Rising STI Rates
Post-COVID

Post-pandemic resurgence: STI trends in Australia

Trends in key bacterial notifiable STIs, as noted in the National Communicable Disease Surveillance Dashboard of Australia, mimic the global trends2. Three years, 2020 to 2022, saw a drop in notifications compared to 2019, reflecting the impact of the pandemic (see Table 1). However, 2023 saw a resurgence of STIs, with notifications significantly higher than in 2019, especially for syphilis < 2 years duration (8.6 % increase), gonococcal infection (16% increase), and congenital syphilis (400% increase; 4 each in VIC, WA, and NSW and 5 in QLD) (Table 1).²

Table 1. Trends in Key Notifiable STIs in Australia – 2019 to 2023

Rising congenital syphilis cases in the US

Addressing missed opportunities, the CDC (Centers for Disease Control) reported a 755% increase in congenital syphilis cases in the United States from 2012 to 2021 (335 versus 2,865 respectively), with 3,761 cases reported in 2022 (231 stillbirths and 51 infant deaths).³ Lack of timely testing and adequate treatment during pregnancy contributed to almost 90% of these preventable cases.

New infections and antibiotic resistance

In addition to the ongoing impact of recognised STIs, other concerning facts include:

• New infections that can be acquired by sexual contact have emerged and are leading to outbreaks in some instances. These include mpox, Shigella sonnei, Neisseria meningitidis, Ebola and Zika, along with the re-emergence of neglected STIs like lymphogranuloma venerum (LGV).¹
• Emergence and spread of multi-drug-resistant gonorrhoea: Resistance of N.gonorrhoeae to the available antimicrobial options continues to evolve, with recognition of high levels of resistance to ciprofloxacin, increasing resistance to azithromycin, and resistance or decreased susceptibility to cefixime and ceftriaxone.⁴

STI co-infections: Implications and recommendations

Accurate rates of STI co-infections are often difficult to discern as the infections are notified separately. However, it is well recognised that persons at risk of STI acquisition are also at risk of co-infection with more than one STI. Co-infection of Chlamydia trachomatis in individuals diagnosed with Neisseria gonorrhoeae is well recognised. However, there is paucity of data on the co-infection of chlamydia and gonorrhoea among persons with early syphilis.

A recent study from the University of Birmingham in Alabama reported that of the 865 adults enrolled for a controlled trial for treatment of early syphilis, 234 (27%) adults had also had documented STI co-infection, of whom 29% had N. gonorrhoeae, 22% had C.trachomatis, and 23% had both. Multisite STI screening for multiple pathogens is recommended for sexually active adults at risk to identify both symptomatic and asymptomatic infections.

N. meningitidis and N. gonorrhoeae: Causes and risks

Neisseria meningitidis (NM) is typically found as a commensal in the upper respiratory tract of humans and is a leading cause of sepsis. It has the unique ability to cause outbreaks of invasive meningococcal disease, which can be fatal. Neisseria gonorrhoeae (NG) traditionally causes gonorrhoea, a sexually transmitted infection involving the genitals, rectum, and throat. These species usually occupy distinct niches but may cause reciprocal diseases. NM may also occasionally be found in the genital tract as a commensal. It has long been recognised that urethral NM infections could be spread by oral sex and were more common in men who have sex with men.⁶

Urogenital and anogenital infections due to N. meningitidis

In recent years, there have been increasing reports worldwide of urogenital and anogenital infections attributed to NM. These may mimic the symptoms of gonorrhoea, causing urethritis, proctitis, cervicitis, and pelvic inflammatory disease, which is indistinguishable from gonorrhoea. In addition, meningococcal urethritis has been documented in long-term monogamous relationships in which the partner has no disease.^7,8

Changing patterns of meningococcal urethritis

At the beginning of the 21st century, meningococcal urethritis was considered to be a rare condition, found almost entirely in MSM and transmitted by oral sex. More recently, clusters of meningococcal urethritis were identified predominantly in heterosexual men, mainly in the 20 to 30 years age group. Symptoms included urethral discharge (>90%) and dysuria, with symptoms ranging from 2 to 7 days. Almost all men with meningococcal urethritis reported oral sex encounters. However, genitalgenital and ano-genital infection can also occur. Like N. gonorrhoeae, N. meningitidis can also cause cervicitis, vulvovaginitis, pelvic inflammatory disease, salpingitis, endometritis, and proctitis. Neonatal conjunctivitis and pre-term birth have also been reported. Cases of invasive meningococcal disease (IMD) secondary to infection and colonisation of urogenital or anorectal sites have been reported, mainly in females.

