Skip to content
2000
Volume 6, Issue 4
  • ISSN: 2666-7967
  • E-ISSN: 2666-7975

Abstract

Till now, 642 million COVID-19 cases have been confirmed, claiming around 6.62 million lives. The impact of SARS-CoV-2 on the male reproductive system, both short and long-term, remains a mystery. This study aims to scrutinize how SARS-CoV-2 affects sexual function, considering potential mediators such as psychological stress. Results reveal that the infection intensifies metabolic stress, directly or indirectly impacting male fertility and causing psychological distress with heightened ROS generation. The exclusive presence of Angiotensin-converting enzyme 2 (ACE2) in type II pneumocytes, serving as the virus receptor, suggests lungs as the primary target. In conclusion, SARS-CoV-2 infection potentially diminishes male fertility, primarily due to psychological stress, raising concerns about COVID-19-induced male infertility amid other factors. Despite limited therapeutic options for COVID-19 and ongoing vaccine efforts, the persistent threat of diverse strains poses a long-term risk to global population health.

Loading

Article metrics loading...

/content/journals/covid/10.2174/0126667975316497240725102111
2024-07-29
2025-10-03
Loading full text...

Full text loading...

References

  1. World Health OrganizationTherapeutics and COVID-19: Living guideline, 13 January 2023.2023Available From: https://www.who.int/publications/i/item/WHO-2019-nCoV-therapeutics-2023.2
    [Google Scholar]
  2. LiH. LiuL. ZhangD. SARS-CoV-2 and viral sepsis: Observations and hypotheses.Lancet2020395102351517152010.1016/S0140‑6736(20)30920‑X 32311318
    [Google Scholar]
  3. LavieM. DubuissonJ. BelouzardS. SARS-CoV-2 spike furin cleavage site and S2′ basic residues modulate the entry process in a host cell-dependent manner.J. Virol.20229613e00474e2210.1128/jvi.00474‑22 35678602
    [Google Scholar]
  4. DhameliyaT.M. NagarP.R. GajjarN.D. Systematic virtual screening in search of SARS CoV-2 inhibitors against spike glycoprotein: Pharmacophore screening, molecular docking, ADMET analysis and MD simulations.Mol. Divers.20222652775279210.1007/s11030‑022‑10394‑9 35132518
    [Google Scholar]
  5. SrivastavaN. In aerosol optical depth and precipitation: Measuring particle concentration, health risks and environmental impacts.ChamSpringer202417718810.1007/978‑3‑031‑55836‑8_10
    [Google Scholar]
  6. ChaC. BaekG. Symptoms and management of long COVID: A scoping review.J. Clin. Nurs.2024331112810.1111/jocn.16150 34913540
    [Google Scholar]
  7. ChenchulaS. SharmaS. TripathiM. ChavanM. MisraA.K. RangariG. Prevalence of overweight and obesity and their effect on COVID‐19 severity and hospitalization among younger than 50 years versus older than 50 years population: A systematic review and meta‐analysis.Obes. Rev.20232411e1361610.1111/obr.13616 37574901
    [Google Scholar]
  8. JacobsM.M. EvansE. EllisC. Racial, ethnic, and sex disparities in the incidence and cognitive symptomology of long COVID-19.J. Natl. Med. Assoc.2023115223324310.1016/j.jnma.2023.01.016 36792456
    [Google Scholar]
  9. LottN. GebhardC.E. BengsS. Sex hormones in SARS-CoV-2 susceptibility: Key players or confounders?Nat. Rev. Endocrinol.202319421723110.1038/s41574‑022‑00780‑6 36494595
    [Google Scholar]
  10. CoqueT.M. CantónR. Pérez-CobasA.E. Fernández-de-BobadillaM.D. BaqueroF. Antimicrobial resistance in the global health network: Known unknowns and challenges for efficient responses in the 21st century.Microorganisms2023114105010.3390/microorganisms11041050 37110473
    [Google Scholar]
  11. AlokeC. AchilonuI. Coping with the ESKAPE pathogens: Evolving strategies, challenges and future prospects.Microb. Pathog.202317510596310.1016/j.micpath.2022.105963 36584930
    [Google Scholar]
  12. HusseinH.A.M. ThabetA.A. WardanyA.A. SARS-CoV-2 outbreak: Role of viral proteins and genomic diversity in virus infection and COVID-19 progression.Virol. J.20242117510.1186/s12985‑024‑02342‑w 38539202
    [Google Scholar]
  13. XiY CaoYL TaoLY A global perspective: Characteristics of infertility-related randomized clinical trials.Andrology2024andr.1359610.1111/andr.13596 38231194
    [Google Scholar]
  14. LeslieS. Soon-SuttonT. KhanM.A. Male infertility.Treasure Island, FLStatPearls2024
    [Google Scholar]
  15. SenguptaP. LeisegangK. AgarwalA. The impact of COVID-19 on the male reproductive tract and fertility: A systematic review.Arab J. Urol.202119342343610.1080/2090598X.2021.1955554 34552795
    [Google Scholar]
  16. AitkenR.J. COVID‐19 and male infertility: An update.Andrology202210181010.1111/andr.13098 34411453
    [Google Scholar]
  17. QiJ. SunM. YueX. HongX. DongM. TanJ. The impact of COVID-19 on the mental and sexual health of patients with infertility: A prospective before-and-after study.Reprod. Biol. Endocrinol.2024221110.1186/s12958‑023‑01174‑7 38167101
    [Google Scholar]
  18. Vander BorghtM. WynsC. Fertility and infertility: Definition and epidemiology.Clin. Biochem.20186221010.1016/j.clinbiochem.2018.03.012 29555319
    [Google Scholar]
  19. SimionescuG. DorofteiB. MafteiR. The complex relationship between infertility and psychological distress (Review).Exp. Ther. Med.202121430610.3892/etm.2021.9737 33717249
    [Google Scholar]
