HIV is an RNA retrovirus, i.e., during replication the viral RNA is first copied into DNA, which is then transcribed into a mRNA.8 It is a bloodborne pathogen acquired most readily either across mucous membranes or parenterally. In healthcare settings the risk for transmission following a percutaneous (needlestick injury) or mucous membrane (eyes, nose, and mouth) exposure to blood infected with the HIV is approximately 0.3% and 0.09%, respectively.
Following an incubation period of 1 to 3 weeks, primary infection in 50% to 80% of patients is characterized by a flu-like illness, i.e., fever, lethargy, malaise, sore throat, arthralgia, myalgia, headaches, photophobia, maculopapular rash, and lymphadenopathy. This is followed by a period of clinical latency (8 to 24 months after exposure), during which the patient is free of overt signs and symptoms of infection (anti-HIV antibodies are detectable at 3 to 6 months).
In the final phase clinically apparent disease is characterized by opportunistic illnesses, including many HIV-associated oral lesions (e.g., erythematous and pseudomembranous candidiasis, hairy leukoplakia, Kaposi’s sarcoma, non-Hodgkin’s lymphoma, linear gingival erythema, and necrotizing ulcerative periodontitis), which are useful markers of HIV disease. Oral candidiasis and hairy leukoplakia are positive predictors of HIV disease progression.
There are no vaccines available for the prevention of HIV infection. Post-exposure prophylaxis (PEP) should be initiated as soon as possible, preferably within 72 hours after a possible exposure to the HIV. This recommendation is based on evidence that following primary exposure systemic infection does not occur immediately, leaving a brief window of opportunity during which PEP might limit the proliferation of HIV in initial target cells or lymph nodes.
A basic 4 week PEP regimen containing 3 (or more) antiretroviral drugs is now routinely prescribed following all occupational exposures. The recommended PEP regimen includes two nucleoside reverse transcriptase inhibitors (NRTIs) plus an integrase strand transfer inhibitor (INSTI), or a non-nucleoside reverse transcriptase inhibitor (NNRTI), or a protease inhibitor (PI) with a pharmacokinetic booster such as cobicistat or ritonavir.
To reduce the risk of disease progression and to prevent the transmission of the virus to others, antiretroviral therapy (ART) is recommended for all patients with HIV infection. The Food and Drug Administration (FDA) has approved more than 25 antiretroviral drugs in 6 mechanistic classes. Recommended regimens are those with durable virologic efficacy, favorable tolerability and toxicity profiles, and ease of use (including some newer combinations).