Sexually Transmissible Infections in Clinical Practice

2. A Woman Requesting a Sexual Health Screen

Alexander McMillan1, 2  


Department of Genitourinary Medicine, NHS Lothian, Edinburgh Royal Infirmary, Edinburgh, Uk


University of Edinburgh, Edinburgh, Uk

Alexander McMillanFormerly, Consultant Physician, part-time Senior Lecturer



A specific history should be taken to elicit any symptoms that the individual may not have recognized. For example

Mary, a 28-year-old dental receptionist, attends a Sexual Health clinic requesting testing for sexually transmissible infections (STIs). She has just discovered that her ex-partner had had other sexual contacts during the time they were in the relationship.

2.1 What History Would You Obtain from Mary?

A specific history should be taken to elicit any symptoms that the individual may not have recognized. For example,

·               Has she noticed increased vaginal discharge?

·                                   This may be physiological or associated with an STI such as Trichomonas vaginalis.

·               Has she noticed “growths” on the genitalia?

·                                   If so, consider genital warts, molluscum contagiosum, or normal anatomical variants, such as pilosebaceous glands.

·               Does she have itch in the skin of the pubic area, genitocrural folds, labia majora, introitus, perineum, buttocks, or perianal region?

·                                   If so, consider phthiriasis, scabies, candidiasis, or a non-STI such as a genital dermatosis (Fig. 2.1).

·               Has she noticed post-coital bleeding or inter-menstrual bleeding?

·                                   If so, consider chlamydial infection.

·               Has she had lower abdominal pain and/or deep dyspareunia?

·                                   These may be features of pelvic inflammatory disease (PID) that may be caused by chlamydial or gonococcal infections. Irregular menstrual bleeding may be an additional feature of PID.

·               Has she had frequency of micturition with or without dysuria?

·                                   Chlamydial and gonococcal infections can be associated with these symptoms, as may a urinary tract infection.

·               Has she noticed swollen lymph glands in the groin or elsewhere in her body?

·                                   Painless inguinal lymph node enlargement may be a feature of primary syphilis, and generalized lymphadenopathy may be associated with secondary syphilis or HIV infection.


Figure 2.1

Lichen simplex of labium minus

The details in the sexual history do not differ significantly from those described in Case 1 for the heterosexual man. Early in the consultation it should be established if her partners are male or female. Note should be made of the date of her last menstrual period, and the menstrual cycle should be recorded. The method of contraception used, if any, and an obstetric history should be noted. It is also helpful to know the date of her most recent cervical smear and the result.

Mary has no symptoms suggestive of the presence of an STI. Her most recent menstrual period had been 2 years previously – she had been fitted with a progestogen-only implant (Implanon ® ) for contraception. Her most recent sexual contact had been 4 months previously with her ex-partner with whom she had been for 3 years. As she thought that her partner was faithful, condoms were not used during sexual intercourse. She has had no other sexual partners during that time, and she has had only one other lifetime partner with whom she had separated 6 years previously. Both partners were British, neither they nor she has injected recreational drugs, and neither man is known to have had homosexual contact. She has had no female sexual partners. Her general health is good, and she is not currently receiving any medication other than Implanon ® , and she has not been treated with antimicrobial drugs within the preceding month. Since the age of 20 years, Mary has had 3-yearly cervical cytology examinations, the most recent having been 6 months previously, and no abnormalities have ever been reported. She has had one pregnancy that was terminated 3 years previously.

2.2 Outline the Physical Examination You Would Perform and Indicate Which Microbiological Tests You Would Undertake in This Case

The extent of the physical examination will be determined by the history (see Case 1). As Mary has no history of a rash or swollen lymph nodes, it is reasonable to confine the physical examination to the anogenital area. The examination should be performed with the woman in the semi-lithotomy position on a couch in a warm and well-lit room. A presence of a chaperone should be offered and one must be present when a male doctor undertakes the examination.

As the majority of women with uncomplicated gonococcal and chlamydial infections are symptomless, it is imperative that at least these infections are specifically looked for when a patient request an STI screen. Untreated, both infections have serious sequelae (see Cases 142427).








In many clinics serving populations with a low prevalence of gonorrhoea, testing for urethral infection has been abandoned.




Facilities are available in some clinics for the detection of trichomonal infection by culture or NAAT. Vaginal specimens should be processed according to the instructions from the local laboratory.





Some laboratories now use a single test for the dual detection of N. gonorrhoeae and C. trachomatis, obviating the need for two swabs.




Mary has no clinical abnormalities suggestive of an STI. Microscopy of a saline-mount preparation of vaginal material does not show T. vaginalis. In the Gram-stained smear from the vagina, lactobacilli are the predominant flora, and only a few polymorphonuclear leucocytes are seen. Microscopy of urethral and cervical material is not undertaken. Cervical material is sent to the laboratory for testing for both N. gonorrhoeae and C. trachomatis by a NAAT. She accepts serological tests for syphilis and HIV infection. She is advised to telephone for the test results in 1 weeks’ time.

At that time, she telephones a Health Adviser in the clinic to discuss the results. Although all the tests are negative, she wants to find out about the reliability of these “new tests” for gonococcal and chlamydial infections. She also asks why a cervical specimen was obtained, as a friend from overseas had only provided a urine test for these infections. How do you respond?

Nuclei acid amplification assays, including polymerase chain reactions (PCRs), have been shown to be more sensitive than culture for the diagnosis of gonorrhoea in women. The sensitivity of PCR for cervical specimens is between 92 and 99%, compared with about 60% for culture; the specificity of the PCRs is almost 100%. In the diagnosis of chlamydial infection by NAATs on cervical material, the sensitivity is about 86% and the specificity is almost 100%.

With respect to urine testing for chlamydiae, the sensitivity (83%) is only slightly less than for cervical specimens, making this a convenient sample for screening. The sensitivity of NAATs on urine samples for the detection of gonococcal infection, however, is significantly lower (about 56%) than on cervical material. Urine testing for gonorrhoea therefore cannot be recommended.



A positive result in a nucleic acid amplification assay should be confirmed by culture.

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