This page compiles our content related to HIV. For further information on diagnosis and treatment, follow the links below to our full BMJ Best Practice topics on the relevant conditions and symptoms.
Introduction
Relevant conditions
HIV in adults | go to our full topic on HIV in adults HIV infection is caused by a retrovirus that infects and replicates in human lymphocytes and macrophages, eroding the integrity of the human immune system over a number of years, culminating in immune deficiency and a susceptibility to a series of opportunistic and other infections as well as the development of certain malignancies. Globally, the HIV incidence rate is believed to have peaked in the 1990s and to have stabilized subsequently, notwithstanding increasing incidence in a number of countries. Most adults are infected through sexual contact or injection drug use. Diagnosis is established using an HIV antibody/antigen immunoassay. |
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HIV infection in pregnancy | go to our full topic on HIV infection in pregnancy Pregnancy in women living with HIV is complicated not only by HIV infection itself but also by the medical and psychosocial comorbidities associated with HIV. HIV infection in pregnancy poses a threat to maternal immune health and can lead to perinatal transmission of HIV in utero, intrapartum, or through breastfeeding postnatally. All pregnant women should be tested for HIV as early as possible in pregnancy. Repeat testing is recommended in the third trimester for pregnant women with initial negative tests who have high potential HIV exposure, live in an area with a high HIV prevalence, or receive care at a facility with a high HIV incidence. Patients who present 2-4 weeks post-exposure may have symptoms and signs of acute retroviral syndrome, characterized by fever, malaise, lymphadenopathy, and rash (typically a maculopapular blanching rash). Signs suggestive of advanced HIV include oral candidiasis, increasing dyspnea, and weight loss. HIV-exposed infants should be tested for HIV at birth and seek specialty care for follow-up testing and treatment. |
Post-exposure HIV prophylaxis | go to our full topic on Post-exposure HIV prophylaxis Exposure to HIV is considered a medical emergency. Post-exposure prophylaxis (PEP) is the administration of antiretroviral therapy to HIV-negative people who may have been occupationally or sexually exposed to HIV. Once exposed to HIV, there may be a brief period before the infection is established, during which antiretroviral therapy may successfully prevent viral replication.[3][4] PEP for HIV must be initiated as soon as possible, ideally within 24 hours, and preferably within 72 hours of exposure.[5] PEP reduces the likelihood of HIV seroconversion by approximately 80%.[6] |
HIV-related opportunistic infections | go to our full topic on HIV-related opportunistic infections Infections that can occur as a result of impaired cell-mediated immunity in advanced stages of HIV infection. These illnesses tend to occur most often in patients who have untreated HIV infection or who fail to respond to antiretroviral therapy. Tuberculosis, Pneumocystis jirovecii pneumonia, candidiasis, cryptococcosis, toxoplasmosis, cytomegalovirus, Mycobacterium avium complex, coccidioidomycosis, and histoplasmosis infections are among the HIV-related opportunistic infections often encountered in clinical practice. The risk of opportunistic infections increases as CD4 count declines. Risk also increases in people who are not virologically suppressed, regardless of the CD4 count. |
Pneumocystis jirovecii pneumonia | go to our full topic on Pneumocystis jirovecii pneumonia An infection of the lung caused by the fungal organism Pneumocystis jirovecii(formerly known as Pneumocystis carinii). Historically one of the most common AIDS-defining illnesses in children, adolescents, and adults in high-income countries.[7] The incidence of Pneumocystis pneumonia (PCP) is declining with the use of combination antiretroviral therapy and PCP prophylaxis. Typically, it causes clinical disease in severely immunocompromised patients, such as HIV-positive patients with CD4 cell counts <200 cells/microliter. In HIV-positive PCP, presentation is often an insidious progression of fatigue, fevers, chills, sweats, nonproductive cough, and dyspnea over several weeks. |
Pulmonary tuberculosis | go to our full topic on Pulmonary tuberculosis An infectious disease caused by Mycobacterium tuberculosis; it is a common opportunistic infection in people newly diagnosed with AIDS. Tuberculosis (TB) most often involves the lungs and is communicable in this form, but may affect almost any organ system including the lymph nodes, central nervous system (CNS), liver, bones, genitourinary tract, and gastrointestinal tract. TB is particularly devastating in areas with high prevalence of HIV infection, and worldwide, it is the leading cause of morbidity and mortality among people with HIV.[8] Symptoms may include cough, fever, and weight loss. If pulmonary TB is suspected, the patient should be isolated, a chest x-ray obtained, and three sputum samples collected for acid-fast bacilli smear and culture; nucleic acid amplification test should be performed on at least one respiratory specimen. |
Mycobacterium avium complex | go to our full topic on Mycobacterium avium complex Mycobacterium avium complex (MAC), also known as Mycobacterium avium-intracellulare, consists of 2 mycobacterium species, M avium and M intracellulare. MAC is commonly found in the environment, including in soil, water, and dust. In humans, MAC traditionally causes 3 disease syndromes: pulmonary disease, cervical lymphadenitis, and disseminated disease. A fourth syndrome, a hypersensitivity pneumonitis associated with hot tub use, has also been described.[9] People living with HIV with a CD4 count <50 cells/microliter are at increased risk of infection.[10] MAC has variable presenting features including chronic cough, weight loss, and fevers. |
