Sexually transmitted infectionsBMJ 2001; 322 doi: https://doi.org/10.1136/bmj.322.7295.1160 (Published 12 May 2001) Cite this as: BMJ 2001;322:1160
All rapid responses
Gilson and Mindel provide an excellent review of sexually transmitted
infections (STI). The recent increase in the reported numbers of STI is
alarming. Some reports indicate that sexually risk taking has increased
now that effective HIV drugs are available1. However, not all of the news
is bad. One important reason for the increased number of cases is that
better tests are being used. The sensitivity of DNA amplification tests
approaches 100 percent. In one study, switching to these newer tests
resulted in an increased positivity of 46 percent2. Newer urine based
testing may help broaden screening to include men.
Chlamydia screening programs are another reassuring reason to expect
more reported cases. The U.K. broadened its screening recommendations in
1998. The number of U.S. states requiring reporting of Chlamydia cases
increased steadily between 1987 and 1996. Implementation of screening is
still inadequate3, but as more physicians begin screening, we can expect
some rise in the number of reported cases.
Many populations being screened for Chlamydia are actually
experiencing lower rates of infection4. University health clinics in the
U.S. have seen a steady decrease in Chlamydia prevalence from over 4
percent in the mid 1990's to less than 2 percent presently5. Despite the
increasing numbers of reported cases, STI screening is effective in
preventing STI and pelvic inflammatory disease6.
1 Aral S, Holmes KK. Social and behavioral determinants of the
epidemiology of STDs: industrialized and developing countries. In: Holmes
KK, ed. Sexually transmitted diseases. 3rd ed. New York: McGraw-Hill,
2 Dicker LW, Mosure DJ, Levine WC, Black CM, Berman SM. Impact of
switching laboratory tests on reported trends in Chlamydia trachomatis
infections. Am J Epidemiol 2000;151:430-5.
3 Torkko KC, Gershman K, Crane LA, Hamman R, Baron A. Testing for
Chlamydia and sexual history taking in adolescent females: results from a
statewide survey of Colorado primary care providers. Pediatrics
4 Division of STD Prevention. Sexually Transmitted Disease
Surveillance, 1999. U.S. Department of Health and Human Services, Atlanta:
Centers for Disease Control and Prevention (CDC), September 2000.
5 American College Health Association. Survey of Sexually
Transmitted Infections. Annual Meeting. Toronto, Canada. June 2000.
6 Scholes D, Stergachis A, Heidrich FE, Andrilla H, Holmes KK, Stamm
WE. Prevention of pelvic inflammatory disease by screening for cervical
Chlamydia infection. NEJM 1996;334:1326-6.
Competing interests: No competing interests
In their article Gilson and Mindel report on the increasing burden of
sexually transmitted infections (STI) in industrialised countries, in
particular in young people (1).
New opportunities for controlling and early detection of STIs are
discussed. Although all very promising, the implementation remains often
problematic. Similarly, this is also valid for the future STI vaccines.
Vaccination remains the most promising intervention for communicable
disease control. Vaccines against herpes simplex and human papillomavirus
are under development, and safe and effective hepatitis B vaccines are now
20 years on the market. All these STI vaccines could offer important
individual as well as collective health gains; there is overwhelming
evidence that a suitable hepatitis B vaccination programme would confer
protection on over 90% of the vulnerable individuals.
The hepatitis B vaccine story illustrates however, as alluded to in
Catchpole’s Editorial, that the availability of efficacious vaccines is
not enough to ensure efficient adoption of these vaccines in the fight
against STIs (2). Recent history has shown that the implementation of a
well-considered hepatitis B vaccination programme can be problematic and
not evident at all (3). Three lessons can be learnt from this story:
-opportunistic vaccination of those in the age group at highest risk (i.e.
adolescents) has been undertaken only in a minority of industrialised
countries, even sometimes at very low vaccination coverage (3).
-vaccination of risk groups hasn’t been very successful up to now, and is
very demanding in terms of manpower and programme costs (4,5).
-as long as decision makers and the public don’t accept the universal
(targeting a whole age cohort) introduction of an STI vaccine, especially
its administration in childhood, control of STI through universal
vaccination will remain difficult.
The time is yet mature for drawing lessons for the future, i.e. learn
from the current experience with hepatitis B vaccination programmes,
evaluate and, if needed, strengthen and improve these vaccination
programmes and prepare the field as well as the public for the venue of
future STI vaccines. If we are not able to use the currently available
hepatitis B vaccines efficiently to protect our future generations of
adolescents in industrialised countries, what is the rationale for
developing new STI vaccines, except conferring protection to a few
We should therefore, in parallel with the development of new STI
vaccines, start thinking today about how to deliver hepatitis B vaccines
to those who need it most; this will open the door to future STI vaccines.