  20. ZhangM. WenT. WangD. The association between COVID-19 and infertility: Mendelian randomization analysis.Medicine (Baltimore)202410310e3734610.1097/MD.0000000000037346 38457599
    [Google Scholar]
  21. BowyerR.C.E. HugginsC. TomsR. Characterising patterns of COVID-19 and long COVID symptoms: Evidence from nine UK longitudinal studies.Eur. J. Epidemiol.202338219921010.1007/s10654‑022‑00962‑6 36680646
    [Google Scholar]
  22. LechienJ.R. VairaL.A. SaussezS. Prevalence and 24‐month recovery of olfactory dysfunction in COVID‐19 patients: A multicentre prospective study.J. Intern. Med.20232931829010.1111/joim.13564 36000469
    [Google Scholar]
  23. SkinnerJ.P. MoranL.V. Persistent effects of COVID‐19 in patients hospitalized during the first wave of the pandemic: The impact of persistent fatigue on quality of life in a cross-sectional study.J. Med. Virol.2023952e2849110.1002/jmv.28491 36832543
    [Google Scholar]
  24. SiaA.S. NeoJ.E. Jen-Wei TanB. TanE.K. “Brain fog” and COVID-19.Am. J. Med. Sci.2023365547247410.1016/j.amjms.2023.01.003 36632867
    [Google Scholar]
  25. AraújoC.R.S. FernandesJ. CaetanoD.S. Endothelial function, arterial stiffness and heart rate variability of patients with cardiovascular diseases hospitalized due to COVID-19.Heart Lung20235821021610.1016/j.hrtlng.2022.12.016 36621104
    [Google Scholar]
  26. VargasI. MuenchA. GrandnerM.A. IrwinM.R. PerlisM.L. Insomnia symptoms predict longer COVID-19 symptom duration.Sleep Med.202310136537210.1016/j.sleep.2022.11.019 36493657
    [Google Scholar]
  27. KułaczkowskaZ. Cardiovascular complications of COVID-19: acute and long-term impacts.ChamSpringer2023401409
    [Google Scholar]
  28. AliyevaA. HanJ.S. ParkS.N. OlgunL. Long-term follow-up results of tinnitus and dizziness disorders in patients after SARS-CoV-2 infection based on a questionnaire.Balkan Med. J.2023401707110.4274/balkanmedj.galenos.2022.2022‑7‑8 36398846
    [Google Scholar]
  29. DavisH.E. McCorkellL. VogelJ.M. TopolE.J. Long COVID: Major findings, mechanisms and recommendations.Nat. Rev. Microbiol.202321313314610.1038/s41579‑022‑00846‑2
    [Google Scholar]
  30. SloumaM. AbbesM. MehmliT. Reactive arthritis occurring after COVID-19 infection: A narrative review.Infection2023511374510.1007/s15010‑022‑01858‑z 35655110
    [Google Scholar]
  31. HeumannE. HelmerS.M. BusseH. Anxiety and depressive symptoms of German university students 20 months after the COVID-19 outbreak – A cross-sectional study.J. Affect. Disord.202332056857510.1016/j.jad.2022.09.158 36220498
    [Google Scholar]
  32. RalliM. ColizzaA. RussoF.Y. Otolaryngology conditions and diseases in migrants: The experience of the PROTECT project.Appl. Sci. (Basel)2023134210410.3390/app13042104
    [Google Scholar]
  33. IrfanY. ShanI. AdnanQ. MuhammadS. Frequency and correlation of gastrointestinal symptoms with outcomes in hospitalized patients with COVID-19.Prof. Med. J.202330219319810.29309/TPMJ/2023.30.02.7229
    [Google Scholar]
  34. SkourtisA. EkmektzoglouK. XanthosT. StouraitouS. IacovidouN. Non-typical clinical presentation of COVID-19 patients in association with disease severity and length of hospital stay.J. Pers. Med.202313113210.3390/jpm13010132 36675793
    [Google Scholar]
  35. PektaşA BükülmezA ÇeleğenM Ekerİ. Rash and gastrointestinal dysfunction may indicate cardiac involvement in children with multisystem inflammatory system associated with coronavirus disease 2019.J Pediatr Infect Dis201918208893
    [Google Scholar]
  36. BoutinS. HildebrandD. BoulantS. Host factors facilitating SARS‐CoV‐2 virus infection and replication in the lungs.Cell. Mol. Life Sci.202178165953597610.1007/s00018‑021‑03889‑5 34223911
    [Google Scholar]
  37. ThakurA.K. The renin angiotensin system in cardiovascular disease.ChamSpringer202343144710.1007/978‑3‑031‑14952‑8_25
    [Google Scholar]
  38. FanC. LuW. LiK. DingY. WangJ. ACE2 expression in kidney and testis may cause kidney and testis infection in COVID-19 patients.Front. Med. (Lausanne)2021756389310.3389/fmed.2020.563893 33521006
    [Google Scholar]
  39. HeY. WangJ. RenJ. ZhaoY. ChenJ. ChenX. Effect of COVID-19 on male reproductive system–a systematic review.Front. Endocrinol. (Lausanne)20211267770110.3389/fendo.2021.677701 34122351
    [Google Scholar]
  40. AgolliA. YukselenZ. AgolliO. SARS-CoV-2 effect on male infertility and its possible pathophysiological mechanisms.Discoveries (Craiova)202192e13110.15190/d.2021.10 34816001
    [Google Scholar]
  41. WangZ. XuX. scRNA-seq profiling of human testes reveals the presence of the ACE2 receptor, a target for SARS-CoV-2 infection in spermatogonia, Leydig and Sertoli cells.Cells20209492010.3390/cells9040920 32283711
    [Google Scholar]
  42. HaghpanahA. MasjediF. AlborziS. Potential mechanisms of SARS‐CoV‐2 action on male gonadal function and fertility: Current status and future prospects.Andrologia2021531e1388310.1111/and.13883 33108833
    [Google Scholar]
  43. SamadianE. AghcheliB. GharaeiR. TabarraeiA. A review on human reproductive systems encountering with the severe acute respiratory syndrome coronavirus 2 infection.Int. J. Reproduct BioMed.2023211116
    [Google Scholar]
  44. ZouX. ChenK. ZouJ. HanP. HaoJ. HanZ. Single-cell RNA-seq data analysis on the receptor ACE2 expression reveals the potential risk of different human organs vulnerable to 2019-nCoV infection.Front. Med.202014218519210.1007/s11684‑020‑0754‑0 32170560
