Human Immunodeficiency Virus Infection

Author(s):  
Zelalem Temesgen

Human immunodeficiency virus (HIV) is a lentivirus, a member of the Retroviridae family (retroviruses). There are 2 genetically distinct types of HIV: HIV-1 and HIV-2 HIV-1 is further classified into subtypes, also known as clades. HIV-1 is the predominant HIV type globally. Donated blood has been screened for HIV-1 since 1985 in the United States. The following factors have been identified with transmission of HIV: sexual contact, perinatal infection, parenteral inoculation (eg, intravenous drug injection, occupational exposure), receipt of blood products, and receipt of donated organs or semen. The most common mode of transmission is sexual intercourse. Traumatic intercourse and ulcerative genital infections increase the risk of HIV transmission. The proper use of condoms greatly reduces the risk of HIV transmission. The diagnosis and treatment of HIV and AIDS are also reviewed.

Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1377
Author(s):  
Giancarlo Ceccarelli ◽  
Marta Giovanetti ◽  
Caterina Sagnelli ◽  
Alessandra Ciccozzi ◽  
Gabriella d’Ettorre ◽  
...  

West Africa has the highest prevalence of human immunodeficiency virus (HIV)-2 infection in the world, but a high number of cases has been recognized in Europe, India, and the United States. The virus is less transmissible than HIV-1, with sexual contacts being the most frequent route of acquisition. In the absence of specific antiretroviral therapy, most HIV-2 carriers will develop AIDS. Although, it requires more time than HIV-1 infection, CD4+ T cell decline occurs more slowly in HIV-2 than in HIV-1 patients. HIV-2 is resistant to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and some protease inhibitors. Misdiagnosis of HIV-2 in patients mistakenly considered HIV-1-positive or in those with dual infections can cause treatment failures with undetectable HIV-1 RNA. In this era of global integration, clinicians must be aware of when to consider the diagnosis of HIV-2 infection and how to test for this virus. Although there is debate regarding when therapy should be initiated and which regimen should be chosen, recent trials have provided important information on treatment options for HIV-2 infection. In this review, we focus mainly on data available and on the insight they offer about molecular epidemiology, clinical presentation, antiretroviral therapy, and diagnostic tests of HIV-2 infection.


2000 ◽  
Vol 74 (9) ◽  
pp. 4414-4419 ◽  
Author(s):  
Rainer Ziermann ◽  
Kay Limoli ◽  
Kalyan Das ◽  
Edward Arnold ◽  
Christos J. Petropoulos ◽  
...  

ABSTRACT Amprenavir (Agenerase, 141-W94, VX-478) is a human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PRI) recently approved for the treatment of HIV-1 infection in the United States. A major cause of treatment failure is the development of resistance to PRIs. One potential use for amprenavir is as salvage therapy for patients for whom treatment that includes one (or more) of the other four currently approved PRIs—saquinavir, indinavir, ritonavir, and nelfinavir—has failed. We evaluated the cross-resistance to amprenavir of viruses that evolved during treatment with the two most commonly prescribed PRIs, nelfinavir and indinavir. Unexpectedly, a dramatic increase in susceptibility (2.5- to 12.5-fold) was observed with 20 of 312 (6.4%) patient viruses analyzed. The most pronounced increases in susceptibility were strongly associated with an N88S mutation in protease. All viruses that carried the N88S mutation were hypersensitive to amprenavir. Site-directed mutagenesis studies confirmed the causal role of N88S in determining amprenavir hypersensitivity. The presence of the N88S mutation and associated amprenavir hypersensitivity may be useful in predicting an improved clinical response to amprenavir salvage therapy.


Author(s):  
Pritish K. Tosh ◽  
M. Rizwan Sohail

Human immunodeficiency virus (HIV) is transmitted sexually, perinatally, through parenteral inoculation (eg, intravenous drug injection, occupational exposure), through blood products, and, less commonly, through donated organs or semen. Sexual transmission is the most common means of infection. Conditions that may increase the risk of sexually acquiring HIV infection include traumatic intercourse (ie, receptive anal), ulcerative genital infections (including syphilis, herpes simplex, and chancroid), and lack of male circumcision. The proper use of latex condoms substantially reduces the risk of HIV transmission.


2004 ◽  
Vol 78 (13) ◽  
pp. 7279-7283 ◽  
Author(s):  
Manish Sagar ◽  
Erin Kirkegaard ◽  
E. Michelle Long ◽  
Connie Celum ◽  
Susan Buchbinder ◽  
...  

