Detection of cytomegalovirus in semen from a population of men seeking infertility evaluation

ORF8 protein of SARS‐CoV‐2 reduces male fertility in mice

As one of the most rapidly evolving proteins of the genus Betacoronavirus, open reading frames (ORF8's) function and potential pathological consequence in vivo are still obscure. In this study, we show that the secretion of ORF8 is dependent on its N‐terminal signal peptide sequence and can be inhibited by reactive oxygen species scavenger and endoplasmic reticulum‐Golgi transportation inhibitor in cultured cells. To trace the effect of its possible in vivo secretion, we examined the plasma samples of coronavirus disease 2019 (COVID‐19) convalescent patients and found that the patients aged from 40 to 60 had higher antibody titers than those under 40. To explore ORF8's in vivo function, we administered the mice with ORF8 via tail‐vein injection to simulate the circulating ORF8 in the patient. Although no apparent difference in body weight, food intake, and vitality was detected between vehicle‐ and ORF8‐treated mice, the latter displayed morphological abnormalities of testes and epididymides, as indicated by the loss of the central ductal lumen accompanied by a decreased fertility in 5‐week‐old male mice. Furthermore, the analysis of gene expression in the testes between vehicle‐ and ORF8‐treated mice identified a decreased expression of Col1a1, the loss of which is known to be associated with mice's infertility. Although whether our observation in mice could be translated to humans remains unclear, our study provides a potential mouse model that can be used to investigate the impact of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection on the human reproductive system.

Can cytomegalovirus infection affect male reproductive function? Results of a retrospective single-centre analysis

Our objective was to investigate whether the chronic cytomegalovirus (CMV) infection can affect semen parameters in men with couple infertility and to assess the impact of male CMV infection on the reproductive outcomes of CMV-seronegative women suffering from tubal factor. Group 1 included CMV IgG-seropositive men, Group 2 CMV IgG-seronegative patients. Seminal parameters, two-pronuclear (2PN) fertilization rate (FR), 1-2-3PN FR, cleavage rate (CR), miscarriage rate (MR), pregnancy rate (PR) and live birth rate (LBR) were collected. Two hundred and twenty-two men were included: 115 (51.8%) in Group 1 and 107 (48.2%) in Group 2. There was reported a low trend towards higher sperm concentration/ml, total sperm count and viability in CMV IgG-seronegative males, compared to CMV IgG-seropositive (p > .05). Semen volume, pH, motility and normal sperm morphology were similar among groups. Considering the subgroup of men, partners of CMV IgG-seronegative females, 65 couples (29.2%) were selected. Median 2PN FR was 67%, total FR 83%, CR 100%, PR/cycle 26.2%, MR 10.8%, LBR/cycle 15.4%. No significant differences were found regarding the reproductive outcomes between CMV IgG-seropositive men and those seronegative. CMV did not seem to play a key role in male reproductive function, as well as in influencing sperm fertility potential in the assisted reproductive outcomes.

Male infertility: a public health issue caused by sexually transmitted pathogens

Sexually transmitted diseases (STDs) are caused by several pathogens, including bacteria, viruses and protozoa, and can induce male infertility through multiple pathophysiological mechanisms. Additionally, horizontal transmission of STD pathogens to sexual partners or vertical transmission to fetuses and neonates is possible. Chlamydia trachomatis, Ureaplasma spp., human papillomavirus, hepatitis B and hepatitis C viruses, HIV-1 and human cytomegalovirus have all been detected in semen from symptomatic and asymptomatic men with testicular, accessory gland and urethral infections. These pathogens are associated with poor sperm quality and decreased sperm concentration and motility. However, the effects of these STD agents on semen quality are unclear, as are the effects of herpes simplex virus type 1 and type 2, Neisseria gonorrhoeae, Mycoplasma spp., Treponema pallidum and Trichomonas vaginalis, because few studies have evaluated the influence of these pathogens on male infertility. Chronic or inadequately treated infections seem to be more relevant to infertility than acute infections are, although in many cases the exact aetiological agents remain unknown.