    [Google Scholar]
  45. BridwellR.E. MerrillD.R. GriffithS.A. WrayJ. OliverJ.J. A coronavirus disease 2019 (COVID-19) patient with bilateral orchitis.Am. J. Emerg. Med.202142260.e3260.e5
    [Google Scholar]
  46. EspositoV. RaniaE. LicoD. Influence of COVID-19 pandemic on the psychological status of infertile couples.Eur. J. Obstet. Gynecol. Reprod. Biol.202025314815310.1016/j.ejogrb.2020.08.025 32866858
    [Google Scholar]
  47. YangM. ChenS. HuangB. Pathological findings in the testes of COVID-19 patients: Clinical implications.Eur. Urol. Focus2020651124112910.1016/j.euf.2020.05.009 32563676
    [Google Scholar]
  48. Duarte-NetoA.N. TeixeiraT.A. CaldiniE.G. Testicular pathology in fatal COVID‐19: A descriptive autopsy study.Andrology2022101132310.1111/andr.13073 34196475
    [Google Scholar]
  49. GuoL. ZhaoS. LiW. Absence of SARS‐CoV‐2 in semen of a COVID‐19 patient cohort.Andrology202191424710.1111/andr.12848 32598557
    [Google Scholar]
  50. ChengG. GuoS. ZhouL. Suggestions on cleavage embryo and blastocyst vitrification/transfer based on expression profile of ACE2 and TMPRSS2 in current COVID‐19 pandemic.Mol. Reprod. Dev.202188321121610.1002/mrd.23456 33624358
    [Google Scholar]
  51. WangL. WangS. WuL. PCIF1-mediated deposition of 5′-cap N6, 2′-O-dimethyladenosine in ACE2 and TMPRSS2 mRNA regulates susceptibility to SARS-CoV-2 infection.Proc. Natl. Acad. Sci. USA20231205e221036112010.1073/pnas.2210361120 36689652
    [Google Scholar]
  52. WambierC.G. GorenA. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is likely to be androgen mediated.J. Am. Acad. Dermatol.202083130830910.1016/j.jaad.2020.04.032 32283245
    [Google Scholar]
  53. MaggioM. BasariaS. CedaG. The relationship between testosterone and molecular markers of inflammation in older men.J. Endocrinol. Invest.200528116119
    [Google Scholar]
  54. MohamadN-V. WongS.K. HasanW.N.W. The relationship between circulating testosterone and inflammatory cytokines in men.Aging Male2018 29925283
    [Google Scholar]
  55. PozzilliP. LenziA. Commentary: Testosterone, a key hormone in the context of COVID-19 pandemic.Metabolism202010815425210.1016/j.metabol.2020.154252 32353355
    [Google Scholar]
  56. KetchemJ.M. BowmanE.J. IsalesC.M. Male sex hormones, aging, and inflammation.Biogerontology202324112510.1007/s10522‑022‑10002‑1 36596999
    [Google Scholar]
  57. Sheikh-AhmadM. NakhlehA. RiskinA. The correlation between testosterone, inflammation and cytokine status in type‐2 diabetes men.Andrologia20225410e1452610.1111/and.14526 35796052
    [Google Scholar]
  58. DaiP. QiaoF. ChenY. SARS-CoV-2 and male infertility: From short- to long-term impacts.J. Endocrinol. Invest.20234681491150710.1007/s40618‑023‑02055‑x 36917421
    [Google Scholar]
  59. MaL. XieW. LiD. Effect of SARS-CoV-2 infection upon male gonadal function: A single center-based study.MedRxiv202010.1101/2020.03.21.20037267
    [Google Scholar]
  60. SaloniaA. PontilloM. CapogrossoP. Severely low testosterone in males with COVID‐19: A case‐control study.Andrology2021941043105210.1111/andr.12993 33635589
    [Google Scholar]
  61. ÇayanS. UğuzM. SaylamB. AkbayE. Effect of serum total testosterone and its relationship with other laboratory parameters on the prognosis of coronavirus disease 2019 (COVID-19) in SARS-CoV-2 infected male patients: A cohort study.Aging Male20202351493150310.1080/13685538.2020.1807930 32883151
    [Google Scholar]
  62. MannurS. JabeenT. KhaderM.A. RaoL.S.S. Post-COVID-19-associated decline in long-term male fertility and embryo quality during assisted reproductive technology.QJM20212021hcab019
    [Google Scholar]
  63. Ardestani ZadehA. ArabD. COVID-19 and male reproductive system: Pathogenic features and possible mechanisms.J. Mol. Histol.202152586987810.1007/s10735‑021‑10003‑3 34232425
    [Google Scholar]
  64. WuJ. ChenL. QinC. CD147 contributes to SARS-CoV-2-induced pulmonary fibrosis.Signal Transduct. Target. Ther.20227138210.1038/s41392‑022‑01230‑5 36424379
    [Google Scholar]
  65. RenH.L. WenG.M. ZhaoZ.Y. LiuD.H. XiaP. Can CD147 work as a therapeutic target for tumors through COVID-19 infection?Int. J. Med. Sci.202219142087209210.7150/ijms.79162 36483594
    [Google Scholar]
  66. NisaA. KumarR. RamasamyS. Modulations of homeostatic ACE2, CD147, GRP78 pathways correlate with vascular and endothelial performance markers during pulmonary SARS-CoV-2 infection.Cells202413543210.3390/cells13050432 38474396
    [Google Scholar]
  67. HabeichiN.J. AminG. LakkisB. Potential alternative receptors for SARS-CoV-2-induced kidney damage: TLR-4, KIM-1/TIM-1, and CD147.Front Biosci-Landmark2024291810.31083/j.fbl2901008 38287815
    [Google Scholar]
  68. LiuY. QiL. LiZ. YongV.W. XueM. Crosstalk between matrix metalloproteinases and their inducer EMMPRIN/CD147: A promising therapeutic target for intracerebral hemorrhage.Transl. Stroke Res.2023202311110.1007/s12975‑023‑01225‑6 38100014
    [Google Scholar]
  69. ChenH. FokK.L. JiangX. CD147 regulates apoptosis in mouse spermatocytes but not spermatogonia.Hum. Reprod.20122761568157610.1093/humrep/des050 22451502
    [Google Scholar]
  70. DaiP. MaC. JiangT. CD147 mediates S protein pseudovirus of SARS-CoV-2 infection and its induction of spermatogonia apoptosis.Endocrine202411110.1007/s12020‑024‑03891‑4 38824220
