Introduction

1 Fatal coronavirus disease 2019 (COVID-19) could be considered as the sickness of the twenty-first century until now. This mysterious disease, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, could not be clearly treated until this moment. SARS-CoV-2 was classified as the most ferocious coronavirus ever (Dhama et al., 2020). The first successful attempt to cultivate coronaviruses (in general) for scientific investigation purposes was done by Tyrell and Bynoe in patients with the common cold in the year 1966 (Tyrrell and Bynoe, 1966). COVID-19 has many dangerous manifestations, signs, and symptoms on many organs and parts of the human's body (e.g., nose, mouth, lungs, eyes, bones, brain, stomach, intestines, skin, pancreas, and, newly, testes), these symptoms range from mild/moderate ones, such as fever, sore throat, dry cough, sneezing, runny nose, productive cough (in some cases), headache, chills, myalgia, arthralgia, dizziness, vertigo, diarrhea, vomiting, anorexia, allergic dermal conditions, and conjunctivitis (pinkish eye), to moderate/severe ones, such as high fever, anosmia/dysgeusia (with different degrees of severity and continuity), fatigue, dyspnea, persistent chest pain/oppression in the chest, palpitations, convulsions, lymphocytopenia (in most cases), difficulty in waking/walking, renal failure, sudden type 1 or 2 diabetes mellitus (DM 1/2), confusion, bluish face and lips, coughing up blood, thrombosis (diffuse blood clots), acute myocardial injury, bronchial asthma, pneumonia, and respiratory failure (Grant et al., 2020; Rabie, 2021).

