Human Immunodeficiency Virus 1
(HIV-1)

HIV-1 taxonomy

Retroviridae - Orthoretrovirinae - Lentivirus - Primate lentivirus group - Human immunodeficiency virus 1

Introduction

• Human Immunodeficiency Virus is a virus that causes Acquired Immunodeficiency Syndrome (AIDS). HIV is in retrovirus family, and two types have been identified: HIV-1 and HIV-2. HIV-1 is responsible for most HIV infections throughout the world, whereas HIV-2 is found primarily in West Africa.
• The vast majority of ~34 million people currently infected with HIV-1 live in developing countries. Because most of them still do not have access to antiretroviral therapy the global spread of the virus continues: ~2.5 million new infections and ~2 million of fatalities from Acquired Immunodeficiency Syndrome (AIDS) caused by the infection annually. In some countries life expectancy has drastically fallen. For example, in Zimbabwe it is only 34 years for women and 37 years for men.
• Highly Active Antiretroviral Therapy (HAART) is name of treatment regimens that aggressively suppress HIV replication and progression to AIDS. The usual HAART regimen combines three or more anti-HIV drugs from at least two different classes to avoid development of resistant viral variants.

HIV-1 discovery and early history

• The first human retrovirus, Human T-cell lymphotropic virus type I (HTLV-1) was first reported by Robert C. Gallo and coworkers in 1980 and reconfirmed by Yorio Hinuma and coworkers in 1981.
• In June 1981 clinicians in the United States reported a number of cases of Pneumocystis carinii in homosexual men. The infections were linked to impaired immune response, which was initially was called the Gay-Related Immune Deficiency Syndrome (GRID). Later, it was more appropriately re-named Acquired Immunodeficiency Syndrome (AIDS), and the San Francisco Chronicle newspaper published a description of the "seven deadly symptoms" associated with the disease:
  • a fever persisting for more than 4 or 5 days;
  • unexplained weight loss of 10 to 20 pounds in a few months;
  • general aches and pains similar to an acute viral syndrome for more than 10 days;
  • sore or swollen lymph glands for more than a week;
  • appearance of blue or purplish spots on the skin (now recognized as Kaposi's sarcoma);
  • herpes sores that worsen and persist for more than 5 weeks;
  • loss of sensory or motor ability or defects in mental or neurological function.
  These clinical features remain today characteristic to AIDS stage of HIV infection.
• In April 1983, Dr. Scott McNutt published report about comparative studies where biopsy samples from eight young homosexual men presented with rather aggressive Kaposi's Sarcoma (KS) have been compared with that of four samples from elderly heterosexuals with "classic" KS. In this study, he stated that a dramatic change in the epidemiology and clinical course of KS had occurred since 1979. In many (15–40%) of these young patients, the disease progressed rapidly, and they died within 1 year, despite standard combination drug chemotherapy regimens. He noted that the chief candidate as an explanation for the very aggressive behavior of KS was the finding of marked immunosuppression in these patients, as indicated by associated opportunistic infections with Pneumocystis carinii and cytomegalovirus as well as by depressed ratios of helper to suppressor T lymphocytes in peripheral blood.
• In May 1983, the isolation of new human retrovirus (at the time known as LAV, Lymphoadenopathy Associated Virus) from lymph node of AIDS patient was first reported and published in Science by Françoise Barré-Sinoussi et al. The virus could be propagated on peripheral blood mononuclear cells and on cord blood lymphocytes and its antigen showed no or weak cross reactivity with HTLV-1 proteins, indicating that it was a new human virus.
• In 1984, the identification of lentivirus, the causative agent of AIDS was published.
• In 1985, the characterization of the viral reverse transcriptase activity provided the rationale for using azidothymine (AZT) as therapy for HIV patients, and importantly, as the first therapeutic approach to prevent mother-to-child transmission of HIV. The efficiency of AZT alone was rapidly reported to be limited because virus quickly developed resistance to the monotherapy.
• In 1985, sequencing of the viral genome performed by molecular biologists at the Institut Pasteur, provided the necessary knowledge at the basis of the test to determine the viral load and to monitor resistance to therapy.

Epidemiology of HIV Infection in Large Urban Areas in the United States

Hall HI, Espinoza L, Benbow N, Hu YW; Urban Areas HIV Surveillance Workgroup. Epidemiology of HIV Infection in Large Urban Areas in the United States. PLoS One. 2010 Sep 15;5(9):e12756.

Introduction

This is the first report using national surveillance data to describe the epidemic of HIV in 12 metropolitan statistical areas (MSA) of United States. The following urban areas were reported: Atlanta-Sandy Springs-Marietta, GA; Baltimore-Towson, MD; Chicago, IL-IN-WI; Dallas, TX; Houston-Baytown-Sugar Land, TX; Los Angeles, CA; Miami, FL; New York, NY-NJ-PA; Philadelphia, PA-NJ-DE-MD; San Francisco, CA; Tampa-St. Petersburg-Clearwater, FL; Washington, DC-VA-MD-WV.