    [Google Scholar]
  71. PérezC.V. PellizzariE.H. CigorragaS.B. IL17A impairs blood–testis barrier integrity and induces testicular inflammation.Cell Tissue Res.2014358388589810.1007/s00441‑014‑1995‑5 25231257
    [Google Scholar]
  72. MollicaV. RizzoA. MassariF. Future Medicine20201620292033
    [Google Scholar]
  73. BasoloA. PomaA.M. MacerolaE. Autopsy study of testicles in COVID-19: Upregulation of immune-related genes and downregulation of testis-specific genes.J. Clin. Endocrinol. Metab.2023108495096110.1210/clinem/dgac608 36260523
    [Google Scholar]
  74. ShafieyS.I. AhmedK.A. Abo-SaifA.A. Abo-YoussefA.M. MohamedW.R. Galantamine mitigates testicular injury and disturbed spermatogenesis in adjuvant arthritic rats via modulating apoptosis, inflammatory signals, and IL-6/JAK/STAT3/SOCS3 signaling.Inflammopharmacology202432140541810.1007/s10787‑023‑01268‑z 37429998
    [Google Scholar]
  75. OjoO.A. Nwafor-EzehP.I. RotimiD.E. IyobhebheM. OgunlakinA.D. OjoA.B. Apoptosis, inflammation, and oxidative stress in infertility: A mini review.Toxicol. Rep.20231044846210.1016/j.toxrep.2023.04.006 37125147
    [Google Scholar]
  76. SalariN. Hosseinian-FarA. JalaliR. Prevalence of stress, anxiety, depression among the general population during the COVID-19 pandemic: A systematic review and meta-analysis.Global. Health20201615710.1186/s12992‑020‑00589‑w 32631403
    [Google Scholar]
  77. MahmudS. MohsinM. DewanM.N. MuyeedA. The global prevalence of depression, anxiety, stress, and insomnia among general population during COVID-19 pandemic: A systematic review and meta-analysis.Trends Psychol.202231114317010.1007/s43076‑021‑00116‑9
    [Google Scholar]
  78. AbelK.M. CarrM.J. AshcroftD.M. Association of SARS-CoV-2 infection with psychological distress, psychotropic prescribing, fatigue, and sleep problems among UK primary care patients.JAMA Netw. Open2021411e213480310.1001/jamanetworkopen.2021.34803 34783824
    [Google Scholar]
  79. LiL. LiF. FortunatiF. KrystalJ.H. Association of a prior psychiatric diagnosis with mortality among hospitalized patients with coronavirus disease 2019 (COVID-19) infection.JAMA Netw. Open202039e202328210.1001/jamanetworkopen.2020.23282 32997123
    [Google Scholar]
  80. StefanoG.B. PtacekR. PtackovaH. MartinA. KreamR.M. Selective neuronal mitochondrial targeting in SARS-CoV-2 infection affects cognitive processes to induce ‘brain fog’and results in behavioral changes that favor viral survival.Med. Sci. Monit.202127e930886e110.12659/MSM.930886 33487628
    [Google Scholar]
  81. DhontS. DeromE. Van BraeckelE. DepuydtP. LambrechtB.N. The pathophysiology of ‘happy’ hypoxemia in COVID-19.Respir. Res.202021119810.1186/s12931‑020‑01462‑5 32723327
    [Google Scholar]
  82. GopalA.B. ChakrabortyS. PadhanP.K. Silent hypoxia in COVID-19: A gut microbiota connection.Curr. Opin. Physiol.20212310045610.1016/j.cophys.2021.06.010 34250324
    [Google Scholar]
  83. MotiejunaiteJ. BalagnyP. ArnoultF. Hyperventilation as one of the mechanisms of persistent dyspnoea in SARS-CoV-2 survivors.Eur. Respir. J.2021582210157810.1183/13993003.01578‑2021 34385265
    [Google Scholar]
  84. MintzioriG. DuntasL.H. VenetiS. GoulisD.G. Metabolic, oxidative and psychological stress as mediators of the effect of COVID-19 on male infertility: A literature review.Int. J. Environ. Res. Public Health2022199527710.3390/ijerph19095277 35564672
    [Google Scholar]
  85. LiA. ZhaoQ. ChenL. LiZ. Apelin/APJ system: An emerging therapeutic target for neurological diseases.Mol. Biol. Rep.20235021639165310.1007/s11033‑022‑08075‑9 36378421
    [Google Scholar]
  86. KolbasiB. BulbulM.V. KarabulutS. Chronic unpredictable stress disturbs the blood–testis barrier affecting sperm parameters in mice.Reprod. Biomed. Online202142598399510.1016/j.rbmo.2020.12.007 33653651
    [Google Scholar]
  87. KhodamoradiK. Amini-KhoeiH. KhosravizadehZ. HosseiniS.R. DehpourA.R. HassanzadehG. Oxidative stress, inflammatory reactions and apoptosis mediated the negative effect of chronic stress induced by maternal separation on the reproductive system in male mice.Reprod. Biol.201919434034810.1016/j.repbio.2019.10.003 31711846
    [Google Scholar]
  88. ZhengX. LiZ. WangG. Sperm epigenetic alterations contribute to inter- and transgenerational effects of paternal exposure to long-term psychological stress via evading offspring embryonic reprogramming.Cell Discov.20217110110.1038/s41421‑021‑00343‑5 34711814
    [Google Scholar]
  89. MicelliE. CitoG. CocciA. Desire for parenthood at the time of COVID-19 pandemic: An insight into the Italian situation.J. Psychosom. Obstet. Gynaecol.202041318319010.1080/0167482X.2020.1759545 32379999
    [Google Scholar]
  90. DennisD. RadnitzC. WheatonM.G. A perfect storm? Health anxiety, contamination fears, and COVID-19: Lessons learned from past pandemics and current challenges.Int. J. Cogn. Ther.202114349751310.1007/s41811‑021‑00109‑7 33907592
    [Google Scholar]
  91. BavelJ.J.V. BaickerK. BoggioP.S. Using social and behavioural science to support COVID-19 pandemic response.Nat. Hum. Behav.20204546047110.1038/s41562‑020‑0884‑z 32355299
    [Google Scholar]