Diagnostic considerations: Co-infections

In patients who present with urethritis or other symptoms suspicious for a sexually transmitted infection, it is important to consider co-infections with other STIs. 15 to 19% of men may have a concurrent infection with Chlamydia trachomatis (CT). It is therefore important to test for both chlamydia and gonorrhea by nucleic acid tests (NATs). Either a first-void urine or urethral swab is suitable for these tests. In addition, a further swab for bacterial culture should be ordered.

Laboratory diagnosis of meningococcal anogenital infection

Gram stain is routinely performed on all genital swabs. The presence of Gram-negative cocci on the gram stain, and increased numbers of leucocytes, predominantly neutrophils, is suggestive of urethritis but cannot distinguish between NG and NM.

Bacterial culture is, therefore, the mainstay of diagnosis. Depending on the site of infection, collection of a urethral, genital, or anorectal swab for bacterial culture is required.

NM will not be detected by routine STI screening if only nucleic acid amplification tests (NATs) are used, but testing should be performed to rule out other infections. Dual infections with both Neisseria meningitidis and Neissseria gonorrheae can also occur, and previous infections with NG are common in MSM.

PCR testing of NG and CT without bacterial culture could lead to a missed diagnosis as the PCR can only detect Neisseria gonorrhoeae; it will not detect Neisseria meningitidis. Currently, there is no TGA-authorised PCR test available for the detection of meningococcal urethritis or anogenital infection.

There have been over 30 cases of NM at a urogenital or anorectal site reported in NSW since September 2023, and it is likely that many have gone undetected. The importance of actively testing, detecting, and treating cannot be overemphasised.

Prevalence and risk factors

The prevalence of Mycoplasma genitalium in young adults (18-27 years old) is estimated to be approximately 1%, but is as high as 15-25% in men with symptomatic NGU and up to 15% of women with pelvic inflammatory disease (PID). In Melbourne, asymptomatic infection was detected in 9.5% of men who have sex with men (MSM). Rectal positivity was higher than urine (7.0% vs. 2.7%), and co-infection with other STIs was found in 17%.

Collection recommendations for accurate diagnosis

Mycoplasma genitalium presents with clinical symptoms and signs very similar to other STIs like chlamydia and gonorrhoea, which may complicate its diagnosis. Nucleic acid amplification tests (NAATs) are the recommended diagnostic method, offering high sensitivity and specificity. The best sample to obtain is a first-pass urine sample in male patients or a high vaginal swab in female patients. A cervical swab is slightly less sensitive, with a first-pass urine sample being the least sensitive in female patients. In high-risk populations, a rectal swab should also be collected. As pharyngeal infection is uncommon, a throat swab is not indicated.

The growing challenge of antibiotic resistance

The primary concern in treating Mycoplasma genitalium is its increasing resistance to antibiotics. Azithromycin (macrolide) resistance is widespread, prompting a shift towards alternative regimens like moxifloxacin. However, resistance to moxifloxacin is also emerging, creating a significant challenge in management. In Australia, the current resistance rate of azithromycin exceeds 60% in the majority of cases and is even as high as 80% in the MSM population.

Treatment is based on the test results and clinical presentation. See STI guidelines.

A doctor’s role in prevention

Preventive measures are crucial in managing Mycoplasma genitalium. Regular STI screening, safe sex practices, and public health campaigns can significantly mitigate its spread. It is vital for doctors to counsel patients on safe sex practices and the importance of regular screening. However, the significance of M. genitalium in asymptomatic individuals remains uncertain. Currently, local guidelines advise against testing asymptomatic patients unless they were exposed to known contact.

Managing the Mycoplasma genitalium challenge

Mycoplasma genitalium represents a significant and growing challenge in sexual health. The evolving nature of its antibiotic resistance profile necessitates a vigilant approach to diagnosis, treatment, and public health strategies. Continuous education and updated guidelines are essential to effectively manage this emerging STI.