Biomedical subjects
M A Shafer
Publications and source records attributed to M A Shafer.
Psychosocial and behavioral factors associated with risk of sexually transmitted diseases, including human immunodeficiency virus infection, among urban high school students.
The main purpose of this study was to evaluate the role of multiple psychosocial and knowledge-related antecedent factors that may predict sexual and alcohol and drug use behaviors that are associated with the transmission of sexually transmitted diseases (STDs), including human immunodeficiency virus infection. Five hundred forty-four ninth-grade urban high school students were surveyed regarding knowledge, attitudes, and behaviors related to STDs and acquired immunodeficiency syndrome (AIDS). Results of multiple regression analyses indicate that higher levels of STD and AIDS knowledge were associated with lower levels of STD and AIDS anxiety (R2 delta = 0.09; p less than 0.001), fewer negative attitudes toward people with AIDS (R2 delta = 0.09; p less than 0.001), stronger perceptions of self-efficacy (R2 delta = 0.03; p less than 0.01), and stronger peer affiliation (R2 delta = 0.02; p less than 0.05). Negative attitudes toward people with AIDS were inversely related to knowledge (R2 delta = 0.08; p less than 0.001), social support (R2 delta = 0.02; p less than 0.01), and perceived self-efficacy (R2 delta = 0.01; p less than 0.05). Predictors of alcohol and drug use included perceived peer norms (R2 delta = 0.08; p less than 0.001) and strong peer affiliation (R2 delta = 0.05; p less than 0.001). The best predictor of sexual risk behavior was alcohol and drug use (R2 delta = 0.07; p less than 0.001). Lower levels of knowledge (R2 delta = 0.14; p less than 0.01) and perceived peer norms (R2 delta = 0.05; p less than 0.05) predicted nonuse of condoms. Our results indicate that several factors relate to adolescent risk for STDs: the connection between peer influence and adolescent risk behaviors, the link between alcohol and drug use and sexual risk behavior, and the role of knowledge in determining nonuse of condoms.
"Understanding AIDS": did female adolescents read it?
Explore the source record for details and available documents.
Ectopic pregnancy in adolescents: a clinical review for pediatricians.
Pediatricians caring for sexually active female adolescents and young adults need to be aware of the history, symptoms, and signs of an ectopic pregnancy. A thorough history and physical examination, including the pelvic examination, as well as specific diagnostic tests such as repeated quantitative hCG measurements, and ultrasonography when indicated, are crucial to proper and early diagnosis of a nonruptured ectopic pregnancy manageable by laparoscopy. The key to early diagnosis is to include ectopic pregnancy in the differential diagnosis in any sexually active female patient who has abnormal vaginal bleeding or abdominal pain. With early diagnosis, close observation, and appropriate management, the outcome is more likely to be favorable, with minimal morbidity and risk of death.
Urinary leukocyte esterase screening test for asymptomatic chlamydial and gonococcal infections in males.
We evaluated the ability of the urinary leukocyte esterase test to predict culture-verified chlamydial and gonococcal urethritis among asymptomatic adolescent males. Nine hundred forty-eight sexually active males provided first-catch urine samples for esterase screening, and 76 (8%) tested positive (greater than or equal to 1+). Among 435 boys who agreed to undergo urethral culture, the esterase was positive in 66 (15%), Chlamydia trachomatis was isolated from 39 (9%), and Neisseria gonorrhoeae was isolated from 14 (3%). The sensitivity, specificity, and positive and negative predictive values for the esterase test were 72%, 93%, and 58% and 96%, respectively. Using the esterase test to screen asymptomatic males for urethritis, we identified 38 culture-verified infections that otherwise would have remained undetected. The urinary leukocyte esterase test is a noninvasive and cost-effective screening method to detect urethritis among asymptomatic adolescent males.
Pelvic inflammatory disease in adolescent females. Epidemiology, pathogenesis, diagnosis, treatment, and sequelae.
The estimated risk of pelvic inflammatory disease in 15- to 19-year-old females is 1:8. If current trends continue, 50 percent of young women aged 15 years old in 1970 will have experienced at least one episode of PID by the year 2000. This article reviews the current state-of-the-art understanding and management of this disease in the adolescent female.