  92. OrnellF. SchuchJ.B. SordiA.O. KesslerF.H.P. “Pandemic fear” and COVID-19: Mental health burden and strategies.Br. J. Psychiatry202042323223510.1590/1516‑4446‑2020‑0008 32267343
    [Google Scholar]
  93. AhorsuD.K. LinC-Y. ImaniV. SaffariM. GriffithsM.D. PakpourA.H. The fear of COVID-19 scale: Development and initial validation.Int. J. Ment. Health Addict.2020202019 32226353
    [Google Scholar]
  94. DoshiD. KarunakarP. SukhabogiJ.R. PrasannaJ.S. MahajanS.V. Assessing coronavirus fear in Indian population using the fear of COVID-19 scale.Int. J. Ment. Health Addict.20211962383239110.1007/s11469‑020‑00332‑x 32837422
    [Google Scholar]
  95. SakibN. BhuiyanA. HossainS. Psychometric validation of the Bangla Fear of COVID-19 Scale: Confirmatory factor analysis and Rasch analysis.Int. J. Ment. Health Addict.20202020112 32395096
    [Google Scholar]
  96. ParkS.H. SongY.J.C. DemetriouE.A. Validation of the 21-item Depression, Anxiety, and Stress Scales (DASS-21) in individuals with autism spectrum disorder.Psychiatry Res.202029111330010.1016/j.psychres.2020.113300 32763554
    [Google Scholar]
  97. LiS. WangY. XueJ. ZhaoN. ZhuT. The impact of covid-19 epidemic declaration on psychological consequences: A study on active weibo users.Int. J. Environ. Res. Public Health20201762032
    [Google Scholar]
  98. QiuJ. ShenB. ZhaoM. WangZ. XieB. XuY. A nationwide survey of psychological distress among Chinese people in the COVID-19 epidemic: Implications and policy recommendations.Gen. Psychiatr.2020332e10021310.1136/gpsych‑2020‑100213 32215365
    [Google Scholar]
  99. AsmundsonG.J.G. TaylorS. How health anxiety influences responses to viral outbreaks like COVID-19: What all decision-makers, health authorities, and health care professionals need to know.J. Anxiety Disord.20207110221110.1016/j.janxdis.2020.102211 32179380
    [Google Scholar]
  100. DubeyS. BiswasP. GhoshR. Psychosocial impact of COVID-19.Diabetes Metab. Syndr.202014577978810.1016/j.dsx.2020.05.035 32526627
    [Google Scholar]
  101. PfefferbaumB. NorthC.S. Mental health and the COVID-19 pandemic.N. Engl. J. Med.2020383651051210.1056/NEJMp2008017 32283003
    [Google Scholar]
  102. RestubogS.L.D. OcampoA.C.G. WangL. Taking control amidst the chaos: Emotion regulation during the COVID-19 pandemic.J. Vocat. Behav.2020119103440
    [Google Scholar]
  103. SherL. COVID-19, anxiety, sleep disturbances and suicide.Sleep Med.20207012410.1016/j.sleep.2020.04.019 32408252
    [Google Scholar]
  104. ShadmiE. ChenY. DouradoI. Health equity and COVID-19: Global perspectives.Int. J. Equity Health202019110410.1186/s12939‑020‑01218‑z 32586388
    [Google Scholar]
  105. KulkarniA. Davey-RothwellM. MossialosE. Accelerating integration of social needs into mainstream healthcare to achieve health equity in the COVID-19 era.Health Econ. Policy Law2023181828710.1017/S1744133122000172 35912976
    [Google Scholar]
  106. VishvkarmaR. RajenderS. Could SARS‐CoV‐2 affect male fertility?Andrologia2020529e1371210.1111/and.13712 32578263
    [Google Scholar]
  107. CohenJ. NassauD.E. PatelP. RamasamyR. Low testosterone in adolescents & young adults.Front. Endocrinol.20201091610.3389/fendo.2019.00916 32063884
    [Google Scholar]
  108. MaL. XieW. LiD. Evaluation of sex-related hormones and semen characteristics in reproductive-aged male COVID‐19 patients.J. Med. Virol.202193145646210.1002/jmv.26259 32621617
    [Google Scholar]
  109. LiR. YinT. FangF. Potential risks of SARS-CoV-2 infection on reproductive health.Reprod. Biomed. Online2020411899510.1016/j.rbmo.2020.04.018 32466994
    [Google Scholar]
  110. SchäferT. The positive effects of online group singing on psycho‐physiological variables during the COVID‐19 pandemic—A pilot randomized controlled trial.Appl. Psychol. Health Well-Being20231541254127010.1111/aphw.12435 36609828
    [Google Scholar]
  111. MinihanE. GavinB. KellyB.D. McNicholasF. COVID-19, mental health and psychological first aid.Ir. J. Psychol. Med.202037425926310.1017/ipm.2020.41 32404221
    [Google Scholar]
  112. O’ConnorK. WrigleyM. JenningsR. HillM. NiaziA. Mental health impacts of COVID-19 in Ireland and the need for a secondary care mental health service response.Ir. J. Psychol. Med.20213829910710.1017/ipm.2020.64 32456713
    [Google Scholar]
  113. LeeY. KimS. Comparison of pregnancy stress, impact and fear of COVID-19 between working and non-working pregnant women in Korea.Curr. Psychol.20234236321943220210.1007/s12144‑022‑04105‑8 36684463
    [Google Scholar]
  114. KhalailaR. Shiovitz-EzraS. Social distancing and trouble sleeping during COVID ‐19 pandemic among older adults in Europe: Mediating and moderating effects.J. Nurs. Scholarsh.202355113114010.1111/jnu.12830 36404594
    [Google Scholar]
  115. AlqahtaniM.S. AbbasM. AlshahraniM.Y. Effects of COVID-19 on synaptic and neuronal degeneration.Brain Sci.202313113110.3390/brainsci13010131 36672112
    [Google Scholar]
  116. GolpanianR.S. KimH.S. YosipovitchG. Effects of stress on itch.Clin. Ther.202042574575610.1016/j.clinthera.2020.01.025 32147148
    [Google Scholar]
  117. KonstantinouG.N. KonstantinouG.N. Psychological stress and chronic urticaria: A neuro-immuno-cutaneous crosstalk. A systematic review of the existing evidence.Clin. Ther.202042577178210.1016/j.clinthera.2020.03.010 32360096
    [Google Scholar]
