risk factor for STI transmission, acquisition, and clinical manifestation may prove to be an important strategy in our efforts to curb morbidity in at risk populations.

Understanding the Evolving Role of Voluntary Medical Male Circumcision as a Public Health Strategy in Eastern and Southern Africa: Opportunities and Challenges

PURPOSE OF REVIEW

Voluntary male medical circumcision (VMMC) has been a cornerstone of HIV prevention in Eastern and Southern Africa (ESA) and is credited in part for declines in HIV incidence seen in recent years. However, these HIV incidence declines change VMMC cost-effectiveness and how it varies across populations.

RECENT FINDINGS

Mathematical models project continued cost-effectiveness of VMMC in much of ESA despite HIV incidence declines. A key data gap is how demand generation cost differs across age groups and over time as VMMC coverage increases. Additionally, VMMC models usually neglect non-HIV effects of VMMC, such as prevention of other sexually transmitted infections and medical adverse events. While small compared to HIV effects in the short term, these could become important as HIV incidence declines. Evidence to date supports prioritizing VMMC in ESA despite falling HIV incidence. Updated modeling methodologies will become necessary if HIV incidence reaches low levels.

Semen: A modulator of female genital tract inflammation and a vector for HIV-1 transmission

In order to establish productive infection in women, HIV must transverse the vaginal epithelium and gain access to local target cells. Genital inflammation contributes to the availability of HIV susceptible cells at the female genital mucosa and is associated with higher HIV transmission rates in women. Factors that contribute to genital inflammation may subsequently increase the risk of HIV infection in women. Semen is a highly immunomodulatory fluid containing several bioactive molecules with the potential to influence inflammation and immune activation at the female genital tract. In addition to its role as a vector for HIV transmission, semen induces profound mucosal changes to prime the female reproductive tract for conception. Still, most studies of mucosal immunity are conducted in the absence of semen or without considering its immune impact on the female genital tract. This review discusses the various mechanisms by which semen exposure may influence female genital inflammation and highlights the importance of routine screening for semen biomarkers in vaginal specimens to account for its impact on genital inflammation.

Effects of HIV voluntary medical male circumcision programs on sexually transmitted infections

PURPOSE OF REVIEW

Evidence of the protective effect of voluntary medical male circumcision (VMMC) against HIV is well established. However, evidence of the protective effect of VMMC against other sexually transmitted infections (STIs) has been inconsistent or scarce across different populations and settings. This review summarizes the current evidence on the effect of VMMC for HIV prevention on acquisition and transmission of other STIs in heterosexual men, women, and men who have sex with men (MSM).

RECENT FINDINGS

Recent findings continue to strongly support the protective effect of male medical circumcision against acquisition and transmission of herpes simplex virus type 2 (HSV-2), human papillomavirus (HPV) and syphilis infections in heterosexual men and women, and bacterial vaginosis and trichomoniasis in women. There is emerging evidence on the protective effect of VMMC against acquisition of hepatitis B and Mycoplasma genitalium infections in heterosexual men, and HSV-2, HPV, and syphilis in MSM.

SUMMARY

Evidence on the protective effect of VMMC against acquisition and transmission of common STIs is available for heterosexual men and women but more evidence is required for MSM. This review supports policy recommendations for the protective benefits of VMMC against STIs.

[Cancers of the external genital organs of male in Hérault: Results from the Hérault tumor register (RTH) over a period of 30 years (1987-2016)]

AIM

The objective of this study is to present the history of cancers of the external genital organs of male in Hérault using data from the Hérault tumor register (RTH) over a period of 30 years.

PATIENTS AND METHODS

Using the RTH database, we studied the development of testicular germ cell tumors (TGCT) and penile cancer (PC) over 30 years, from 1987 to 2016. We analyzed the incidence and mortality data for these tumors. We compared these results to French, European and global data.

RESULTS

In 30 years of registration we have recorded 725 cases of TGCT and 175 cases of PC. The age standardized incidence rate (ASR) of TGCT has doubled between 1987 and 2016 (4.2 per 100,000 in 1987 and 9.3 per 100,000 in 2016). It was multiplied by 2.63 in the population of patients aged 30 to 44. There is a decrease of the mortality rate with a ASR of 0.8 deaths per 100,000 in 1987, and 0.4/100 000 in 2016. The PC incidence ASR was stable between 1987 and 2016 (0.4-0.9/100,000). Mortality is stable with a ASR between 0.1 and 0.3 deaths per 100,000 between 1987 and 2016.

CONCLUSION

The incidence of TGCT has increased sharply in the Hérault over the past 30 years, while a decrease in mortality has been observed. The proportion of seminomas is increasing; it has gone from 53 % to 60 % in 30 years in the Hérault. The incidence and mortality of PC shows a stability in the Hérault over the past 30 years.

The Penile Microbiota in Uncircumcised and Circumcised Men: Relationships With HIV and Human Papillomavirus Infections and Cervicovaginal Microbiota

While the human microbiota especially that of the gut, cervix, and vagina continue to receive great attention, very little is currently known about the penile (glans, coronal sulcus, foreskin, and shaft) microbiota. The best evidences to date for the potential role of the penile microbiota in human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs) acquisition have come from studies examining medical male circumcision. We are still at the foothills of identifying specific penile bacteria that could be associated with increased risk of STI/HIV acquisition. In this review, we summarize the available literature on the human penile microbiota and how it is impacted by circumcision. We also discuss the potential role of penile microbiota in STIs and its impact on cervicovaginal microbiota. Taken together, the findings from the penile microbiota studies coupled with observational studies on the effect of male circumcision for reduction of STI/HIV infection risk suggest that specific penile anaerobic bacteria such as Prevotella spp. potentially have a mechanistic role that increases the risk of genital infections and syndromes, including bacterial vaginosis in sexual partners. Although penile Corynebacterium and Staphylococcus have been associated with healthy cervicovaginal microbiota and have been found to increase following male circumcision, further investigations are warranted to ascertain the exact roles of these bacteria in the reproductive health of men and women. This review aims to address existing gaps and challenges and future prospects in the penile microbiota research. The information described here may have translational significance, thereby improving reproductive health and management of STI/HIV.