Rates of diagnoses in 2007

In 2007, a total of 52,755 adolescents and adults were diagnosed with HIV in the United States and reported to CDC by the end of June 2009. Of these, 43,024 (81.6%) were living in urban areas with populations of 500,000 or more, and 25,997 (49.3%) were living in the 12 MSAs included in these analyses. The rates of diagnosis of HIV infection in the MSAs ranged from 22.8 per 100,000 population (Chicago MSA) to 77.2 (Miami MSA), and in cities/counties ranged from 29.2 (Los Angeles County) to 246.4 (Washington, DC). Forty-eight percent (Tampa MSA) to 85.7% (Baltimore MSA) of the new diagnoses were among non-whites.

Differences in HIV-1 prevalence of HIV-1 in racial groups in 2007

At the end of 2007, a total of 793,348 adolescents and adults were diagnosed and living with HIV in the United States and reported to CDC by the end of June 2009. Of these, 400,814 (50.5%) were diagnosed in the 12 MSAs and included in these analyses. More than 1% of the population of the Miami MSA was living with HIV infection by the end of 2007 (1021.8 per 100,000 population). Overall HIV prevalence was also high in the MSAs of New York (806.3 per 100,000), Baltimore (777.6), DC (641.0) and San Francisco (622.7). In 9 of the 13 corresponding cities more than 1% of the population living with HIV infection, and in Atlanta, Baltimore, Fort Lauderdale, San Francisco, and Washington, DC the prevalence was more than 2%. In each MSA, more than 1% of the black/African American population was living with HIV at the end of 2007; prevalence was more than 2% in Miami, New York, and Baltimore. Among Hispanics, prevalence was above 1% in the MSAs of New York and Philadelphia.

Differences between age categories in 2007

About a fifth of the persons diagnosed with HIV in Baltimore, Miami, and Tampa MSAs were aged less than 30 years at diagnosis, while more than 36% of diagnoses were among this age group in Atlanta, Chicago, Dallas, Houston, and Los Angeles. Conversely, in MSAs with the lowest percentage of diagnoses among the young more than 20% of diagnoses were among those aged 50 years or older. While information on country of birth was incomplete (data completeness ranged from less than 1% to almost 50%), some differences emerged with the largest percentage of persons diagnosed with HIV who were foreign-born in Los Angeles (21.1%), followed by Miami (14.9), San Francisco (10.3%), Houston (10.5%), New York (9.0%), Tampa (7.0%), and Chicago 5.8%).

Differences between genders and nature of sexual transmission in 2007

About 14% (Los Angeles and San Francisco MSAs) to 36.5% (Baltimore MSA) of persons diagnosed with HIV in 2007 were women; the majority of these infections were attributed to heterosexual contact. Baltimore MSA (30.3%) and San Francisco MSA (27.0%) had the highest percentages of women with reported injection drug use (IDU). Among men diagnosed with HIV, in the MSAs more than 70% were men who have sex with men (MSM) except in Baltimore (52.4%), New York (66.8), Philadelphia (46.9%) and Washington (65.3%). Heterosexual contact accounted for about 20% of HIV infections among men in DC, Miami, and Baltimore MSAs, and 33.8% in Philadelphia. The distribution of HIV risk categories among men diagnosed with HIV in 2007 in the cities was similar to the distribution for the respective MSAs. Overall among all persons diagnosed with HIV, more than 50% of the HIV diagnoses in 2007 were attributed to male-to-male sexual contact in 7 of the 12 MSAs; heterosexual transmission surpassed or equaled male-to-male sexual transmission in Baltimore, Philadelphia, and Washington, DC.

HIV-1 in medical literature (PubMed database)

Please note that your results may vary slightly.

• Query "HIV-1"[Majr] AND "2009"[pdat] - 2504 articles; compare with "Influenza A virus"[Majr] AND "2009"[pdat] - 2464 articles.
• Query "Acquired Immunodeficiency Syndrome"[Majr] AND "2009"[pdat] - 568 articles; compare with "Breast Neoplasms"[Majr] AND "2009"[pdat] - 8404 articles and "Leukemia"[Majr] AND "2009"[pdat] - 4306 articles.
• Query "Antiretroviral Therapy, Highly Active" AND "2009"[pdat] - 1207 articles; compare with "Radiotherapy"[Majr] AND "2009"[pdat] - 2772 articles and "Antineoplastic Protocols"[Majr] AND "2009"[pdat] - 3309 articles.

AIDS is one of the worst scourges that descended on the mankind as recently as about 100 years ago. Today, AIDS and HIV-1 are in the main stream of modern medical research together with influenza, cardiovascular and respiratory diseases, and, of course, cancers.