Diagnosing sexually transmitted infections with point of care testing

• Sexually transmitted infections affect many people worldwide and can lead to serious complications without appropriate treatment
• Syndromic management of STIs can result in overtreatment or missed treatment
• Recent advances in molecular point of care testing provide an opportunity for improved patient care and public health benefits

According to the World Health Organization (WHO), more than one million curable sexually transmitted infections (STIs) are acquired every day worldwide.¹ Although infections such as chlamydia and gonorrhea are curable, if left undiagnosed and untreated they can lead to complications such as pelvic inflammatory disease (PID), ectopic pregnancy, and infertility.^2,3

In the absence of rapid testing, symptomatic STI diagnosis is based on observed syndromes, for example, urethral or vaginal discharge. While this approach is simple and assures rapid treatment, it often results in overtreatment, or alternatively could result in missed treatment as many STIs can be asymptomatic.

In a recent webinar Dr. Rebecca Lillis, MD (Louisiana State University, Department of Medicine), discussed the problems associated with this approach and outlined how rapid point of care testing (POCT), which enables same day results, has great potential to improve patient care and prevent the spread of STIs.

Because syndromic management is a common approach to the treatment of patients with suspected chlamydia or gonorrhea infections, and patients are often treated before test results are verified, overprescription of antibiotics (overtreatment) is a real issue. Dr. Lillis looked at a range of studies regarding the syndromic management approach and found rates of overtreatment as high as 94% in one Ugandan care setting.⁴

Undertreatment is also an issue, where a delay in diagnosis, especially common for asymptomatic infections, can lead to a delay in treatment or no treatment at all. Such circumstances easily lead to further spread of gonorrhea or chlamydia to sexual partners, or progression of infection in untreated patients and their partners, resulting in complications such as PID, infertility, chronic pelvic pain, or ectopic pregnancy.

By looking at several studies comparing the results of rapid STI point of care testing to traditional laboratory testing, Dr. Lillis has found that there are clear benefits to reduced turnaround times.

One study in a Washington DC emergency department demonstrated a reduction in empirical treatment in the rapid test group compared to the standard of care group (21.6% vs 55%).⁵

Another study which found that rapid testing also reduces the cost of overall care more generally, was done in Grand Rapids, Michigan. A 90-minute rapid diagnostic test was used in the emergency department from December 2014 to January 2015. Subjects were compared to a traditional lab-based test control group from the prior year. Results showed that not only were the costs associated with rapid diagnostic tests cheaper than the standard of care test, but the rapid test decreased antimicrobial utilization and the need for emergency department readmission – all factors that led to an overall decrease in the cost of care.⁶

These findings were echoed in an Australian study in Melbourne, where implementation of point of care testing was associated with reduced antibiotic prescription, more specific STI treatment among symptomatic clients, and an increase in rapid notification of their sex partners. The authors also found that the use of point of care testing reduced cost per client as compared to standard of care for symptomatic and asymptomatic contacts with STIs, with cost savings ranging from 13% to 35%.^7,8

Dr. Lillis noted there have been several modeling studies looking at the cost of testing and highlighted one study performed across four sexual health centers in England. The authors evaluated patient pathways and found these to be shorter and less expensive when using point of care tests for asymptomatic and symptomatic patients with chlamydia and gonorrhea. In this context, rapid testing could reduce the cost per patient by as much as £16, and healthcare professionals’ time by 10 minutes per patient.⁹

Rapid testing and rapid results were also found to improve patient experience for those who might struggle to return to a clinic for treatment. Dr. Lillis explained, “If you know that a patient has a job where it’s difficult for them to come in, or if they have transportation difficulties, or live a large distance from the clinic, it’s important to get them treated as soon as possible and avoid return trips to the clinic.”

Trips can also be costly for a patient who might have to take unpaid time off work and pay for transportation or parking. Fewer trips to the clinic is more economical for patients.

Giving timely answers to patients is also beneficial for a patient’s mental health, especially patients who may be anxious about their diagnosis, for example, pregnant women concerned about passing an infection to their baby.

Dr. Lillis also reported wider benefits for patients and their partners from a study in Durban, South Africa where women were tested for gonorrhea, chlamydia, and trichomonas with rapid testing. Following diagnosis, the authors conducted focus groups with women treated for STIs. They found women were relieved to receive a specific STI diagnosis with immediate treatment and a meaningful STI discussion with the nursing staff.

Women were also provided with an “expedited partner therapy (EPT) pack.” Women reported the STI diagnosis and EPT allowed them to begin communicating with their partners about sexual relationships, and to start to renegotiate these if required. Women reported outcomes of these discussions, including leaving their partners, improved condom use, or continuing their relationship after partner treatment. These women reported their male partners found EPT helpful for practical reasons such as not having to travel to the clinic or take time off of work to be treated.¹⁰

Another group to benefit from rapid point of care testing are patients who present to the clinic as contacts of an STI. In an Australian study in Melbourne, it was found that of all the patients who presented to the clinic, less than 30% were infected with the STI their sexual contact reported to them. This means that in two thirds of participants, no bacterial STI was detected, highlighting the advantage of timely diagnosis to mitigate antibiotic overuse in settings where patients with suspected exposure are commonly treated empirically.⁷

Dr. Lillis also pointed out that rapid testing can reduce the spread of infections in the first place, by allowing immediate treatment for patients who might spread infection in the absence of same day treatment. Examples could include patients who have multiple partners, where there is an increased chance they transmit infection to a new partner while awaiting test results

With advances in point of care testing bringing short waiting times, Dr. Lillis is keen to see this solution becoming more available to healthcare providers and patients in more settings.

She concluded that “molecular point of care testing is a useful tool in gonorrhea and chlamydia management with the potential to improve antimicrobial stewardship, improve the timeliness and accuracy of STI treatment, improve patient and provider satisfaction and potentially decrease costs”. She also noted, “there’s less time spent trying to contact patients for follow-up, less time spent on those follow-up visits and there are fewer patients lost to follow up, which is extremely important.”