Find out about the diseases and illnesses we specialise in

Aids File (HIV)

SIda VIH Hospital Vall d Hebron



Human immunodeficiency virus (HIV) is a retrovirus, made up of two copies of single-chain RNA enclosed within a capsid. It is transmitted by blood and genital secretions (unprotected sex) and from mother to foetus during pregnancy or birth or through breast-feeding (where the mother does not have her infection controlled). HIV is NOT transmitted through other channels, such as objects, insects or physical contact without sharing blood or secretions.

HIV can be prevented by using condoms during sex and by not sharing any materials that may contain infected blood.



HIV infects a particular type of the body’s defences, CD4+ lymphocytes. It reduces the number of its host's lymphocytes, thereby increasing the latter’s risk of suffering certain infections from micro-organisms (bacteria, viruses, fungi and parasites) that normally do not cause problems when the immune system is working correctly; these are known as opportunistic infections. In addition, the virus infects the body’s other cells and remains in a latent state in areas such as lymphatic ganglia and intestinal mucus. This latent virus is known as a viral reservoir and is one of the main obstacles to curing this infection.

Acquired immunodeficiency syndrome (AIDS) is diagnosed where the number of CD4+ lymphocytes drop below 200/μl or one of the syndrome's defining diseases (infections or neoplasia) appears. It is for this reason, and for the sake of preventing new infections, that early diagnosis of the infection is very important. Anyone who has been in a risk situation should be tested for HIV (and other STDs), irrespective of the presence or absence of symptoms. Having any other STD raises the risk of acquiring and transmitting HIV.



Acute infection with HIV can manifest itself non-specifically, like any other viral infection such as the flu (fever, general malaise, skin rash, swollen lymph glands, pain in the joints or in swallowing, fatigue etc.,) or may be completely asymptomatic.

Once the infection has become chronic, a variable period of time passes during which patients may be completely without symptoms but can transmit their infection. As the (CD4+) defences drop, clinical symptoms may appear with the associated pathologies, whether infections or neoplasias, which can affect several organs/systems.


Who is affected by the disease?

Anyone who is sexually active runs the risk of being infected by HIV if they do not know the state of health of the person they are having sexual relations with and do not take the following precautions: use of condoms or pre-exposure prophylaxis (PrEP: taking a combination of two anti-retroviral medicines without being infected with HIV, to prevent such infection in the event of coming into contact with the virus). Fortunately, the risk of transmission through other channels, such as blood or mother to foetus, has dropped significantly in our environment, thanks to harm-reduction and HIV-screening programmes for pregnant women and blood and organ donors, among other measures.



HIV is diagnosed in the laboratory by detecting antibodies the patient creates against the virus (but which are not used for neutralising the virus and curing the infection and which remain positive for life as a marker of the infection) and the direct detection of parts of HIV, whether the virus’ antigens or by determining the number if HIV particles that are circulating through the bloody (viral load). Note that there is a period of time between the virus’ entry into the body and the detection of these antigens/antibodies during which all tests are negative, known as the window period. Today’s new techniques have reduced this period to 2-3 weeks after infection.



The recommendation these days is for all patients infected with HIV to start anti-retroviral treatment irrespective of the number of CD4+ lymphocytes or viral load. The only exception would be elite controllers, that is, people whose viral load remains undetectable without treatment. For all other infected individuals, treatment is started with patients as soon as they are ready to receive it and have the necessary information for choosing the best option possible in each case. An effective treatment makes the viral load undetectable, although it does not eliminate HIV from the body. The immune system can therefore remain intact/recover, reducing the possibility of new infections. In fact, when the virus is undetectable in the blood thanks to this anti-retroviral treatment, the infection is not transmitted to other people (undetectable=untransmittable).[AJ1] 

There are various families of medicines that act at several points in the HIV life cycle, halting its replication within the body. So we now have analogue and non-analogue nucleoside reverse transcriptase inhibitors[AJ2] , integrase inhibitors, protease inhibitors and entry inhibitors.

Anti-retroviral treatment is currently administered in pills, although injectable medicines are expected to appear in the coming years. Standard treatment involves a combination of 3 different medicines, which can often be combined in two pills or a single tablet. Even so, it may be sufficient for patients in some circumstances to receive treatment with two or even just one drug in order to control the virus. Today's anti-retroviral treatment is for life, given that, if patients stop their treatment, their latent HIV reservoir will re-activate and replicate. Depending on the drugs patients are taking, the possibility of interactions with any other medications they may receive needs to be monitored and a follow-up analysis or specific explorations may be necessary for certain drugs.



Today, HIV infection has become a chronic illness and, with the current treatment, people diagnosed with it now have a life expectancy similar to that of the general population. If someone infected with HIV performs their controls correctly and takes their anti-retroviral medication they can lead a completely normal life, and that includes having children without transmitting their infection to them. Routine visits are made to monitor the infection, usually every 3 to 6 months, during which the number of defence cells (CD4+ lymphocytes) and viral load are measured.

That analysis also measures other parameters to monitor any other pathologies which patients may have (blood count, renal function, liver function, lipids). In addition, a series of specific complementary explorations may also be performed, such as early detection of STDs, screening certain neoplasias (cervix, anus), osseous pathology and so on. People living with HIV can also be given advice on certain preventive measures, such as taking vaccinations against influenza and invasive pneumococcal disease.

The inflammation that the virus’ replication in the body causes also increases the risk of suffering diseases we find in the general population, such as cardiovascular, liver, renal and neurological pathologies and certain cancers, which may appear more severely or at younger ages. That is why it is very important for people living with HIV to control conventional risk factors and adopt healthy life habits.



As an STD, HIV infection can be better treated through early detection and prevented through the use of barrier methods during sex, basically male or female condoms. As mentioned above, the last few years have seen studies on the use of PrEPs as a prevention strategy. This strategy has proven to be highly effective in preventing HIV infection, although it has the disadvantage, unlike using condoms, that it does not protect users from other kinds of STDs.

A person who has been exposed to HIV can also undergo post-exposure prophylaxis (PEP), which involves being administered 3 anti-retroviral drugs for 28 days, although this will have to start within the first 72 hours after exposure to the virus.


Related departments that treat this condition

Infectious Diseases, Pharmacy, Preventive Medicine, Gynaecology/Obstetrics, Internal Medicine, General Laboratory, Microbiology, Immunology, Neurology, Pneumology, Rheumatology, Hepatology, Oncology, Haematology.


Hospital o serveis complementaris relacionats

General Hospital

Where to find it

Cross-departmental services

Where to find it
Related professionals
Dr. Adrià
Curran Fàbregas
Dra. Magda
Campins Martí
Head of Department
Preventive Medicine and Epidemiology
Epidemiology and Public Health
Dr. Benito
Almirante Gragera
Head of Department
Infectious Diseases
Sra. Carmen
Ferrer Barbera
Nursing Supervisor
Infectious Diseases
Dr. Israel
Molina Romero
Dr. Adrián
Sánchez Montalvá
Dr. Pau
Bosch Nicolau
Dr. Fernando
Salvador Vélez
Dr. Vicenç
Falcó Ferrer
Infectious Diseases
Sra. Desideria
Martinez Rascon
Infectious Diseases
News and events