Cytomegalovirus and human immunodeficiency virus in semen of homosexual men

OBJECTIVE

To assess the accuracy of serology to predict the presence of cytomegalovirus (CMV) in semen of homosexual men without and with HIV coinfection.

DESIGN

Semen CMV was detected by electron microscopy and by polymerase chain reaction (PCR) amplification; paired serum was tested for CMV IgG/IgM. Semen HIV was detected by reverse transcription-PCR.

SETTING

Licensed clinical and research laboratory.

PATIENT(S)

Sixty-eight men.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Frequency of CMV and HIV in semen.

RESULT(S)

Cytomegalovirus was detected by electron microscopy in 3 of 10 specimens examined. Forty-six (89%) of 52 HIV-infected men were seropositive for CMV by combined assay for IgG/IgM; two more (48 of 52, 92%) were seropositive for CMV IgG by separate assay; 25 (48%) of the HIV-infected men had PCR-detectable CMV DNA in at least one semen specimen, 22 of whom (42%) had CMV in all specimens. Nineteen (13%) of the 150 specimens tested positive for HIV, whereas 67 (45%) tested positive for CMV; seven specimens tested positive for both CMV and HIV. Cytomegalovirus, but not HIV, detection in semen correlated with decreased CD4(+) lymphocytes in peripheral blood (<700/μL) but was not accurately predicted by serology, leukocytospermia, or age.

CONCLUSION(S)

Cytomegalovirus in semen is not accurately predicted by serology. Sperm banking needs to include direct assessment of CMV in semen specimens. Strategies to eliminate CMV from semen specimens are needed to alleviate the risk of virus transmission.

Seminal shedding of human herpesviruses

Most of the human herpesviruses can be found in semen, although the reported prevalence varies considerably between individual studies. The frequent presence of herpesvirus in semen raises the question whether sexual transmission of the virus could have an impact on human reproduction. Only few studies have associated seminal shedding of herpesviruses with impaired sperm quality, reduced fertility, or reduced chances of pregnancy, whereas most studies fail to find an association. Taken together, no firm evidence is so far linking the presence of herpesviruses in semen to impaired human reproduction.

Human herpesvirus-6A/B binds to spermatozoa acrosome and is the most prevalent herpesvirus in semen from sperm donors

An analysis of all known human herpesviruses has not previously been reported on sperm from normal donors. Using an array-based detection method, we determined the cross-sectional frequency of human herpesviruses in semen from 198 Danish sperm donors. Fifty-five of the donors had at least one ejaculate that was positive for one or more human herpesvirus. Of these 27.3% (n = 15) had a double herpesvirus infection. If corrected for the presence of multiple ejaculates from some donors, the adjusted frequency of herpesviruses in semen was 27.2% with HSV-1 in 0.4%; HSV-2 in 0.1%; EBV in 6.3%; HCMV in 2.7%; HHV-6A/B in 13.5%; HHV-7 in 4.2%, whereas none of the samples had detectable VZV or HHV-8. Subsequently, we examined longitudinally data on ejaculates from 11 herpesvirus-positive donors. Serial analyses revealed that a donor who tested positive for herpesvirus at one time point did not necessarily remain positive over time. For the most frequently found herpesvirus, HHV-6A/B, we examined its association with sperm. For HHV-6A/B PCR-positive semen samples, HHV-6A/B could be detected on the sperm by flow cytometry. Conversely, PCR-negative semen samples were negative by flow cytometry. HHV-6B was shown to associate with sperm within minutes in a concentration dependent manner. Confocal microscopy demonstrated that HHV-6B associated with the sperm head, but only to sperm with an intact acrosome. Taken together, our data suggest that HHV-6A/B could be transported to the uterus via binding to the sperm acrosome. Moreover, we find a 10 times higher frequency of HHV-7 in semen from healthy individuals than previously detected. Further research is required to determine the potential risk of using herpesvirus-positive donor semen. Longitudinally analyses of ejaculate series indicate that implementation of quarantine for a donor shown to shed a herpesvirus is not a tenable solution.