  118. QinC. ZiweiM.P.L.Z.M. TaoS.Y.M.Y. KeP.C.X.M.P. ShangM.M.P.K. Dysregulation of immune response in patients with COVID-19 in Wuhan, China; Clinical Infectious Diseases; Oxford Academic.Clin. Infect. Dis.2020
    [Google Scholar]
  119. ZhangW. ZhaoY. ZhangF. The use of anti-inflammatory drugs in the treatment of people with severe coronavirus disease 2019 (COVID-19): The perspectives of clinical immunologists from China.Clin. Immunol.202021410839310.1016/j.clim.2020.108393 32222466
    [Google Scholar]
  120. ZhouF. YuT. DuR. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: A retrospective cohort study.Lancet2020395102291054106210.1016/S0140‑6736(20)30566‑3 32171076
    [Google Scholar]
  121. MillerG.E. CohenS. RitcheyA.K. Chronic psychological stress and the regulation of pro-inflammatory cytokines: A glucocorticoid-resistance model.Health Psychol.200221653154110.1037/0278‑6133.21.6.531 12433005
    [Google Scholar]
  122. QuirogaB. Muñoz RamosP. GiorgiM. Dynamic assessment of interleukin-6 during hemodialysis and mortality in coronavirus disease-19.Ther. Apher. Dial.202125690891610.1111/1744‑9987.13626 33497039
    [Google Scholar]
  123. Hara-IsonoK. MatsubaraK. NakamuraA. Risk assessment of assisted reproductive technology and parental age at childbirth for the development of uniparental disomy-mediated imprinting disorders caused by aneuploid gametes.Clin. Epigenetics20231517810.1186/s13148‑023‑01494‑w
    [Google Scholar]
  124. LottiF. MaggiM. Sexual dysfunction and male infertility.Nat. Rev. Urol.201815528730710.1038/nrurol.2018.20 29532805
    [Google Scholar]
  125. KaputovskijA. The role of herbal therapy, vitamins and micronutrients formanagement of male sexual dysfunction and male infertility.Urologiia201920194158170
    [Google Scholar]
  126. GaskinsA.J. SundaramR. Buck LouisG.M. ChavarroJ.E. Predictors of sexual intercourse frequency among couples trying to conceive.J. Sex. Med.201815451952810.1016/j.jsxm.2018.02.005 29523477
    [Google Scholar]
  127. IkedaM. OkugawaS. KashiwabaraK. Multicenter, single-blind, randomized controlled study of the efficacy and safety of favipiravir and nafamostat mesilate in patients with COVID-19 pneumonia.Int. J. Infect. Dis.202312835536310.1016/j.ijid.2022.12.039 36610659
    [Google Scholar]
  128. TharakanS. NomotoK. MiyashitaS. IshikawaK. Body temperature correlates with mortality in COVID-19 patients.Crit. Care202024129810.1186/s13054‑020‑03045‑8 32503659
    [Google Scholar]
  129. HutchisonJ.S. WardR.E. LacroixJ. Hypothermia therapy after traumatic brain injury in children.N. Engl. J. Med.2008358232447245610.1056/NEJMoa0706930 18525042
    [Google Scholar]
  130. IvellR. Lifestyle impact and the biology of the human scrotum.Reprod. Biol. Endocrinol.2007511510.1186/1477‑7827‑5‑15 17448228
    [Google Scholar]
  131. DurairajanayagamD. Male infertility.ChamSpringer201410512510.1007/978‑1‑4939‑1040‑3_8
    [Google Scholar]
  132. RajakP. RoyS. DuttaM. Understanding the cross-talk between mediators of infertility and COVID-19.Reprod. Biol.202121410055910.1016/j.repbio.2021.100559 34547545
    [Google Scholar]
  133. JungA. SchuppeH.C. SchillW.B. [Fever as etiology of temporary infertility in the man].Hautarzt200152121090109310.1007/s001050170018 11910858
    [Google Scholar]
  134. SoehadiK. Azoospermia caused by typhoid fever.A case report. Andrologia198214131-34, 34.10.1111/j.1439‑0272.1982.tb03092.x 7199835
    [Google Scholar]
  135. AndradeD.L. VianaM.C. EstevesS.C. Differential diagnosis of azoospermia in men with infertility.J. Clin. Med.20211014314410.3390/jcm10143144 34300309
    [Google Scholar]
  136. Andrade-RochaF.T. Temporary impairment of semen quality following recent acute fever.Ann. Clin. Lab. Sci.20134319497 23462613
    [Google Scholar]
  137. RadwanM. JurewiczJ. Merecz-KotD. Sperm DNA damage—the effect of stress and everyday life factors.Int. J. Impot. Res.201628414815410.1038/ijir.2016.15 27076112
    [Google Scholar]
  138. SergerieM. MieussetR. CrouteF. DaudinM. BujanL. High risk of temporary alteration of semen parameters after recent acute febrile illness.Fertil. Steril.2007884970.e1970.e710.1016/j.fertnstert.2006.12.045
    [Google Scholar]
  139. LinP.H. HuangK.H. TianY.F. Exertional heat stroke on fertility, erectile function, and testicular morphology in male rats.Sci. Rep.2021111353910.1038/s41598‑021‑83121‑3 33574487
    [Google Scholar]
  140. GhoshS. MukherjeeS. Testicular germ cell apoptosis and sperm defects in mice upon long-term high fat diet feeding.J. Cell. Physiol.2018233106896690910.1002/jcp.26581 29665058
    [Google Scholar]
  141. QariS.A. AlahmadiA.A. AliS.S. MohammedsalehZ.M. IbrahimR.F.A. El-ShitanyN.A. Effect of prolonged whole‐body hyperthermia on adult male rat testes and the protective role of vitamin C and E: A histological and biochemical study.Andrologia2021537e1407510.1111/and.14075 33877689
    [Google Scholar]
  142. StarkJ. KusterS.P. HungerbühlerV. Impact of COVID-19 disease on the male factor in reproductive medicine – how-to advise couples undergoing IVF/ICSI.Reprod. Fertil. Dev.2024363RD2320510.1071/RD23205 38185121
    [Google Scholar]
  143. DuttaS. SenguptaP. SARS-CoV-2 and male infertility: Possible multifaceted pathology.Reprod. Sci.2021281232610.1007/s43032‑020‑00261‑z 32651900
    [Google Scholar]
