STIs are caused by infectious agents. These can be viruses, bacteria, or parasites. In this sense, we can classify them into 3 main categories.
Bacterial Sexually Transmitted Infections
In France, the number of syphilis diagnoses in CeGIDD (free STI information, screening, and diagnosis center) has been relatively stable since 2016. In 2021, 3300 cases of syphilis were diagnosed. Syphilis affects the vast majority of men who have sex with men: 78% of cases diagnosed in 2021 in CeGIDD. If left untreated early, this disease becomes chronic and the risk of transmission increases.
· Gonorrhoea (or gonococcus)
Gonorrhoea, also known as the clap, mostly affects people under the age of 30, especially men. An upsurge in gonorrhoea cases has been observed in recent years in France (between 15,000 and 20,000 new cases each year, more than half of which are in men under 30 years of age). If left undiagnosed and untreated, this infection can lead to infertility.
Chlamydia infections are very common in young people between the ages of 15 and 25 and affect both men and women. They are one of the leading causes of infertility in women. In France, it is estimated that nearly 4% of girls under the age of 25 are infected with chlamydia, and this figure is estimated to be between 10% and 15% in the Paris region.
Sexually transmitted parasitic infections
Trichonomasis is the most common sexually transmitted infection and young adults are particularly at risk. In 2020, the WHO estimated that 156 million people worldwide had contracted it. Trichonomasis accounts for 40% of STIs contracted worldwide every day.
Other Viral Diseases
· Hepatitis B
Hepatitis B is a liver disease caused by a virus that is mainly transmitted through sex or contact with infected blood. This infection is mild in most cases. But in about 10% of infected people, hepatitis B becomes a chronic infection that can cause serious disorders, such as cirrhosis or liver cancer. In France, it is estimated that 280,000 to 300,000 French people have chronic hepatitis B, but nearly half of them are unaware of it.
· Genital herpes
Genital herpes is a highly contagious and sexually transmitted viral disease. After the primary infection, the virus settles in the body and "falls asleep". It then manifests itself, during flare-ups, by small blisters that develop into sores, located on or near the sexual organs. Globally, it is the fourth most commonly transmitted infection. In France, the most recent studies show that genital herpes affects about 17% of the population. The latter also show that women are more affected than men.
The human immunodeficiency virus (HIV) is an infection that attacks the body's immune system: HIV destroys these cells, weakening the effectiveness of the infected person's immune system against infections such as tuberculosis and certain cancers. In France, the number of HIV positive discoveries in 2021 was estimated at 5013, a stable number compared to 2020. AIDS (acquired immunodeficiency syndrome) is the most advanced stage of HIV infection.
· Human papillomavirus (HPV)
Human papillomaviruses are highly contagious: 70% to 80% of men and women will encounter at least one papillomavirus in their lifetime. In 90% of cases, the virus is eliminated by our immune system within 2 years of infection, while in the remaining 10% of cases, the infection persists and can have serious consequences, such as a possible progression to a precancerous lesion and, within 10 to 30 years, to cancer. Genital warts (or condylomas) are benign lesions that are highly contagious and annoying and can appear as a result of a papillomavirus infection. 100,000 new cases per year of genital warts are counted in France in men and women. In France, nearly 3,000 new cases of cervical cancer are diagnosed each year, and about 1,000 women die from it. A total of 6,400 cancers are linked to HPV viruses each year, one in four of which are in men.