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Steven J Skov, Penny Miller, Wayne Hateley, Ivan B Bastian, Jenny Davis and Peter W Tait
MJA 1997; 166: 468
For editorial comment see Waddell
Abstract - Introduction - Methods - Results - Discussion - Acknowledgements - References - Authors' details
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©MJA1997
Urine tests for the detection of gonorrhoea and chlamydia are now
commercially available. Enzyme immunoassay (EIA) tests have
sensitivities above 80% and specificities above 93%,6-9 while polymerase chain reaction
(PCR) tests have reported sensitivities of 90%-100% and
specificities of 98%-100%.10-14
These technologies offered exciting possibilities to
address some of the difficulties in delivering STD services, so,
after receiving approval from the Alice Springs Institutional
Ethics Committee, the Tri-State STD/HIV Project (TSP), in
collaboration with Nganampa Health Council (NHC) and the Central
Australian Aboriginal Congress (CAAC), both organisations
controlled by Aboriginal communities, undertook the programs
described in this article.
Phase I: NHC provides health services to several remote
Aboriginal communities and conducts annual syphilis serology
screening programs in these communities. NHC maintains a population
register, and all persons between the ages of 12 and 40 years who are in
the communities during the screening programs are sought out and
asked to participate. In April 1995, 189 men participating in this
program in three communities serviced by NHC were asked to give a
first-void urine sample in addition to the blood sample for the
syphilis test.
Phase II: In June 1995, another 218 men in the remaining three
NHC communities had urine tests only; all males over the age of 12 who
were present in the communities at the time were asked to participate.
Phase III: In October 1995, a further 53 men were tested who had
not been previously tested.
Phase IV: CAAC, as part of its many functions, provides the
health service to the Alice Springs Gaol. In June 1995, 33 new inmates
were asked to give a first-void urine sample as part of their
comprehensive health check on admission.
Diagnostic tests used for gonorrhoea were culture, EIA (Abbott
Gonozyme, Chicago, IL) and PCR (Roche Amplicor CT/NG, Branchburg,
NJ) and for chlamydia were EIA (SYVA MicroTrak II, Palo Alto, CA) and
PCR (Roche Amplicor, Branchburg, NJ) (Box 1, below). If there was
insufficient urine for all tests, the order of priority was to do PCR
first, then culture, chlamydia EIA and finally gonococcal EIA. To
check for cross-contamination between PCR specimens, all Phase III
specimens that provided sufficient urine were divided before any PCR
procedures were performed. When a positive result was obtained the
other half of the original sample was retested.
Chocolate and/or Thayer-Martin agar plates incubated in candle jars
or CO2 gaspacks were used for gonococcal culture.
BioCult GC tubes (Orion Diagnostica, Espoo, Finland), which contain
a modified Thayer-Martin dipslide and a CO2-generating
tablet, were also trialled. Culture media were inoculated with
sediment from 10 mL of centrifuged urine and incubated for up to 72
hours at 35oC on-site and/or at Western Pathology in
Alice Springs. Neisseria gonorrhoeae was identified by
standard methods: typical morphology of colonies, oxidase paper
test, microscopy with Gram stain, and latex agglutination
(Phadebact GC, Boule Diagnostics AB, Huddinge, Sweden). Urine
samples for EIA and PCR were prepared on-site according to the test
manufacturer's specifications and then sent to Western Pathology in
Alice Springs for processing.
Male Aboriginal health workers and registered nurses in each clinic
were responsible for liaison with the community and collection of
specimens. Each man was asked to give 25-40 mL of first-void urine in a
sterile collection jar. No urethral swabs were sought. Initial
preparation of urine specimens for transport to the laboratory was
completed within three hours of collection. A diagnosis of infection
was made and treatment was initiated if any test was positive.
Resident clinic staff were responsible for offering treatment,
further investigation and safe-sex education to infected men and
their sexual partners.
During Phase II, culture for gonorrhoea using both BioCult GC tubes
and standard Thayer-Martin plates was performed on 193 urine
specimens. Thirteen diagnoses were made with the BioCult GC tubes and
only seven were made with standard Thayer- Martin plates: all cases
positive on Thayer-Martin plates were also positive on the BioCult GC
tubes.
During Phase III, 19 of the 20 initially positive PCR results were
retested (in one case there was insufficient urine). In 18 of these
cases there was complete agreement between the first and second test.
One chlamydia-positive specimen was negative on the second testing.
However, because of delays in transport, the tests on this specimen
were done at six and eight days after collection, well in excess of the
four days maximum recommended by the test manufacturers.
The variation in participation rates in different communities and
age-groups was largely attributable to the numbers of people who
happened to be present at the time of the study (people in these remote
communities being highly mobile), the working relationship between
community members and the health staff, and the assiduousness of the
health staff in conducting the program. In central Australia it is
often considered, without specific evidence, that people who do not
participate in such programs may be at higher risk of infection.