1. Gilson R, Mindel A. Recent advances: sexually transmitted
infections. BMJ 2001; 322: 1160-4.
2. Catchpole M. Sexually transmitted infections: control strategies. BMJ
2001; 322: 1135-6 (editorial).
3. Van Damme P. Hepatitis B vaccination programmes in Europe: an update.
Vaccine 2001; 19: 2375-2379.
4. Bhatti N, Gilson RJC, Beecham M, Williams P, Matthews MP, Tedder RS,
Weller IVD. Failure to deliver hepatitis B vaccine: confessions from a
genitourinary medicine clinic. BMJ 1991; 303: 97-101.
5. Hoebe CJPA, Ruijs WLM, Schutten M, Waldhober Q, van Steenbergen JE.
Results of the first year of a hepatitis B pilot vaccination program for
hard drug users, homosexual men and promiscuous heterosexuals in the
Netherlands. Antiviral Therapy 2000; 5 (suppl. 1): 20-21.
Castermans S, medical student, research training programme
Verheyen J, medical student, research training programme
Van Damme P, head, Centre for the Evaluation of Vaccination
Dept. Epidemiology and Social Medicine,
University of Antwerp, Belgium
Competing interests: No competing interests
Editor,-We read with interest the article by Gilson and Mindel1 on
recent advances in the management of sexually transmitted infections,
which emphasised some important diagnostic issues. As the authors state,
many studies have shown that DNA amplification tests are now the gold
standard tests for the diagnosis of genital Chlamydia trachomatis.
However, we are concerned with the unreferenced statement that a ‘vaginal
swab is a better alternative’ for the detection of genital chlamydial
infection. We could find two studies which have examined the utility of
vaginal swabs, collected either by health care personnel or patients
themselves.2,3 Both found high sensitivity for vaginal swabs, but this
was matched by the sensitivity of sampling both urine (as a surrogate for
the urethra) and the cervix. Indeed, in some cases of genital chlamydial
infections (cervical swab positive) vaginal swabs were negative.2
women, the sensitivity of C. trachomatis PCR testing is increased by
approximately 12% if both cervical swab and urine specimens are examined
as opposed to urine alone.4 However, this approach is expensive,
particularly considering the relatively high cost of PCR tests versus
enzyme immunoassays. We found that combining a cervical swab with a urine
specimen in the clinic setting is acceptable for PCR testing for genital
C. trachomatis infection,5 and has the potential to increase further the
cost-effectiveness of DNA based screening for C. trachomatis genital
infection. Thus, this approach has the advantage of sampling both the
main sites of genito-urinary chlamydial infection and being more cost-
effective. Also, the well known problem of DNA amplification inhibition
by endogenous substances present in urine, and more commonly in cervical
secretions, is not increased by combining the two sample types.5
Mark H Wilcox
Leeds General Infirmary, Leeds.
Department of Microbiology, Leeds General Infirmary,
1. Gilson RJC, Mindel A. Recent advances: Sexually transmitted infections.
BMJ 2001; 322: 1160-1164.
2. Domeika M, Bassiri M, Butrimiene I, Venalis A, Ranceva J, Vasjanova V.
Evaluation of vaginal introital sampling as an alternative approach for
the detection of genital Chlamydia trachomatis infection in women. Acta
Obstet Gynecol Scand. 1999; 78(2):131-6.
3. Wiesenfeld HC, Heine RP, Rideout A, Macio I, DiBiasi F, Sweet RL.The
vaginal introitus: a novel site for Chlamydia trachomatis testing in
women. Am J Obstet Gynecol. 1996; 174(5):1542-6.
4. Quinn TC, Welsh L, Lentz A, Crotchfelt K, Zenilman J, Newhall J et
al. Diagnosis by AMPLICOR PCR of Chlamydia trachomatis infection in urine
samples from women and men attending sexually transmitted disease clinics.
J Clin Microbiol 1996; 34: 1401-6.
5. Wilcox MH, Reynolds MT, Hoy CM, Brayson J.Combined cervical swab
and urine specimens for PCR diagnosis of genital Chlamydia trachomatis
infection.Sex Transm Infect. 2000; 76(3):177-8.
Competing interests: No competing interests