In Spain, STD diagnoses have been on the rise in recent years, and the data confirms this: in 2024, 41,918 cases of chlamydia, 37,257 cases of gonorrhoea, 11,930 cases of syphilis and nearly 2,000 cases of lymphogranuloma venereum were reported, according to the 2024 Epidemiological Surveillance Report. This sustained increase highlights the need for regular screening, consultation at the first sign of symptoms, and ongoing prevention.
That is why, at Ambar Lab, we provide our clients with all the necessary tools to perform STD testing and thus detect any infection early on, receive professional guidance, and take preventive measures to protect your sexual health.
We also understand the need to understand the current landscape of STDs in Spain: we tell you about the 5 most common sexually transmitted diseases in the country.
Chlamydia
It is caused by the bacterium Chlamydia trachomatis and is transmitted mainly through unprotected sexual intercourse, whether vaginal, anal or oral. It can affect the cervix, urethra, rectum and, less frequently, the throat. In male partners, the most common signs include burning during urination and urethral discharge; in female partners, abnormal discharge, bleeding between periods, or mild pelvic pain may occur. However, a large number of infections are asymptomatic, which facilitates transmission and delays diagnosis.
When left untreated, the infection can cause pelvic inflammatory disease in women and increase the risk of infertility or ectopic pregnancy. In men, it can cause epididymitis and persistent discomfort when urinating. Antibiotic treatment prescribed by a healthcare professional (usually doxycycline, according to current guidelines) resolves the infection in most cases. Prevention involves the correct use of condoms during all sexual practices, reducing the number of casual partners, and regular screening.
Gonorrhea
Caused by Neisseria gonorrhoeae, it spreads through unprotected sexual contact. It usually causes burning during urination and urethral discharge in men; in women, it may go unnoticed or present with increased vaginal discharge, bleeding after intercourse, or lower abdominal pain. It can also affect the rectum and pharynx, causing local discomfort or pain when swallowing in oral infections.
The biggest problem with gonorrhoea, apart from its complications if left untreated (pelvic inflammatory disease, infertility or spread to the joints), is the development of drug resistance. Today, the treatment of choice includes parenteral or combination antibiotics, always prescribed by a professional, with follow-up to confirm microbiological response. As with other STIs, physical barriers such as condoms, open communication with partners, and screening when there is risk exposure are key to stopping transmission.
Human papillomavirus (HPV)
HPV encompasses a large group of viruses that are widely distributed. Most sexually active people will come into contact with some type of HPV during their lifetime, often without symptoms. There are low-risk genotypes that can cause anogenital warts and high-risk genotypes linked to precancerous lesions and cervical cancer, as well as other anogenital and oropharyngeal cancers.
The HPV vaccine has proven highly effective in reducing warts and high-grade lesions. The recommendation covers pre-adolescents and adolescents, and may also be considered for young adults depending on sexual history and clinical criteria. Even with vaccination, barrier measures remain useful, and in women, smear tests and HPV tests are part of screening programmes, which are essential for detecting lesions before they progress. It is important to remember that the absence of visible lesions does not rule out infection, so follow-up according to age and screening protocols is crucial.
Genital herpes (HSV-1 and HSV-2)
Genital herpes is caused by herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2). It is transmitted through intimate skin-to-skin contact and through oral, vaginal, or anal sex. The first episode usually involves painful blisters that break and leave small ulcers, accompanied by itching, burning when urinating and, occasionally, fever and general malaise. After the first outbreak, the virus remains in the nerve ganglia and can reactivate with subsequent outbreaks, which are usually milder.
There is no definitive cure, but antiviral drugs shorten the duration of outbreaks, relieve symptoms and reduce the ability to transmit the virus, especially if started early. Outside of outbreaks, transmission is less likely, although not impossible. Therefore, it is advisable to avoid sexual contact during an outbreak and to use condoms consistently. Informing your partner and recognising the signs of reactivation helps to reduce the risk of spreading this STD.
Syphilis
It is caused by Treponema pallidum and progresses through several stages. The primary stage is characterized by a painless ulcer (chancre) at the site of bacterial entry, which resolves spontaneously within weeks. The secondary stage may manifest with a skin rash, low-grade fever, sore throat, and swollen lymph nodes. Without treatment, the infection enters a latent phase and, over time, can progress to late-stage forms that damage the heart, nervous system, and other organs. Transmission occurs through unprotected sexual contact, including oral sex, when active lesions are present. Diagnosis is based on serological tests and, in cases of early lesions, on direct examination techniques. Treatment with benzathine penicillin is highly effective, and the choice of penicillin depends on the stage of the infection. It is important to treat partners, report recent contacts, and perform serological follow-up to confirm the response.
What tests are available to detect an STD?
The choice of test depends on the microorganism, the site of exposure, and the time elapsed since the last risky practice. For chlamydia and gonorrhoea, the test of choice is usually nucleic acid amplification testing (NAAT), which detects the genetic material of the bacteria in urine samples or exudates from the cervix, urethra, rectum, or pharynx, depending on sexual practices.
For syphilis, diagnosis is based on serological tests: treponemal and non-treponemal tests. The former confirms contact with the microorganism; the latter helps to assess activity and response to treatment. In the presence of an ulcer, a direct test on the lesion may be considered. For herpes, diagnosis during an outbreak is made using PCR on the lesion; serology can provide information on previous exposure, although it does not accurately differentiate between active and past infection. HPV requires a specific approach: in women, cervical screening includes cytology and, depending on age and protocols, high-risk HPV testing. Anogenital warts are diagnosed clinically and, if there is any doubt, the specialist will consider a biopsy. In addition, in the case of unprotected practices with a risk of HIV or other STIs, a complete evaluation is recommended, which may include fourth-generation HIV and hepatitis testing, adjusted to the time since exposure.
How long does it take for an STD to appear after infection?
Each infection has a different incubation period and ‘diagnostic window’, i.e. the interval between exposure and the point at which the test can reliably detect the infection.
- Chlamydia: symptoms (when present) usually appear between one and three weeks after exposure. In clinical practice, many guidelines recommend testing 7–14 days after risky sexual contact.
- Gonorrhoea: symptoms usually appear within 2 to 7 days in men, while in women it may take longer or show no symptoms. NAATs and cultures detect infection early; if the initial result is negative and the risk was high, it is advisable to repeat the test after a short period of time.
- Genital herpes: it usually has an incubation period of 2 to 12 days. If you attend a consultation when the lesions have already healed, the accuracy of the test decreases and the professional may opt for other diagnostic or follow-up strategies.
- Syphilis: the average incubation period is around three weeks, although it can vary between 10 and 90 days. Serological tests may take a while to become positive after the initial chancre, so if the test is done too soon, it may need to be repeated after a few weeks.
HPV: the infection often causes no symptoms and can remain dormant for months or years. Therefore, in the case of HPV, the key is to comply with screening programmes and consider vaccination if indicated.
Prevention and sexual health at your fingertips
Knowing the most common STDs, their symptoms, incubation periods, and available tests helps protect your health and that of those around you. That is why at Ambar Lab we emphasise prevention: it is the best way to avoid infection, detect possible infections early, and ensure safe and responsible sexual well-being.
If you’re looking for a reliable clinical laboratory to perform these and many other screening tests, we have a team of professionals ready to advise you and conduct the analyses with the utmost rigor. Contact our team to learn about the different STI tests and take a step forward in protecting your sexual health.
