Prevalence and correlates of sexually transmitted infections among female survivors of sexual assault at the university teaching hospital, Lusaka, Zambia

Abstract

Sexual assault contributes to the burden of Sexually Transmitted Infections (STIs) in women and children of all ages. In children, the isolation of a sexually transmitted organism may be the first indication that sexual assault has occurred whilst in adults, the risk of acquiring a sexually transmitted infection as a result of sexual assault is not known in part because it is difficult to ascertain whether the infections were present before the assault or acquired during this act. STIs in women pose a major burden of complications such as infertility, ectopic pregnancy and cervical cancer. The objective of this study was to determine the prevalence and correlates of STIs in female sexual assault survivors at the University Teaching Hospital (UTH). This was a prospective cross-sectional study conducted at the one stop Centres at the Emergency Gynaecology ward and the Pediatric Centre of Excellence at UTH, Lusaka Zambia between August and November 2017. All eligible consenting survivors were recruited and the minimum age was 12 years. Data was collected by use of questionnaires, review of files for pelvic examination findings and collection of endocervical swab specimens to test for Neisseria gonorrhoeae by culture and antigen test, Chlamydia trachomatis by antigen test and Trichomonas vaginalis by microscopic examination of wet mount. Blood was also collected to test for Syphilis and Human Immunodeficiency Virus (HIV) as baseline. Participants were asked for a follow visit two weeks after the initial visit and retested for gonorrhoeae, chlamydia and trichomonas vaginalis. A total of 281 female sexual assault survivors were included. At baseline the overall STI prevalence was 23.5%; Neisseria gonorrhoeae had the highest percentage 26/281(9.3%) followed by HIV 13/281(4.65%) and Trichomonas vaginalis 12/281 (4.3%), Syphilis 7/281(2.5%) and Chlamydia trachomatis 4/281(1.4%). At two weeks review, excluding survivors who were given antibiotics or had presence of STIs (within 72 hours of sexual assault), there were 5/96 (5.2%) survivors with Neisseria gonorrhoea, 4/96 (4.2%) survivors with Trichomonas vaginalis, and 2/96 (2.1%) survivors with Chlamydia. Thus, the incidence of STIs was 11.5%. The mean age of the survivors was 16.0 years (SD = 5.14). For every increase in age by one year, the odds for STI acquisition reduced on average by 35% (OR = 0.65, CI = 0.40 – 1.06, P-value = 0.08). The majority of survivors were unmarried 261/281(92.1%), had attained primary education 167/281(59.4%) and resided in high density areas 175/281(62.3%). In most of the cases the perpetrator was known to the survivor (70.3%) and vaginal penetration occurred in 97% of the cases with less than 10 % of the perpetrators 26/281(9.3%) using a condom. About half of the survivors 146/281(52%) reported to UTH within 72 hours of the assault and were given prophylactic antibiotics 165/281(58.7%). Injuries of the genitals were present in 30/281 (10.7%) survivors. Sexual assault survivors who had injuries on the genitals had elevated odds of acquisition of STIs [(OR = 28.56, CI = 1.93 – 423.13), P = 0.02]. The overall prevalence of STIs was 23.5% at baseline and the incidence was 11.5%. Thus, the female survivors of sexual assault had substantial risk of acquiring STIs after sexual assault and injuries on the genitals (OR=28.56 ,CI=1.93-423.13,P=0.02) were found as the only significant correlated factors of STIs in female sexual assault survivors. Key words: Sexual Assault Survivors, Sexually transmitted infections, Genital Injuries & Prophylactic Antibiotics