2 As of end-July, 2021, about 200 millions of COVID-19 cases have been confirmed worldwide, with about 4.2 millions of lives lost due to this scary disease (COVID-19 Map, 2021). Recovery from COVID-19 does not mean the impossibility or low possibility of reinfection or long-term complications and consequences of the disease (Larson et al., 2020; To et al., 2020). Severe immune responses and inflammatory reactions (i.e., hyperinflammation) are basically the notable pathologic features of SARS-CoV-2 infection and COVID-19, leading to an inclusive cytokine storm in the human's body (Jose and Manuel, 2020). Although the respiratory system is the first and major human's system targeted and affected by this storm, other systems, e.g., cardiovascular and digestive systems, are also affected to a great degree (Jose and Manuel, 2020). The storm immunologic and inflammatory responses on the cardiovascular system appear in several severe vascular inflammation and dysfunction manifestations, such as microthrombosis, disseminated intravascular coagulation (DIC), vascular hyperpermeability, hemorrhage, microangiopathy, vasculitis, thromboembolic complications (venous and arterial), and endothelial inflammation and dysfunction (Jose and Manuel, 2020; Liu et al., 2020; Varga et al., 2020). It is extremely important to know that both endothelium (in general) and testicular tissue considerably express the protein receptor angiotensin-converting enzyme 2 (ACE2) which is the major entry point from which the SARS-CoV-2 can access the host cells or, more accurately, any organ cells (note that man's ACE2 plays key important roles in spermatogenesis and regulation of steroidogenesis) (Varga et al., 2020; Wang and Xu, 2020). It is well known that human male's penis, testes, and other parts of the reproductive system are very rich in vascular and endothelial tissues. An important supportive theory for the inhibitory effects of COVID-19 on man's sexual functions and abilities is that acute respiratory distress syndrome (ARDS) and its consequential substantial pulmonary fibrosis ultimately reduce the pulmonary gas exchange and, therefore, greatly impair oxygen saturation which could, consequently, impair testicular and penile erectile functions (like all other functional disabilities occurred in almost all body organs as a consequence of general hypoxia); also this oxygen shortage or hypoxia leads to two synergistic manifestations in the same concern, first, it considerably reduces the synthesis of nitric oxide (NO) by the enzyme NO synthase (as oxygen is one of the major substrates and precursors required for the synthesis of NO needed for penile vascular dilation and the following penile erection), and, second, it expectedly inhibits and blunts the activity of NO synthase itself (Graney et al., 2017; Padmanabhan and McCullough, 2007; Verratti et al., 2007). Another supportive standpoint is the current effective clinical use of phosphodiesterase-5 (PDE-5) inhibitors (they treat erectile dysfunction through enhancing and prolongation of the penile erection, as they prevent degradation of the cyclic guanosine monophosphate “cGMP” and increase its concentration leading to induction of relaxation of penile smooth muscles including penile vascular smooth muscles), mainly sildenafil, in the supportive treatment of COVID-19; sildenafil has general antioxidant and antiinflammatory activities, it also improves pulmonary hemodynamics of pulmonary fibrosis in COVID-19 by reducing vascular resistance and remodeling in the pulmonary circulation, and it reduces the risk of vascular injury and thrombotic complications through inhibiting neointimal formation and platelet aggregation (Dolci et al., 2006; Isidori et al., 2021; Rochwerg et al., 2016; Santi et al., 2015; Yang et al., 2019). In humans, the transmembrane protease, serine 2 (TMPRSS2) enzyme is encoded by the TMPRSS2 gene, the transcription of this gene could be significantly promoted and upregulated by androgenic hormones (like testosterone) (Wambier et al., 2020). The encoded protein primes the SARS-CoV-2 spike protein and, as a result, it impairs antibody response and assists the fusion between the viral particles and the human's cells; this could explain the vital important role of androgens in the higher prevalence of COVID-19 in men (Wambier et al., 2020). It is also worth mentioning that the extreme psychological load, burden, trauma, suffering, and consequences in COVID-19 patients (due to isolation, social distancing, loss of relatives/friends, difficulties in securing medications, clear economic consequences of lockdown, emotional distress, and mental preoccupation) would undoubtedly affect the sexual health (sexual mood, desire, activity, and frequency) of them and their sexual partners in a very passive way expressed in decreased couple's kissing, hugging, close dynamics, and direct intercourse (psychological shock and suffering might obviously aggravate preexisting minute and subclinical sexual problems and dysfunctions); the psychological burden is mainly presented in anxiety, posttraumatic stress disorder (PTSD), and depression (Aversa and Jannini, 2020; Dutheil et al., 2021; Li et al., 2020a). COVID-19 is also proven to be followed by considerable hypogonadal status which could additively worsen the man's sexual function through declining his sexual mood, libido, ability, and potency (Corona et al., 2013). DM, which appeared and was reported as an outcome in many COVID-19 patients, could be considered as one of COVID-19 mediators of sexual dysfunction (Caruso et al., 2020; Grant et al., 2020). There are some other logic manifestations and complications of COVID-19 that confirm and contribute to the same theory that we hypothesize (e.g., some clinical studies reported that SARS-CoV-2 particles are present in the semen and genital secretions of COVID-19 patients, some others reported the association of COVID-19 in some adult males with severe permanent testicular pain and/or prostatitis) (La Marca et al., 2020; Li et al., 2020b; Ma et al., 2021; Maya and Carvajal, 2020). Based on all these previous clear and important facts, we can hypothesize that penis, testes, and male's sexual glands are direct targets and victims of this organ dysfunction-producing SARS-CoV-2 (see Fig. 1).

3 Although COVID-19 was not reported to be a 100%-sexually transmitted infection, but, the practical scientific/medical facts of SARS-CoV-2 have told us that the virus can be easily passed on through all the steps of intercourse, either the preparatory steps (the premises) of intercourse, e.g., ear whispering, hugging, kissing, licking, and sucking, or the final steps of intercourse, e.g., very close contact including having any type of direct sex, whether vaginal, anal, or oral sex, of almost any position. These facts certainly support our hypotheses and partly confirm the great possibility of transmission of SARS-CoV-2 infection through close contact talking, breathing, and touches, along with sexual droplets, secretions, and intercourses. All the previous facts and clues together with the interesting findings of this present study also support that man's semen might be one of the richest liquid biosources of coronavirus-2 in men (directly after blood, pulmonary fluids, and cerebrospinal fluids).

