Literature review > Issue 7 > Review on Joyee et al. 

Joyee and colleagues have reported the results of a study in which men and women attending an STD clinic in the city of Chennai, in southeastern India, were assessed for chlamydial infection. All patients were symptomatic. Of the 63 men studied, 1 had urethral discharge alone, 33 complained of dysuria alone, 26 had both urethral discharge and dysuria, and 3 had unspecified symptoms. Of the 80 women studied, 60 had vaginal discharge alone, 4 complained of dysuria alone, 8 had both vaginal discharge and dysuria, and 8 had unspecified symptoms. Chlamydial infection was assessed by cervical swab culture and by direct fluorescent antibody (DFA) testing of cervical swab specimens. Interestingly, culture was noted to be the gold standard, but there were more positive chlamydia cases diagnosed by DFA, suggesting either that culture was not as sensitive as DFA, or that DFA was less specific than culture.

In any case, even with chlamydial infection defined as a positive result by DFA, the overall positivity rate for chlamydia was 24.5%. This is a lower positivity rate than would be expected in this kind of a population if a more sensitive test for detecting chlamydial infection, such as PCR, were used. For example, in another study from Chennai using PCR to detect chlamydial infection in a different STD clinic population, chlamydia rates among men and women were over 30% [1]. In a population of women attending a gynecology out-patient department in New Delhi with genitourinary complaints, the prevalence of chlamydial infection by PCR was 43% [2]. Because many of the men and women in their study who did not test positive for chlamydial infection had symptoms of discharge and/or dysuria (in fact the rates of the individual symptoms were similar to those among patients with chlamydial infection), Joyee and colleagues comment that clinical symptoms alone can be unreliable in specifically predicting chlamydial infections. Although this is certainly true, it would be misleading to suggest that a laboratory test such as DFA or culture should be used among symptomatic patients attending STD clinics as a basis for determining which ones should be treated. Most observers would instead recommend a syndromic case management approach for treating men presenting with urethral discharge or dysuria, or women presenting with vaginal discharge, dysuria or dyspareunia [3, 4].

There are many reasons for advocating a syndromic case management approach in these settings. As indicated above, culture, DFA testing, and most other available tests (with the exception of nucleic acid amplification tests) are not sufficiently sensitive, and many STD cases would be missed and would go untreated. In a population attending an STD clinic with STD-related symptoms, a high proportion will likely have a confirmed STD if tests with high sensitivity are employed, so treating individuals with symptoms presumptively is generally recommended. In addition, neither DFA testing nor chlamydial culture is generally available in most STD clinic settings in India or other developing countries, and even where they are, such testing may be of unknown quality. Furthermore, clinical symptoms in men and women can be caused by other pathogens, such as N. gonorrhoeae, T. vaginalis, and M. genitalium. Microbiological diagnosis of these pathogens is equally challenging. It is very difficult to distinguish among them on the basis of clinical presentation, and it is important that they not go untreated, so providing treatment that will cover the majority of these pathogens is generally recommended. Finally, syndromic case management can be applied by health workers in a variety of settings, including primary care level centres as well as in STD clinics. Given this approach, the importance of chlamydial culture or DFA testing, even in an STD clinic setting, is questionable, other than for surveillance purposes.

One limitation of the syndromic case management approach for women presenting to an STD clinic with symptoms of vaginal discharge is that it is a poor predictor of cervical infection. It is important to bear in mind though that vaginal discharge is a good predictor of the presence of vaginal infections, including candidiasis, trichomoniasis, and bacterial vaginosis, all of which can be treated. However, to more accurately diagnose cervical infection, it would be extremely helpful to have available a simple "bedside" screening test for gonorrhea and chlamydial infection in particular that could be used to screen women who present with vaginal discharge for cervicitis. Such tests are now under active development and evaluation, but because of its technical complexity, it is unlikely that the DFA test would be a good candidate in this context.

References:

1. George JA, Panchatcharam TS, Paramasivam R, Balasubramanian S, Chakrapani V, Murugan G. Evaluation of diagnostic efficacy of PCR methods for Chlamydia trachomatis infection in genital and urine specimens of symptomatic men and women in India. Jpn J Infect Dis 2003; 56:88-92.

2. Singh V, Rastogi S, Garg S, et al. A. Polymerase chain reaction for detection of endocervical Chlamydia trachomatis infection in women attending a gynecology outpatient department in India. Acta Cytol 2002; 46:540-4.

3. World Health Organization. Guidelines for the management of sexually transmitted infections. WHO/HIV_AIDS-2001.01; WHO/RHR/01.10. Geneva: World Health Organization, 2001.

4. National AIDS Control Organization (NACO), India. Sexually transmitted infections - treatment guidelines, June 2004. http://www.saathii.org/Training%20Mannuals/RTI%20Guidelines.html.

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