The use and limitations of endocervical Gram stains and mucopurulent cervicitis as predictors for Chlamydia trachomatis in female adolescents.
We evaluated the presence of polymorphonuclear cells on endocervical Gram stains and clinical indices of cervicitis as predictors of Chlamydia trachomatis infection in 193 sexually active female adolescents; 148 (77%) subjects had no complaints. C. trachomatis was isolated from 34 (18%) subjects. The incidence of C. trachomatis differed by race: it was isolated from 30% of black subjects and 7% of nonblack subjects. Polymorphonuclear cells on Gram stains were found to be associated with the presence of C. trachomatis (chi 2 = 33.2, p less than 0.0001). The sensitivity, specificity, and positive predictive value for polymorphonuclear cells to predict the presence of C. trachomatis were 91% (31/34), 65% (103/159), and 36% (31/87), respectively. When examined by ethnicity, polymorphonuclear cells remained significantly associated with C. trachomatis for black subjects (chi 2 = 24.3, p less than 0.001) but not for nonblack subjects (chi 2 = 2.49, p less than 0.1). Mucopurulent discharge, friability, or erythema-edema of ectopy were not reliable indicators for C. trachomatis. Endocervical Gram stains alone are useful to identify populations at risk for C. trachomatis infection. Caution must be advised when interpreting data from different population groups because of the variability in C. trachomatis prevalence.
Microflora of the urethra in adolescent boys: relationships to sexual activity and nongonococcal urethritis.
Urethral cultures were obtained from 90 adolescent youth, 16 of whom denied previous sexual activity. Among the sexually active boys was a group of 32 with clinically significant pyuria, consistent with the diagnosis of urethritis, on a first-part urinalysis (FPU) specimen. To relate differences in urethral microflora to sexual activity, 42 sexually active patients with a negative FPU were compared with the never sexually active group. The profile of anaerobic, but not aerobic, bacteria isolated from the urethra was related to the presence or absence of previous sexual activity. Mycoplasma species and Ureaplasma urealyticum were isolated from sexually active patients only, and may be markers of sexual activity in adolescent boys. Of the 32 patients with FPU evidence of urethritis, 22 (69%) had cultures positive for Chlamydia trachomatis, and an additional three (9%) had cultures positive for Neisseria gonorrhoeae. The findings in sexually active patients with a positive FPU were otherwise similar to those of sexually active patients without evidence of urethritis. C. trachomatis appears to be the most important agent of urethritis among adolescent boys with a positive FPU.
Prevalence of urethral Chlamydia trachomatis and Neisseria gonorrhoeae among asymptomatic, sexually active adolescent boys.
Explore the source record for details and available documents.
Evaluation of fluorescein-conjugated monoclonal antibody test to detect Chlamydia trachomatis endocervical infections in adolescent girls.
We evaluated the fluorescein-conjugated monoclonal antibody (FA) test for screening for Chlamydia trachomatis endocervical infection in a general adolescent clinic. Three hundred sixty-three consecutive adolescent girls, ages 13 to 20 years (mean 17.3 years) were examined. Forty-five (12%) FA smears had insufficient cells. Reason for visit included non-lower genital tract-related disorders in 241 (76%) girls, and lower genital tract-related disorders in 77 (24%). C. trachomatis was isolated by tissue culture in 46 (14%) patients, and Neisseria gonorrhoeae by culture in 22 (7%), and Trichomonas vaginalis was identified by wet mount in 13 (5%). Compared with our tissue culture technique, the performance of the FA test was as follows: sensitivity 61% (28 of 46), specificity 97% (264 of 272), positive predictive value 78% (28 of 36), and negative predictive value 94% (264 of 282). There was no significant difference in test performance by race, although the sensitivity rate (64%) of the test in blacks was twice that (30%) in nonblacks. This apparent difference in test performance by race may actually represent variations in group characteristics, including exposure rate, susceptibility, and number of inclusion forming units available for tissue culture of Chlamydia in blacks compared with nonblacks. In our adolescent clinic, the tissue culture is superior to FA in detecting Chlamydia. We recommend that the FA test be used where tissue culture isolation for Chlamydia is not readily available, where known or predicted chlamydial infection rates are high, and where known or predicted numbers of inclusion forming units of Chlamydia in tissue culture are high.