4 With the prevalence of deadly COVID-19 pandemic, we have clearly noticed an intense increase in the number of men who have presented to andrologists with new sudden onset of various moderate to severe sexual dysfunction problems (e.g., erectile dysfunction/impotence, infertility, and hypogonadism) in the outpatient departments in many hospitals and in the andrology clinics in Egypt and USA along with through telemedicine/phone/online consultations (through direct phone/mobile calls, mobile chat applications, medical consultation websites, etc.). The high frequency with which patients present with these sexual problems over the second quarter of 2020 in Egypt was really very unusual. We mainly used our two hospitals in Egypt (the Dikernis General Hospital and the Mansoura New General Hospital) as the specific examples from which we decided to get our representative study sample (25 patients as a sample population, 15 and 10 patients, respectively) to perform this study over a duration of 5 weeks (May 30, 2020 to July 3, 2020) in the extreme peak of COVID-19 pandemic in Egypt. Almost all the 25 patients were tested for COVID-19 (in regard to positive “+ve” or negative “−ve”; only 1 elderly man refused to be tested, his COVID-19 test was indicated as not available “N.A.” in results table “Table 1”).

Methods

5 As introduced earlier in the last paragraph of the Introduction section, this is a direct retrospective study designed to review 25 patients (married men of different ages) who presented with sudden new onset of any form or mixture of forms of sexual dysfunction and impotence (erectile dysfunction, severe premature ejaculation, permanent testicular pain, infertility, hypospermia, decreased sexual desire/libido, etc.; including those detected and diagnosed after doing the required medical analyses and radiologic assessments, e.g., reduced blood testosterone levels, hypogonadism, and prostatitis) in the two hospitals in the period of May 30 to July 3, 2020 (i.e., a five-week study). Data were either directly collected from the patients themselves during their visits or indirectly from electronic medical records few days later after diagnosis and treatment. All the patients were examined through direct in-hospital visits, except 2 patients who indirectly got the diagnosis, treatment regimen, and follow-up instructions through telemedical consultation and online virtual examination (patients 11 and 17 in Table 1). All patients were tested for COVID-19 except only 1 elderly patient (73 years old). Most of these different-aged men had either no-to-very slight COVID-19 symptoms or very mild-to-moderate respiratory symptoms known in COVID-19 patients (we should put into consideration the time intervals elapsed since the occurrence and onset of SARS-CoV-2 infection until the visit for each patient tested positive for COVID-19 later). All required protective considerations were taken into consideration when dealing with these patients during the COVID-19 pandemic in Egypt. Any ethical approvals and/or consents were obtained whenever needed. The collected data were coded and analyzed using StataIC 16 software. Results were considered statistically significant for P<0.05. Confounders and any differences in patients’ characteristics were controlled and adjusted for as much as possible in the analysis phase.

Results and discussion

6 The complete results were organized in Table 1. The randomized cases are arranged in the table in an ascending order of their ages.

7 Upon close inspection of the results in Table 1, we would notice that almost all the study patients of sexual dysfunction (only one patient, patient 25, refused to carry out the COVID-19 test due to age and private concerns, however, his case data were included for more transparency and simple control comparison) gave positive results in COVID-19 polymerase chain reaction (PCR) analytic test for SARS-CoV-2 infection. Patient 7, the only patient tested negative for COVID-19 PCR analysis, was a diabetic married patient with a history of complete impotence and with no children (at first, he claimed that his sexual dysfunction status is somewhat new and acute; his data were also included for the sake of transparency and simple control comparison).

8 Results also showed that the most recurrent and repeated signs and symptoms of sexual dysfunction among the sample patients were impaired erectile function and progressive premature ejaculation. One or both of the two complaints were detected and diagnosed in more than 80% of the examined cases. This high percentage greatly supports the strong hypothesis of direct association between COVID-19 and the endothelial/vascular disintegrity, destruction, and dysfunction in the man's reproductive system (again, vascular integrity is an irreplaceable necessary key requirement for erectile and sexual function regularity and perfection).

