Sexually Transmitted Infections (STIs) continue to be a significant global health concern, affecting millions of people each year, irrespective of geographical location or economic status. While the spotlight often falls on diseases like HIV and syphilis due to their severe consequences and historical significance, other STIs such as chlamydia, gonorrhoea, and human papillomavirus (HPV) also pose substantial threats to public health worldwide.

 

STI Trends and Insights

While syphilis and HIV have historically been central to STI discussions, it’s crucial to address the wide spectrum of STIs affecting populations globally. Diseases like chlamydia, often asymptomatic, can lead to infertility if untreated. HPV, the most common STI, is a leading cause of cervical cancer, underscoring the importance of vaccination and regular screenings.

  • Chlamydia: A common STI caused by infection with the bacterium Chlamydia trachomatis. The WHO estimated that in 2020 there were 5 million new infections worldwide among adults aged 15 to 49 years.
  • Syphilis: Despite being one of the oldest known STIs, syphilis cases have surged, particularly in high-income countries, with an increase in Europe of 70% from 2010 to 2017 and cases are still rising with an increase of 34% between 2021 to 2022.
  • Human Papillomavirus (HPV): The WHO estimates that nearly all sexually active individuals will get at least one type of HPV at some point in their lives. Whilst in 90% of people the body controls the infection by itself, persistent HPV infection with high-risk HPV types is a leading cause of cervical cancer.
  • Trichomoniasis: The most common non-viral STI. Caused by the protozoan Trichomonas vaginalis which specifically targets the urogenital tract. There were an estimated 156 million new cases of vaginalis infection among people aged 15–49 years old globally in 2020 with approximately one third of infections in the WHO African Region.

 

Gonorrhoea- An Urgent Threat

Caused by the bacteria Neisseria gonorrhoeae, cases of Gonorrhoea have increased significantly. In the UK whilst there was an increase of 13% in the number of sexual health screens between 2021 and 2022, there was a larger increase in diagnoses of gonorrhoea (50%), which may either reflect more targeted testing of people more likely to have an STI, or an increase in STI transmission in the community. A recent publication from the European Centre for Disease Prevention and Control (ECDC) confirms the worrying trend across Europe with the number of reported cases of gonorrhoea rising by 48% compared to the previous year.

Alongside the increasing incidence is the concern over antibiotic-resistant gonorrhoea which has emerged as a significant public health challenge, with the US CDC identifying it as an “urgent threat” and estimating that there are 550,000 drug-resistant infections per year.

 

The Interconnectedness of STIs and Other Health Risks

The relationship between different STIs can exacerbate health outcomes. For example, genital ulcers from syphilis can increase the risk of acquiring HIV, a phenomenon seen with other ulcerative STIs as well. Two types of HPV (HPV 16 and HPV 18) are responsible for approximately 70% of cervical cancer cases. Moreover, co-infections can complicate treatment and disease management, highlighting the need for comprehensive testing and prevention strategies.

 

The Importance of Comprehensive STI Testing and Prevention

With more than 1 million sexually transmitted infections acquired every day worldwide, the majority of which are asymptomatic, testing is vital to reduce the transmission. Beyond the successful models of HIV and syphilis testing in pregnant women, there’s a pressing need to enhance screening and prevention for other STIs. Approaches include:

  • Expanded Testing: Point-of-care (POC) tests and integrated screening programs to include a broader range of STIs, making it easier to identify and treat diseases early. Increased screening for chlamydia and gonorrhoea has been shown to reduce incidence rates, particularly in high-risk populations.
  • Vaccination: Promoting vaccines, especially against HPV, can significantly reduce the incidence of cervical cancer and other HPV-related diseases. The WHO recommends HPV vaccination for girls aged 9-14 to prevent cervical cancer, with studies showing vaccine efficacy of nearly 100% for certain HPV types.
  • Education and Awareness: Increasing awareness about the importance of safe sex practices and regular testing can help reduce the transmission of STIs.
  • Integrated Health Services: Combining STI screening with other health services can improve access to testing and treatment, especially in LMICs where healthcare resources are limited.

 

Conclusion: A Call for Global Action Against STIs

The data underscores the critical need for a global response to the STI epidemic that encompasses not only HIV and syphilis but also other prevalent infections like chlamydia, gonorrhoea, and HPV. By investing in comprehensive strategies that include education, vaccination, and accessible testing, the global community can make significant strides in reducing the burden of STIs and safeguarding public health.

 

STI Biospecimens from Logical Biological

Logical Biological can provide a wide variety of serum, plasma and swabs for the research and development of STI tests and manufacture of control material. All specimens can be provided according to your custom specifications and are supplied with patient demographic information. A variety of testing methods can be utilised to confirm positivity for the disease marker requested and provide titre values.