ABSTRACT African women frequently acquire several genetically distinct human immunodeficiency virus type 1 (HIV-1) variants from a heterosexual partner, whereas the acquisition of multiple variants appears to be rare in men. To determine whether newly infected individuals in other risk groups acquire genetically diverse viruses, we examined the viral envelope sequences in plasma samples from 13 women and 4 men from the United States infected with subtype B viruses and 10 men from Kenya infected with non-subtype B viruses. HIV-1 envelope sequences differed by more than 2% in three U.S. women, one U.S. man, and one Kenyan man near the time of seroconversion. These findings suggest that early HIV-1 genetic diversity is not exclusive to women from Africa or to infection with any particular HIV-1 subtype.


2007 ◽  
Vol 20 (3) ◽  
pp. 478-488 ◽  
Author(s):  
Susan Hariri ◽  
Matthew T. McKenna

SUMMARY The human immunodeficiency virus (HIV) epidemic emerged in the early 1980s with HIV infection as a highly lethal disease among men who have sex with men and among frequent recipients of blood product transfusions. Advances in the treatment of HIV infection have resulted in a fundamental shift in its epidemiology, to a potentially chronic and manageable condition. However, challenges in the prevention of this infection remain. In particular, increasing evidence suggests that transmission of drug-resistant virus is becoming more common and that the epidemic is having a profound impact on morbidity and mortality in ethnic and racial minority subgroups in the United States. New population-based data collection systems designed to describe trends in behaviors associated with HIV transmission and better methods for measuring the true incidence of transmission will better elucidate the characteristics of HIV infection in the United States and inform future public health policies.


2004 ◽  
Vol 78 (5) ◽  
pp. 2586-2590 ◽  
Author(s):  
Udaykumar Ranga ◽  
Raj Shankarappa ◽  
Nagadenahalli B. Siddappa ◽  
Lakshmi Ramakrishna ◽  
Ramalingam Nagendran ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is correlated with increased monocyte migration to the brain, and the incidence of HAD among otherwise asymptomatic subjects appears to be lower in India than in the United States and Europe (1 to 2% versus 15 to 30%). Because of the genetic differences between HIV-1 strains circulating in these regions, we sought to identify viral determinants associated with this difference. We targeted Tat protein for these studies in view of its association with monocyte chemotactic function. Analyses of Tat sequences representing nine subtypes revealed that at least six amino acid residues are differentially conserved in subtype C Tat (C-Tat). Of these, cysteine (at position 31) was highly (>99%) conserved in non-subtype C viruses and more than 90% of subtype C viruses encoded a serine. We hypothesized a compromised chemotactic function of C-Tat due to the disruption of CC motif and tested it with the wild type C-Tat (CS) and its two isogenic variants (CC and SC) derived by site-directed mutagenesis. We found that the CS natural variant was defective for monocyte chemotactic activity without a loss in the transactivation property. While the CC mutant is functionally competent for both the functions, in contrast, the SC mutant was defective in both. Therefore, the loss of the C-Tat chemotactic property may underlie the reduced incidence of HAD; although not presenting conclusive evidence, this study provides the first evidence for a potential epidemiologic phenomenon associated with biological differences in the subtype C viruses.


2019 ◽  
Vol 70 (6) ◽  
pp. 1096-1102 ◽  
Author(s):  
William C Goedel ◽  
Maximilian R F King ◽  
Mark N Lurie ◽  
Sandro Galea ◽  
Jeffrey P Townsend ◽  
...  

Abstract Background Syringe services programs (SSPs) are effective venues for delivering harm-reduction services to people who inject drugs (PWID). However, SSPs often face significant barriers to implementation, particularly in the absence of known human immunodeficiency virus (HIV) outbreaks. Methods Using an agent-based model, we simulated HIV transmission in Scott County, Indiana, a rural county with a 1.7% prevalence of injection drug use. We compared outcomes arising in the absence of an SSP, in the presence of a pre-existing SSP, and with implementation of an SSP after the detection of an HIV outbreak among PWID over 5 years following the introduction of a single infection into the network. Results In the absence of an SSP, the model predicted an average of 176 infections among PWID over 5 years or an incidence rate of 12.1/100 person-years. Proactive implementation averted 154 infections and decreased incidence by 90.3%. With reactive implementation beginning operations 10 months after the first infection, an SSP would prevent 107 infections and decrease incidence by 60.8%. Reductions in incidence were also observed among people who did not inject drugs. Conclusions Based on model predictions, proactive implementation of an SSP in Scott County had the potential to avert more HIV infections than reactive implementation after the detection of an outbreak. The predicted impact of reactive SSP implementation was highly dependent on timely implementation after detecting the earliest infections. Consequently, there is a need for expanded proactive SSP implementation in the context of enhanced monitoring of outbreak vulnerability in Scott County and similar rural contexts.


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