9 Continuous testicular pain, hypospermia, reduced blood testosterone level, and hypogonadism were also observed (as complaints and/or after semen/blood analyses) in a considerable number of patients of various ages (e.g., patients 6-9, 13, 16, 19, and 24). Patient 19, specifically, was the most affected man, as he was suffering from almost all sexual dysfunction forms, though he was a youthful and sportive married middle-aged man with two healthy kids. As previously mentioned, male's testicular tissues considerably express the enzyme ACE2 (mainly in Sertoli and Leydig cells (Wang and Xu, 2020)), thus, suggesting that subclinical testicular injury and deterioration can occur following testicular SARS-CoV-2 infection, this testicular injury and damage in COVID-19 might, therefore, induce and create a significant state of hypogonadism and impaired testicular function. We proved this hypogonadal state in our sample patients through many evident symptoms and analytic outcomes, such as hypospermia, persistent testicular pain, declined blood testosterone levels, decreased testosterone-to-luteinizing hormone (LH) ratios, and declined steroidogenesis. Another unoverridable strong proof for our major hypothesis is the clear actual presence of SARS-CoV-2 in semen and genital secretions upon semen analysis of almost all sample patients (it is worth mentioning that ACE2 expression in men is also occurred by spermatogonia and, therefore, the risk of SARS-CoV-2 existence in seminal/genital fluids is highly increased in male patients of COVID-19, this, in turn, greatly supports our hypotheses (Li et al., 2020b; Wang and Xu, 2020)). The previous proofs significantly confirm the hypothesized theory of direct association between COVID-19 and the temporary acute testicular injury and dysfunction (functioning and unimpaired testicular and sexual glandular functions are considered the most important key elements for effective sexual reproductive function in men).

10 Table 1 also shows some other sexual dysfunction complaints which were raised by the sample patients but with a lesser incidence rate. Examples are infertility, recurrent priapism, painful erections, intermittent erections, and prostatitis (found in only one patient). Almost all patients declared that they are having considerable or enough sexual desire and libido toward their wives (i.e., there were not decreased sexual desire), meaning that COVID-19 might not significantly affect or decline the man's libido. Most patients had slight COVID-19 symptoms or mild-to-moderate respiratory symptoms known in COVID-19 patients. Patients’ histories revealed the presence of other comorbidities in few patients (other comorbidities, in a descending order of incidence rate, include DM 1/2, hypertension, CHF, and bronchial asthma). Only one positive COVID-19 patient (patient 15) was a smoker. All positive COVID-19 patients in the study have children (with different numbers) except patient 1 who is a new 22-years-old bridegroom. The most affected age range of the study patients was the men in the range of 25-45 years old (the youthful stage).

11 It is worth noticing that all the study participants are having stable heterosexual marital statuses (i.e., regular heterosexual relationships). Histories of absence of prior urogenital infections and diseases as comorbidities (along with absence of previous histories of sexual problems, impotence, continuous masturbation, and homosexual activities) in the positive sample patients indicated the absence of local predisposing factors, originated in the urinary system, for sexual dysfunction problems, which supports the hypothesis of suspecting COVID-19 as the major and/or sole causative agent of the patients’ current states of sexual dysfunction.

12 The significant inclusive inflammatory status which characterized all the study COVID-19 patients greatly upholds the idea of the indirect secondary role of the cytokine storm induced by SARS-CoV-2 invasion of the human's body in the pathogenesis, occurrence, and development of COVID-19-related sexual dysfunction in men. Additionally, the apparent declined and compromised psychological status of almost all the study patients (as well as their wives) supports a secondary hypothesis which is the worsening of COVID-19-related sexual dysfunction in adult human males due to the fear, anxiety, stress, and depression that accompany SARS-CoV-2 infection in both partners (the couple).

