Bacterial sexually transmitted infections (STIs) have been on the rise since the early 2000s, particularly infections caused by Chlamydia trachomatis and Neisseria gonorrhoeae. In 2016, 270,000 Chlamydia trachomatis infections and 50,000 gonococcal infections were diagnosed in France, a threefold increase compared to 2012. Human papillomavirus (HPV) infections are among the most common STIs and are responsible for genital warts in approximately 100,000 men and women each year in France.

STIs represent a major public health challenge due to their prevalence, the risks of complications such as upper genital tract infection or ectopic pregnancy, long-term consequences such as infertility, and an increased risk of HIV transmission.

In this context, Santé publique France launched the PrévIST study in 2022, in collaboration with Inserm, the National Reference Center (CNR) for Bacterial STIs, and the CNR for Papillomaviruses. To this end, participants aged 18 to 59 who had already had sexual intercourse and were part of the “Context and Sexuality” survey—promoted and funded by ANRS | MIE—were invited to perform a self-collection screening test at home. This screening targeted infections with Chlamydia trachomatis, Neisseria gonorrhoeae (gonococcus), and Mycoplasma genitalium for individuals aged 18 to 59, with the addition of human papillomavirus (HPV) screening for those aged 18 to 29. The objective of this component was to estimate the prevalence of the most common STIs, while evaluating the HPV vaccination strategy among younger individuals.

Which infections were tested for?

The PrévIST study tested people aged 18–59 for several bacterial STIs: infections caused by Chlamydia trachomatis, Neisseria gonorrhoeae (gonococcus), and Mycoplasma genitalium.

These infections are transmitted through sexual contact, are often asymptomatic, but can have health consequences. It is important to get tested because generally simple and effective treatments are available.

Among those under 30, testing was conducted for human papillomavirus (HPV). This virus is common and can affect both women and men. Genital infection is usually mild and temporary, as the virus is most often cleared spontaneously by the body. However, in some cases, the virus can persist and lead to the development of condylomas (genital warts). Furthermore, certain human papillomaviruses can cause precancerous lesions that may progress over several years to genital or anal cancer. Due to the high prevalence of transient HPV infections before age 30, HPV testing is not recommended for screening these infections.

Study Objectives

• To estimate the proportion of people aged 18 to 59 who are infected with Chlamydia trachomatis (Ct), Neisseria gonorrhoeae (Ng), or Mycoplasma genitalium (Mg), and the proportion of people aged 18 to 29 who are infected with human papillomavirus (HPV).

• To investigate the risk factors associated with these infections.

• To measure the effectiveness of HPV vaccination in women (recommended for adolescents since 2007) and to obtain baseline prevalence data immediately following the introduction of vaccination for boys (recommended since 2021).

The PrévIST study aims to contribute to policies for combating STIs.

Study Procedure

All individuals who completed the entire “Context and Sexuality” survey were invited to participate in the PrévIST study if they met two conditions:

• Be between the ages of 18 and 59

• Having had sexual intercourse at least once in their lifetime

In practice, how was the study conducted?

Study Results

The prevalence of Chlamydia trachomatis infections was estimated at 0.93% and 0.58% among women and men aged 18–59 who had previously had sexual intercourse. These prevalence rates are comparable to the 2006 estimates for women, but show a slight (non-significant) decrease for men. Given the proposed policy of routine screening for those under 26, a low prevalence is observed among the youngest age group (18–25 years old) (1.5% for women and 1.6% for men), while prevalence increases substantially in the 26–29 age group, which is not covered by screening (7.9% for women and 4.4% for men). Furthermore, individuals who have had more than one partner in the past 12 months are at higher risk than those reporting only one partner (1.5% for women and 2.9% for men aged 18–59).

Only a single Neisseria gonorrhoeae infection was detected, while the prevalence of Mycoplasma genitalium infections was estimated at 3.1% and 1.3% among women and men aged 18–59, respectively—prevalences comparable to those observed in other European countries.

These results provide, for the first time, data on the prevalence of Mycoplasma genitalium infections in France. Against the current backdrop of rising Chlamydia trachomatis and Neisseria gonorrhoeae infections at the European level and in France, they suggest that these increases affect only highly exposed populations and not the general population.

These are preliminary results for the time being, covering only mainland France and the three bacterial STIs. They will be supplemented by a more detailed analysis of risk factors and screening uptake, as well as by data on HPV prevalence and prevalence in the overseas territories (Martinique, Guadeloupe, French Guiana, and Réunion).

• Learn more about the study results | ANRS-MIE press kit

Data Privacy

Participants’ contact information (last name, first name, and mailing address) was requested to facilitate the mailing of self-collection kits and the return of results. This data remains in the laboratory’s possession in accordance with its legal obligations and cannot be disclosed to anyone else.

The screening results were processed electronically in a completely anonymous manner by Santé publique France and Inserm, which will never have access to personally identifiable data.

The “Context and Sexuality” survey and the PrévIST study received approval from the National Commission on Informatics and Liberty (CNIL) on September 23, 2022.