Detection of human cytomegalovirus in motile spermatozoa and spermatogenic cells in testis organotypic culture

Background

The presence of human cytomegalovirus (HCMV) in male genital tract suggests its vertical transmission with spermatozoa and the development of a potentially dangerous fetal infection. The objective of the present study was to evaluate the possibility of intracellular HCMV localization in male germ cells and to examine the effect of the virus on human spermatogenesis.

Methods

Semen samples from 91 infertile and 47 fertile men were analyzed. HCMV was detected by real time PCR, rapid culture method and PCR in situ. Human testis organotypic culture and quantitative karyological analysis were used to investigate viral effects on spermatogenesis. Localization of HCMV in immature germ cells and spermatozoa was studied by immunostaining with monoclonal antibodies and ultrastructural analysis of infected organotypic culture.

Results

Viral DNA was detected in 12.3% samples of motile spermatozoa, while infectious activity only in 2.9% infertile and fertile men without statistically significant intergroup difference. According to PCR in situ, the mean percentage of infected cell in both groups was 1.5% (0.25%-15%), which can serve as a criterion for evaluating the risk of HCMV transmission. In HCMV-infected organotypic culture viral antigens were identified in spermatides on day 4, in spermatogonia and spermatocytes on day 8, and in spermatozoa on day 14. Empty and full capsides and virions were visualized in germ cells by electron microscopy. The number of cells before introduction in culture was taken for 100%. On day 14 infected culture contained 36.8% spermatogonia, 18.7% spermatocytes, 27.6% round spermatides and 42.5% elongated spermatides; in comparison with 82.2%, 51.5%, 70.4% and 65.7% in uninfected culture, respectively (all p < 0.05). There were no changes in the number and viability of spermatozoa.

Conclusions

HCMV was detected in male germ cells, both in sperm samples and in testis organotypic culture. The virus may infect immature germ cells which develop to mature HCMV-carrying spermatozoa. A considerable decrease in the number of immature germ cells indicates that HCMV produces a direct gametotoxic effect and can contribute to male infertility.

Human cytomegalovirus seroprevalence and risk of seroconversion in a fertility clinic population

OBJECTIVE

To retrospectively evaluate factors influencing human cytomegalovirus serologic status of couples consulting our fertility clinic.

METHODS

Human cytomegalovirus individual serologic status of 3,227 women and 2,565 men was studied according to age, serologic status of the sexual partner, and presence of children in the family at entry in the clinic. Among 1,906 initially seronegative individuals, human cytomegalovirus seroconversions during follow-up were recorded and correlated to age, serologic status of the sexual partner, and presence of children aged younger than 3 years in the family.

RESULTS

Human cytomegalovirus status at entry in the fertility clinic depended on age, but women were more frequently seropositive (54%) than men (43%), although they were younger (mean age 33 years for women and 37 years for men). The probability of seroconversion of women and men was significantly associated with the presence of children aged younger than 3 years; 35 of 217 women (16%) and 17 of 130 men (13%) living with children aged younger than 3 years seroconverted compared with 37 of 1,066 women (3.4%) and 16 of 493 men (3.2%) without children. Moreover, women's seroconversion was significantly associated with the seropositivity of the sex partner; 13 of 96 (13.5%) women with a cytomegalovirus seropositive partner seroconverted compared with 33 of 452 (7.3%) of those without such a partner.

CONCLUSION

Our results suggest that human cytomegalovirus is sexually transmitted among couples in our fertility clinic. Safe sex practices should be included in hygiene precaution advice given to pregnant women to avoid human cytomegalovirus contamination.

LEVEL OF EVIDENCE

II.

Prevalence of human herpes virus types 1-7 in the semen of men attending an infertility clinic and correlation with semen parameters

OBJECTIVE

To determine the prevalence of herpes viruses in the semen of an asymptomatic male cohort with and without infertility problems and its association with altered semen parameters.

DESIGN

A prospective randomized study.

SETTING

Medical school and IVF clinic.

PATIENT(S)

One hundred seventy-two male patients undergoing routine semen analysis: 80 with normal semen parameters (control group) and 92 with abnormal semen parameters.

INTERVENTION(S)

Semen samples were collected by masturbation.

