Spain recorded 44,511 chlamydia cases in 2025, while recent figures for several sexually transmitted infections have flattened after years of sharp growth. The CNE says rates remain high and the trend ahead is uncertain.
Spain recorded 44,511 chlamydia cases in 2025, the highest annual total among the sexually transmitted infections covered by a new report from the Centro Nacional de Epidemiología (CNE). Rates for the infection have risen without interruption since 2016, although expert Viky Hernando says the increase is less pronounced than in earlier periods.
The broader pattern has changed. After a marked rise in sexually transmitted infections from 2016, particularly from 2021, figures in the past two years have become more similar. The CNE describes this as a plateau of sorts, while warning that it is too early to know whether rates will stabilise. They remain elevated.
Gonorrhoea accounted for 37,467 reported cases in 2025. Its rates fell sharply until 2001, then increased through 2025. Syphilis cases reached 11,879, with the highest figures recorded in 2024. Catalonia and Madrid had the highest reported syphilis figures, as did the Canary Islands and the Balearic Islands; La Rioja and Aragón had the lowest, as did Castilla-La Mancha.
The report also records where syphilis lesions appeared: 82.2% of affected people had genital lesions, while 12.2% had lesions in the anus or rectum. Throat lesions accounted for 7.8%. These figures describe reported cases and locations, rather than the overall number of people who may have an infection.
Chlamydia was most common among people aged 25 to 34 and those aged 20 to 25, with higher incidence among men. The report found higher incidence among men for every STI it examined. Young adults had the highest rates overall, though the age profile varied by disease. People under 25 made up the largest share of reported chlamydia cases and the smallest share of lymphogranuloma venereum cases.
Lymphogranuloma venereum, caused by an infection with Chlamydia trachomatis, accounted for 1,824 cases; 98.6% were in men. The authors say surveillance for this infection should be introduced in every autonomous community. They also caution that regional comparisons can be affected by differences between local surveillance systems.
Hernando said information and prevention campaigns, alongside improved diagnosis, may have helped slow the rise in cases. The report cannot establish how much each factor contributed. Its findings concern population surveillance, rather than clinical treatment; a separate development at the Hospital Universitario de Bellvitge was its single-port kidney transplant.
STIs can be caused by several types of organisms. Viruses and bacteria are among them, as are protozoa and ectoparasites. They can spread through routes other than sexual contact, and more than 20 are currently described. The report was published by the CNE and its source is ISCIII.