Recent work by NHC showed no difference in rates of syphilis infection
between those tested during the main body of a screening program and
those tested later as part of an effort to test non-participants (Dr
Penny Miller, unpublished data).
The screening programs in our study were intended to identify the most
effective and practical tests for everyday use in remote clinics.
Collection of urethral swabs was avoided because it would not have
been acceptable to the community. Hence, the study lacked a
diagnostic "gold standard" and could not formally evaluate
sensitivities and specificities. The published specificities of
all the tests were high -- above 98% for urine PCR tests.10-14 The procedures used in Phase
III demonstrated no problems with cross-contamination in PCR
testing. Several studies have suggested that urine PCR tests for
chlamydia are more sensitive than urethral-swab culture and highly
specific.10-13 Less work
has been done on urine PCR for diagnosing gonococcal infection, but
two studies indicate sensitivities above 90% and specificities of
100%.13,14
In ideal conditions, the sensitivities of urethral-swab microscopy
and culture are 90%-98%,15,16
but are likely to be much less in remote communities because of
high staff turnover, the use of non-nutritive transport media, and
frequently prolonged transport times. In such circumstances, urine
PCR may be as good as or better than urethral-swab microscopy and
culture for diagnosis of gonorrhoea. In any event, according to local
management protocols,17
all men presenting to clinics with urethritis are offered immediate
treatment for both gonorrhoea and chlamydia.
In terms of practical application, PCR was superior to culture for
gonorrhoea and EIA for both infections. PCR tests detected more
infections with either organism than did the other tests (Box 3).
Assuming that the high published specificities for the PCR tests held
under field conditions, this increased rate of detection would be
attributable to a superior sensitivity. The PCR test was also the
easiest to use: urine is simply stored and transported at 4¡-8¡C in the
same jar used to collect it. The urine must then be processed in the
laboratory within four days (test manufacturer's instructions),
which is usually feasible in most remote situations. In contrast,
both EIA tests used require centrifuging before transport, and the
SYVA MicroTrak II EIA required addition of a transport buffer.
However, PCR tests do not provide information about antibiotic
susceptibility. If PCR technology is to be used as the principal
diagnostic tool for gonorrhoea, there would need to be accompanying
sentinel systems for gonococcal culture and antibiotic
susceptibility. We found that culture of first-void urine was
positive in 72% of diagnoses of gonorrhoea. Sensitivities of
70%-100% for urine culture of gonorrhoea have been reported.18,19 On this basis, urine culture in
addition to urine PCR for diagnosis of gonorrhoea could be performed
routinely at sentinel sites and during similar programs to those
reported here in order to maintain antibiotic-sensitivity
surveillance. In the field situation, the BioCult GC tubes detected
more gonorrhoea than standard Thayer-Martin plates and were easier
and more convenient to use.
The accuracy, ease of use and acceptability to men of urine PCR tests
suggest several strategies to make clinical services more
accessible to people, reduce the amount of disease in the community
and identify individuals who are in need of safe-sex education. The
use of urine tests for routine diagnosis may encourage more men to
present with an STD, even if there is no male practitioner present.
Health services could adopt active case-finding strategies such as
opportunistic testing when people present for other reasons,
including annual comprehensive health checks or community surveys.
Such strategies are under consideration by health services in
central Australia. For example, CAAC is seeking funding to establish
an outreach program via a mobile clinic to make comprehensive
well-men's check-ups, including STD checks, accessible to
Aboriginal men in Alice Springs.
We also examined screening as an STD control strategy. With fewer than
10 men refusing to participate, these programs resulted in 88 men who
had either gonorrhoea or chlamydia and at least 45 of their sexual
partners being treated. We did not have the resources to determine
whether the men were symptomatic at the time of the test. However, none
of them had presented to the clinic for treatment. When these findings
are considered in the light of routine notifications and our own local
experience, it is likely that most of these people would not have been
diagnosed and treated outside these programs. Health services
catering to remote Aboriginal communities in other parts of
Australia may wish to consider this new technology and its usefulness
in comprehensive STD education and control programs.
(Received 24 June, accepted 17 Oct, 1996)
<URL: http://www.mja.com.au/>
© 1997 Medical Journal of Australia.
Abstract
Aims: (1) To evaluate the acceptability and validity
of an intervention based on urine tests for diagnosis and treatment of
gonorrhoea and chlamydia in men in remote Aboriginal communities.
(2) To provide a prevalence estimate of these infections in the male
population in the surveyed communities.
Methods: First-void urine samples from 460 men in
remote communities and 33 men in the Alice Springs Gaol were tested for
gonorrhoea and chlamydia with at least one of polymerase chain
reaction (PCR), enzyme immunoassay (EIA) and culture (gonorrhoea
only).