Comparison of monoclonal antibody staining and culture in diagnosing cervical chlamydial infection.
We compared a fluorescein-conjugated monoclonal antibody (FA) direct specimen test (MicroTrak; Syva Co., Palo Alto, Calif.) with culture (TC) in McCoy cells (vials, with blind passage and iodine staining of inclusions) for diagnosis of Chlamydia trachomatis infection in the cervix. Duplicate specimens were collected from 1,230 women, but for 262 of these subjects, both results were unavailable (150 FA smears were inadequate, indicating a need for clinical training in specimen collection), leaving 968 comparisons. Prevalence of chlamydiae by culture was 13% (126/968). Compared with TC results, the sensitivity of FA was 70% (88/126) and the specificity was 94% (795/842). There was a 91% agreement (883/968). The predictive value of a positive FA test was 65% (88/135), and that of a negative FA was 95% (795/833). We reexamined 38 smears for which paired results were discrepant, and the reread would have changed the result in only 5 of these. TC is less than 100% sensitive and some FA-positive, TC-negative specimens represent positive specimens not detected by TC. Unfortunately, it is not possible to identify which results in this group are truly false-positive. Clearly, the FA procedure has a performance profile which would make it a useful tool in screening high-risk populations (particularly when TC is not available) but it is less suited to screening low-risk populations, for which false-positive results are more important. The greater utility of the FA procedure in a venereal disease clinic was confirmed by testing 172 evaluable specimen pairs, of which 34 (20%) were Chlamydia isolate positive. The FA sensitivity was 76% (26/34) and specificity was 96% (133/138), giving a predictive value of 84% (26/31) for a positive test.
Normal reproductive development in the adolescent female.
Explore the source record for details and available documents.
Chlamydial endocervical infections and cytologic findings in sexually active female adolescents.
The association of infection with Chlamydia trachomatis and cytologic changes on Papanicolaou smear was examined in 148 sexually active postmenarchial++ female subjects, aged 13 to 21 years (mean = 17.2) attending a teen clinic. Endocervical samples for micro-organisms (C. trachomatis and Neisseria gonorrhoeae) and a cervical sample for cytologic examination were taken. A detailed evaluation of the cytologic results was made independently of the C. trachomatis status. In 23 (15.5%) subjects tests for isolation of C. trachomatis were positive. Inflammatory changes in epithelial cells, nuclear changes in metaplastic cells, and lymphocytes in the inflammatory exudate were associated with C. trachomatis isolation but suspected "chlamydial inclusions" and cytoplasmic vacuoles in metaplastic cells were not. The results reported here do not support the use of cervical cytologic examination as a definitive diagnostic test for presence of an endocervical chlamydial infection. However, it may be possible to use the cytologic pattern described here to identify a population with a high prevalence of C. trachomatis.
Microbiology of the lower genital tract in postmenarchal adolescent girls: differences by sexual activity, contraception, and presence of nonspecific vaginitis.
The prevalence of selected microorganisms in the lower genital tract in postmenarchal adolescent girls was assessed, including vaginal Gardnerella vaginalis, group B streptococcus, lactobacillus, Mycoplasma species, Ureaplasma urealyticum, Staphylococcus aureus, and yeast, and endocervical Mycoplasma species, U. urealyticum, Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis. Specific attention was focused on important sexually transmitted disease organisms, and differences in isolations by age, sexual activity, ethnicity, contraception, and the diagnosis of nonspecific vaginitis were measured. Sexually active subjects had a mean of 6.05 organisms (SD = 3.16), compared with 3.12 organisms (SD = 3.92) in non-sexually active subjects (P = 0.001). Sexually active subjects had significantly more vaginal G. vaginalis, lactobacilli, Mycoplasma species, and U. urealyticum, as well as endocervical Mycoplasma species and U. urealyticum, compared with non-sexually active subjects; C. trachomatis, N. gonorrhoea, and T. vaginalis were isolated exclusively from the sexually active group. Significant differences in isolation rates by ethnicity were found in vaginal Mycoplasma species and U. urealyticum, and endocervical Mycoplasma species, U. urealyticum, C. trachomatis, N. gonorrhoeae, and T. vaginalis. In general, organisms were isolated from blacks most frequently; N. gonorrhoea was isolated from blacks exclusively. Differences were found in microbiologic isolations by the presence or absence of nonspecific vaginitis. Vaginal G. vaginalis and Mycoplasma species and endocervical Mycoplasma species and U. urealyticum were found significantly more often in isolates from the group with nonspecific vaginitis. It is important to define the microbial flora of the lower genital tract in adolescent girls in order to understand its role in the pathogenesis of acute salpingitis.