MAIN OUTCOME MEASURE(S)

The DNA from the Herpesviridae family (herpes simplex virus 1 [HSV-1], herpes simplex virus 2 [HSV-2], Varicella zoster virus [VZV], Epstein-Barr virus [EBV], cytomegalovirus [CMV], human herpes virus type 6 [HHV-6], human herpes virus type 7 [HHV-7]) and routine semen parameters.

RESULT(S)

Viral DNA was detected in 143/172 (83.1%) of the total samples for at least one herpes virus: HSV-1, 2.5%; VZV, 1.2%; EBV, 45%; CMV, 62.5%; HHV-6, 70%; HHV-7, 0% in the normal semen samples and HSV-1, 2.1%; VZV, 3.2%; EBV, 39.1%; CMV, 56.5%; HHV-6, 66.3%; HHV-7, 0% in the abnormal semen samples. No association was found between the presence of viral DNA and semen parameters. Interestingly, a statistical significance between leukocytospermia and the presence of EBV DNA was observed.

CONCLUSION(S)

The DNA of herpes viruses is frequently detected in the semen of asymptomatic fertile and infertile male patients. Further studies are required to investigate the role of herpes viruses in male factor infertility.

[Male genital tract infection: the point of view of the virologist]

Attention to viral infection of the male genital tract has been renewed over the last 15 years as a result of the prolific ongoing research on AIDS. Epidemiological studies of the virus in sperm and male genital tract contributes to the understanding of STD physiopathology and helps assessing their impact on male fertility. Recent advances in this field have allowed to offer Assisted reproductive techniques to couples with chronic viral infection, under strict and specific protocols. This paper presents an overview of these recent developments.

Transmission risk of hepatitis C virus via semen during assisted reproduction: how real is it?

The risk of viral transmissibility in assisted reproduction is still a much-debated issue, especially for hepatitis C virus (HCV). HCV is a common causative agent for parenterally transmitted viral hepatitis. In addition, it has been incriminated in other routes of transmission, including sexual transmission and nosocomial infections. The management of infertility, in association with HCV, has sparked debates about the potential risk of spread of infection to virus-free individuals, embryos and/or semen. The lack of worldwide-accepted screening policies has helped to fuel this debate. Today, it is evident that there is a potential risk of spread of HCV through biological fluids, including semen, to other individuals. This risk can only be marginalized by the use of well-established criteria for safety in infertility centres, and by the use of proper initial detection and segregation of potentially hazardous materials. Techniques and protocols have been established to help the andrologist and embryologist to safeguard patients against such dangers, and should be imposed in all centres, allowing HCV-positive males to enter their assisted reproduction programmes.

Transmission virale et assistance médicale à la procréation : le cas des Herpesviridae

Procreation with sperm donation is at present achieved by insemination either in the uterus or in vitro, always from ejaculated and washed spermatozoa. Then, the infectious risk only exists if the donor sperm is capable of transporting the virus or its DNA, either by adhesion or by integration. With CMV, HSV1 and HSV2, medically assisted procreation in couples (AI or IVF-ET) does not increase the risk of viral contamination as compared with natural procreation, except possibly the cases of surgical procedure to pick up testicular sperm to be used in ICSI. Animal experiments show that, even if viral material is introduced in the oocyte, it may be eliminated from the embryo, at least for CMV.

Detection and characterization of hepatitis C virus RNA in seminal plasma and spermatozoon fractions of semen from patients attempting medically assisted conception

To investigate the risk of transmission of hepatitis C virus (HCV) via semen in assisted reproduction techniques, semen samples from 32 men chronically infected with HCV attending a center for assisted procreation were tested for HCV RNA by a reverse transcription-PCR protocol by using a modified version of the Cobas AMPLICOR HCV assay (version 2.0; Roche Diagnostics). The sensitivity of the test was 40 copies/ml. Four of 32 seminal plasma samples (12.5%) were found to be positive for the presence of HCV RNA. The median HCV load in blood was significantly higher in patients who were found to be positive for the presence of HCV RNA in semen than in those who tested negative (P = 0.02). In one man, seven consecutive seminal plasma samples tested positive for HCV RNA, as did two consecutive motile spermatozoon fractions; the corresponding fractions obtained after migration of the spermatozoa remained negative. Despite the absence of the proven infectivity of virus in semen samples that test positive for HCV RNA, these findings highlight the fact that seminal fluid may exhibit prolonged HCV RNA excretion. The usefulness of HCV RNA detection in both seminal plasma and spermatozoon fractions before the start of a program of medically assisted reproduction in couples in whom the male partner is chronically infected with HCV would need to be evaluated prospectively with a larger population of subjects exhibiting HCV RNA in their semen.