Popular products available include:

Marker Matrix
HIV Plasma, Serum
HIV O (Human Immunodeficiency Virus Subtype O) Plasma, Serum
Syphilis Plasma, Serum, Swab, PBMC, Urine
Syphilis IgM Plasma, Serum
Gonorrhoea IgM Plasma
Neisseria gonorrhoeae Swab, Urine, Plasma
Chlamydia trachomatis Swabs, Urine
Chlamydia trachomatis IgA/ IgG/ IgM Plasma, Serum
Trichomonas vaginalis Swab, Urine
Trichomonas vaginalis IgM Plasma
HPV (Human Papillomavirus) Swab
HPV (Human Papillomavirus) IgG Plasma

A full range of infectious disease products available can be found in our product table

Sexually transmitted infection (STI) cases across the world are an ever present and ever-increasing issue, not only to adults but to a foetus. Two diseases of particular importance are HIV and Syphilis (caused by the bacterium Treponema pallidum).

How big a threat are STIs in today’s world?

The most recent figures show that in the US, Syphilis cases have tripled between 2013 and 2018 , which includes 5,726 pregnant women. Between 2008 and 2018 Europe also saw a 50% increase in Syphilis and Canada’s cases have more than doubled. In these high-income countries men are disproportionately  affected, however, in low to middle income countries (LMIC), syphilis is endemic to the general population and makes up over 90% of worldwide case numbers. This also means high numbers of infections in pregnant women, leading to increased cases of congenital Syphilis.

Syphilis is classed as an ulcerative STI, which means it causes genital ulcers. These ulcers facilitate the acquisition of HIV during intercourse, increasing the chance of transmission five-fold. Coinfections of Syphilis and HIV can increase the HIV viral load and HIV can accelerate the natural history of Syphilis. This means that individuals suffering from a coinfection will more frequently develop neurosyphilis than those with syphilis alone. In LMIC countries such as Tanzania, Uganda, and Ethiopia, the number of HIV positive patients with Syphilis are nearly 10%, and in Ghana, it is as high as 14.8%.

Source: UNAIDS WHO

What does Syphilis mean for pregnant women?

Globally, Congenital syphilis is the second leading cause of preventable stillbirths and there are a plethora of other complications that can arise from untreated congenital Syphilis, such as severe anaemia, jaundice, and ultimately blindness and deafness. In 2016, the World Health Organisation (WHO) estimated that there were 661,000 infants born with congenital Syphilis, and that approximately 40% of babies born to untreated Syphilis, or an estimated 143,000 infants, will suffer early deaths or stillbirths. This is not to say that this is inevitable, and in fact syphilis can be effectively treated with penicillin if caught early enough. This is why testing pregnant women for these infections is so important.

The World Health Organisation (WHO) ‘Prevention of Mother-to-Child Transmission of HIV/AIDS Program’ (PMTCT) aims to eliminate mother-to-child transmission of HIV and syphilis by providing technical support to member states on the uptake of antenatal services like HIV and Syphilis testing, as well as collecting and analysing regional trends.

In higher income countries, high sensitivity and high specificity tests for HIV and Syphilis are performed in labs and protocols are defined for screening of these diseases. In LMIC’s, there are often limited centralised health services or appropriate lab availability for these kinds of tests and so a point of care (POC) approach is taken, which allows for the collecting of a sample, and testing to be conducted in a single visit. POC tests for HIV have proved successful in LMIC countries, with 70-100% of pregnant women being screened. However, there is a clear deficit for pregnant women being screened for Syphilis, falling short at 40-60%. The high prevalence of syphilis in HIV infected patients indicates that there is a need to increase syphilis testing efforts.

What can be done to bridge the gap between HIV and Syphilis testing rates?

There are several combined HIV/ Syphilis POC rapid diagnostic tests (RTD) which aim to increase the rate of syphilis testing by leveraging existing HIV testing programs. To be successful the combined tests must be affordable, easy to use, and appropriate for a POC scenario. The widespread distribution of these combined tests is cheaper and more efficient than two individual tests and can allow for the early detection and treatment of HIV and Syphilis, saving both pregnant women and their unborn children.

Source: World Health Organization

Tests designed with decentralised testing and POC scenarios in mind can be visually interpreted and are easily used. Storage and distribution are big concerns and so these HIV/ syphilis POC tests are compact, have a 2-year shelf life, and can be stored across a broad temperature range. It is important to understand that these tests are only for initial screening, and if positives come back more specific alternative diagnosis methods should be used.

The importance of dual HIV/ Syphilis POC tests in LMIC’s cannot be understated. These tests are projected to allow for an additional 4.4 million women to be tested, with at least 285,000 Syphilis infections in women to be identified. Ultimately this could lead to 38,000 fewer cases of congenital syphilis, and 51,500 child mortalities being avoided.

HIV/ Syphilis Serum and Plasma from Logical Biological

Logical Biological provide a large portfolio of HIV and syphilis serum and plasma products. Testing can be performed on syphilis serum and syphilis plasma using a wide selection of methodologies including TPHA, ELISA and EIA. Available testing for HIV serum and HIV plasma includes LIA, EIA, PCR (copies/ml), Nucleic Acid Amplification, Western Blot, Ratio CD4/CD8 profiling and Chemiluminescent Immunoassay (ChLIA) (S/CO units).

All serum and plasma specimens can be provided according to your custom specifications and are supplied with demographic information available.

Table: HIV and Syphilis serum and plasma available from Logical Biological