Pelvic inflammatory disease and its sequelae in adolescents.
Pelvic Inflammatory Disease (PID) is the most common serious complication of sexually transmitted diseases (STDs). Each year over one million women in the United States experience an episode of PID, with approximately 16-20% of cases occurring in teenagers. Acute PID increases a woman's risk for recurrent PID, chronic pelvic pain, infertility, and ectopic pregnancy. Recent reports indicating that PID rates are rising and are highest among adolescent females aged 15-19 underscore the need to remain current on the clinical as well as the epidemiologic aspects of PID. We present such an update in this article. Trends in incidence and key risk factors are discussed; besides adolescence itself and STD, other important categories of risk factors include sexual activity, contraceptive method, and previous episode(s) of PID. The polymicrobial nature of PID is discussed along with an analysis of the role of specific organisms, such as Chlamydia trachomatis, Neisseria gonorrhoeae, anaerobic and aerobic bacteria, and mycoplasmas in PID. Early diagnosis and the institution of appropriate treatment regimens are essential to the prevention of PID's devastating sequelae. Clinicians must maintain a high index of suspicion for the wide range of clinical presentations associated with PID and be prepared to provide effective management, including proper evaluation and prompt treatment of sexual partners.
Female adolescents with Chlamydia. Tomorrow's candidates for in vitro fertilization?
Explore the source record for details and available documents.
Screening for Chlamydia trachomatis and Neisseria gonorrhoeae in adolescent males: value of first-catch urine examination.
50 adolescent males attending a general teen clinic (aged 13-21) were evaluated for urethritis. After examination of sediment from the initial 15-20 ml of voided urine, first-catch urine (FCU), specimen urethral swabs were taken for culture of Chlamydia trachomatis and Neisseria gonorrhoeae. 21 of 23 (91%) males with greater than 10 leucocytes per high-power field of resuspended sediment (FCU-positive) had positive urethral cultures for C trachomatis or N gonorrhoeae compared with only 1 of 27 (4%) FCU-negative subjects (p less than 0.001). 12 of 22 culture-positive subjects had no genitourinary symptoms and 11 of the 12 had C trachomatis infections. The sensitivity of FCU examination in identifying culture-positive urethritis was 95%, the specificity 93%, and the predictive value of a positive FCU 91%. FCU examination is a useful, noninvasive screening test to detect urethritis associated with C trachomatis and N gonorrhoeae. The test may be especially helpful in identifying symptom-free males with chlamydia-associated urethritis.
Chlamydia trachomatis: important relationships to race, contraception, lower genital tract infection, and Papanicolaou smear.
Chlamydia trachomatis is a common cause of sexually transmitted disease in adolescent girls. Of 366 adolescent patients screened, 15.3% were found to have chlamydial endocervical infections, with an infection rate of 23.3% in blacks, 14.3% in Hispanics, and 10.3% in whites (P = 0.01, excess for blacks). Of Chlamydia-positive patients, 63.6% had a diagnosis of lower genital tract infection, compared with 35.4% of Chlamydia-negative patients (P = 0.004). Oral contraceptive users had a higher prevalence of infection (23.8%) compared with those using a barrier method (16.2%) or with nonusers (9.3%) (P = 0.004). Inflammatory changes on Papanicolaou smears were associated with chlamydial infection (P = 0.0001). Other variables identified as risk factors for chlamydial infection included both a younger age at first intercourse (P = 0.02) and more years of sexual activity (P = 0.02). Chronologic, menarchal, and gynecologic age, biologic age of the cervix, the number of sexual partners in the last month and during a lifetime, and parity were not found to be associated with recovery of Chlamydia.