Diagnosis of Sexually Transmitted Infection

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As soon as an individual is diagnosed with a HIV, syphilis, gonorrhoea, lymphogranuloma venereum or Chlamydia infection they must visit a doctor (particularly a unit specialising in STIs) so they may assess the need for action. If less than 72 hours have passed and a HIV infection is suspected, individuals must visit an emergency department to assess the need to administer a prophylaxis (a medication that reduces the risk of transmission) against various STIs (HIV and others). 

If human papillomavirus or herpes virus infection is suspected, then patients should discuss it with their family doctor. It is important to be aware that while there are no signs or symptoms of infection, then no further tests or treatment are recommended.

In the case of pregnant women who have had sexual contact with someone infected with genital herpes, they must inform the midwife or gynaecologist managing the pregnancy as they may need to receive a prophylactic treatment before childbirth to prevent infecting the newborn baby. 

In any event, whenever there is any doubt about the presence of an infection, patients should discuss it with their primary care doctor. Less serious complaints, such as genital warts or condylomas, repeat episodes of genital herpes, trichomonas, crabs or scabies, can be treated by staff at gynaecological or dermatological units.

At weekends or during holiday periods, individuals who suspect they have contracted an STI will be treated by the emergency department.

Tests used to diagnose the presence of an Sexually Transmitted Infection

Most tests used to detect sexually transmitted infections (STIs) are quick, straightforward and painless. What is more, some infections can be diagnosed through a simple physical examination without having to perform any tests, for example genital herpes, genital warts, crabs or scabies.

Diagnostic tests are indicated after considering the medical suspicion, symptoms, sexual behaviour described by the patient and physical examination.

Blood collection tube

Collection of a blood sample. This helps diagnose certain STIs such as syphilis, hepatitis or HIV infection.

Urine sample cup with bar code

Urethral, vaginal, oral or rectal discharge. Chlamydia, gonorrhea, trichomonas and lymphogranuloma venereum infections are diagnosed by collecting a sample of either the urethral, vaginal, oral or rectal discharge, or the discharge from an ulcer. A urine sample can sometimes be used to diagnose these infections.

Substantiated information by:

Irene Fuertes De Vega
José Luis Blanco Arévalo
Mercè Alsina Gibert
Núria Borrell Iragari

Published: 20 February 2018
Updated: 20 February 2018

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