Toxoplasmosis | go to our full topic on Toxoplasmosis Caused by the protozoan parasite Toxoplasma gondii. Infection spreads through food or water contaminated with oocysts, infected meat, or contact with oocysts from feline feces.[11] Toxoplasmosis may be the initial opportunistic infection in a person living with HIV who is unaware of their HIV infection. Toxoplasmosis occurs worldwide, with a higher prevalence in tropical areas and low- and middle-income countries.[12] Infection in humans is lifelong and usually asymptomatic. HIV-infected patients with severe immunosuppression should be tested for prior exposure. Symptomatic disease can be seen in patients who are immunocompromised with reactivation of latent infection or with acquisition of new infection. If a patient who is immunosuppressed presents with fever or malaise and hepatitis, pneumonitis or myocarditis, or with chorioretinitis, toxoplasmosis should be included in the differential diagnosis. CNS lesions are usually multiple and are more commonly seen in HIV-infected patients. |
Cryptococcosis | go to our full topic on Cryptococcosis An opportunistic fungal infection caused by Cryptococcus species. Patients with HIV and CD4 count of <100 cells/microliter are at highest risk of infection. HIV infection is associated with >80% of cryptococcosis cases worldwide. Cutaneous infections can manifest as a molluscum contagiosum-like lesion (especially in people with HIV), granulomas, plaques, and cellulitis. HIV-associated cryptococcosis is characterized by more CNS and extrapulmonary involvement and presents with a higher burden of organisms.[13] It is also associated with a poor inflammatory reaction at the site of infection.[13] |
Cytomegalovirus infection | go to our full topic on Cytomegalovirus infection Cytomegalovirus (CMV) is a ubiquitous beta-herpes virus that infects the majority of humans. Primary infection in individuals with normal immune function is usually asymptomatic. After primary infection, CMV establishes a state of lifelong latency in various host cells, with periodic subclinical reactivations that are controlled by a functioning immune system. When reactivation (or primary infection) occurs in patients with severely compromised immune function (e.g., or patients with a CD4 count <50 cells/microliter), uncontrolled CMV replication often ensues, which leads to the clinical manifestations characterized by fever, bone marrow suppression, and tissue-invasive disease conditions (e.g., retinitis, pneumonitis, hepatitis, colitis, nephritis).[14] Routine screening for CMV immunoglobulin G is not generally useful because CMV seroprevalence is extremely high; however, testing is recommended prior to blood transfusion for people with HIV at low risk of CMV exposure, and for all infants exposed to HIV in utero.[15][16] |
Oral candidiasis | go to our full topic on Oral candidiasis A local infection of oral tissues by yeasts of the genus Candida, mostly Candida albicans. Seen most frequently in association with local and systemic immunologic suppression. Candida carriage rate has been shown to increase with HIV infection.[17][18] The risk of oropharyngeal or esophageal candidiasis is significantly higher when the CD4 count is below 200 cells/microliter.[19] Linear gingival erythema is a specific HIV-related periodontal manifestation. Candidiasis is clinically diagnosed, usually based on characteristic symptoms and appearance of lesions. Pseudomembranous oral candidiasis, commonly known as "thrush", is characterized by creamy white, curd-like patches on the tongue and oral mucous membranes that can be removable by scraping. Thrush may be asymptomatic or can cause a cottony sensation in the mouth and potentially altered taste and difficulty swallowing. Candida esophagitis can present with painful swallowing and a sensation of obstruction. Mucosal candidiasis involving the vaginal and rectal regions causes edema, pruritis, and thick, curd-like discharge. |
Kaposi sarcoma | go to our full topic on Kaposi sarcoma A low-grade lymphovascular neoplasm that is associated with human herpesvirus-8 infection. There are four main subtypes of Kaposi sarcoma (KS): classic (sporadic); endemic (observed in sub-Saharan Africa); HIV-associated (formerly known as epidemic or AIDS-related); iatrogenic (transplant-related). HIV-associated KS is one of the most common cancers arising in people living with HIV. It usually arises in people with low CD4+ T-cell counts and high HIV viral load. HIV coinfection is thought to be synergistic, resulting in a more aggressive and widespread KS disease. Lesions frequently involve mucocutaneous sites, but may become more extensive to involve the lymph nodes and visceral organs. Skin lesions evolve from an early patch, to a plaque, and later to ulcerating tumor nodules. |
Evaluation of dermatologic disorders in HIV | go to our full topic on Evaluation of dermatologic disorders in HIV In the early phases of the HIV epidemic, skin disease was frequently a presenting manifestation of the infection.[20] Cutaneous manifestations often reflect immune status and may offer insight into the long-term prognosis. Dermatologic disorders in HIV may be categorized as infectious, inflammatory, neoplastic, drug reaction, and metabolic. Some skin diseases are fairly specific to HIV (e.g., HIV-related lipodystrophy, eosinophilic folliculitis, oral hairy leukoplakia, papular pruritic eruption of HIV, HIV photodermatitis, prurigo nodularis, Kaposi sarcoma). Other skin diseases may appear in non-HIV-infected populations but have altered presentations in those with HIV. Although morbidity from skin diseases, particularly from opportunistic infections, has decreased with the advent of antiretroviral treatment, significant dermatologic problems may still occur. |
Evaluation of HIV-related mental status changes | go to our full topic on Evaluation of HIV-related mental status changes HIV-related mental status changes and associated cognitive disorders have profound consequences for people living with HIV, and their caregivers. Causes of altered mental status among people living with HIV include both acutely presenting conditions (which often represent HIV-related opportunistic infection or associated systemic illness) and more progressive neurocognitive disease or psychological comorbidities. Neuropsychological deficit may arise as a direct effect of HIV infection (e.g., as part of a spectrum of HIV-associated neurocognitive disorders) or as a psychiatric comorbidity (e.g., depression or alcohol/substance misuse). Psychiatric comorbidities are highly prevalent among people living with HIV. |
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Disclosures
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References
Reference articles
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