Literature review > Issue 9 > Review on Hylton-Kong  et al. 

This is a well-designed study for the assessment of syndromic management for reproductive tract infections among pregnant women. From the study, the algorithm had low sensitivities for all RTI (66.7% for cervicitis, 35.4% for trichomoniasis, 11.1% for bacterial vaginosis (BV), and 24% for candidiasis). Specificities for BV (88.9%) and candidiasis (81.1%) were higher than for cervicitis (62.8%) and trichomoniasis (68.5%). The positive predictive values were lower than 36% for all diagnoses, especially BV (6.9%). Those findings were consistent with results of other reports that the algorithms for vaginal discharge have poor diagnostic value, particularly among antenatal clinic attendees or other low-risk populations [1,2,3].

To evaluate the diagnostic value of algorithms, the gold standard laboratory tests for various RTIs should be applied for the purpose of comparison. It is noticed that proper laboratory tests were used in this study. However, enzyme immunoassay for the detection of Chlamydia trachomatis is suboptimal due to relatively low sensitivity and positive predictive value, in comparison with nucleic acid based tests [4,5]. Of course, the performance of enzyme immunoassays may vary among different products and methodologies. The authors also mentioned that a ligase chain reaction (LCR) testing was performed on a subset of specimens for quality control. Unfortunately the authors didn't give any results of such quality control.

It is of interest that most of participants (71.2%) did not have any RTI complaints on presentation, and only 8.1% of the study sample presented with a complaint of vaginal discharge. However, when tested for RTI, 5.4% tested positive on gonorrhea culture, and 17.8% tested EIA positive for chlamydia. The prevalence of gonococcal and chlamydial infections was much higher among pregnant women in Jamaica, similar to that in other African countries [6,7]. Originally the WHO algorithm was designed for the management of women with spontaneous complaint of vaginal discharge. Flowcharts for screening of asymptomatic women should be different. However, given the high prevalence of chlamydia and gonococcal infections in this study, application of the WHO algorithm might work, though "disappointing results" were gained. Development of algorithms suitable for screening purposes is necessary, especially the establishment of a proper risk score.

There is increasing evidence indicating that Mycoplasma genitalium is a common infection associated with cervicitis [8,9] and with a high prevalence of infected sexual partners supporting its role as a cause of sexually transmitted infection [8], although a report of low prevalence of M. genitalium in pregnant women suggested the organism is unlikely to be an important risk factor in adverse pregnancy outcome [10]. Therefore, it may be useful for the validation of WHO algorithms if evaluation of the role of M. genitalium is included. The relationship between the presence of M. genitalium and pregnancy outcome warrants further assessment.

References:

1. Adler MW. Sexually transmitted diseases control in developing countries. Genitourin Med 1996; 72: 83-88

2. Mayaud P, ka-Gina G, Cornelissen J, et al. Validation of a WHO algorithm with risk assessment for the clinical management of vaginal discharge in Mwanza, Tanzania. Sex Transm Infect 1998; 74:S77-84

3. Mayaud P, Grosskurth H, Changalucha J, et al. Risk assessment and other screening options for gonorrhoea and chlamydial infections in women attending rural Tanzanian antenatal clinics. Bull WHO 1995;73:621-630

4. Kluytmans JA, Goessens WHF, Mouton JW, et al. Evaluation of Clearview and Magic Lite tests, polymerase chain reaction, and cell culture for detection of Chlamydia trachomatis in urogenital specimens. J Clin Microbiol 1993, 31: 3204-3210

5. Black CM. Current methods of laboratory diagnosis of Chlamydia trachomatis infections. Clin Microbiol Rev 1997, 10: 160-184

6. Sturm AW, Wilkinson D, Ndovela N, et al. Pregnant women as a reservoir of undetected sexually transmitted diseases in rural South Africa: implications for disease control. Am J Public Health 1998;88:1243-1245

7. Urassa EJN, Massawe SN, Mhalu FS. Some sexually transmitted diseases among pregnant women in Dar es Salaam. In: Venereal Diseases. Proceedings of the fourth meeting organized by the ItalianMedical Team in Tanzania, 1985:27-34

8. Falk L, Fredlund H, Jensen JS. Sign and symptoms of urethritis and cervicitis among women with or without Mycoplasma genitalium of Chlamydia trachomatis infection. Sex Transm Infect 2005, 81(1): 73-78

9. Manhart LE, Critchlow CW, Holmes KK, et al. Mucopurulent cervicitis and Mycoplasma genitalium. J Infect Dis 2003, 187(4): 650-657

10. Oakeshott P, Hay P, Taylor-Robinson D, et al. Prevalence of Mycoplasma genitalium in early pregnancy and relationship between its presence and pregnancy outcome. BJOG, 2004, 111(12):1464-1467

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