Symptoms are a poor way of detecting
discharge-causing sexually transmitted infections (STIs) in women,
investigators report in the 1 July edition of the Journal of Infectious Diseases. The
research was conducted in South Africa, where diagnosis of STIs relies on the
presence of symptoms. The women recruited to the study had multiple partners
and many were sex workers, meaning that they had a high risk of HIV infection.
Symptoms were present in only 12% of women
with laboratory-confirmed infections. The study also showed that
laboratory-diagnosed STIs were associated with a threefold increase in the
risk of infection with HIV. There was no such association for symptoms.
“These data create a compelling argument
for readdressing the STI management strategy in high-risk populations,” comment
the authors. “Healthcare systems should include regular screening for STIs by
means of laboratory testing in these groups rather than relying on symptoms
The diagnosis and treatment of STIs is a
major public health priority. If left untreated, infections such as gonorrhoea
can cause long-term complications and can also increase the risk of HIV transmission and acquisition.
In resource-limited countries, such as South Africa,
the diagnosis of STIs is reliant upon the detection of symptoms. Genital
discharge is the most obvious symptom of infections such as chlamydia and
However, it is well known that STIs can be
asymptomatic. Investigators from South Africa therefore designed a prospective
study involving 242 women at high risk of HIV to assess the prevalence of asymptomatic
Enrolled in the CAPRISA 002 study, the
women were screened for STIs at baseline and again at six-monthly intervals.
Symptoms of STIs were recorded and
laboratory testing for common STIs was conducted at each follow-up appointment.
The investigators also conducted tests to see if symptomatic and asymptomatic
STIs were associated with levels of inflammatory cytokines. Elevated levels could
increase susceptibility to HIV. The researchers also performed analysis to see
if symptomatic and asymptomatic infections were associated with an increased
risk of HIV.
Almost all the women (95%) reported one or
more casual sex partner in the three months before enrolment and 79% identified as
There was a high prevalence of laboratory-confirmed STIs at enrolment. Overall, a fifth of women were diagnosed with having any
sort of infection. During the study, the incidence of any STI was 27 cases per 100
Vaginal discharge was present in 15% of
women at baseline. The prevalence of discharge at the six- and twelve-month
follow-up visits was 2 and 5% respectively.
However, laboratory monitoring showed that
28% of woman had a discharge-causing STI at baseline, with 19 and 24% testing
positive for such infections at their six- and twelve-month visits.
Many of the women presenting with discharge
did not have a STI. Only 34% of discharge incidents were accompanied by a
positive laboratory test confirming the presence of an infection. In contrast,
77% of laboratory-confirmed STIs had no accompanying symptoms.
Using laboratory tests as the “gold
standard”, the investigators calculated that symptoms for screening had a
sensitivity of just 12% and a specificity of 94%.
“Therefore, only 12.3% of women with a
confirmed laboratory-diagnosed STI would have been appropriately treated using
vaginal discharge as an indicator for syndromic treatment,” write the authors.
Both symptomatic and asymptomatic
infections were associated with elevated concentrations of inflammatory
cytokines in the genital tract. “Women who had asymptomatic STIs had
subclinical inflammation that may increase their susceptibility to HIV
A total of 28 women became infected with
HIV (incidence, 7.2 cases per 100 person-years).
The presence of laboratory-confirmed
discharge-causing STIs was associated with a threefold increase in the risk of
infection with HIV (HR = 3.3; 95% CI, 1.5-7.2).
Gonorrhoea was associated with an
especially high risk of infection with HIV. The unadjusted analysis showed that
this infection increased the risk almost eightfold (HR = 7.74; 95% CI,
2.82-21.24; p < 0.001). The association remained highly significant after
controlling for potential confounders (HR = 4.62; 95% CI, 1.34-15.93; p =
There was no association between the
presence of vaginal discharge and risk of infection with HIV.
“The current symptom-driven syndromic
management system is untenable for high-risk populations and underscores the
need for a paradigm shift in diagnosing STIs,” conclude the authors. “Only when
more effective STI treatment is achieved are we likely to see STI management
playing a role in HIV prevention.”
This conclusion is echoed by Dr Myron Cohen
in an editorial that accompanies the study: “We must redouble our efforts to
think of every possible way to recognize and treat classical STDs. Surely this
problem is no more impossible to attack or less important than any other part
of the HIV-1 pandemic.”