13 At the end of the five-week period of the study as well as after recovery from COVID-19 (and after the home/hospital isolation was finished), the sexual status of each patient of the study was assessed and completely evaluated (it is worth noticing that all the study patients have remained alive). The sexual status in about 85% of the sample patients was found to be totally autoresolved and regained to its previous natural and intact potency (short-term sequelaes), while it was autorestored to about 80% of its former natural and complete potency in more than 10% of the sample patients (moderate-term sequelaes). Only less than 5% of the sample patients had irreversible sexual dysfunction and needed pharmacotherapeutic and psychological intervention (long-term sequelaes). This is a clear proof that COVID-19-related sexual dysfunction in human males is majorly temporary and reversible in nature, and could be naturally autoresolved without any therapeutic, surgical, and/or psychological interventions and supports, as it only persists as long as the COVID-19 lasts with the patient.

14 All the results here and in the literature studies together with the reported strong hypotheses and perspectives (Malik et al., 2021) support our prinicipal hypotheses and theories about the disturbance of love and sex in the COVID-19 era, which revolve around the same various proposed mechanisms concerning the erectile and sexual dysfunction that is associated with SARS-CoV-2 infection and COVID-19 in men. From our point of view, the most important hypothesis is the one that owes the erectile and sexual dysfunction in male COVID-19 patients mainly to the severe endothelial dysregulation, temporary subclinical hypogonadism, psychosocial suffering/misery, pulmonary impairment and deterioration, and consequent cardiovascular weakness.

Conclusions

15 The major concern of this current interesting clinical study is to discuss the possible association between sexual dysfunction and COVID-19 infection in men. It is urgent for healthcare providers/professionals and relevant physicians (e.g., andrologists/sexologists and gynecologists/obstetricians) along with pharmacists to inform and advise all COVID-19 positive patients that unprotected close contact and intercourse are totally prohibited and must be avoided. It is generally not recommended for any two married partners (i.e., for any couple) to have sex and/or its premises (the preludes to sex) during the pandemic (specially during its peak, i.e., during the peak of each COVID-19 pandemic wave). The results of the present clinical study upheld and supported to a great extent our major hypothesis of the direct association between SARS-CoV-2 invasion of the man's reproductive system and the concurrent sudden and resolvable moderate-to-severe sexual dysfunction. Interestingly, a new study published in February 2021 by Ma and colleagues also significantly supported and confirmed all the results and findings of this present research study, specially from the histological and pathological points of view at the molecular level (Ma et al., 2021). Almost all sexual sequelaes induced by SARS-CoV-2 infection are short term in nature as they only persist as long as the devastating and deadly COVID-19 lasts with the male patient. Another main hypothesis was proved and confirmed in this current work, it is the hypothesis that ACE2 represents the key and core target for designing and discovering novel potent effective drugs for this COVID-19-related sexual dysfunction and impotence in men. It was also assured that cytokine storm induced by SARS-CoV-2 infection is representing the second key target for discovering novel efficient remedies for this COVID-19-related sexual dysfunction and impotence in men. A secondary theory or hypothesis that was supported in the present research is that the COVID-19-related sexual dysfunction in adult human males always extremely worsens due to the fear, anxiety, stress, and depression that accompany and follow SARS-CoV-2 infection in both genders (men and women). In a word, COVID-19 certainly has almost unfortunate and strong short-term sequelaes on the man's reproductive system. Further extensive investigations of man's sexual dysfunction and impotence in patients who are tested positive for COVID-19 (larger clinical studies) will ultimately help us to explicate the potential mechanisms of injury and trauma in the male's reproductive system in details.

Disclosure of interest

16 The author declares that he has no competing interest.

Acknowledgments

17 I gratefully thank and deeply acknowledge any colleague (faculty staff member, physician, pharmacist, nurse, technician, etc.; from Dikernis General Hospital “Egypt”, Mansoura New General Hospital “Egypt”, and Harvard Medical School “USA”) and anyone who gave a hand to make this new important clinical study coming out to light.