Results: One hundred and three men (20.9%) were
infected with gonorrhoea or chlamydia. The prevalence of infection
for gonorrhoea only was 11.7%, for chlamydia only 4.1% and for dual
infection 5.1%. Eighty-eight infected men and 45 of their sexual
partners were recorded as having been treated within two months of
testing. PCR tests detected the largest number of infections and were
the easiest to use.
Conclusions: The prevalence of these infections was
higher than anticipated. Urine PCR tests were acceptable to men and
are well suited to the remote-community setting. As an effective
alternative to urethral swabs, they permit a range of
community-based strategies to address high rates of infection with
gonorrhoea and chlamydia.
Introduction
The rates of sexually transmitted diseases (STDs) in central
Australia, particularly gonorrhoea and chlamydia, are among the
highest in Australia and indeed the world,1,2 despite a modest decline in
gonorrhoea over the past 15 years (according to notifiable diseases
data from the health departments of South Australia, Western
Australia and the Northern Territory). Although these infections
are more common in this region than in the rest of Australia among both
Aboriginal and non-Aboriginal people, most of the excess morbidity
occurs among Aboriginal people (health departments' data). Many
factors contribute to this situation. Dispossession, unemployment
and their sequelae are the fundamental determinants of the poor
health of Aboriginal people and also underlie the observed high
levels of STDs. The serious under-resourcing of central Australian
health services, the difficulty in maintaining confidentiality in
small communities, the stigma attached to STDs, the unpleasant
nature of urethral and endocervical swabs and, in particular, the
frequent lack of male health care workers -- all militate against
effective STD programs.3-5
Methods
The study was undertaken in four parts.
Results
Study population
We tested urine samples from 493 men, of whom 460 lived in six remote
communities and 33 were gaol inmates. Acceptability to clients was
high, with fewer than 10 men (exact count not possible)
declining testing. The 460 men from remote communities represented
about 60% of the male population over the age of 12 in the area serviced
by the participating clinics (Box 2, below). The proportion of men tested in
different communities varied from 28% to 85%.
The rate of infection
Based on all methods of diagnosis combined, 103 of the men tested
(20.9%) were found to be infected with either gonorrhoea or
chlamydia. The rate of infection in different communities varied
between 14.5% and 26%. Among the gaol inmates, who originated from all
parts of the southern NT, seven (21.2%) were infected. Most
infections (90.3%) occurred in men aged 15-39 years and the five-year
age-specific prevalence of infection in this group varied from 22% to
27% (Box 2, above).
Treatment and follow-up
Eighty-eight men were treated within two months of testing. The
average delay between testing and treatment was 18 days. Forty-five
sexual partners of infected men were also recorded as having been
treated.
Performance of the tests used
Different combinations of tests were used in different phases. The
volume of urine received from each man varied, so it was not always
possible to do all the intended tests. A summary of the numbers of
specimens subjected to the various tests and their relative
performance is shown in Box 3 (below). 
Discussion
These results highlight the need for improvements in current STD
control, including surveillance programs. Based on routine clinic
activity and notifications, NHC reported only 38 men with either
gonorrhoea or chlamydia during the whole of 1994 (health
departments' notifiable diseases data), compared with the 96 cases
detected in this study. Other regions of Australia that have
comparable notification rates of these infections1 may have similar problems in
underdetection.
Acknowledgements
The Tri-State STD/HIV Project (TSP) is jointly funded and managed by
the Commonwealth Department of Health and Family Services,
Territory Health Services, the South Australian Health Commission
and the Western Australian Health Department. The work would not have
been possible without the support of the clinical staff of Nganampa
Health Council (NHC) and the Central Australian Aboriginal Congress
(CAAC). Technical advice and material resources were contributed by
the TSP, NHC, CAAC, Western Pathology, Alice Springs Hospital
laboratory, the Australian Army, the Northern Territory AIDS/STD
Unit, Roche Diagnostics, and the Institute of Medical and Veterinary
Science. John Kaldor, Russell Waddell, Frank Bowden and John Boffa
all commented on earlier drafts of this paper.
References
Authors' details
Tri-State STD/HIV Project, Alice Springs, NT.
Steven J Skov, MPH, FAFPHM, Medical Officer, Tri-State
STD/HIV Project.
Nganampa Health Council, Alice Springs, NT.
Penny Miller, MB BS, STD/HIV Program Coordinator.
Wayne Hateley, STD/HIV Aboriginal Health Worker.
Royal Darwin Hospital, NT.
Ivan B Bastian, MB BS, MSc, Microbiology Registrar.
Australian Army, Darwin, NT.
Jenny Davis, Medical Technician.
Central Australian Aboriginal Congress, Alice Springs, NT.
Peter W Tait, MB BS, DipRACOG, FRACGP, Acting Senior Doctor.
Reprints will not be available. Correspondence: Dr Penny Miller,
Nganampa Health Council, PO Box 2232, Alice Springs, NT 0871.
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