Failure to infect embryos after virus injection in mouse zygotes

BACKGROUND

The intracytoplasmic injection of sperm raises the problem that viral elements may be transported into the oocyte by the spermatozoon or the surrounding medium. It also raises questions about how the developing zygote will behave.

METHODS

We used the murine model to microinject murine cytomegalovirus (MCMV) into the zygote ooplasm and followed the changes in these microinjected zygotes in vivo and in vitro over time.

RESULTS

80% of zygotes microinjected with viral suspension, and 80% injected with medium alone, survived. Although MCMV DNA was detected in 56% of injected embryos, up until the blastocyst stage, the mice born from these injected zygotes developed normally and did not contain MCMV DNA. When embryonic stem cells were co-incubated with MCMV and then transferred into healthy blastocysts, the offspring were normal and did not contain any MCMV DNA.

CONCLUSIONS

Our observations suggest that even if MCMV DNA persists from the zygote to the blastocyst stage, its presence has no detrimental effect on pre-implantation or post-implantation development.

Experimental inoculation of male mice with murine cytomegalovirus and effect on offspring

BACKGROUND

Murine cytomegalovirus (MCMV) was used to examine aspects of viral infection in male mice, and its possible transmission to their offspring.

METHODS AND RESULTS

FVB/N mice inoculated intratesticularly with 5x10(5) plaque forming units (PFU) of MCMV, developed peritoneal haemorrhagic exudates, spleen hypertrophy and acute local infection. Infectiousness was detected until 15 days post-inoculation (D15 PI) in the genital organs, and virus DNA up to D35 PI. Testicular endothelial and Leydig cells were infected, and peritubular cells severely damaged. Spermatogenesis was affected, but neither germ cells nor Sertoli cells were infected. No virus was found in the epididymal epithelial cells. Viral DNA was detected in cells extracted from vas deferens samples until D15 PI. Neither infectious virus nor viral DNA were found in spermatozoa recovered from uterine fluid, fertilized oocytes, blastocysts, fetal tissues or newborn animals following the mating of infected males with uninfected females.

CONCLUSIONS

MCMV harboured in the male genital organs was not transmitted to their offspring, even when mating occurred during the acute phase of CMV disease. Although the infection may have had an impact on spermatogenesis, fertility was not affected. These results do not support the hypothesis of conceptus MCMV infection by the fertilizing spermatozoon in natural conception.

Screening standards in assisted reproductive technologies. Is the British Andrology Society recommendation to recruit cytomegalovirus negative semen donors only, a reasonable one?

The British Andrology Society recently recommended the exclusion of all cytomegalovirus (CMV) seropositive semen donors to prevent the risk of congenital CMV infection. The recommendation is based on the results of recent studies that identified a high percentage of symptomatic congenital CMV infections in newborns of women with CMV seropositivity pre-existing to pregnancy and on the fact that CMV can be detected in semen of CMV seropositive men. These are not new data. CMV seropositive women can infect their fetuses with their own latent CMV strain that can reactivate, or with an exogenous strain that can be transmitted to them by a sexual partner, but also by contacts, for example with an excreting child. The efficiency of these various ways of transmission to the fetus and the factors that could influence this transmission are for the moment completely unknown. An infectious virus is recovered by culture in the semen of <5% of CMV seropositive men. Exclusion of a large population of donors on the sole criteria of a positive CMV serology introduces the general message that this part of the male population is also not suitable as possible partners in couples who have no fertility problems. The problem of congenital infection in neonates of CMV seropositive women is a complex one that has just begun to be investigated. No data exists concerning this risk in the setting of assisted reproduction. We think that alternatives to the drastic BAS recommendation exist and should be more deeply discussed.