  144. SenguptaP. DuttaS. SlamaP. RoychoudhuryS. COVID-19, oxidative stress, and male reproductive dysfunctions: Is vitamin C a potential remedy?Physiol. Res.2022711475410.33549/physiolres.934827 35043653
    [Google Scholar]
  145. KleinB. HaggeneyT. FietzD. Specific immune cell and cytokine characteristics of human testicular germ cell neoplasia.Hum. Reprod.201631102192220210.1093/humrep/dew211 27609978
    [Google Scholar]
  146. HavrylyukA. ChopyakV. BoykoY. KrilI. KurpiszM. Cytokines in the blood and semen of infertile patients.Cent. Eur. J. Immunol.20153333734410.5114/ceji.2015.54596 26648778
    [Google Scholar]
  147. AttiaH. FinocchiF. OrcianiM. Pro-inflammatory cytokines and microRNAs in male infertility.Mol. Biol. Rep.20214885935594210.1007/s11033‑021‑06593‑6 34319544
    [Google Scholar]
  148. HuangG. YuanM. ZhangJ. IL-6 mediates differentiation disorder during spermatogenesis in obesity-associated inflammation by affecting the expression of Zfp637 through the SOCS3/STAT3 pathway.Sci. Rep.2016612801210.1038/srep28012 27329259
    [Google Scholar]
  149. NicholsonA. RaitG. Murray-ThomasT. HughesG. MercerC.H. CassellJ. Management of epididymo-orchitis in primary care: Results from a large UK primary care database.Br. J. Gen. Pract.201060579e407e42210.3399/bjgp10X532413 20883615
    [Google Scholar]
  150. LovelandK.L. KleinB. PueschlD. Cytokines in male fertility and reproductive pathologies: Immunoregulation and beyond.Front. Endocrinol. (Lausanne)2017830710.3389/fendo.2017.00307 29250030
    [Google Scholar]
  151. LottiF. CoronaG. MondainiN. Seminal, clinical and colour‐Doppler ultrasound correlations of prostatitis‐like symptoms in males of infertile couples.Andrology201421304110.1111/j.2047‑2927.2013.00156.x 24288243
    [Google Scholar]
  152. SadasivamM. RamatchandirinB. BalakrishnanS. PrahalathanC. TNF-α-mediated suppression of Leydig cell steroidogenesis involves DAX-1.Inflamm. Res.201564754955610.1007/s00011‑015‑0835‑8 26047595
    [Google Scholar]
  153. QianL. ShiQ. GuY. SongJ. ZhouM. HuaM. The relationship between IL-17 and male infertility: Semen analysis.Afr. J. Microbiol. Res.201262756725677
    [Google Scholar]
  154. SchuppeH-C. Atlas on the Human Testis.ChamSpringer201311312110.1007/978‑1‑4471‑2763‑5_9
    [Google Scholar]
  155. ZhengW. ZhangS. JiangS. Evaluation of immune status in testis and macrophage polarization associated with testicular damage in patients with nonobstructive azoospermia.Am. J. Reprod. Immunol.2021865e1348110.1111/aji.13481 34192390
    [Google Scholar]
  156. OhY.S. JoN.H. ParkJ.K. GyeM.C. Changes in inflammatory cytokines accompany deregulation of claudin-11, resulting in inter-sertoli tight junctions in varicocele rat testes.J. Urol.201619641303131210.1016/j.juro.2016.05.004 27164517
    [Google Scholar]
  157. BiałasM. FiszerD. RozwadowskaN. KosickiW. JedrzejczakP. KurpiszM. The role of IL-6, IL-10, TNF-α and its receptors TNFR1 and TNFR2 in the local regulatory system of normal and impaired human spermatogenesis.Am. J. Reprod. Immunol.2009621515910.1111/j.1600‑0897.2009.00711.x 19527232
    [Google Scholar]
  158. Delgado-RocheL. MestaF. Oxidative stress as key player in severe acute respiratory syndrome coronavirus (SARS-CoV) infection.Arch. Med. Res.202051538438710.1016/j.arcmed.2020.04.019 32402576
    [Google Scholar]
  159. FernandesI.G. De BritoC.A. Dos ReisV.M.S. SatoM.N. PereiraN.Z. SARS-CoV-2 and other respiratory viruses: What does oxidative stress have to do with it?Oxid. Med. Cell. Longev.202020208844280
    [Google Scholar]
  160. DuttaS. SandhuN. SenguptaP. AlvesM.G. HenkelR. AgarwalA. Somatic-immune cells crosstalk in-the-making of testicular immune privilege.Reprod. Sci.20212021112 34580844
    [Google Scholar]
  161. FanC. LiK. DingY. LuW. WangJ. ACE2 expression in kidney and testis may cause kidney and testis damage after 2019-nCoV infection.MedRxiv202010.1101/2020.02.12.20022418
    [Google Scholar]
  162. HedgerM.P. Toll-like receptors and signalling in spermatogenesis and testicular responses to inflammation—a perspective.J. Reprod. Immunol.201188213014110.1016/j.jri.2011.01.010 21333360
    [Google Scholar]
  163. DuttaS. SenguptaP. HassanM.F. BiswasA. Role of toll-like receptors in the reproductive tract inflammation and male infertility.Chem Biol Lett202072113123
    [Google Scholar]
  164. AndoH. In Handbook of Hormones.AmsterdamElsevier202155956210.1016/B978‑0‑12‑820649‑2.00142‑X
    [Google Scholar]
  165. O’DonnellL. Seminars in Cell & Developmental Biology.AmsterdamElsevier2021
    [Google Scholar]
  166. SenguptaP. DuttaS. COVID-19 and hypogonadism: Secondary immune responses rule-over endocrine mechanisms.Hum. Fertil. (Camb.)2023261182185 33439057
    [Google Scholar]
  167. DarbandiM. DarbandiS. AgarwalA. Reactive oxygen species and male reproductive hormones.Reprod. Biol. Endocrinol.20181618710.1186/s12958‑018‑0406‑2 30205828
    [Google Scholar]
  168. AbdelhamidM.H.M. WalschaertsM. AhmadG. MieussetR. BujanL. HamdiS. Mild experimental increase in testis and epididymis temperature in men: Effects on sperm morphology according to spermatogenesis stages.Transl. Androl. Urol.20198665166510.21037/tau.2019.11.18 32038961
    [Google Scholar]
  169. MahmudpourM. RoozbehJ. KeshavarzM. FarrokhiS. NabipourI. COVID-19 cytokine storm: The anger of inflammation.Cytokine202013315515110.1016/j.cyto.2020.155151 32544563
