Sensitivity of Zinc test after intercourse by time intervals and affecting factors
Keywords:
Zinc test, acid phosphatase test, sperm detection, semen, sexual assaultAbstract
Objective : To discover sensitivity of Zinc test as forensic semen screening test. To compare sensitivity between Zinc test (Zn) and Acid phosphatase (AP) to determine which had better performance. To investigate affecting factors of Zinc test.
Methods : Semen detection results from vaginal specimen of intercourse females were included in this retrospective study. Main criteria were 1) exactly interval time record and 2) no condom usage. The Mann-Whitney U test, Pearson χ2 test, Fisher exact test, Cohen’s Kappa test, McNemar test, Cochran Q test, and Linear-by-Linear Association were used by statistical significance at 0.05.
Result : In case of semen detection, Overall Zn test sensitivity was 11.14% and Zn test had lower sensitivity performance than AP test in every time intervals (P < 0.05). Significant declination sensitivity rate of Zn test was limit until between within 48 h versus more than
48 h (P < 0.05) and no further. Significant associating factors to Zn test were older females
(P = 0.001), shorter time since incidence (P < 0.001), no genital cleaning (P = 0.004) and history of rape (P = 0.001).
Conclusion : Zn test had very low sensitivity and had obviously lower performance than AP test. AP test alone could replace these double tests for semen screening test. Earlier hospital arrival and no anogenital cleansing could increase Zn detection rate.
References
Thai Criminal Code Coucil of State Web Site [cited 2025 May, 10]. Available from: https://krisdika.ocs.go.th/librarian/get?sysid=443287&ext=pdf
Kellogg ND, Farst KJ, Adams JA. Interpretation of medical findings in suspected child sexual abuse: An update for 2023. Child Abuse Negl. 2023;145:106283.
Suttipasit P. Forensic Spermatozoa Detection. Am J Forensic Med Pathol. 2019;40(4):304–11.
Hooft PJ, van de Voorde HP. Interference of body products, food and products from daily life with the modified zinc test and the acid phosphatase test. Forensic Sci Int. 1994;66(3):187–96.
Suttipasit P. Comparison of two seminal detection methods, the acid phosphatase test and the zinc test for sensitivities in sexually assaulted females positive of sperm. Siriraj Med J. 2015;67:168–72.
de Oliveira SSJ, Alvarenga AD, Correa DS, Mercante LA, Santana RMM. Blown spun fibers-based colorimetric sensor for detecting trace zinc in seminal fluid. Biosens Bioelectron. 2025;270:116943.
Allery JP, Telmon N, Blanc A, Mieusset R, Rouge D. Rapid detection of sperm: comparison of two methods. J Clin Forensic Med. 2003;10(1):5–7.
Davies A, Wilson E. The persistence of seminal constituents in the human vagina. Forensic Sci. 1974;3(1):45–55.
Suzuki O, Asano M, Kido A, Oya M. Zinc test as a new tool for identification of human seminal stains. Forensic Sci Int. 1983;22(2-3):231–5.
Hooft P, van de Voorde H, Van Dijck P. A more sensitive modification of the zinc test for seminal traces suitable for stable test paper strips. Forensic Sci Int. 1992;53(2):131–3.
Hooft PJ, van de Voorde HP. Bayesian evaluation of the modified zinc test and the acid phosphatase spot test for forensic semen investigation. Am J Forensic Med Pathol. 1997;18(1):45–9.
Silverman EM, Silverman AG. Persistence of spermatozoa in the lower genital tracts of women. JAMA. 1978;240(17):1875–7.
Willott GM, Allard JE. Spermatozoa--their persistence after sexual intercourse. Forensic Sci Int. 1982;19(2):135–54.
Charlier P, Mathelin L, Benredjem A, Lorin de la Grandmaison G. Declining of spermatozoa viability in forensic practice: a consequence of environmental hazards? Med Hypotheses. 2011;77(2):310–1.
Peonim V, Worasuwannarak W, Sujirachato K, Teerakamchai S, Srisont S, Udnoon J, et al. Comparison between prostate specific antigen and acid phosphatase for detection of semen in vaginal swabs from raped women. J Forensic Leg Med. 2013;20(6):578–81.
Romero-Montoya L, Martinez-Rodriguez H, Perez MA, Arguello-Garcia R. Relationship of spermatoscopy, prostatic acid phosphatase activity and prostate-specific antigen (p30) assays with further DNA typing in forensic samples from rape cases. Forensic Sci Int. 2011;206(1-3):111–8.
Suttipasit P. Genitoanal Injury in Sexually Assaulted Adult Women: Six-Year Retrospective in Bangkok. Am J Forensic Med Pathol. 2018;39(4):312–24.
Suttipasit P, Sinlapamongkolkul P, Wongwittayapanich S. Comparative Study of Acute Anogenital Injury Between Consensual and Nonconsensual Postmenarche Adolescents. Am J Forensic Med Pathol. 2022;43(2):126–41.
Yoshida M, Yoshida K. Sperm chemotaxis and regulation of flagellar movement by Ca2+. Mol Hum Reprod. 2011;17(8):457–65.
Kolle S. Transport, Distribution and Elimination of Mammalian Sperm Following Natural Mating and Insemination. Reprod Domest Anim. 2015;50 Suppl 3:2–6.
Suttipasit P, Wongwittayapanich S. Detection of prostate specific antigen and semenogelin in specimens from female rape victims. J Forensic Leg Med. 2018;54:102–8.
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