Human immunodeficiency virus (HIV), a retrovirus, infects CD4 lymphocytes and destroys them resulting in immunocompromised leading to opportunistic infections and tumours. 

Blood borne virus, transmitted through sexual exposure, intravenous drug use, vertical transmission through vaginal delivery, unscreened blood transfusions.

Seroconversion illness (2-10 weeks post-exposure): fever, headache, rash, sore throat, lymphadenopathy. First presenting symptoms often due to opportunistic infections.

Bloods: HIV test, CD4 count, viral load, screen for other blood borne viruses.

Follow up: Contact tracing .

Combined highly active antiretroviral therapy (HAART) 

x2 Nucleoside Reverse Transcriptase Inhibitors (NRTIs) 

Plus either non-nucleoside reverse transcriptase inhibitors (NNRTI) or boosted protease inhibitor (PI)

Post-exposure prophylaxis: Reduces transmission of HIV 

Without antiretroviral therapy progression to AIDS and death occurs within 7-10 years

With antiretroviral therapy, life expectancy is similar to that of a non-HIV infected person. Antiretroviral therapy also reduces the risk of transmission.