    [Google Scholar]
  170. VellaniE. ColasanteA. MamazzaL. MinasiM.G. GrecoE. BevilacquaA. Association of state and trait anxiety to semen quality of in vitro fertilization patients: A controlled study.Fertil. Steril.20139961565157210.1016/j.fertnstert.2013.01.098
    [Google Scholar]
  171. ZouP. WangX. SunL. Semen quality in chinese college students: Associations with depression and physical activity in a cross-sectional study.Psychosom. Med.201880656457210.1097/PSY.0000000000000595 29794946
    [Google Scholar]
  172. AlmasryS.M. HassanZ.A. ElsaedW.M. ElbastawisyY.M. Structural evaluation of the peritubular sheath of rat’s testes after administration of ribavirin: A possible impact on the testicular function.Int. J. Immunopathol. Pharmacol.201730328229610.1177/0394632017726261 28799438
    [Google Scholar]
  173. BukhariS.A. AhmedM.M. AnjumF. Post interferon therapy decreases male fertility through gonadotoxic effect.Pak. J. Pharm. Sci.2018314Suppl.15651570 30058549
    [Google Scholar]
  174. PecouS. MoinardN. WalschaertsM. PasquierC. DaudinM. BujanL. Ribavirin and pegylated interferon treatment for hepatitis C was associated not only with semen alterations but also with sperm deoxyribonucleic acid fragmentation in humans.Fertil. Steril.2009913933.e17933.e2210.1016/j.fertnstert.2008.07.1755
    [Google Scholar]
  175. AsuquoO.R. IgiriA.O. OlawoyinO.O. EyongE.U. Correlation of histological and histometric changes in rats testes treated with chloroquine phosphate.Niger. J. Physiol. Sci.2007221-2135139 18379633
    [Google Scholar]
  176. SansoneA. MollaioliD. CioccaG. Addressing male sexual and reproductive health in the wake of COVID-19 outbreak.J. Endocrinol. Invest.202144222323110.1007/s40618‑020‑01350‑1 32661947
    [Google Scholar]
  177. MaiorinoM.I. BellastellaG. GiuglianoD. EspositoK. From inflammation to sexual dysfunctions: A journey through diabetes, obesity, and metabolic syndrome.J. Endocrinol. Invest.201841111249125810.1007/s40618‑018‑0872‑6 29549630
    [Google Scholar]
  178. ZhaoZ. WeiY. TaoC. An enlightening role for cytokine storm in coronavirus infection.Clin. Immunol.202122210861510.1016/j.clim.2020.108615 33203513
    [Google Scholar]
  179. SharmaI. KumariP. SharmaA. SahaS.C. SARS-CoV-2 and the reproductive system: Known and the unknown.!!Middle East Fertil. Soc. J.20212611910.1186/s43043‑020‑00046‑z 33437145
    [Google Scholar]
  180. FathiM. VakiliK. AliaghaeiA. NematollahiS. PeirouviT. Shalizar-JalaliA. Coronavirus disease and male fertility: A systematic review.Middle East Fertil. Soc. J.20212612610.1186/s43043‑021‑00073‑4 34421291
    [Google Scholar]
  181. MitchellM.J. BillingsleyM.M. HaleyR.M. WechslerM.E. PeppasN.A. LangerR. Engineering precision nanoparticles for drug delivery.Nat. Rev. Drug Discov.202120210112410.1038/s41573‑020‑0090‑8 33277608
    [Google Scholar]
  182. HoltmannN. EdimirisP. AndreeM. Assessment of SARS-CoV-2 in human semen—a cohort study.Fertil. Steril.2020114223323810.1016/j.fertnstert.2020.05.028 32650948
    [Google Scholar]
  183. LiD. JinM. BaoP. ZhaoW. ZhangS. Clinical characteristics and results of semen tests among men with coronavirus disease 2019.JAMA Netw. Open202035e208292-2e210.1001/jamanetworkopen.2020.8292 32379329
    [Google Scholar]
  184. SongC. WangY. LiW. Detection of 2019 novel coronavirus in semen and testicular biopsy specimen of COVID-19 patients.MedRxiv202010.1101/2020.03.31.20042333
    [Google Scholar]
  185. PanF. XiaoX. GuoJ. No evidence of SARS-CoV-2 in 393 semen of males recovering from COVID-19.Fertil. Steril.202011361135113910.1016/j.fertnstert.2020.04.024 32482249
    [Google Scholar]
  186. BensmanA. Non-steroidal anti-inflammatory drugs (NSAIDs) systemic use: The risk of renal failure.Front Pediatr.2020751710.3389/fped.2019.00517 32039104
    [Google Scholar]
  187. MorelliF. MeirellesL.E.F. de SouzaM.V.F. COVID-19 infection in the human reproductive tract of men and nonpregnant women.Am. J. Trop. Med. Hyg.2021104381482510.4269/ajtmh.20‑1098 33534765
    [Google Scholar]
  188. RoychoudhuryS. DasA. JhaN.K. Viral pathogenesis of SARS-CoV-2 infection and male reproductive health.Open Biol.202111120034710.1098/rsob.200347 33465325
    [Google Scholar]
  189. CattriniC. BersanelliM. LatoccaM.M. ConteB. VallomeG. BoccardoF. Sex hormones and hormone therapy during COVID-19 pandemic: Implications for patients with cancer.Cancers (Basel)2020128232510.3390/cancers12082325 32824674
    [Google Scholar]
  190. JeyaramanM. JohnA. KoshyS. Fostering mesenchymal stem cell therapy to halt cytokine storm in COVID-19.Biochim. Biophys. Acta Mol. Basis Dis.20211867216601410.1016/j.bbadis.2020.166014 33232817
    [Google Scholar]
  191. SatyamR. BhardwajT. GoelS. miRNAs in SARS-CoV 2: A spoke in the wheel of pathogenesis.Curr. Pharm. Des.202127131628164110.2174/18734286MTEwbMzkg1 33023438
    [Google Scholar]
  192. KimJ. ThomsenT. SellN. GoldsmithA.J. Abdominal and testicular pain: An atypical presentation of COVID-19.Am. J. Emerg. Med.20203871542.e11542.e310.1016/j.ajem.2020.03.052
    [Google Scholar]
/content/journals/covid/10.2174/0126667975316497240725102111
Loading
/content/journals/covid/10.2174/0126667975316497240725102111
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error
Please enter a valid_number test